Int J Clin Oncol DOI 10.1007/s10147-014-0737-8
ORIGINAL ARTICLE
Late toxicity of proton beam therapy for patients with the nasal cavity, para-nasal sinuses, or involving the skull base malignancy: importance of long-term follow-up Sadamoto Zenda • Mitsuhiko Kawashima • Satoko Arahira Ryosuke Kohno • Teiji Nishio • Makoto Tahara • Ryuichi Hayashi • Tetsuo Akimoto
•
Received: 20 March 2014 / Accepted: 30 July 2014 Ó Japan Society of Clinical Oncology 2014
Background Although several reports have shown that proton beam therapy (PBT) offers promise for patients with skull base cancer, little is known about the frequency of late toxicity in clinical practice when PBT is used for these patients. Here, we conducted a retrospective analysis to clarify the late toxicity profile of PBT in patients with malignancies of the nasal cavity, para-nasal sinuses, or involving the skull base. Methods Entry to this retrospective study was restricted to patients with (1) malignant tumors of the nasal cavity, paranasal sinuses, or involving the skull base; (2) definitive or postoperative PBT ([50 GyE) from January 1999 through December 2008; and (3) more than 1 year of follow-up. Late toxicities were graded according to the common terminology criteria for adverse events v4.0 (CTCAE v4.0). Results From January 1999 through December 2008, 90 patients satisfied all criteria. Median observation period was 57.5 months (range, 12.4–162.7 months), median time This topic was presented at the ASTRO 55th 2011 annual meeting as a scientific session. S. Zenda (&) M. Kawashima S. Arahira R. Kohno T. Nishio T. Akimoto Division of Radiation Oncology, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577, Japan e-mail: [email protected] M. Tahara Division of Head and Neck Medical Oncology, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577, Japan R. Hayashi Division of Head and Neck Surgery, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577, Japan
to onset of grade 2 or greater late toxicity except cataract was 39.2 months (range, 2.7–99.8 months), and 3 patients had toxicities that occurred more than 5 years after PBT. Grade 3 late toxicities occurred in 17 patients (19 %), with 19 events, and grade 4 late toxicities in 6 patients (7 %), with 6 events (encephalomyelitis infection 2, optic nerve disorder 4). Conclusions In conclusion, the late toxicity profile of PBT in patients with malignancy involving the nasal cavity, para-nasal sinuses, or skull base malignancy was partly clarified. Because late toxicity can still occur at 5 years after treatment, long-term follow-up is necessary. Keywords Proton beam therapy Late toxicity Followup Head and neck cancer
Introduction Malignant tumors that arise in the nasal cavity or paranasal sinuses, or which invade the skull base, usually present a difficult clinical problem. Most cases are treated by craniofacial surgery and postoperative radiotherapy, either singly or in combination [1–5]. Surgical approaches are often complicated by serious functional deformity and the difficulty of complete resection. In these cases, definitive radiotherapy is performed as an alternative treatment, but aggressive irradiation of the intracranial region increases the risk of severe late toxicity [6–8]. The depth–dose distribution of a proton beam, the Bragg curve, is characterized by an entrance region with a slowly increasing dose followed by a sharp increase near the end of the range, the Bragg peak. This improved dose distribution of proton beam therapy is of therapeutic merit in the
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treatment of deeply seated tumors. The difference between three-dimensional (3D)-conventional radiotherapy (RT) and PBT is clear in dose-painting simulation. Dose coverage to target in intensity-modulated radiotherapy (IMRT) is sufficient; however, the low-dose area is much larger than that of PBT [9]. Therefore, PBT may not be inferior to IMRT or 3Dconventional RT in safety. Although several reports [10–12] have shown that PBT holds promise for patients with skull base cancer, little is known about the frequency of late toxicity in clinical practice using PBT for these patients. Here, we conducted a retrospective analysis to clarify the late toxicity profile of PBT for the intracranial region with long-term follow-up.
Patients and methods Patients Entry to this retrospective study was limited to patients with (1) malignant tumors of the nasal cavity, para-nasal sinuses, and/or involving the skull base; (2) definitive or postoperative PBT ([50 GyE) from January 1999 through December 2008; and (3) more than 1 year of follow-up. Written informed consent to treatment was obtained from all patients before the initiation of treatment. Pretreatment evaluation Pretreatment clinical evaluation was performed using magnetic resonance imaging (MRI), cervical, chest, and abdominal computed tomography (CT), or positron emission tomography (PET)-CT. Tumor staging in the present study was based on the sections on the nasal cavity and paranasal sinuses in the TNM classification of the International Union Against Cancer (UICC 7th), regardless of histology type. Radiologic evaluations for staging were jointly reviewed by radiologists, head-and-neck surgeons, and medical oncologists at our institution. Late toxicity evaluation Late toxicity evaluation was mainly performed using MRI and routine physical examination every 3 months until 2 years after treatment, and every 6–12 months thereafter. Final grade of late toxicities was retrospectively graded by a radiation oncologist based on clinical charts and radiologic findings. Time to onset of toxicity grade 2 or greater was defined as from the day of initiation of treatment to the first day of confirmation of late toxicity of grade 2 or greater.
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Proton beam therapy Treatment planning was performed on a three-dimensional (3D)-CT planning system. In this system, the proton beam was generated with a Cyclotron C235 with an energy of 235 MeV at the exit. Relative biological effectiveness was defined as 1.1, based on our preclinical experiments. Proton beam therapy at our institution is conducted using passive irradiation with dual-ring double-scatter methods. Dose distribution is optimized using the spread-out Bragg peak method and obtained using a broad-beam algorithm. Gross tumor volume (GTV) was determined pretreatment with CT, MRI, and PET-CT, either alone or in combination. Clinical target volume (CTV) was defined for each disease individually. The CTV of patients who had cervical lymph node metastases was defined the same as for those without lymph node metastasis, because this study included only patients who did not have lymph node metastasis or had lymph node metastasis near the primary site. No prophylactic nodal RT was done for any of the patients. Planning target volume (PTV) was basically defined as the CTV plus a 3-mm margin but could be finely adjusted where necessary in consideration of organs at risk. Beam energy and spread-out Bragg peak were fine tuned such that the PTV was at least covered in a 90 % isodose volume of the prescribed dosage. The most common regimen was 65 GyE/26 fr (2.5 GyE/fr), and for only 14 mucosal melanoma patients, a 60 GyE/15 fr (4GyE/fr) regimen was adapted at National Cancer Center Hospital East. Dose constraints for organs at risk in 2.5 GyE fractions were as follows (Dmax): (1) surface of brainstem, 60 GyE; (2) center of brainstem, 50 GyE; (3) optic nerves of the healthy side/chiasm, 54 GyE; and (4) optic lens, 15 GyE. However, we gave priority to sufficient target coverage when the GTV or CTV was located close to or adjacent to critical organs. Statistical analysis Patient demographics and pathological and clinical characteristics were described using descriptive statistics, including mean, standard deviation, median, range, and percentage. Univariate analysis was conducted using the log-rank test. Overall survival and progression-free survival time were estimated by the Kaplan–Meier product– limits method using commercially available statistical software (Stat Mate IV; SAS Institute, Cary, NC, USA). Definition of local control, progression-free survival, and overall survival Overall survival time was calculated from the start of treatment to the date of death or last confirmed date of survival. Survival
Int J Clin Oncol Table 1 Patient characteristics Age (range) (years)
57 (17–84)
Gender (male/female)
52/38
Primary site Maxillary sinus
12
Ethmoid sinus
8
Sphenoid sinus
5
Nasal cavity
62
Other site
3
Tumor type Squamous cell carcinoma
22
Adenoid cystic carcinoma
15
Olfactory neuroblastoma
27
Melanoma
14
Others
12
TNM stage T T1
4
T2
16
T3
9
T4
54
Tx
7
N N0 N1
88 a
N2
3 0
PBT dose schedule (BED3.0) 70 GyE/28 fr (128.3 Gy)
5
70 GyE/35 fr (116.7 Gy)
4
66 Gy/33 fr (110 Gy)
1
65 GyE/26 fr (119.2 Gy)
61
60 GyE/15 fr (140 Gy) 60 GyE\
14 5
fr Fraction, PBT proton beam therapy, BED biological equivalent dose a
All lymph node metastases had located nearby primary tumor.
time was censored at the last confirmed date of survival if the patient was alive. Progression-free survival time was defined from the start of treatment to the first day of confirmation of progressive disease at any site or any cause of death.
Fig. 1 Overall and progression-free survival for all the 112 patients. Solid line indicates overall survival curve; broken line indicates progression-free survival curve. With a median follow-up period of 57.5 months, 3-year overall survival and progression-free survival rates were 74.7 % and 48.2 %, respectively, and the 5-year overall and progression-free rates were 64.2 % and 44.5 %, respectively
our institution from hospitals or institutions located far from our institution. Another 12 patients died within 1 year after PBT. Therefore, as for late toxicities, the remaining 90 patients were reviewed in the current study. Median age was 57 years (range, 17–84 years). The major primary site was the nasal cavity (n = 62, 69 %). Regarding treatment, 16 patients received surgery before PBT, and 20 patients received induction chemotherapy before PBT. Eleven patients received PBT concurrently with cisplatin, and the remaining patients received PBT alone. The most common treatment was PBT alone at 65 GyE in 26 fractions. Patient characteristics are listed in Table 1. Treatment outcome Median observation period was 57.5 months (range, 12.4–162.7 months). Among 112 patients, the 5-year progression-free and overall survival rates were 44.5 % and 64.2 %, respectively (Fig. 1). A total of 55 patients were confirmed to have tumor progression, consisting of 26, 14, and 15 patients with local, regional, and distant failure, respectively. Eleven patients had not visited for more than 2 years, and we were unable to confirm death. Of these 11, recurrence could not be confirmed in 7 patients. Late toxicity profile
Results Patient characteristics A total of 112 patients with malignancies of the nasal cavity, paranasal sinuses, or involving the skull base were treated using PBT. For 10 patients, the follow-up duration was 1 year or less, mainly because patients were referred to
The toxicity profile is listed in Table 2. Median time to onset of grade 2 or greater late toxicity, except cataract, was 39.2 months (range, 2.7–99.8 months), and 3 patients developed grade 2 or more severe toxicities; the interval from the completion of PBT was more than 5 years. Grade 3 late toxicities occurred in 17 patients (19 %) with 19 events. Grade 3 osteonecrosis caused by exodontia after
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Case 1: optic nerve disorder Gr. 4
Table 2 Late toxicity (n = 90) Grade (CTCAE version 4.0)
1
2
3
4
Hearing loss
1
1
2
0
a
0
1
1
0
Encephalomyelitis infection Cataract
0
0
0
2
1
1
5
0
Optic nerve disorder
0
4
1
4
Nerve disorder
Necrosis (other, specify)b Brain
5
1
1
0
Soft tissue
0
0
1
0
Bone
0
4
2
0
a
All central nervous system disorders (I–XII) were classified in this category b In-field necrosis induced by PBT was classified in the nearest implication of CTCAE v4.0
PBT was observed in 2 patients. Grade 4 late toxicities occurred in 6 patients (7 %) with 6 events (encephalomyelitis infection 2, optic nerve disorder 4). Fig. 2 Optic nerve disorder in a patient treated with proton beam therapy (PBT). a Magnetic resonance imaging (MRI) at pretreatment; b dose distribution of PBT; c MRI at 3 years after treatment. Dosepainting simulation of PBT indicated a maximum dose to the right optic nerve of 61.4 GyE. Although MRI at 3 years after treatment revealed no evidence of malignancy or change in the optic nerve, the patient became blind at 51 months after treatment
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A 79-year-old man with T4 olfactory neuroblastoma of the nasal cavity received PBT alone. At 42 months after PBT, MRI revealed no evidence of malignancy (Fig. 2). However, he gradually became aware of decreased visual acuity 3 years after treatment, and finally became blind at 51 months after treatment. Detailed information about patients with grade 4 optic nerve disorder is shown in Table 3. Case 2: brain necrosis Gr. 1 A 68-year-old man whose disease was T4N0M0 squamous cell carcinoma of the nasal cavity received proton beam therapy with cisplatin. Three months after PBT, MRI revealed no evidence of malignancy, and no toxicity. This finding did not change during long-term follow-up for 24 months at 3-month intervals. However, at 24 months after treatment, an edematous change was found in a frontal lobe, and brain necrosis without symptoms was confirmed
Int J Clin Oncol Table 3 Grade 4 optic nerve disorder in detail Gender
Age
Primary site
T stage
Treatment
M
56
Nasal cavity
1
PBT alone
F
52
Nasopharynx
4
PBT alone
M M
79 79
Nasal cavity Nasal cavity
4 4
PBT alone PBT alone
Chiasm and optic nerve volume [50 Gy/(max)
Time to onset
Status
65 GyE/26 fr
0.5 cc/(63.7 GyE)
6Y2M
Alive w/o disease
65 GyE/26 fr
0.2 cc/(65.3 GyE)
4Y3M
Alive w/o disease
6Y2 M
65 GyE/26 fr 60 GyE/15 fr
0.17 cc/(61.4 GyE) 0.03 cc/(53.2 GyE)
4Y3M 1Y5M
Alive w/o disease Died of disease
4Y5 M 4Y6 M
8Y2 M
M Male, F female, Y years, M months, PBT proton beam therapy, w/o without
Fig. 3 Brain necrosis in a patient treated with PBT: MRI at pretreatment (a), 2 years after treatment (b), 2.5 years after treatment (c), and 3 years after treatment (d). The volume of brain to which was prescribed [ 60 GyE was 17.5 cc and maximum dose was 65 GyE. The patient developed no serious symptoms throughout the follow-up period, and he presently remains alive at more than 4 years after treatment
at 30 months after treatment. This late toxicity gradually improved on MRI without additional treatment (Fig. 3). Univariate analyses In univariate analysis, T stage (T4 vs. non-T4), sex, age (less than 65 years vs. 65 years or more),induction chemotherapy (on vs. off), concurrent chemotherapy(on vs. off), dose per fraction (C2.5 Gy vs. \2.5 Gy), and primary site (nasal cavity vs. others) were investigated. However, no significant factors with an impact on the frequency of brain necrosis and optic nerve disorder were identified (Table 4).
Mild to serious optic nerve disorder as late toxicities occurred in seven patients with T4 who had not received induction chemotherapy; these did not occur in patients with T4 who had received induction chemotherapy.
Discussion This study clarified details of the late toxicity profile of PBT and late toxicity. The several previous reports of late toxicity following radiotherapy for the intracranial region have shown considerable variation in frequency. We
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Int J Clin Oncol Table 4 Univariate analysis
Total
Brain necrosis % C Gr. 1
T4
54
9.3
Non-T4
36
5.6
Male
52
3.8
Female
38
13.2
65\
66
7.6
65C
24
8.3
Induction chemotherapy (?)
20
5.0
(-)
70
8.6
Concurrent chemotherapy (?)
11
0.0
(-)
79
8.9
B2.5 Gy/1 fr
76
7.9
[2.5 Gy/1 fr
14
7.1
Nasal cavity
62
6.5
Others T4
28 54
10.7
T4 ? induction
18
10.5
T4 w/o induction
36
11.1
consider that a relatively short observation period will result in the underestimation of late toxicity. Debus et al. [13] reported an incidence of chronic therapy-induced toxicity on median follow-up of 35 months (range, 3 months to 12 years) in 189 patients who underwent fractionated radiotherapy of only 1 % for grades 1–2 toxicity and 2.1 % for grade 3 disease. With a median follow-up of 56 months, in contrast, Lee et al. [14] reported the unexpected development of severe late complications in 34.6 % of patients receiving hypofractionated stereotactic body radiotherapy (SBRT) as a boost treatment. In our present data, median time to onset of grade 2 or greater late toxicity except cataract was 39.2 months (range, 2.7–99.8 months). Further, although only 5 patients (5.5 %) had severe late toxicities (Cgrade 3) within 3 years after treatment, 17 patients (18.9 %) experienced 20 events during the total follow-up period. Mizoe et al. [15]. reported the late toxicity profile of carbon-ion therapy for their series of head and neck cancer patients of 52 (22 %, 52/236) events of all grades, and four cases of blindness. Previous reports are summarized in Table 5. With regard to brain necrosis, several investigators [16–18] reported that severe brain injury was usually irreversible, and sometimes fatal. Surgical resection of a focal region of necrosis can be of benefit and may be life saving [19]. On the other hand, little is known about the outcome of mild or intermediate brain injury. In the
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Optic nerve disorder
Odds ratio
95 % CI
1.73
0.32–9.47
% C Gr. 2 14.9
Odds ratio
95 % CI
2.53
0.49–13.0
1.46
0.39–5.48
1.36
0.26–7.06
0.36
0.04–3.00
–
–
0.64
0.15–2.79
1.13
0.23–5.47
–
–
5.6 0.29
0.60–1.43
11.5 7.9
0.91
0.19–4.38
10.6 8.3
1.12
0.21–6.03
–
–
1.11
0.14–8.50
5.0 10.0 0.0 11.4 9.2 14.3
0.60
0.14–2.51
8.1 7.1
0.82
0.14–4.99
0.0 19.4
present study, we found that some cases of mild or intermediate brain necrosis improved spontaneously after a long period. In our present study, we experienced many events that would not usually be encountered without long-term follow-up, and an adequate understanding of the toxicity profile of PBT in these patients thus requires long-term follow-up. For T4 disease, severe late toxicities might be avoided by induction chemotherapy. We speculate that subsequent decrease in tumor size after PBT might have an positive impact on decrease in irradiation dose to the brain. As for efficacy, Zenda et al. [10] reported a 5-year overall survival rate with PBT for unresectable carcinoma of the paranasal sinuses of 55.0 %, whereas Hoppe et al. reported a 5-year survival rate of definitive (chemo)radiotherapy for these patients of only 15 %. These results emphasize the ongoing need for considerable improvement in treatment strategies for these conditions. One major limitation of this study warrants mention. The precision of dose calculations was made uncertain by the internal heterogeneity, which in turn prevented any medical physics analysis of the late toxicity profile. In particular, precise analysis of dosage from the current pencil-beam dosimeter algorithm is not possible [20]. As part of an ongoing physics evaluations, our group is presently conducting further recalculations of treatment plans for patients with fatal late toxicity using Monte Carlo methods.
Int J Clin Oncol Table 5 Previous reports of late toxicity Age (range)
Follow-up period
Author
Year
Disease
SchulzErtner et al.
2005
ACC of skull base
Uy et al.
2002
Intracranial meningioma
Pt No. 53
40
Treatment
Per fraction
Total dose
Median (range)
Late toxicity in detail (%)
24: RT-FSRT/ IMRT boost
–
70 Gy
24 (2–92) M
CGr. 3 late toxicity
1.8
29: RT-CI boost
54 Gy– 3 GyEx6
72 GyE
16 (2–60) M
25: Ope-IMRT
1.7–2.0 Gy
40–56 Gy
30 (6–71) M
CGr. 3 late toxicity
7.5
15: IMRT Debus et al.
2001
Skull base meningioma
Pehlivan et al.
2011
Skull base tumor
Weber et al.
2012
Intracranial meningioma
189
RT alone
1.8 Gy
56.8 Gy
35 (3–144) M
CGr. 3 late toxicity
2.1
62
PBT alone
1.8–2.0 GyE
63–74 GyE
38 (14–92) M
CGr. 3 TL toxicity
3.2
CGr. 1 TL toxicity
11.2
5-year toxicity free survival
84.5
CGr. 3 late toxicity
12.8
CGr. 4 late toxicity
3.8
39
31: Ope-PBT
–
55.5–66.1 GyE
49.3 (11.5–93.3) M
8: PBT Lee et al.
2012
Head and neck cancer
26
EBRT-SBRT
EBRT: 45–50.4 Gy/25–28 fr SBRT: 10–25 Gy/3–5 fr
56 (27.6–80.2) M
34.6
CGr. 3 late toxicity Mizoe et al.
2012
Present study
Head and neck cancer Nasal/paranasal malignancies and skull base tumors
236 90
Carbon-ion therapy
3.6 GyE (4GyE)
57.6 GyE (64 GyE)
\60 months
All grade late toxicity
22.0
16: OpePBT(?CDDP)
2.0–4.0 GyE
60–70 GyE
59.7 (12.4–169.7) M
CGr. 4 late toxicity
6.6
CGr. 3 late toxicity
21.1
74: PBT(?CDDP)
Pt patient, No number, ACC adenoid cystic carcinoma, RT radiotherapy, FSRT fractionated stereotactic radiotherapy, IMRT intensity modulated radiotherapy, M months, Gr Grade, PBT proton beam therapy, TL temporal lobe, EBRT external-beam radiotherapy, SBRT stereotactic body radiotherapy
In conclusion, the late toxicity profile of proton beam therapy in patients with malignancy involving the nasal cavity, para-nasal sinuses, or skull base was partly clarified. Because late toxicity can occur as late as 5 years after treatment, long-term follow-up is necessary.
Conflict of interest of interest.
The authors declare that they have no conflict
References 1. Ketcham AS, Wilkins RH, Vanburen JM, Vanburen JM, Smith RR (1963) A combined intracranial facial approach to the paranasal sinuses. Am J Surg 106:698–703 2. Blanco AI, Chao KS, Ozyigit G et al (2004) Carcinoma of paranasal sinuses: long-term outcomes with radiotherapy. Int J Radiat Oncol Biol Phys 59(1):51–58
3. Hoppe BS, Stegman LD, Zelefsky MJ et al (2007) Treatment of nasal cavity and paranasal sinus cancer with modern radiotherapy techniques in the postoperative setting: the MSKCC experience. Int J Radiat Oncol Biol Phys 67(3):691–702 4. Jansen EP, Keus RB, Hilgers FJ, Haas RL, Tan IB, Bartelink H (2000) Does the combination of radiotherapy and debulking surgery favor survival in paranasal sinus carcinoma? Int J Radiat Oncol Biol Phys 48(1):27–35 5. Dulguerov P, Jacobsen MS, Allal AS, Lehmann W, Calcaterra T (2001) Nasal and paranasal sinus carcinoma: are we making progress? A series of 220 patients and a systematic review. Cancer (Phila) 92(12):3012–3029 6. Snyers A, Janssens GO, Twickler MB et al (2009) Malignant tumors of the nasal cavity and paranasal sinuses: long-term outcome and morbidity with emphasis on hypothalamic-pituitary deficiency. Int J Radiat Oncol Biol Phys 73(5):1343–1351 7. Dirix P, Nuyts S, Geussens Y et al (2007) Malignancies of the nasal cavity and paranasal sinuses: long-term outcome with conventional or three-dimensional conformal radiotherapy. Int J Radiat Oncol Biol Phys 69(4):1042–1050 8. Hoppe BS, Nelson CJ, Gomez DR et al (2008) Unresectable carcinoma of the paranasal sinuses: outcomes and toxicities. Int J Radiat Oncol Biol Phys 72(3):763–769
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Int J Clin Oncol 9. Nutting CM, Morden JP, Harrington KJ et al (2011) Parotidsparing intensity modulated versus conventional radiotherapy in head and neck cancer (PARSPORT): a phase 3 multicentre randomised controlled trial. Lancet Oncol 12(2):127–136 10. Zenda S, Kohno R, Kawashima M et al (2011) Proton beam therapy for unresectable malignancies of the nasal cavity and paranasal sinuses. Int J Radiat Oncol Biol Phys 81(5):1473–1478 11. Nishimura H, Ogino T, Kawashima M et al (2007) Proton-beam therapy for olfactory neuroblastoma. Int J Radiat Oncol Biol Phys 68(3): 758–762 12. Fuji H, Nakasu Y, Ishida Y et al (2011) Feasibility of proton beam therapy for chordoma and chondrosarcoma of the skull base. Skull Base 21(3):201–206 13. Debus J, Wuendrich M, Pirzkall A et al (2001) High efficacy of fractionated stereotactic radiotherapy of large base-of-skull meningiomas: long-term results. J Clin Oncol 19(15):3547–3553 14. Lee DS, Kim YS, Cheon JS et al (2012) Long-term outcome and toxicity of hypofractionated stereotactic body radiotherapy as a boost treatment for head and neck cancer: the importance of boost volume assessment. Radiat Oncol 7:85
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15. Mizoe JE, Hasegawa A, Jingu K et al (2012) Results of carbon ion radiotherapy for head and neck cancer. Radiother Oncol 103(1):32–37 16. Stelzer KJ (2000) Acute and long-term complications of therapeutic radiation for skull base tumors. Neurosurg Clin N Am 11(4):597–604 17. Sheline GE, Wara WM, Smith V (1980) Therapeutic irradiation and brain injury. Int J Radiat Oncol Biol Phys 6(9):1215–1228 18. Marks JE, Baglan RJ, Prassad SC, Blank WF (1981) Cerebral radionecrosis: incidence and risk in relation to dose, time, fractionation and volume. Int J Radiat Oncol Biol Phys 7(2):243–252 19. Woo E, Lam K, Yu YL, Lee PW, Huang CY (1987) Cerebral radionecrosis: is surgery necessary? J Neurol Neurosurg Psychiatry 50(11):1407–1414 20. Hotta K, Kohno R, Takada Y et al (2010) Improved dose-calculation accuracy in proton treatment planning using a simplified Monte Carlo method verified with three-dimensional measurements in an anthropomorphic phantom. Phys Med Biol 55(12):3545–3556
ORIGINAL ARTICLE
Late toxicity of proton beam therapy for patients with the nasal cavity, para-nasal sinuses, or involving the skull base malignancy: importance of long-term follow-up Sadamoto Zenda • Mitsuhiko Kawashima • Satoko Arahira Ryosuke Kohno • Teiji Nishio • Makoto Tahara • Ryuichi Hayashi • Tetsuo Akimoto
•
Received: 20 March 2014 / Accepted: 30 July 2014 Ó Japan Society of Clinical Oncology 2014
Background Although several reports have shown that proton beam therapy (PBT) offers promise for patients with skull base cancer, little is known about the frequency of late toxicity in clinical practice when PBT is used for these patients. Here, we conducted a retrospective analysis to clarify the late toxicity profile of PBT in patients with malignancies of the nasal cavity, para-nasal sinuses, or involving the skull base. Methods Entry to this retrospective study was restricted to patients with (1) malignant tumors of the nasal cavity, paranasal sinuses, or involving the skull base; (2) definitive or postoperative PBT ([50 GyE) from January 1999 through December 2008; and (3) more than 1 year of follow-up. Late toxicities were graded according to the common terminology criteria for adverse events v4.0 (CTCAE v4.0). Results From January 1999 through December 2008, 90 patients satisfied all criteria. Median observation period was 57.5 months (range, 12.4–162.7 months), median time This topic was presented at the ASTRO 55th 2011 annual meeting as a scientific session. S. Zenda (&) M. Kawashima S. Arahira R. Kohno T. Nishio T. Akimoto Division of Radiation Oncology, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577, Japan e-mail: [email protected] M. Tahara Division of Head and Neck Medical Oncology, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577, Japan R. Hayashi Division of Head and Neck Surgery, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577, Japan
to onset of grade 2 or greater late toxicity except cataract was 39.2 months (range, 2.7–99.8 months), and 3 patients had toxicities that occurred more than 5 years after PBT. Grade 3 late toxicities occurred in 17 patients (19 %), with 19 events, and grade 4 late toxicities in 6 patients (7 %), with 6 events (encephalomyelitis infection 2, optic nerve disorder 4). Conclusions In conclusion, the late toxicity profile of PBT in patients with malignancy involving the nasal cavity, para-nasal sinuses, or skull base malignancy was partly clarified. Because late toxicity can still occur at 5 years after treatment, long-term follow-up is necessary. Keywords Proton beam therapy Late toxicity Followup Head and neck cancer
Introduction Malignant tumors that arise in the nasal cavity or paranasal sinuses, or which invade the skull base, usually present a difficult clinical problem. Most cases are treated by craniofacial surgery and postoperative radiotherapy, either singly or in combination [1–5]. Surgical approaches are often complicated by serious functional deformity and the difficulty of complete resection. In these cases, definitive radiotherapy is performed as an alternative treatment, but aggressive irradiation of the intracranial region increases the risk of severe late toxicity [6–8]. The depth–dose distribution of a proton beam, the Bragg curve, is characterized by an entrance region with a slowly increasing dose followed by a sharp increase near the end of the range, the Bragg peak. This improved dose distribution of proton beam therapy is of therapeutic merit in the
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Int J Clin Oncol
treatment of deeply seated tumors. The difference between three-dimensional (3D)-conventional radiotherapy (RT) and PBT is clear in dose-painting simulation. Dose coverage to target in intensity-modulated radiotherapy (IMRT) is sufficient; however, the low-dose area is much larger than that of PBT [9]. Therefore, PBT may not be inferior to IMRT or 3Dconventional RT in safety. Although several reports [10–12] have shown that PBT holds promise for patients with skull base cancer, little is known about the frequency of late toxicity in clinical practice using PBT for these patients. Here, we conducted a retrospective analysis to clarify the late toxicity profile of PBT for the intracranial region with long-term follow-up.
Patients and methods Patients Entry to this retrospective study was limited to patients with (1) malignant tumors of the nasal cavity, para-nasal sinuses, and/or involving the skull base; (2) definitive or postoperative PBT ([50 GyE) from January 1999 through December 2008; and (3) more than 1 year of follow-up. Written informed consent to treatment was obtained from all patients before the initiation of treatment. Pretreatment evaluation Pretreatment clinical evaluation was performed using magnetic resonance imaging (MRI), cervical, chest, and abdominal computed tomography (CT), or positron emission tomography (PET)-CT. Tumor staging in the present study was based on the sections on the nasal cavity and paranasal sinuses in the TNM classification of the International Union Against Cancer (UICC 7th), regardless of histology type. Radiologic evaluations for staging were jointly reviewed by radiologists, head-and-neck surgeons, and medical oncologists at our institution. Late toxicity evaluation Late toxicity evaluation was mainly performed using MRI and routine physical examination every 3 months until 2 years after treatment, and every 6–12 months thereafter. Final grade of late toxicities was retrospectively graded by a radiation oncologist based on clinical charts and radiologic findings. Time to onset of toxicity grade 2 or greater was defined as from the day of initiation of treatment to the first day of confirmation of late toxicity of grade 2 or greater.
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Proton beam therapy Treatment planning was performed on a three-dimensional (3D)-CT planning system. In this system, the proton beam was generated with a Cyclotron C235 with an energy of 235 MeV at the exit. Relative biological effectiveness was defined as 1.1, based on our preclinical experiments. Proton beam therapy at our institution is conducted using passive irradiation with dual-ring double-scatter methods. Dose distribution is optimized using the spread-out Bragg peak method and obtained using a broad-beam algorithm. Gross tumor volume (GTV) was determined pretreatment with CT, MRI, and PET-CT, either alone or in combination. Clinical target volume (CTV) was defined for each disease individually. The CTV of patients who had cervical lymph node metastases was defined the same as for those without lymph node metastasis, because this study included only patients who did not have lymph node metastasis or had lymph node metastasis near the primary site. No prophylactic nodal RT was done for any of the patients. Planning target volume (PTV) was basically defined as the CTV plus a 3-mm margin but could be finely adjusted where necessary in consideration of organs at risk. Beam energy and spread-out Bragg peak were fine tuned such that the PTV was at least covered in a 90 % isodose volume of the prescribed dosage. The most common regimen was 65 GyE/26 fr (2.5 GyE/fr), and for only 14 mucosal melanoma patients, a 60 GyE/15 fr (4GyE/fr) regimen was adapted at National Cancer Center Hospital East. Dose constraints for organs at risk in 2.5 GyE fractions were as follows (Dmax): (1) surface of brainstem, 60 GyE; (2) center of brainstem, 50 GyE; (3) optic nerves of the healthy side/chiasm, 54 GyE; and (4) optic lens, 15 GyE. However, we gave priority to sufficient target coverage when the GTV or CTV was located close to or adjacent to critical organs. Statistical analysis Patient demographics and pathological and clinical characteristics were described using descriptive statistics, including mean, standard deviation, median, range, and percentage. Univariate analysis was conducted using the log-rank test. Overall survival and progression-free survival time were estimated by the Kaplan–Meier product– limits method using commercially available statistical software (Stat Mate IV; SAS Institute, Cary, NC, USA). Definition of local control, progression-free survival, and overall survival Overall survival time was calculated from the start of treatment to the date of death or last confirmed date of survival. Survival
Int J Clin Oncol Table 1 Patient characteristics Age (range) (years)
57 (17–84)
Gender (male/female)
52/38
Primary site Maxillary sinus
12
Ethmoid sinus
8
Sphenoid sinus
5
Nasal cavity
62
Other site
3
Tumor type Squamous cell carcinoma
22
Adenoid cystic carcinoma
15
Olfactory neuroblastoma
27
Melanoma
14
Others
12
TNM stage T T1
4
T2
16
T3
9
T4
54
Tx
7
N N0 N1
88 a
N2
3 0
PBT dose schedule (BED3.0) 70 GyE/28 fr (128.3 Gy)
5
70 GyE/35 fr (116.7 Gy)
4
66 Gy/33 fr (110 Gy)
1
65 GyE/26 fr (119.2 Gy)
61
60 GyE/15 fr (140 Gy) 60 GyE\
14 5
fr Fraction, PBT proton beam therapy, BED biological equivalent dose a
All lymph node metastases had located nearby primary tumor.
time was censored at the last confirmed date of survival if the patient was alive. Progression-free survival time was defined from the start of treatment to the first day of confirmation of progressive disease at any site or any cause of death.
Fig. 1 Overall and progression-free survival for all the 112 patients. Solid line indicates overall survival curve; broken line indicates progression-free survival curve. With a median follow-up period of 57.5 months, 3-year overall survival and progression-free survival rates were 74.7 % and 48.2 %, respectively, and the 5-year overall and progression-free rates were 64.2 % and 44.5 %, respectively
our institution from hospitals or institutions located far from our institution. Another 12 patients died within 1 year after PBT. Therefore, as for late toxicities, the remaining 90 patients were reviewed in the current study. Median age was 57 years (range, 17–84 years). The major primary site was the nasal cavity (n = 62, 69 %). Regarding treatment, 16 patients received surgery before PBT, and 20 patients received induction chemotherapy before PBT. Eleven patients received PBT concurrently with cisplatin, and the remaining patients received PBT alone. The most common treatment was PBT alone at 65 GyE in 26 fractions. Patient characteristics are listed in Table 1. Treatment outcome Median observation period was 57.5 months (range, 12.4–162.7 months). Among 112 patients, the 5-year progression-free and overall survival rates were 44.5 % and 64.2 %, respectively (Fig. 1). A total of 55 patients were confirmed to have tumor progression, consisting of 26, 14, and 15 patients with local, regional, and distant failure, respectively. Eleven patients had not visited for more than 2 years, and we were unable to confirm death. Of these 11, recurrence could not be confirmed in 7 patients. Late toxicity profile
Results Patient characteristics A total of 112 patients with malignancies of the nasal cavity, paranasal sinuses, or involving the skull base were treated using PBT. For 10 patients, the follow-up duration was 1 year or less, mainly because patients were referred to
The toxicity profile is listed in Table 2. Median time to onset of grade 2 or greater late toxicity, except cataract, was 39.2 months (range, 2.7–99.8 months), and 3 patients developed grade 2 or more severe toxicities; the interval from the completion of PBT was more than 5 years. Grade 3 late toxicities occurred in 17 patients (19 %) with 19 events. Grade 3 osteonecrosis caused by exodontia after
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Int J Clin Oncol
Case 1: optic nerve disorder Gr. 4
Table 2 Late toxicity (n = 90) Grade (CTCAE version 4.0)
1
2
3
4
Hearing loss
1
1
2
0
a
0
1
1
0
Encephalomyelitis infection Cataract
0
0
0
2
1
1
5
0
Optic nerve disorder
0
4
1
4
Nerve disorder
Necrosis (other, specify)b Brain
5
1
1
0
Soft tissue
0
0
1
0
Bone
0
4
2
0
a
All central nervous system disorders (I–XII) were classified in this category b In-field necrosis induced by PBT was classified in the nearest implication of CTCAE v4.0
PBT was observed in 2 patients. Grade 4 late toxicities occurred in 6 patients (7 %) with 6 events (encephalomyelitis infection 2, optic nerve disorder 4). Fig. 2 Optic nerve disorder in a patient treated with proton beam therapy (PBT). a Magnetic resonance imaging (MRI) at pretreatment; b dose distribution of PBT; c MRI at 3 years after treatment. Dosepainting simulation of PBT indicated a maximum dose to the right optic nerve of 61.4 GyE. Although MRI at 3 years after treatment revealed no evidence of malignancy or change in the optic nerve, the patient became blind at 51 months after treatment
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A 79-year-old man with T4 olfactory neuroblastoma of the nasal cavity received PBT alone. At 42 months after PBT, MRI revealed no evidence of malignancy (Fig. 2). However, he gradually became aware of decreased visual acuity 3 years after treatment, and finally became blind at 51 months after treatment. Detailed information about patients with grade 4 optic nerve disorder is shown in Table 3. Case 2: brain necrosis Gr. 1 A 68-year-old man whose disease was T4N0M0 squamous cell carcinoma of the nasal cavity received proton beam therapy with cisplatin. Three months after PBT, MRI revealed no evidence of malignancy, and no toxicity. This finding did not change during long-term follow-up for 24 months at 3-month intervals. However, at 24 months after treatment, an edematous change was found in a frontal lobe, and brain necrosis without symptoms was confirmed
Int J Clin Oncol Table 3 Grade 4 optic nerve disorder in detail Gender
Age
Primary site
T stage
Treatment
M
56
Nasal cavity
1
PBT alone
F
52
Nasopharynx
4
PBT alone
M M
79 79
Nasal cavity Nasal cavity
4 4
PBT alone PBT alone
Chiasm and optic nerve volume [50 Gy/(max)
Time to onset
Status
65 GyE/26 fr
0.5 cc/(63.7 GyE)
6Y2M
Alive w/o disease
65 GyE/26 fr
0.2 cc/(65.3 GyE)
4Y3M
Alive w/o disease
6Y2 M
65 GyE/26 fr 60 GyE/15 fr
0.17 cc/(61.4 GyE) 0.03 cc/(53.2 GyE)
4Y3M 1Y5M
Alive w/o disease Died of disease
4Y5 M 4Y6 M
8Y2 M
M Male, F female, Y years, M months, PBT proton beam therapy, w/o without
Fig. 3 Brain necrosis in a patient treated with PBT: MRI at pretreatment (a), 2 years after treatment (b), 2.5 years after treatment (c), and 3 years after treatment (d). The volume of brain to which was prescribed [ 60 GyE was 17.5 cc and maximum dose was 65 GyE. The patient developed no serious symptoms throughout the follow-up period, and he presently remains alive at more than 4 years after treatment
at 30 months after treatment. This late toxicity gradually improved on MRI without additional treatment (Fig. 3). Univariate analyses In univariate analysis, T stage (T4 vs. non-T4), sex, age (less than 65 years vs. 65 years or more),induction chemotherapy (on vs. off), concurrent chemotherapy(on vs. off), dose per fraction (C2.5 Gy vs. \2.5 Gy), and primary site (nasal cavity vs. others) were investigated. However, no significant factors with an impact on the frequency of brain necrosis and optic nerve disorder were identified (Table 4).
Mild to serious optic nerve disorder as late toxicities occurred in seven patients with T4 who had not received induction chemotherapy; these did not occur in patients with T4 who had received induction chemotherapy.
Discussion This study clarified details of the late toxicity profile of PBT and late toxicity. The several previous reports of late toxicity following radiotherapy for the intracranial region have shown considerable variation in frequency. We
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Int J Clin Oncol Table 4 Univariate analysis
Total
Brain necrosis % C Gr. 1
T4
54
9.3
Non-T4
36
5.6
Male
52
3.8
Female
38
13.2
65\
66
7.6
65C
24
8.3
Induction chemotherapy (?)
20
5.0
(-)
70
8.6
Concurrent chemotherapy (?)
11
0.0
(-)
79
8.9
B2.5 Gy/1 fr
76
7.9
[2.5 Gy/1 fr
14
7.1
Nasal cavity
62
6.5
Others T4
28 54
10.7
T4 ? induction
18
10.5
T4 w/o induction
36
11.1
consider that a relatively short observation period will result in the underestimation of late toxicity. Debus et al. [13] reported an incidence of chronic therapy-induced toxicity on median follow-up of 35 months (range, 3 months to 12 years) in 189 patients who underwent fractionated radiotherapy of only 1 % for grades 1–2 toxicity and 2.1 % for grade 3 disease. With a median follow-up of 56 months, in contrast, Lee et al. [14] reported the unexpected development of severe late complications in 34.6 % of patients receiving hypofractionated stereotactic body radiotherapy (SBRT) as a boost treatment. In our present data, median time to onset of grade 2 or greater late toxicity except cataract was 39.2 months (range, 2.7–99.8 months). Further, although only 5 patients (5.5 %) had severe late toxicities (Cgrade 3) within 3 years after treatment, 17 patients (18.9 %) experienced 20 events during the total follow-up period. Mizoe et al. [15]. reported the late toxicity profile of carbon-ion therapy for their series of head and neck cancer patients of 52 (22 %, 52/236) events of all grades, and four cases of blindness. Previous reports are summarized in Table 5. With regard to brain necrosis, several investigators [16–18] reported that severe brain injury was usually irreversible, and sometimes fatal. Surgical resection of a focal region of necrosis can be of benefit and may be life saving [19]. On the other hand, little is known about the outcome of mild or intermediate brain injury. In the
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Optic nerve disorder
Odds ratio
95 % CI
1.73
0.32–9.47
% C Gr. 2 14.9
Odds ratio
95 % CI
2.53
0.49–13.0
1.46
0.39–5.48
1.36
0.26–7.06
0.36
0.04–3.00
–
–
0.64
0.15–2.79
1.13
0.23–5.47
–
–
5.6 0.29
0.60–1.43
11.5 7.9
0.91
0.19–4.38
10.6 8.3
1.12
0.21–6.03
–
–
1.11
0.14–8.50
5.0 10.0 0.0 11.4 9.2 14.3
0.60
0.14–2.51
8.1 7.1
0.82
0.14–4.99
0.0 19.4
present study, we found that some cases of mild or intermediate brain necrosis improved spontaneously after a long period. In our present study, we experienced many events that would not usually be encountered without long-term follow-up, and an adequate understanding of the toxicity profile of PBT in these patients thus requires long-term follow-up. For T4 disease, severe late toxicities might be avoided by induction chemotherapy. We speculate that subsequent decrease in tumor size after PBT might have an positive impact on decrease in irradiation dose to the brain. As for efficacy, Zenda et al. [10] reported a 5-year overall survival rate with PBT for unresectable carcinoma of the paranasal sinuses of 55.0 %, whereas Hoppe et al. reported a 5-year survival rate of definitive (chemo)radiotherapy for these patients of only 15 %. These results emphasize the ongoing need for considerable improvement in treatment strategies for these conditions. One major limitation of this study warrants mention. The precision of dose calculations was made uncertain by the internal heterogeneity, which in turn prevented any medical physics analysis of the late toxicity profile. In particular, precise analysis of dosage from the current pencil-beam dosimeter algorithm is not possible [20]. As part of an ongoing physics evaluations, our group is presently conducting further recalculations of treatment plans for patients with fatal late toxicity using Monte Carlo methods.
Int J Clin Oncol Table 5 Previous reports of late toxicity Age (range)
Follow-up period
Author
Year
Disease
SchulzErtner et al.
2005
ACC of skull base
Uy et al.
2002
Intracranial meningioma
Pt No. 53
40
Treatment
Per fraction
Total dose
Median (range)
Late toxicity in detail (%)
24: RT-FSRT/ IMRT boost
–
70 Gy
24 (2–92) M
CGr. 3 late toxicity
1.8
29: RT-CI boost
54 Gy– 3 GyEx6
72 GyE
16 (2–60) M
25: Ope-IMRT
1.7–2.0 Gy
40–56 Gy
30 (6–71) M
CGr. 3 late toxicity
7.5
15: IMRT Debus et al.
2001
Skull base meningioma
Pehlivan et al.
2011
Skull base tumor
Weber et al.
2012
Intracranial meningioma
189
RT alone
1.8 Gy
56.8 Gy
35 (3–144) M
CGr. 3 late toxicity
2.1
62
PBT alone
1.8–2.0 GyE
63–74 GyE
38 (14–92) M
CGr. 3 TL toxicity
3.2
CGr. 1 TL toxicity
11.2
5-year toxicity free survival
84.5
CGr. 3 late toxicity
12.8
CGr. 4 late toxicity
3.8
39
31: Ope-PBT
–
55.5–66.1 GyE
49.3 (11.5–93.3) M
8: PBT Lee et al.
2012
Head and neck cancer
26
EBRT-SBRT
EBRT: 45–50.4 Gy/25–28 fr SBRT: 10–25 Gy/3–5 fr
56 (27.6–80.2) M
34.6
CGr. 3 late toxicity Mizoe et al.
2012
Present study
Head and neck cancer Nasal/paranasal malignancies and skull base tumors
236 90
Carbon-ion therapy
3.6 GyE (4GyE)
57.6 GyE (64 GyE)
\60 months
All grade late toxicity
22.0
16: OpePBT(?CDDP)
2.0–4.0 GyE
60–70 GyE
59.7 (12.4–169.7) M
CGr. 4 late toxicity
6.6
CGr. 3 late toxicity
21.1
74: PBT(?CDDP)
Pt patient, No number, ACC adenoid cystic carcinoma, RT radiotherapy, FSRT fractionated stereotactic radiotherapy, IMRT intensity modulated radiotherapy, M months, Gr Grade, PBT proton beam therapy, TL temporal lobe, EBRT external-beam radiotherapy, SBRT stereotactic body radiotherapy
In conclusion, the late toxicity profile of proton beam therapy in patients with malignancy involving the nasal cavity, para-nasal sinuses, or skull base was partly clarified. Because late toxicity can occur as late as 5 years after treatment, long-term follow-up is necessary.
Conflict of interest of interest.
The authors declare that they have no conflict
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