Pediatric Radiology
Pediatr. Radiol. 8, 103-107 (1979)
9 by Springer-Verlag1979
CT Whole-Body Scanning and Scintigraphy in Children with Malignant Tumours A Comparative Retrospective Study K a r e n D a m g a a r d - P e d e r s e n , C. J. E d e l i n g , a n d H. H e r t z Departments of Diagnostic Radiology, Nuclear Medicine and Pediatrics, Rigshospitalet (University of Copenhagen), Copenhagen, Denmark
Abstract. A r e t r o s p e c t i v e c o m p a r i s o n b e t w e e n C T a n d s c i n t i g r a p h y w i t h 9 9 m T e c h n e t i u m - p h o s p h a t e (TcP) a n d 6 7 - G a l l i u m - c i t r a t e ( G a ) has b e e n p e r f o r m e d in 8 c h i l d r e n w i t h m a l i g n a n t e x t r a c r a n i a l t u m o u r s a n d in 9 c h i l d r e n d u r i n g c o n c u r r e n t c o n t r o l a f t e r t r e a t m e n t . C T w a s s u p e r i o r to s c i n t i g r a p h y in t h e p r i m a r y t u m o u r e v a l u a t i o n with r e g a r d size, t y p e a n d i n v a s i v e n e s s of t h e t u m o u r . I n t h e s a m e way, r e g r e s sion, p r o g r e s s i o n o r local r e c u r r e n c e a f t e r t r e a t m e n t was b e t t e r v i s u a l i z e d b y C T t h a n b y G a a n d T c - P scanning. I n t h e d e t e c t i o n of s e c o n d a r y s p r e a d of t h e t u m o u r , C T is t h e m o s t sensitive of t h e m o d a l i t i e s in t h e e x a m i n a t i o n of t h e lungs, w h e r e a s T c - P scintigrap h y still is t h e m e t h o d of c h o i c e to s t u d y m e t a s t a s e s in t h e s k e l e t o n .
Key words: C o m p u t e r t o m o g r a p h y - C T - s c a n n i n g CT wholebody scanning - Scintigraphy - Technet i u m - p h o s p h a t e s c i n t i g r a p h y - G a l l i u m - c i t r a t e scintigraphy
I n t h e p r e s e n t s t u d y t h e v a l u e of s c i n t i g r a p h y a n d C T h a s b e e n c o m p a r e d in r e t r o s p e c t in a series of c h i l d r e n with m a l i g n a n t e x t r a c r a n i a l t u m o u r s .
Materials and Methods During 12 months, from December 1976 scintigraphy as well as CT was performed in 14 children with malignant tumours - with a total of 18 examinations. Eight examinations were made in preliminary turnout investigation (Table 1), and 11 examinations in 10 children were carried out as concurrent studies during or after treatment of the tumour (Table 2). In the first group of children CT, Tc-P and Ga-scanning were performed in five patients, CT and Ga-seanning in two patients and CT and Tc-P-scanning in one patient. In the second group, eight patients had CT, Ga and Tc-Pscanning, two patients had CI" and Tc-P-scanning, and finally one patient was examined with CT and Ga only. All scintigraphies were whole-body examinations, whereas CT included the chest and the abdomen in 10 patients, the abdomen in seven patients and the chest only in just one patient. The maximum time interval between CT and scintigraphy was three weeks, but only a few days when pathological findings demanded immediate therapeutic intervention.
Procedure S c i n t i g r a p h y has b e e n a r a t h e r sensitive m e t h o d in t h e l o c a l i z a t i o n a n d c o n t r o l of m a l i g n a n t t u m o u r s . 67 G a l l i u m c i t r a t e ( G a ) has b e e n u s e d in t h e d e t e c t i o n of soft tissue lesions of v a r i o u s o r g a n s [8], a n d 99-m T e c h n e t i u m - P h o s p h a t e c o m p l e x e s ( T c - P ) in t h e vis u a l i z a t i o n of focal lesions of t h e s k e l e t o n [5, 10]. R e c e n t l y c o m p u t e r i z e d t o m o g r a p h y ( C T ) has off e r e d a n e w a p p r o a c h in d e m o n s t r a t i n g p a t h o l o g i c a l s t r u c t u r e s t h r o u g h o u t t h e b o d y [9, 14]. R e p o r t s o n t h e d i a g n o s t i c v a l u e of s c i n t i g r a p h y as well as of C T in t u m o u r e v a l u a t i o n of p e d i a t r i c p a tients h a v e b e e n given in a s m a l l n u m b e r of r e p o r t s [3, 4, 6, 7, 13], b u t c o m p a r i s o n b e t w e e n t h e t w o m o d a l i t i e s has to o u r k n o w l e d g e n o t b e e n p u b l i s h e d .
In the comparison between CT and scintigraphy the results are based upon the primary descriptions of the examinations. These descriptions were correlated to the final diagnoses obtained by autopsy, or by operation, biochemical investigation, radiology and clinical course. Finally a score (Table 1) was given from 0 to 4 depending on the success of the examination in elucidating the following parameters: localization of tumour, size, invasiveness and type of neoplasia. Examinations without positive information about a tumour, but nevertheless not considered normal were called suspicious. Furthermore, information about metastases were noted. When found, the metastases were registrated as positive findings, either localized to the bones (b) or to the parenchyma (p). In the examinations concerning concurrent studies of treated malignant turnouts information about the following parameters were noted: regression/progression of unremoved tumours, local recurrence after resection of tumour, and finally if signs of metastases were found.
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Table 1. Results of CT and scintigraphy in the group of children examined in primary tumour evaluation
Patient
Sex
Age
1. N.A. 2. Li. C. 3. L.N. 4. A.H. 5. Lo. C. 6. R.J.
F F F M F F
4 1 9 4 1 1
7. R.W. 8. L.N.
M M
2 14
CT: Tc-P: Ga: 0: 1: 2: 3: 4:
Primary tumour r ~ CT Tc-P Ga
Metastases ^ Tc-P
CT
3 3 4 susp. 3 3
Susp. 3 0 2 -
0 0 susp. 1 1
Neg. Pos. p Neg. Pos. b Neg. Pos. p, b
Pos. b Neg. Neg. Neg. Neg. Pos. b, p Neg. Neg. Pos. b
4 3
0
2 1
Pos. p Susp. p
Pos. b
Computer tomography Technetium-phosphate scintigraphy Gallium-citrate scintigraphy No information Information about localization of the tumour 1 + size of the tumour 2 + invasion of surrounding structures 3 + type of neoplasia
CT-Scanning An EMI CI" 5005 General Diagnostic Scanner was used. Scantime was 20 sec, kV 120, a matrix of 320 • 320 and a reconstructionfield of 10inches [11]. Time of examination varied from 50 to 120 rain [4].
Scintigraphy The children recieved 150 ~tCi of an 99mTc-phosphatecomplex per kg bodyweight by intravenous injection. The patients were asked to void shortly before the examination in order to minimize interference from radioactivity in the bladder. The examination was carried out by means of a whole body Ohio Nuclear rectilinear scanner. After bone scintigraphy, carrier-free 67-Ga (as gallium citrate) was injected intravenously. The 67-Ga-dose was about 30 p.Ci per kg body weight. Scintigraphy was carried out 48-72 h after the injection [6, 7].
Results
A. Primary Tumour Investigation ( T a b l e 1) I n t h r e e p a t i e n t s with r e t r o p e r i t o n e a l n e u r o b l a s t o m a s (No. 1, 2, 3) C T gave m a x i m u m p o i n t s in o n e case a n d t h r e e p o i n t s in t w o cases. O n e p a t i e n t (No. 2) w a s s u s p e c t e d of h a v i n g s m a l l p u l m o n a r y m e tastases. S c i n t i g r a p h y was suspicious in o n e case, s c o r e d t h r e e p o i n t s in a n o t h e r case a n d w a s n o r m a l in t h e last case; b o n e m e t a s t a s e s w e r e f o u n d in o n e p a t i e n t (No. 1). I n o n e p a t i e n t (No. 4) with m u l t i p l e b o n e m e t a s tases of a n a p l a s t i c t y p e - p r i m a r y t u m o u r u n k n o w n C T i n d i c a t e d a small lesion in t h e r e t r o p e r i t o n e a l s p a c e a n d s h o w e d m u l t i p l e affections of t h e v e r t e b r a l b o d i e s of t h e d o r s a l a n d l u m b a r spine. T c - P s h o w e d p a t h o l o g i c a l a c c u m u l a t i o n of activity in the chest,
Ga
Final diagnosis Retroperitoneal neuroblastoma Retroperitoneal neuroblastoma Retroperitoneal neuroblastoma Bone metastases, unfound primary turnout Malignant sacrococcygeal teratoma Malignant sacrococcygeal teratoma, pulmonary metastases Wilms' tumour, pulmonary metastases Intestinal lymphosarcoma
(Neg.) Neg. Susp.: Pos.: Neg.: ( ): b: p: -:
Suspicious findings Positive findings Negative findings False findings Bone affection Parenchymal affection Examination not performed
a n d t h e G a - e x a m i n a t i o n gave a s u s p i c i o n of a lesion in t h e s a m e area. B o n e m e t a s t a s e s w e r e d e m o n s t r a t e d b y T c - P scanning. M a l i g n a n t s a c r o c o c c y g e a l t e r a t o m a s in two p a tients (No. 5, 6) w e r e d i a g n o s e d b y CT, a p a r t f r o m the type of tumour. The CT-diagnoses included the d e s t r u c t i o n of t h e s a c r o c o c c y g e a l b o n e a n d m u l t i p l e p u l m o n a r y m e t a s t a s e s in t h e o n e of t h e p a t i e n t s (Fig. 1 a - d ) . G a l l i u m s c i n t i g r a p h y i n d i c a t e d t h e t u m o u r s , o n e of t h e m w i t h p o s s i b l e affection of t h e p e l v i n e b o n e s (Fig. 2), b u t n o o t h e r i n f o r m a t i o n was o b t a i n e d . N o n e of t h e p a t i e n t s w e r e e x a m i n e d w i t h Tc-P. O n e case of W i l m s ' t u m o u r (No. 7) was e x a m i n e d to m a x i m u m p o i n t s - plus p u l m o n a r y m e t a s t a s e s b y CT. S c i n t i g r a p h y with G a l o c a l i z e d a m a l i g n a n t t u m o u r , a n d this was t h o u g h t to b e a n e u r o b l a s t o m a . N o p u l m o n a r y m e t a s t a s e s w e r e found. T c - P scintig r a p h y was n o t p e r f o r m e d . F i n a l l y , in o n e p a t i e n t w i t h i n t e s t i n a l l y m p h o s a r c o m a (No. 8) t h e C T d e s c r i p t i o n of t u m o u r , site a n d i n v a s i o n was in a c c o r d a n c e w i t h t h e p r e o p e r a t i v e findings. L i v e r m e t a s t a s e s - as s u s p e c t e d b y t h e C T examination - could not be confirmed. Tc-P scanning gave no information about the turnout, but indicated m e t a s t a s e s t o t h e l o w e r limbs, lesions w h i c h h a v e n o t b e e n c o n f i r m e d b y a n y o t h e r e x a m i n a t i o n s a n d clinically c o n s i d e r e d as false positive. G a - s c i n t i g r a p h y s h o w e d an a b d o m i n a l t u m o u r - b u t n o i n f o r m a t i o n of type, size a n d invasiveness.
B. Turnout Control Examinations ( T a b l e 2 ) I n t w o p a t i e n t s with i n o p e r a b l e r e t r o p e r i t o n e a l n e u roblastomas, CT demonstrated tumour regression
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F i g . 1 a-d. A one year old girl with a malignant sacrococygeal teratoma, a Conventional X-ray of the pelvis revealing no pathology, b CT of the pelvis showing a solid, high absorptive tumour behind the rectum, c CT of the pelvis with bone windowsettings. The most distal part of the coccygeal bone is destroyed (arrow). No affection of the other parts of the pelvine bones is seen. d CT of the mid chest showing subpleural metastases
Table 2. Results of CT and scintigraphy in tumour control examinations Tumour Patient
Sex Age
~"--"~Tc-P
1. N.A. 2. L.N. 3. K . H . J . do. 4. S. D.N. 5. K.S.
F F F F F F
4 9 1 1 1 4
T. regr. T. regr. TR TR TR LR
Susp. N N N N
6. A . H . 7. M.W.
M F
4 3
T. regr. T
8. A.N. 9. R.W. 10. P. M.P.
F M M
15 2 8
N N N
-
Metastases G~
CT
Tc-P
G~
Final diagnosis
N N N N N
Neg. Pos. p Neg. (Susp. p) (Susp. p) Neg.
Neg. Pos. b Neg. Neg. Pos. b
Neg. Susp. b (Pos. p) Neg. Pos. b
Retroperitoneal neuroblastoma Retroperitoneal neuroblastoma Thoraco-abdominal neuroblastoma operated
Susp. N T
Pos. b Pos. b
Pos. b Neg.
Pos. p
N
Neg. (Susp. p) (Susp. p)
Neg. Neg.
Neg. Neg. Neg.
N
N N N
Mediastinal neuroblastoma operated Retroperitoneal neuroblastoma operated, progression Bone metastases, unfound primary turnour Anaplastic tumour of the chest and the abdomen, bone metastases Vaginal botrioid sarcoma operated Wilms' tumour operated Mediastinal lymphosarcoma operated
T: Tumour; TR: Tumour remnant; T. regr.: Tumour regression; LR: Local recurrence; N: Normal. Other abbreviations as in Table 1
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In one case of a resected anaplastic tumour of the chest-wall, CT showed no signs of local recurrence or metastases. A tumour in the retroperitoneal space, however, was found together with metastatic destruction of two of the lumbar vertebral bodies. Tc-P scanning was described as being identical with former examinations, i.e. without accumulation in the abdomen and spine. Ga-scintigraphy identified pathological areas in the chest localized to the primary site of the tumour and indicated a tumour of the abdomen. Finally, in three patients without metastases or tumour recurrence (No. 8, 9, 10): CT was normal in one case, raised suspicion of metastases to the kidney in one patient treated for Wilms' tumour and to a paraaortic gland in a patient treated for lymphosarcoma. Scintigraphy of these three patients was normal.
Discussion Fig. 2. Gallium scintigraphy of the same patient as in Figure 1, seen in a lateral position in the left side of the figure and in frontal position in the fight side. Normal activity is seen in the liver and the spleen, but pathologicalaccumulationof activityis found in the lower abdomen (arrow) following radio- and chemotherapy. Furthermore, the chest scanning in one of the patients indicated a small subpleural metastasis. Scintigraphy was suspicious in the first case and normal in the last case. Three patients with surgically removed neuroblastomas (No. 3, 4, 5) were evaluated by all three techniques. In patient No. 3 and 4, CT showed small tumour remnants or scars following operation, but no signs of progression. Both patients were suspected of having secondary spread of malignancy because of minor alterations in the liver and kidney, respectively. Tc-P and Ga were normal in respect of the area of operation, but metastases to the shoulder and the chest were indicated in patient No. 3, while patient No. 4 was without signs of metastases. In the last of these patients (No. 5) CT revealed a minor local recurrence and no parenchymal or bone metastases were identified. The scintigrams did not indicate a relapse, but multiple metastases to the extremities were found. In one patient with bone metastases from an occult primary tumour (No. 6), CT localized a minor mediastinal tumour, also seen in retrospect in previous scannings. Furthermore, slight regression of the vertebral metastases was found. Tc-P study, prior to CT had raised suspicion of a mediastinal tumour, suggestive of being a neuroblastoma, a parenchymal lesion of the chest and finally bone metastases.
The ability of CT to outline the anatomy and the pathology is well established [9, 14] and confirmed in this investigation. Of seven malignant tumours of primary evaluation, CT demonstrated the exact site, size and degree of invasion of surrounding structures in all cases. Furthermore, the type of malignant tumour was suggested in two of the cases. Secondary deposits of malignancy were found in both groups of patients (Table 1 and 2), and in accordance with other reports [12, 13], CT is more sensitive especially concerning pulmonary metastases than any other existing method. In the control of treated malignant tumours it is our opinion, that CT is the examination of choice. In case of treated Wilms' tumours intravenous urography must still be carried out. Urography is easy to perform and to compare with former examinations, and so far more sensitive than CT in the detection of small parenchymal lesions. Regression following radio- and chemotherapy, as well as local recurrence have been found in regions, which are difficult to examine by other means. Furthermore, small structures in the area of operation, representing either scars or minor tumour remnants, can be controlled and early changes can be diagnosed. The disadvantages of CT, however, must be mentioned. The time of examination is rather long and sedation or even general anaesthesia is necessary in smaller children [2, 4]. Muscular and intestinal movements might degrade the quality of image in an important way [1], which may explain some of the false positive and suspicious findings concerning parenchymal metastases in both groups of children examined. Furthermore, CT studies usually include the
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K. Damgaard-Pedersen et al.: CT and Scintigraphy trunk only; scanning of the extremities by routine is out of question due to the vast n u m b e r of scans, which would be necessary to visualize the whole skeleton. Scintigraphy with Tc-P and G a in the group of primary tumour evaluation localized a malignant t u m o u r in six out of eight cases, but further information was only achieved in three of the cases. It should be noted, that scintigraphy alone did localize a suspicious soft tissue focus in the patient with an occult t u m o u r and bone metastases. This focus was then evaluated by C T and, retrospectively, it was considered to be the possible primary tumour. T h e ability of T c - P to detect bone metastases to the entire skeleton is out of question [6, 10]. This is in contrast to parenchymal metastases, as we have demonstrated in our material, where two patients with multiple p u l m o n a r y metastases had normal scintigrams of the chest. T h e results of scintigraphy in the group of tumour control examinations illustrate the difficulties of this technique in demonstrating regression, progression and remnants of tumours during treatment. T h e r e is, however, preliminary evidence, that in some cases of treated neuroblastomas, uptake of G a occasionally can be seen in the primary tumour and/or the m e tastases. T h e reason for this p h e n o m e n o n is still not clearly understood. In conclusion: C T is an important tool in the prim a r y t u m o u r evaluation and control of treated m a lignant tumours, supplemented with Tc-P scintigraphy in the search for b o n e metastases. Scintigraphy with G a is of minor help in patients with otherwise diagnosed malignant tumours, but might serve as a screening examination in patients with occult m a lignancy, and in a few patients during concurrent t u m o u r evaluation to determine activity of a t u m o u r remnant.
References 1. Alfidi, R.J., Mac Intyre, W.J., Haaga, J. R.: The Effects of biological motion on CT resolution. Am. J. Roentgenol. 127, 11 (1976) 2. Anderson, R.E., Osborn, A. G.: Efficacy of simple sedation for pediatric computed tomography. Radiology 124, 739 (1977) 3. Boldt, D. W., Reilly, B. J.: Computed tomography of abdominal mass lesions in children. Radiology 124, 371 (1977) 4. Damgaard-Pedersen, K., Jensen, J., Hertz, H.: CT whole-body scanning in pediatric radiology. Pediatr. Radiol. 6, 222 (1978) 5. Eckelman, W.R., Reba, C., Kubota, H., Stevenson, J.S.: 99mTc-pyrophosphatefor bone imaging. J. Nucl. Med. 15, 279 (1974) 6. Edeling, C.-J.: Bone scintigraphy in children. Nucl. Med. 15, 228 (1976) 7. Edeling, C.-J.: Tumour imaging in children. Cancer 38, 921 (1976) 8. Edwards, C.L., Hayes, R.L.: Tumour scanning with 67Gacitrate. J. Nucl. Med. 10, 103 (1969) 9. Kreel, L.: The EMI wholebody scanner: An interim clinical evaluation of the prototype. Br. J. Clin. Equipment (1976) 10. Krishnamurthy, G.T., Blahd, W.H.: Technetium-99mpolyphosphate bone imaging for early detection of skeletal metastasis. Nucl. Med. 13, 330 (1974) 11. McCullough, E. C., Payne, J. T.: X-ray transmission computed tomography. Med. Phys, 4, 85 (1977) 12. Muhm, J. R., Brown, L. R., Crowe, J. K.: Detection of pulmonary nodules by computed tomography. Am. J. Roentgenol. 128, 267 (1977) 13. Reilly, B.J.: Extracranial computerized tomography in children. Comp. Axial Tomogr. 1, 257 (1977) 14. Sheedy, P.F., Stephens, D. H., Hattery, R. R., Muhm, J.R., Hartman, G.W.: Computed tomography of the body: Initial clinical trial with the EMI prototype. Am. J. Roentgenol. 127, 23 (1976) Date of final acceptance: September 15, 1978 K. Damgaard-Pedersen X 2023, Rigshospitalet Blegdamvej DK-2100 Copenhagen Denmark
Pediatr. Radiol. 8, 103-107 (1979)
9 by Springer-Verlag1979
CT Whole-Body Scanning and Scintigraphy in Children with Malignant Tumours A Comparative Retrospective Study K a r e n D a m g a a r d - P e d e r s e n , C. J. E d e l i n g , a n d H. H e r t z Departments of Diagnostic Radiology, Nuclear Medicine and Pediatrics, Rigshospitalet (University of Copenhagen), Copenhagen, Denmark
Abstract. A r e t r o s p e c t i v e c o m p a r i s o n b e t w e e n C T a n d s c i n t i g r a p h y w i t h 9 9 m T e c h n e t i u m - p h o s p h a t e (TcP) a n d 6 7 - G a l l i u m - c i t r a t e ( G a ) has b e e n p e r f o r m e d in 8 c h i l d r e n w i t h m a l i g n a n t e x t r a c r a n i a l t u m o u r s a n d in 9 c h i l d r e n d u r i n g c o n c u r r e n t c o n t r o l a f t e r t r e a t m e n t . C T w a s s u p e r i o r to s c i n t i g r a p h y in t h e p r i m a r y t u m o u r e v a l u a t i o n with r e g a r d size, t y p e a n d i n v a s i v e n e s s of t h e t u m o u r . I n t h e s a m e way, r e g r e s sion, p r o g r e s s i o n o r local r e c u r r e n c e a f t e r t r e a t m e n t was b e t t e r v i s u a l i z e d b y C T t h a n b y G a a n d T c - P scanning. I n t h e d e t e c t i o n of s e c o n d a r y s p r e a d of t h e t u m o u r , C T is t h e m o s t sensitive of t h e m o d a l i t i e s in t h e e x a m i n a t i o n of t h e lungs, w h e r e a s T c - P scintigrap h y still is t h e m e t h o d of c h o i c e to s t u d y m e t a s t a s e s in t h e s k e l e t o n .
Key words: C o m p u t e r t o m o g r a p h y - C T - s c a n n i n g CT wholebody scanning - Scintigraphy - Technet i u m - p h o s p h a t e s c i n t i g r a p h y - G a l l i u m - c i t r a t e scintigraphy
I n t h e p r e s e n t s t u d y t h e v a l u e of s c i n t i g r a p h y a n d C T h a s b e e n c o m p a r e d in r e t r o s p e c t in a series of c h i l d r e n with m a l i g n a n t e x t r a c r a n i a l t u m o u r s .
Materials and Methods During 12 months, from December 1976 scintigraphy as well as CT was performed in 14 children with malignant tumours - with a total of 18 examinations. Eight examinations were made in preliminary turnout investigation (Table 1), and 11 examinations in 10 children were carried out as concurrent studies during or after treatment of the tumour (Table 2). In the first group of children CT, Tc-P and Ga-scanning were performed in five patients, CT and Ga-seanning in two patients and CT and Tc-P-scanning in one patient. In the second group, eight patients had CT, Ga and Tc-Pscanning, two patients had CI" and Tc-P-scanning, and finally one patient was examined with CT and Ga only. All scintigraphies were whole-body examinations, whereas CT included the chest and the abdomen in 10 patients, the abdomen in seven patients and the chest only in just one patient. The maximum time interval between CT and scintigraphy was three weeks, but only a few days when pathological findings demanded immediate therapeutic intervention.
Procedure S c i n t i g r a p h y has b e e n a r a t h e r sensitive m e t h o d in t h e l o c a l i z a t i o n a n d c o n t r o l of m a l i g n a n t t u m o u r s . 67 G a l l i u m c i t r a t e ( G a ) has b e e n u s e d in t h e d e t e c t i o n of soft tissue lesions of v a r i o u s o r g a n s [8], a n d 99-m T e c h n e t i u m - P h o s p h a t e c o m p l e x e s ( T c - P ) in t h e vis u a l i z a t i o n of focal lesions of t h e s k e l e t o n [5, 10]. R e c e n t l y c o m p u t e r i z e d t o m o g r a p h y ( C T ) has off e r e d a n e w a p p r o a c h in d e m o n s t r a t i n g p a t h o l o g i c a l s t r u c t u r e s t h r o u g h o u t t h e b o d y [9, 14]. R e p o r t s o n t h e d i a g n o s t i c v a l u e of s c i n t i g r a p h y as well as of C T in t u m o u r e v a l u a t i o n of p e d i a t r i c p a tients h a v e b e e n given in a s m a l l n u m b e r of r e p o r t s [3, 4, 6, 7, 13], b u t c o m p a r i s o n b e t w e e n t h e t w o m o d a l i t i e s has to o u r k n o w l e d g e n o t b e e n p u b l i s h e d .
In the comparison between CT and scintigraphy the results are based upon the primary descriptions of the examinations. These descriptions were correlated to the final diagnoses obtained by autopsy, or by operation, biochemical investigation, radiology and clinical course. Finally a score (Table 1) was given from 0 to 4 depending on the success of the examination in elucidating the following parameters: localization of tumour, size, invasiveness and type of neoplasia. Examinations without positive information about a tumour, but nevertheless not considered normal were called suspicious. Furthermore, information about metastases were noted. When found, the metastases were registrated as positive findings, either localized to the bones (b) or to the parenchyma (p). In the examinations concerning concurrent studies of treated malignant turnouts information about the following parameters were noted: regression/progression of unremoved tumours, local recurrence after resection of tumour, and finally if signs of metastases were found.
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K. Damgaard-Pedersen et al.: CT and Scintigraphy
Table 1. Results of CT and scintigraphy in the group of children examined in primary tumour evaluation
Patient
Sex
Age
1. N.A. 2. Li. C. 3. L.N. 4. A.H. 5. Lo. C. 6. R.J.
F F F M F F
4 1 9 4 1 1
7. R.W. 8. L.N.
M M
2 14
CT: Tc-P: Ga: 0: 1: 2: 3: 4:
Primary tumour r ~ CT Tc-P Ga
Metastases ^ Tc-P
CT
3 3 4 susp. 3 3
Susp. 3 0 2 -
0 0 susp. 1 1
Neg. Pos. p Neg. Pos. b Neg. Pos. p, b
Pos. b Neg. Neg. Neg. Neg. Pos. b, p Neg. Neg. Pos. b
4 3
0
2 1
Pos. p Susp. p
Pos. b
Computer tomography Technetium-phosphate scintigraphy Gallium-citrate scintigraphy No information Information about localization of the tumour 1 + size of the tumour 2 + invasion of surrounding structures 3 + type of neoplasia
CT-Scanning An EMI CI" 5005 General Diagnostic Scanner was used. Scantime was 20 sec, kV 120, a matrix of 320 • 320 and a reconstructionfield of 10inches [11]. Time of examination varied from 50 to 120 rain [4].
Scintigraphy The children recieved 150 ~tCi of an 99mTc-phosphatecomplex per kg bodyweight by intravenous injection. The patients were asked to void shortly before the examination in order to minimize interference from radioactivity in the bladder. The examination was carried out by means of a whole body Ohio Nuclear rectilinear scanner. After bone scintigraphy, carrier-free 67-Ga (as gallium citrate) was injected intravenously. The 67-Ga-dose was about 30 p.Ci per kg body weight. Scintigraphy was carried out 48-72 h after the injection [6, 7].
Results
A. Primary Tumour Investigation ( T a b l e 1) I n t h r e e p a t i e n t s with r e t r o p e r i t o n e a l n e u r o b l a s t o m a s (No. 1, 2, 3) C T gave m a x i m u m p o i n t s in o n e case a n d t h r e e p o i n t s in t w o cases. O n e p a t i e n t (No. 2) w a s s u s p e c t e d of h a v i n g s m a l l p u l m o n a r y m e tastases. S c i n t i g r a p h y was suspicious in o n e case, s c o r e d t h r e e p o i n t s in a n o t h e r case a n d w a s n o r m a l in t h e last case; b o n e m e t a s t a s e s w e r e f o u n d in o n e p a t i e n t (No. 1). I n o n e p a t i e n t (No. 4) with m u l t i p l e b o n e m e t a s tases of a n a p l a s t i c t y p e - p r i m a r y t u m o u r u n k n o w n C T i n d i c a t e d a small lesion in t h e r e t r o p e r i t o n e a l s p a c e a n d s h o w e d m u l t i p l e affections of t h e v e r t e b r a l b o d i e s of t h e d o r s a l a n d l u m b a r spine. T c - P s h o w e d p a t h o l o g i c a l a c c u m u l a t i o n of activity in the chest,
Ga
Final diagnosis Retroperitoneal neuroblastoma Retroperitoneal neuroblastoma Retroperitoneal neuroblastoma Bone metastases, unfound primary turnout Malignant sacrococcygeal teratoma Malignant sacrococcygeal teratoma, pulmonary metastases Wilms' tumour, pulmonary metastases Intestinal lymphosarcoma
(Neg.) Neg. Susp.: Pos.: Neg.: ( ): b: p: -:
Suspicious findings Positive findings Negative findings False findings Bone affection Parenchymal affection Examination not performed
a n d t h e G a - e x a m i n a t i o n gave a s u s p i c i o n of a lesion in t h e s a m e area. B o n e m e t a s t a s e s w e r e d e m o n s t r a t e d b y T c - P scanning. M a l i g n a n t s a c r o c o c c y g e a l t e r a t o m a s in two p a tients (No. 5, 6) w e r e d i a g n o s e d b y CT, a p a r t f r o m the type of tumour. The CT-diagnoses included the d e s t r u c t i o n of t h e s a c r o c o c c y g e a l b o n e a n d m u l t i p l e p u l m o n a r y m e t a s t a s e s in t h e o n e of t h e p a t i e n t s (Fig. 1 a - d ) . G a l l i u m s c i n t i g r a p h y i n d i c a t e d t h e t u m o u r s , o n e of t h e m w i t h p o s s i b l e affection of t h e p e l v i n e b o n e s (Fig. 2), b u t n o o t h e r i n f o r m a t i o n was o b t a i n e d . N o n e of t h e p a t i e n t s w e r e e x a m i n e d w i t h Tc-P. O n e case of W i l m s ' t u m o u r (No. 7) was e x a m i n e d to m a x i m u m p o i n t s - plus p u l m o n a r y m e t a s t a s e s b y CT. S c i n t i g r a p h y with G a l o c a l i z e d a m a l i g n a n t t u m o u r , a n d this was t h o u g h t to b e a n e u r o b l a s t o m a . N o p u l m o n a r y m e t a s t a s e s w e r e found. T c - P scintig r a p h y was n o t p e r f o r m e d . F i n a l l y , in o n e p a t i e n t w i t h i n t e s t i n a l l y m p h o s a r c o m a (No. 8) t h e C T d e s c r i p t i o n of t u m o u r , site a n d i n v a s i o n was in a c c o r d a n c e w i t h t h e p r e o p e r a t i v e findings. L i v e r m e t a s t a s e s - as s u s p e c t e d b y t h e C T examination - could not be confirmed. Tc-P scanning gave no information about the turnout, but indicated m e t a s t a s e s t o t h e l o w e r limbs, lesions w h i c h h a v e n o t b e e n c o n f i r m e d b y a n y o t h e r e x a m i n a t i o n s a n d clinically c o n s i d e r e d as false positive. G a - s c i n t i g r a p h y s h o w e d an a b d o m i n a l t u m o u r - b u t n o i n f o r m a t i o n of type, size a n d invasiveness.
B. Turnout Control Examinations ( T a b l e 2 ) I n t w o p a t i e n t s with i n o p e r a b l e r e t r o p e r i t o n e a l n e u roblastomas, CT demonstrated tumour regression
K. Damgaard-Pedersen et al.: CI" and Scintigraphy
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F i g . 1 a-d. A one year old girl with a malignant sacrococygeal teratoma, a Conventional X-ray of the pelvis revealing no pathology, b CT of the pelvis showing a solid, high absorptive tumour behind the rectum, c CT of the pelvis with bone windowsettings. The most distal part of the coccygeal bone is destroyed (arrow). No affection of the other parts of the pelvine bones is seen. d CT of the mid chest showing subpleural metastases
Table 2. Results of CT and scintigraphy in tumour control examinations Tumour Patient
Sex Age
~"--"~Tc-P
1. N.A. 2. L.N. 3. K . H . J . do. 4. S. D.N. 5. K.S.
F F F F F F
4 9 1 1 1 4
T. regr. T. regr. TR TR TR LR
Susp. N N N N
6. A . H . 7. M.W.
M F
4 3
T. regr. T
8. A.N. 9. R.W. 10. P. M.P.
F M M
15 2 8
N N N
-
Metastases G~
CT
Tc-P
G~
Final diagnosis
N N N N N
Neg. Pos. p Neg. (Susp. p) (Susp. p) Neg.
Neg. Pos. b Neg. Neg. Pos. b
Neg. Susp. b (Pos. p) Neg. Pos. b
Retroperitoneal neuroblastoma Retroperitoneal neuroblastoma Thoraco-abdominal neuroblastoma operated
Susp. N T
Pos. b Pos. b
Pos. b Neg.
Pos. p
N
Neg. (Susp. p) (Susp. p)
Neg. Neg.
Neg. Neg. Neg.
N
N N N
Mediastinal neuroblastoma operated Retroperitoneal neuroblastoma operated, progression Bone metastases, unfound primary turnour Anaplastic tumour of the chest and the abdomen, bone metastases Vaginal botrioid sarcoma operated Wilms' tumour operated Mediastinal lymphosarcoma operated
T: Tumour; TR: Tumour remnant; T. regr.: Tumour regression; LR: Local recurrence; N: Normal. Other abbreviations as in Table 1
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In one case of a resected anaplastic tumour of the chest-wall, CT showed no signs of local recurrence or metastases. A tumour in the retroperitoneal space, however, was found together with metastatic destruction of two of the lumbar vertebral bodies. Tc-P scanning was described as being identical with former examinations, i.e. without accumulation in the abdomen and spine. Ga-scintigraphy identified pathological areas in the chest localized to the primary site of the tumour and indicated a tumour of the abdomen. Finally, in three patients without metastases or tumour recurrence (No. 8, 9, 10): CT was normal in one case, raised suspicion of metastases to the kidney in one patient treated for Wilms' tumour and to a paraaortic gland in a patient treated for lymphosarcoma. Scintigraphy of these three patients was normal.
Discussion Fig. 2. Gallium scintigraphy of the same patient as in Figure 1, seen in a lateral position in the left side of the figure and in frontal position in the fight side. Normal activity is seen in the liver and the spleen, but pathologicalaccumulationof activityis found in the lower abdomen (arrow) following radio- and chemotherapy. Furthermore, the chest scanning in one of the patients indicated a small subpleural metastasis. Scintigraphy was suspicious in the first case and normal in the last case. Three patients with surgically removed neuroblastomas (No. 3, 4, 5) were evaluated by all three techniques. In patient No. 3 and 4, CT showed small tumour remnants or scars following operation, but no signs of progression. Both patients were suspected of having secondary spread of malignancy because of minor alterations in the liver and kidney, respectively. Tc-P and Ga were normal in respect of the area of operation, but metastases to the shoulder and the chest were indicated in patient No. 3, while patient No. 4 was without signs of metastases. In the last of these patients (No. 5) CT revealed a minor local recurrence and no parenchymal or bone metastases were identified. The scintigrams did not indicate a relapse, but multiple metastases to the extremities were found. In one patient with bone metastases from an occult primary tumour (No. 6), CT localized a minor mediastinal tumour, also seen in retrospect in previous scannings. Furthermore, slight regression of the vertebral metastases was found. Tc-P study, prior to CT had raised suspicion of a mediastinal tumour, suggestive of being a neuroblastoma, a parenchymal lesion of the chest and finally bone metastases.
The ability of CT to outline the anatomy and the pathology is well established [9, 14] and confirmed in this investigation. Of seven malignant tumours of primary evaluation, CT demonstrated the exact site, size and degree of invasion of surrounding structures in all cases. Furthermore, the type of malignant tumour was suggested in two of the cases. Secondary deposits of malignancy were found in both groups of patients (Table 1 and 2), and in accordance with other reports [12, 13], CT is more sensitive especially concerning pulmonary metastases than any other existing method. In the control of treated malignant tumours it is our opinion, that CT is the examination of choice. In case of treated Wilms' tumours intravenous urography must still be carried out. Urography is easy to perform and to compare with former examinations, and so far more sensitive than CT in the detection of small parenchymal lesions. Regression following radio- and chemotherapy, as well as local recurrence have been found in regions, which are difficult to examine by other means. Furthermore, small structures in the area of operation, representing either scars or minor tumour remnants, can be controlled and early changes can be diagnosed. The disadvantages of CT, however, must be mentioned. The time of examination is rather long and sedation or even general anaesthesia is necessary in smaller children [2, 4]. Muscular and intestinal movements might degrade the quality of image in an important way [1], which may explain some of the false positive and suspicious findings concerning parenchymal metastases in both groups of children examined. Furthermore, CT studies usually include the
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K. Damgaard-Pedersen et al.: CT and Scintigraphy trunk only; scanning of the extremities by routine is out of question due to the vast n u m b e r of scans, which would be necessary to visualize the whole skeleton. Scintigraphy with Tc-P and G a in the group of primary tumour evaluation localized a malignant t u m o u r in six out of eight cases, but further information was only achieved in three of the cases. It should be noted, that scintigraphy alone did localize a suspicious soft tissue focus in the patient with an occult t u m o u r and bone metastases. This focus was then evaluated by C T and, retrospectively, it was considered to be the possible primary tumour. T h e ability of T c - P to detect bone metastases to the entire skeleton is out of question [6, 10]. This is in contrast to parenchymal metastases, as we have demonstrated in our material, where two patients with multiple p u l m o n a r y metastases had normal scintigrams of the chest. T h e results of scintigraphy in the group of tumour control examinations illustrate the difficulties of this technique in demonstrating regression, progression and remnants of tumours during treatment. T h e r e is, however, preliminary evidence, that in some cases of treated neuroblastomas, uptake of G a occasionally can be seen in the primary tumour and/or the m e tastases. T h e reason for this p h e n o m e n o n is still not clearly understood. In conclusion: C T is an important tool in the prim a r y t u m o u r evaluation and control of treated m a lignant tumours, supplemented with Tc-P scintigraphy in the search for b o n e metastases. Scintigraphy with G a is of minor help in patients with otherwise diagnosed malignant tumours, but might serve as a screening examination in patients with occult m a lignancy, and in a few patients during concurrent t u m o u r evaluation to determine activity of a t u m o u r remnant.
References 1. Alfidi, R.J., Mac Intyre, W.J., Haaga, J. R.: The Effects of biological motion on CT resolution. Am. J. Roentgenol. 127, 11 (1976) 2. Anderson, R.E., Osborn, A. G.: Efficacy of simple sedation for pediatric computed tomography. Radiology 124, 739 (1977) 3. Boldt, D. W., Reilly, B. J.: Computed tomography of abdominal mass lesions in children. Radiology 124, 371 (1977) 4. Damgaard-Pedersen, K., Jensen, J., Hertz, H.: CT whole-body scanning in pediatric radiology. Pediatr. Radiol. 6, 222 (1978) 5. Eckelman, W.R., Reba, C., Kubota, H., Stevenson, J.S.: 99mTc-pyrophosphatefor bone imaging. J. Nucl. Med. 15, 279 (1974) 6. Edeling, C.-J.: Bone scintigraphy in children. Nucl. Med. 15, 228 (1976) 7. Edeling, C.-J.: Tumour imaging in children. Cancer 38, 921 (1976) 8. Edwards, C.L., Hayes, R.L.: Tumour scanning with 67Gacitrate. J. Nucl. Med. 10, 103 (1969) 9. Kreel, L.: The EMI wholebody scanner: An interim clinical evaluation of the prototype. Br. J. Clin. Equipment (1976) 10. Krishnamurthy, G.T., Blahd, W.H.: Technetium-99mpolyphosphate bone imaging for early detection of skeletal metastasis. Nucl. Med. 13, 330 (1974) 11. McCullough, E. C., Payne, J. T.: X-ray transmission computed tomography. Med. Phys, 4, 85 (1977) 12. Muhm, J. R., Brown, L. R., Crowe, J. K.: Detection of pulmonary nodules by computed tomography. Am. J. Roentgenol. 128, 267 (1977) 13. Reilly, B.J.: Extracranial computerized tomography in children. Comp. Axial Tomogr. 1, 257 (1977) 14. Sheedy, P.F., Stephens, D. H., Hattery, R. R., Muhm, J.R., Hartman, G.W.: Computed tomography of the body: Initial clinical trial with the EMI prototype. Am. J. Roentgenol. 127, 23 (1976) Date of final acceptance: September 15, 1978 K. Damgaard-Pedersen X 2023, Rigshospitalet Blegdamvej DK-2100 Copenhagen Denmark
