The American Journal of Surgery (2014) 207, 682-685
North Pacific Surgical Association
Experience with partial breast irradiation for treatment of breast cancer at a community-based cancer center Jennifer Pasko, M.D., Mark Schray, M.D., Misa Lee, M.D., Nathalie Johnson, M.D.* Division of Surgical Oncology and Radiation Oncology, Legacy Good Samaritan Hospital, 1040 NW 22nd Avenue, Suite 560, Portland, OR 97210, USA
KEYWORDS: Breast cancer; Female; Lumpectomy; Accelerated partial breast irradiation; Local recurrence; ASTRO criteria
Abstract BACKGROUND: Many patients after lumpectomy have barriers to whole breast radiation. Accelerated partial breast irradiation (APBI) was introduced at our institution as an alternative. METHODS: Retrospective review of patients who were treated with ABPI from March 2003 to December 2011 was conducted. Results of demographics, tumor pathology, infection, and recurrence were reviewed. RESULTS: Two hundred ninety-four patients received 298 treatments of APBI. The mean follow-up was 58.5 months. Using the American Society for Radiation Oncology criteria, 101 patients were suitable, 142 cautionary, and 52 patients were unsuitable. The average age was 65 with a range of 37 to 93. In our study, true local recurrence occurred in only 1.0% (n 5 3). Patients recurring in the same breast elsewhere was 2% (n 5 6). CONCLUSIONS: Outcomes after treatment with APBI were excellent, and breast recurrence was similar to whole breast irradiation. It may safely be offered to patients with less than suitable criteria or barriers to whole breast radiation. Ó 2014 Elsevier Inc. All rights reserved.
In the United States, 226,000 women are diagnosed with a new breast cancer each year. The surgical options for most of these women are either breast conservation therapy (BCT) or mastectomy. When these options are presented to patients, the one caveat is that women electing to have BCT require the addition of radiation. Both NSABP B06 and B17, even after 20 years, continue to show a local control advantage in the group with breast conservation that had added whole breast radiation.1,2 Those women who do not * Corresponding author. Tel.: 11-503-413-5525; fax: 11-503-4135526. E-mail address: [email protected] Manuscript received November 9, 2013; revised manuscript December 17, 2013 0002-9610/$ - see front matter Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjsurg.2013.12.025
choose to have radiation have an average recurrence risk of 27.9%.2,3 The standard whole breast radiation currently used requires the patient to have 4 to 6.5 weeks of radiation for completion of therapy. Although radiation therapy facilities are readily found in urban and metropolitan areas, patients in small and rural communities can have difficulty with access to radiation therapy close to home. Elderly patients also may have barriers, such as transportation, even in urban areas. Recognizing this struggle, accelerated partial breast radiation (APBI) was introduced as an alternative at our institution in 2003. When the program was started, multicatheter interstitial implants were used and then transitioned to a predominantly intracavitary approach. Guidelines set forth by the American Society for Radiation Oncology (ASTRO)
J. Pasko et al.
Partial breast irradiation for treatment of breast cancer
influenced our practice over this time period. Before the ASTRO guidelines, the criteria we used were those set by the American Society of Breast surgeons. These criteria were far less stringent, and after the ASTRO guidelines, we became more concerned about choosing patients appropriately. We reviewed our experience and patient outcomes.
Table 2 Rates of recurrence local, elsewhere, and contralateral
True local Elsewhere Ipsilateral Contralateral
Methods A retrospective review of all patients treated with PBI from March 2003 to December 2011 was conducted. We included demographics and tumor pathology with prognostics in the review. The patients were then categorized based on the current ASTRO guidelines of suitability (Table 1). All patients received high-dose brachytherapy twice daily for 10 fractions in 5 days to a dose of 34 gray. Initially, adjunctive imaging was not always obtained, but additional imaging has now become part of preoperative workup. Currently, every patient considered for APBI now has adjunctive imaging. Most patient’s breast tissue in this review was evaluated with breast-specific gamma imaging or MRI before proceeding with APBI to rule out multifocal disease. We followed the institutional review board protocol for data review. Over the time period of review, APBI was performed with multicatheter interstitial implants, Mammosite, Contura, and SAVI intracavitary devices. Toward the end of the review, multichannel balloon catheters were also used. Our current practice is to place a cavity evaluation balloon device at the time of surgery. CT imaging is performed postoperatively to evaluate the cavity and conformance to the balloon. Once pathology is available, usually within 48 hours, confirming clear margins and negative nodes, then the true intracavitary device is placed. Physics and treatment planning is then completed and treatment commences. The patient then receives 2 treatments per day for 5 days. The planning target volume for intracavitary devices used was 10 mm from cavity surface. The treatments each day are separated by 6 hours.
Table 1
683
ASTRO criteria4
Suitable
Cautionary
Unsuitable
Age .60 Size ,2.0 cm Margins .2.0 mm
Age 50–59 Size 2.1–3.0 cm Margins negative but .2.0 mm ER ER negative
Age ,50 BRCA mutation Size .3.0 cm
ER positive Invasive ductal Node negative (i2, i1) No neoadjuvant LVSI negative
Invasive lobular
Margin positive Node positive (or unknown) Neoadjuvant LVSI extensive
DCIS Her2 Neu1 LVSI focal
ASTRO 5 American Society for Radiation Oncology; DCIS 5 ductal carcinoma in situ; ER = estrogen receptor; LVSI 5 lymphovascular invasion.
Breast reoccurrence
%
Minimum (248) follow-up, 58.5 mo (%)
3 6 9 8
1 2 3.1 2.7
1.2 2.4 3.6 3.2
Results There were 294 patients who received 298 treatments from March 2003 to December 2011. The median follow-up was 58.5 months. Forty patients had multicatheter therapy, 241 patients had single catheter balloon therapy, and 17 patients multichannel single catheter therapy. Applying current ASTRO guidelines, we classified 101 patients as suitable for APBI, 142 patients cautionary for APBI, and 52 patients unsuitable for APBI category. The average age of the women in our review was 65 although the age ranged from 37 to 93 years. There were 20 patients younger than 50 years, which represented 6% of the overall treatment group. Women older than 75 years comprised about 20% of the overall treatment group. There were 19 different surgeons who performed lumpectomies for our APBI group; however, 1 surgeon performed 80% of the operations. Pathology of the treatment group included 203 invasive ducal carcinomas, 10 invasive lobular carcinomas, 12 mucinous carcinomas, 66 ductal carcinoma in situ, 2 tubular adenocarcinomas, and 1 signet cell carcinoma. Tumor size varied from 1 to 35 mm; the median tumor size was 11 mm. The mean margin size was 6.5 mm. There were 17 patients in our series with a margin of 1 mm, and there were none with positive margins. Metastasis without local breast reoccurrence was seen evenly throughout the 3 ASTRO categories. Eight people had distant metastasis with 3 dead from disease. Additional recurrence data can be seen in Tables 2, 3 and 4. We defined a cancer occurrence in the same breast as an ‘‘elsewhere’’ cancer if it was located more than 2 cm away from the original treatment bed.
Table 3
Recurrence stratified by risk determined by ASTRO
ASTRO criteria
Suitable Cautionary Unsuitable All (n 5 101) (n 5 142) (n 5 51) (n 5 294)
Local Elsewhere Contralateral Metastasis
0 2 4 2
2 3 4 3
1 1 0 3
ASTRO 5 American Society for Radiation Oncology.
3 6 8 8
684 Table 4
The American Journal of Surgery, Vol 207, No 5, May 2014 Characteristics of local and elsewhere recurrent patients
ASTRO grade
Age
Cancer
Reoccurrence
ER
PR
Her2
Margin (mm)
S C C C U C C U S
66 69 52 73 48 64 67 37 73
IDC DCIS IDC Lobular DCIS IDC DCIS Tubular adenocarcinoma IDC
Elsewhere Elsewhere Local Elsewhere Local Elsewhere Local Elsewhere Elsewhere
1 2 1 1 1 1 1 1 *
1 2 2 1 1 1 1 1 *
UNK UNK 1 2 2 UNK 1 2 UNK
2.0 5.0 5.0 .10 1 2.0 .10 13 8
ASTRO 5 American Society for Radiation Oncology; C 5 cautionary; DCIS 5 ductal carcinoma in situ; ER = estrogen receptor; PR = progesterone receptor; S 5 suitable; U 5 unsuitable; UNK 5 unknown.
Seroma is very common using balloons for APBI. Despite this complications associated with APBI-induced seroma, infection is not prevalent. At our institution, all patients are placed on antibiotics from the time the catheter is placed until it is removed, and there is a standard wound care protocol for the balloon insertion site. Despite this, there were 36 patients who received additional antibiotics for erythema, only 7 having a documented infection. Seroma was very common; however, only 22 required intervention with drainage of the seroma.
Comments Accelerated partial breast irradiation can be offered as an alternative to whole breast radiation for selected patients. APBI offers shorter length of therapy, less radiation exposure, and for some patients can remove barriers to care. There has been some concern that such focused radiation treatment may be inferior to whole breast radiation. However, historically, we know that most breast recurrence occurs within 1 to 2 cm of the lumpectomy bed. Hence, treatment within that range should offer good control. In fact, early studies have shown that APBI has equivalent breast recurrence rates to whole breast radiation in a series of low-risk patients.5–7 Antonucci et al6 in a recent matched-pair prospective 10-year review showed that rates of recurrence averaged approximately 5% at 5 years. When looking at our median follow-up of 58.5 months, we found 2.8% rate of recurrence in our group. Although the validity of our breast recurrence could be enhanced by longer term analysis, we feel that these data are good evidence that APBI can be successfully performed in the community setting. In fact before the ASTRO guidelines, we offered APBI to patients who fall into the unsuitable group, and the breast recurrence rate was still low at less than 2%. These outcomes are within published outcomes of breast recurrences with BCT and whole breast radiation.7,8 There is always the concern of missing additional disease in the breast when only tumor bed radiation is being applied. For this reason, breast-specific gamma imaging or MRI was used to assist in identification of multifocal disease. This use of additional breast imaging may have also played a role in our excellent outcomes. In
addition, we use 2 mm as the standard for a negative margin. There were 17 cases that had margins of 1 mm. No patient had a positive margin. Although there is current debate on margin widths and outcomes, our median margin width of 6.5 mm may also have played a role in low rates of local tumor bed recurrence. In the patients who did experience a breast recurrence, we noted that 2 patients were Her2 Neu1, and 2 of the 9 women with ipsilateral breast recurrence were younger than 50 years. Ductal carcinoma in situ occurred in 2 of the 9 women. There were, however, some higher risk tumors treated, with 25 estrogen receptor2/progesterone receptor1 tumors and 42 estrogen receptor1/progesterone receptor2. No strong conclusions can be made based on the small number of patients who recurred, but they all fit the cautionary or unsuitable criteria. Only one of the patients in this group had a 1-mm margin. Many patients will develop a chronic seroma after removal of balloon catheters. Most of these are asymptomatic.9 This held true in our patient population as well with only 15% requiring an intervention for seroma. Early in our experience, several patients were started on antibiotics for mild erythema that was difficult to discern from radiation reaction. Only 2% had a documented infection. Although risk factors for wound infection were not assessed in this study, in future studies, a focus on risk factors that increase chance for significant infection in patients undergoing APBI should be evaluated. We may find that factors such as diabetes mellitus, smoking status, and nutrition play a role, and we may be proactive in interventions. We did not have many patients with long-term poor cosmetic outcome because of radiation skin fibrosis.
Conclusions Outcomes after treatment with APBI are excellent, and rates of breast recurrence are similar to whole breast irradiation in selected patients. This was true in our community-based series, even in patients who would be considered cautionary by current ASTRO guidelines. APBI is a viable, safe alternative with similar outcomes to whole breast radiation. It may be safely offered to patients with less than suitable criteria that have barriers to whole breast radiation.
J. Pasko et al.
Partial breast irradiation for treatment of breast cancer
References 1. Fisher ER, Anderson S, Redmond C, et al. Ipsilateral breast tumor recurrence and survival following lumpectomy and irradiation: pathological findings from NSABP protocol B-06. Semin Surg Oncol 1992;8:161–6. 2. Fisher B, Anderson S, Fisher ER, et al. Significance of ipsilateral breast tumour recurrence after lumpectomy. Lancet 1991;338:327–31. 3. Fisher B, Redmond C, Poisson R, et al. Eight-year results of a randomized clinical trial comparing total mastectomy and lumpectomy with or without irradiation in the treatment of breast cancer. N Engl J Med 1989;320:822–8. 4. Smith BD, Arthur DW, Buchholz TA, et al. Accelerated partial breast irradiation consensus statement from the American Society for Radiation Oncology (ASTRO). Int J Radiat Oncol Biol Phys 2009;74:987–1001. 5. Ferraro DJ, Garsa AA, DeWees TA, et al. Comparison of accelerated partial breast irradiation via multicatheter interstitial brachytherapy versus whole breast radiation. Radiat Oncol 2012;7:53. 6. Antonucci JV, Wallace M, Goldstein NS, et al. Differences in patterns of failure in patients treated with accelerated partial breast irradiation versus whole-breast irradiation: a matched-pair analysis with 10-year follow-up. Int J Radiat Oncol Biol Phys 2009;74:447–52. 7. Mouw KW, Harris JR. Irradiation in early-stage breast cancer: conventional whole-breast, accelerated partial-breast, and accelerated wholebreast strategies compared. Oncology 2012;26:820–30. 8. Fowble B, Solin LJ, Schultz DJ, et al. Breast recurrence following conservative surgery and radiation: patterns of failure, prognosis, and pathologic findings from mastectomy specimens with implications for treatment. Int J Radiat Oncol Biol Phys 1990;19:833–42. 9. Khan AJ, Arthur D, Vicini F, et al. Six- year analysis of treatmentrelated toxicities in patients treated with accelerated partial breast irradiation on the American Society of Breast Surgeons MammoSite Breast Brachytherapy Registry Trial. Ann Surg Oncol 2012;19:1477–83.
Discussion David Beatty, M.D.: This article is a retrospective review outlining the experience with intracavitary APBI for breast cancer treated with breast conserving surgery over the past decade at a community-based cancer center. Almost 300 APBI treatments were administered, and mean followup was 60 months. The investigators have outlined the
685
guidelines generated by ASTRO and classified each patient treated by these guidelinesdsuitable, cautionary, or unsuitable. Almost half of the patients were in the cautionary category and one sixth in the unsuitable category. The authors report a 1% local recurrence rate at a mean 42.5 months and distinguished this from the new ipsilateral, but elsewhere, breast cancers (1.3%) and contralateral breast cancers (1.3%). They note a 15% postoperative seromas requiring intervention and overall conclude that intracavitary APBI is a viable, safe alternative with similar outcomes to whole breast radiation therapy of breast cancer. Specific recommendations for the authors are Distinguish between local, regional, and distant recurrence and new breast cancers (incident) in the ipsilateral (elsewhere) and contralateral breast. Outline the other methods of APBI used in your center (with frequency), such as conformal external beam, Cyberknife, radioseed implantation, and traditional multicatheter brachytherapy. Provide the 5-year local, regional, and distant recurrence rates, 5-year disease-free survival and overall survival. Specific questions for the authors are How many cavitary evaluation balloons were placed, but not used? Once you started using the cavitary evaluation balloons, how did you manage suitable patients desiring APBI who did not have the balloon placed and what was the frequency of this? What was the frequency of excessive induration after APBI and your management of this complication? Overall, this report provides a good outline of the experience with intracavitary APBI for breast cancer treated with breast conserving surgery at a communitybased cancer center over the past decade.
North Pacific Surgical Association
Experience with partial breast irradiation for treatment of breast cancer at a community-based cancer center Jennifer Pasko, M.D., Mark Schray, M.D., Misa Lee, M.D., Nathalie Johnson, M.D.* Division of Surgical Oncology and Radiation Oncology, Legacy Good Samaritan Hospital, 1040 NW 22nd Avenue, Suite 560, Portland, OR 97210, USA
KEYWORDS: Breast cancer; Female; Lumpectomy; Accelerated partial breast irradiation; Local recurrence; ASTRO criteria
Abstract BACKGROUND: Many patients after lumpectomy have barriers to whole breast radiation. Accelerated partial breast irradiation (APBI) was introduced at our institution as an alternative. METHODS: Retrospective review of patients who were treated with ABPI from March 2003 to December 2011 was conducted. Results of demographics, tumor pathology, infection, and recurrence were reviewed. RESULTS: Two hundred ninety-four patients received 298 treatments of APBI. The mean follow-up was 58.5 months. Using the American Society for Radiation Oncology criteria, 101 patients were suitable, 142 cautionary, and 52 patients were unsuitable. The average age was 65 with a range of 37 to 93. In our study, true local recurrence occurred in only 1.0% (n 5 3). Patients recurring in the same breast elsewhere was 2% (n 5 6). CONCLUSIONS: Outcomes after treatment with APBI were excellent, and breast recurrence was similar to whole breast irradiation. It may safely be offered to patients with less than suitable criteria or barriers to whole breast radiation. Ó 2014 Elsevier Inc. All rights reserved.
In the United States, 226,000 women are diagnosed with a new breast cancer each year. The surgical options for most of these women are either breast conservation therapy (BCT) or mastectomy. When these options are presented to patients, the one caveat is that women electing to have BCT require the addition of radiation. Both NSABP B06 and B17, even after 20 years, continue to show a local control advantage in the group with breast conservation that had added whole breast radiation.1,2 Those women who do not * Corresponding author. Tel.: 11-503-413-5525; fax: 11-503-4135526. E-mail address: [email protected] Manuscript received November 9, 2013; revised manuscript December 17, 2013 0002-9610/$ - see front matter Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjsurg.2013.12.025
choose to have radiation have an average recurrence risk of 27.9%.2,3 The standard whole breast radiation currently used requires the patient to have 4 to 6.5 weeks of radiation for completion of therapy. Although radiation therapy facilities are readily found in urban and metropolitan areas, patients in small and rural communities can have difficulty with access to radiation therapy close to home. Elderly patients also may have barriers, such as transportation, even in urban areas. Recognizing this struggle, accelerated partial breast radiation (APBI) was introduced as an alternative at our institution in 2003. When the program was started, multicatheter interstitial implants were used and then transitioned to a predominantly intracavitary approach. Guidelines set forth by the American Society for Radiation Oncology (ASTRO)
J. Pasko et al.
Partial breast irradiation for treatment of breast cancer
influenced our practice over this time period. Before the ASTRO guidelines, the criteria we used were those set by the American Society of Breast surgeons. These criteria were far less stringent, and after the ASTRO guidelines, we became more concerned about choosing patients appropriately. We reviewed our experience and patient outcomes.
Table 2 Rates of recurrence local, elsewhere, and contralateral
True local Elsewhere Ipsilateral Contralateral
Methods A retrospective review of all patients treated with PBI from March 2003 to December 2011 was conducted. We included demographics and tumor pathology with prognostics in the review. The patients were then categorized based on the current ASTRO guidelines of suitability (Table 1). All patients received high-dose brachytherapy twice daily for 10 fractions in 5 days to a dose of 34 gray. Initially, adjunctive imaging was not always obtained, but additional imaging has now become part of preoperative workup. Currently, every patient considered for APBI now has adjunctive imaging. Most patient’s breast tissue in this review was evaluated with breast-specific gamma imaging or MRI before proceeding with APBI to rule out multifocal disease. We followed the institutional review board protocol for data review. Over the time period of review, APBI was performed with multicatheter interstitial implants, Mammosite, Contura, and SAVI intracavitary devices. Toward the end of the review, multichannel balloon catheters were also used. Our current practice is to place a cavity evaluation balloon device at the time of surgery. CT imaging is performed postoperatively to evaluate the cavity and conformance to the balloon. Once pathology is available, usually within 48 hours, confirming clear margins and negative nodes, then the true intracavitary device is placed. Physics and treatment planning is then completed and treatment commences. The patient then receives 2 treatments per day for 5 days. The planning target volume for intracavitary devices used was 10 mm from cavity surface. The treatments each day are separated by 6 hours.
Table 1
683
ASTRO criteria4
Suitable
Cautionary
Unsuitable
Age .60 Size ,2.0 cm Margins .2.0 mm
Age 50–59 Size 2.1–3.0 cm Margins negative but .2.0 mm ER ER negative
Age ,50 BRCA mutation Size .3.0 cm
ER positive Invasive ductal Node negative (i2, i1) No neoadjuvant LVSI negative
Invasive lobular
Margin positive Node positive (or unknown) Neoadjuvant LVSI extensive
DCIS Her2 Neu1 LVSI focal
ASTRO 5 American Society for Radiation Oncology; DCIS 5 ductal carcinoma in situ; ER = estrogen receptor; LVSI 5 lymphovascular invasion.
Breast reoccurrence
%
Minimum (248) follow-up, 58.5 mo (%)
3 6 9 8
1 2 3.1 2.7
1.2 2.4 3.6 3.2
Results There were 294 patients who received 298 treatments from March 2003 to December 2011. The median follow-up was 58.5 months. Forty patients had multicatheter therapy, 241 patients had single catheter balloon therapy, and 17 patients multichannel single catheter therapy. Applying current ASTRO guidelines, we classified 101 patients as suitable for APBI, 142 patients cautionary for APBI, and 52 patients unsuitable for APBI category. The average age of the women in our review was 65 although the age ranged from 37 to 93 years. There were 20 patients younger than 50 years, which represented 6% of the overall treatment group. Women older than 75 years comprised about 20% of the overall treatment group. There were 19 different surgeons who performed lumpectomies for our APBI group; however, 1 surgeon performed 80% of the operations. Pathology of the treatment group included 203 invasive ducal carcinomas, 10 invasive lobular carcinomas, 12 mucinous carcinomas, 66 ductal carcinoma in situ, 2 tubular adenocarcinomas, and 1 signet cell carcinoma. Tumor size varied from 1 to 35 mm; the median tumor size was 11 mm. The mean margin size was 6.5 mm. There were 17 patients in our series with a margin of 1 mm, and there were none with positive margins. Metastasis without local breast reoccurrence was seen evenly throughout the 3 ASTRO categories. Eight people had distant metastasis with 3 dead from disease. Additional recurrence data can be seen in Tables 2, 3 and 4. We defined a cancer occurrence in the same breast as an ‘‘elsewhere’’ cancer if it was located more than 2 cm away from the original treatment bed.
Table 3
Recurrence stratified by risk determined by ASTRO
ASTRO criteria
Suitable Cautionary Unsuitable All (n 5 101) (n 5 142) (n 5 51) (n 5 294)
Local Elsewhere Contralateral Metastasis
0 2 4 2
2 3 4 3
1 1 0 3
ASTRO 5 American Society for Radiation Oncology.
3 6 8 8
684 Table 4
The American Journal of Surgery, Vol 207, No 5, May 2014 Characteristics of local and elsewhere recurrent patients
ASTRO grade
Age
Cancer
Reoccurrence
ER
PR
Her2
Margin (mm)
S C C C U C C U S
66 69 52 73 48 64 67 37 73
IDC DCIS IDC Lobular DCIS IDC DCIS Tubular adenocarcinoma IDC
Elsewhere Elsewhere Local Elsewhere Local Elsewhere Local Elsewhere Elsewhere
1 2 1 1 1 1 1 1 *
1 2 2 1 1 1 1 1 *
UNK UNK 1 2 2 UNK 1 2 UNK
2.0 5.0 5.0 .10 1 2.0 .10 13 8
ASTRO 5 American Society for Radiation Oncology; C 5 cautionary; DCIS 5 ductal carcinoma in situ; ER = estrogen receptor; PR = progesterone receptor; S 5 suitable; U 5 unsuitable; UNK 5 unknown.
Seroma is very common using balloons for APBI. Despite this complications associated with APBI-induced seroma, infection is not prevalent. At our institution, all patients are placed on antibiotics from the time the catheter is placed until it is removed, and there is a standard wound care protocol for the balloon insertion site. Despite this, there were 36 patients who received additional antibiotics for erythema, only 7 having a documented infection. Seroma was very common; however, only 22 required intervention with drainage of the seroma.
Comments Accelerated partial breast irradiation can be offered as an alternative to whole breast radiation for selected patients. APBI offers shorter length of therapy, less radiation exposure, and for some patients can remove barriers to care. There has been some concern that such focused radiation treatment may be inferior to whole breast radiation. However, historically, we know that most breast recurrence occurs within 1 to 2 cm of the lumpectomy bed. Hence, treatment within that range should offer good control. In fact, early studies have shown that APBI has equivalent breast recurrence rates to whole breast radiation in a series of low-risk patients.5–7 Antonucci et al6 in a recent matched-pair prospective 10-year review showed that rates of recurrence averaged approximately 5% at 5 years. When looking at our median follow-up of 58.5 months, we found 2.8% rate of recurrence in our group. Although the validity of our breast recurrence could be enhanced by longer term analysis, we feel that these data are good evidence that APBI can be successfully performed in the community setting. In fact before the ASTRO guidelines, we offered APBI to patients who fall into the unsuitable group, and the breast recurrence rate was still low at less than 2%. These outcomes are within published outcomes of breast recurrences with BCT and whole breast radiation.7,8 There is always the concern of missing additional disease in the breast when only tumor bed radiation is being applied. For this reason, breast-specific gamma imaging or MRI was used to assist in identification of multifocal disease. This use of additional breast imaging may have also played a role in our excellent outcomes. In
addition, we use 2 mm as the standard for a negative margin. There were 17 cases that had margins of 1 mm. No patient had a positive margin. Although there is current debate on margin widths and outcomes, our median margin width of 6.5 mm may also have played a role in low rates of local tumor bed recurrence. In the patients who did experience a breast recurrence, we noted that 2 patients were Her2 Neu1, and 2 of the 9 women with ipsilateral breast recurrence were younger than 50 years. Ductal carcinoma in situ occurred in 2 of the 9 women. There were, however, some higher risk tumors treated, with 25 estrogen receptor2/progesterone receptor1 tumors and 42 estrogen receptor1/progesterone receptor2. No strong conclusions can be made based on the small number of patients who recurred, but they all fit the cautionary or unsuitable criteria. Only one of the patients in this group had a 1-mm margin. Many patients will develop a chronic seroma after removal of balloon catheters. Most of these are asymptomatic.9 This held true in our patient population as well with only 15% requiring an intervention for seroma. Early in our experience, several patients were started on antibiotics for mild erythema that was difficult to discern from radiation reaction. Only 2% had a documented infection. Although risk factors for wound infection were not assessed in this study, in future studies, a focus on risk factors that increase chance for significant infection in patients undergoing APBI should be evaluated. We may find that factors such as diabetes mellitus, smoking status, and nutrition play a role, and we may be proactive in interventions. We did not have many patients with long-term poor cosmetic outcome because of radiation skin fibrosis.
Conclusions Outcomes after treatment with APBI are excellent, and rates of breast recurrence are similar to whole breast irradiation in selected patients. This was true in our community-based series, even in patients who would be considered cautionary by current ASTRO guidelines. APBI is a viable, safe alternative with similar outcomes to whole breast radiation. It may be safely offered to patients with less than suitable criteria that have barriers to whole breast radiation.
J. Pasko et al.
Partial breast irradiation for treatment of breast cancer
References 1. Fisher ER, Anderson S, Redmond C, et al. Ipsilateral breast tumor recurrence and survival following lumpectomy and irradiation: pathological findings from NSABP protocol B-06. Semin Surg Oncol 1992;8:161–6. 2. Fisher B, Anderson S, Fisher ER, et al. Significance of ipsilateral breast tumour recurrence after lumpectomy. Lancet 1991;338:327–31. 3. Fisher B, Redmond C, Poisson R, et al. Eight-year results of a randomized clinical trial comparing total mastectomy and lumpectomy with or without irradiation in the treatment of breast cancer. N Engl J Med 1989;320:822–8. 4. Smith BD, Arthur DW, Buchholz TA, et al. Accelerated partial breast irradiation consensus statement from the American Society for Radiation Oncology (ASTRO). Int J Radiat Oncol Biol Phys 2009;74:987–1001. 5. Ferraro DJ, Garsa AA, DeWees TA, et al. Comparison of accelerated partial breast irradiation via multicatheter interstitial brachytherapy versus whole breast radiation. Radiat Oncol 2012;7:53. 6. Antonucci JV, Wallace M, Goldstein NS, et al. Differences in patterns of failure in patients treated with accelerated partial breast irradiation versus whole-breast irradiation: a matched-pair analysis with 10-year follow-up. Int J Radiat Oncol Biol Phys 2009;74:447–52. 7. Mouw KW, Harris JR. Irradiation in early-stage breast cancer: conventional whole-breast, accelerated partial-breast, and accelerated wholebreast strategies compared. Oncology 2012;26:820–30. 8. Fowble B, Solin LJ, Schultz DJ, et al. Breast recurrence following conservative surgery and radiation: patterns of failure, prognosis, and pathologic findings from mastectomy specimens with implications for treatment. Int J Radiat Oncol Biol Phys 1990;19:833–42. 9. Khan AJ, Arthur D, Vicini F, et al. Six- year analysis of treatmentrelated toxicities in patients treated with accelerated partial breast irradiation on the American Society of Breast Surgeons MammoSite Breast Brachytherapy Registry Trial. Ann Surg Oncol 2012;19:1477–83.
Discussion David Beatty, M.D.: This article is a retrospective review outlining the experience with intracavitary APBI for breast cancer treated with breast conserving surgery over the past decade at a community-based cancer center. Almost 300 APBI treatments were administered, and mean followup was 60 months. The investigators have outlined the
685
guidelines generated by ASTRO and classified each patient treated by these guidelinesdsuitable, cautionary, or unsuitable. Almost half of the patients were in the cautionary category and one sixth in the unsuitable category. The authors report a 1% local recurrence rate at a mean 42.5 months and distinguished this from the new ipsilateral, but elsewhere, breast cancers (1.3%) and contralateral breast cancers (1.3%). They note a 15% postoperative seromas requiring intervention and overall conclude that intracavitary APBI is a viable, safe alternative with similar outcomes to whole breast radiation therapy of breast cancer. Specific recommendations for the authors are Distinguish between local, regional, and distant recurrence and new breast cancers (incident) in the ipsilateral (elsewhere) and contralateral breast. Outline the other methods of APBI used in your center (with frequency), such as conformal external beam, Cyberknife, radioseed implantation, and traditional multicatheter brachytherapy. Provide the 5-year local, regional, and distant recurrence rates, 5-year disease-free survival and overall survival. Specific questions for the authors are How many cavitary evaluation balloons were placed, but not used? Once you started using the cavitary evaluation balloons, how did you manage suitable patients desiring APBI who did not have the balloon placed and what was the frequency of this? What was the frequency of excessive induration after APBI and your management of this complication? Overall, this report provides a good outline of the experience with intracavitary APBI for breast cancer treated with breast conserving surgery at a communitybased cancer center over the past decade.
