A Three-Dimensional Bioabsorbable Tissue Marker for Volume Replacement and Radiation Planning: A Multicenter Study of Surgical and Patient-Reported Outcomes for 818 Patients with Breast Cancer

Background

Accurate identification of the tumor bed after breast-conserving surgery (BCS) ensures appropriate radiation to the tumor bed while minimizing normal tissue exposure. The BioZorb^® three-dimensional (3D) bioabsorbable tissue marker provides a reliable target for radiation therapy (RT) planning and follow-up evaluation while serving as a scaffold to maintain breast contour.

Methods

After informed consent, 818 patients (826 breasts) implanted with the BioZorb^® at 14 U.S. sites were enrolled in a national registry. All the patients were prospectively followed with the BioZorb^® implant after BCS. The data collected at 3, 6, 12, and 24 months included all demographics, treatment parameters, and provider/patient-assessed cosmesis.

Results

The median follow-up period was 18.2 months (range, 0.2–53.4 months). The 30-day breast infection rate was 0.5 % of the patients (n = 4), and re-excision was performed for 8.1 % of the patients (n = 66), whereas 2.6 % of the patients (n = 21) underwent mastectomy. Two patients (0.2 %) had local recurrence. The patient-reported cosmetic outcomes at 6, 12, and 24 months were rated as good-to-excellent by 92.4 %, 90.6 %, and 87.3 % of the patients, respectively and similarly by the surgeons. The radiation oncologists reported planning of target volume (PTV) reduction for 46.2 % of the patients receiving radiation boost, with PTV reduction most commonly estimated at 30 %.

Conclusions

This report describes the first large multicenter study of 818 patients implanted with the BioZorb^® tissue marker during BCS. Radiation oncologists found that the device yielded reduced PTVs and that both the patients and the surgeons reported good-to-excellent long-term cosmetic outcomes, with low adverse effects. The BioZorb^® 3D tissue marker is a safe adjunct to BCS and may add benefits for both surgeons and radiation oncologists.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-09271-2) contains supplementary material, which is available to authorized users.

Long-term primary results of accelerated partial breast irradiation after breast-conserving surgery for early-stage breast cancer: a randomised, phase 3, equivalence trial

BACKGROUND

Whole-breast irradiation after breast-conserving surgery for patients with early-stage breast cancer decreases ipsilateral breast-tumour recurrence (IBTR), yielding comparable results to mastectomy. It is unknown whether accelerated partial breast irradiation (APBI) to only the tumour-bearing quadrant, which shortens treatment duration, is equally effective. In our trial, we investigated whether APBI provides equivalent local tumour control after lumpectomy compared with whole-breast irradiation.

METHODS

We did this randomised, phase 3, equivalence trial (NSABP B-39/RTOG 0413) in 154 clinical centres in the USA, Canada, Ireland, and Israel. Adult women (>18 years) with early-stage (0, I, or II; no evidence of distant metastases, but up to three axillary nodes could be positive) breast cancer (tumour size ≤3 cm; including all histologies and multifocal breast cancers), who had had lumpectomy with negative (ie, no detectable cancer cells) surgical margins, were randomly assigned (1:1) using a biased-coin-based minimisation algorithm to receive either whole-breast irradiation (whole-breast irradiation group) or APBI (APBI group). Whole-breast irradiation was delivered in 25 daily fractions of 50 Gy over 5 weeks, with or without a supplemental boost to the tumour bed, and APBI was delivered as 34 Gy of brachytherapy or 38·5 Gy of external bream radiation therapy in 10 fractions, over 5 treatment days within an 8-day period. Randomisation was stratified by disease stage, menopausal status, hormone-receptor status, and intention to receive chemotherapy. Patients, investigators, and statisticians could not be masked to treatment allocation. The primary outcome of invasive and non-invasive IBTR as a first recurrence was analysed in the intention-to-treat population, excluding those patients who were lost to follow-up, with an equivalency test on the basis of a 50% margin increase in the hazard ratio (90% CI for the observed HR between 0·667 and 1·5 for equivalence) and a Cox proportional hazard model. Survival was assessed by intention to treat, and sensitivity analyses were done in the per-protocol population. This trial is registered with ClinicalTrials.gov, NCT00103181.

FINDINGS

Between March 21, 2005, and April 16, 2013, 4216 women were enrolled. 2109 were assigned to the whole-breast irradiation group and 2107 were assigned to the APBI group. 70 patients from the whole-breast irradiation group and 14 from the APBI group withdrew consent or were lost to follow-up at this stage, so 2039 and 2093 patients respectively were available for survival analysis. Further, three and four patients respectively were lost to clinical follow-up (ie, survival status was assessed by phone but no physical examination was done), leaving 2036 patients in the whole-breast irradiation group and 2089 in the APBI group evaluable for the primary outcome. At a median follow-up of 10·2 years (IQR 7·5-11·5), 90 (4%) of 2089 women eligible for the primary outcome in the APBI group and 71 (3%) of 2036 women in the whole-breast irradiation group had an IBTR (HR 1·22, 90% CI 0·94-1·58). The 10-year cumulative incidence of IBTR was 4·6% (95% CI 3·7-5·7) in the APBI group versus 3·9% (3·1-5·0) in the whole-breast irradiation group. 44 (2%) of 2039 patients in the whole-breast irradiation group and 49 (2%) of 2093 patients in the APBI group died from recurring breast cancer. There were no treatment-related deaths. Second cancers and treatment-related toxicities were similar between the two groups. 2020 patients in the whole-breast irradiation group and 2089 in APBI group had available data on adverse events. The highest toxicity grade reported was: grade 1 in 845 (40%), grade 2 in 921 (44%), and grade 3 in 201 (10%) patients in the APBI group, compared with grade 1 in 626 (31%), grade 2 in 1193 (59%), and grade 3 in 143 (7%) in the whole-breast irradiation group.

INTERPRETATION

APBI did not meet the criteria for equivalence to whole-breast irradiation in controlling IBTR for breast-conserving therapy. Our trial had broad eligibility criteria, leading to a large, heterogeneous pool of patients and sufficient power to detect treatment equivalence, but was not designed to test equivalence in patient subgroups or outcomes from different APBI techniques. For patients with early-stage breast cancer, our findings support whole-breast irradiation following lumpectomy; however, with an absolute difference of less than 1% in the 10-year cumulative incidence of IBTR, APBI might be an acceptable alternative for some women.

FUNDING

National Cancer Institute, US Department of Health and Human Services.

Patient-reported outcomes (PROs) in NRG oncology/NSABP B-39/RTOG 0413: A randomized phase III study of conventional whole breast irradiation (WBI) versus partial breast irradiation (PBI) in stage 0, I, or II breast cancer

508

Background: PBI is an alternative to WBI, with potentially greater therapy (tx) compliance, and better integration with chemotherapy (CTX). NSABP B-39/RTOG 0413 clinical outcome results from 2018 did not show equivalence of PBI to WBI in local tumor control; PBI was statistically inferior, but with clinically small differences. PBI may be an acceptable alternative to WBI for some women. Understanding cosmesis and quality of life (QOL) treatment outcomes is important. Methods: B-39/0413 included a prospective QOL substudy with PRO evaluation of breast cancer treatment outcomes (cosmesis, function, pain) and fatigue using BCTOS and SF-36 vitality scales. Secondary QOL parameters included treatment related symptoms, perceived convenience of care, and the BPI pain scale. The study sample was stratified by CTX or not, as CTX is given before WBI but after PBI. PRO assessments occurred before randomization, the last day of adjuvant tx [CTX or radiation], 4 wks later, and 6, 12, 24, and 36 mo later. Primary aims included comparisons of change in fatigue from baseline to end of tx and equivalency of change in cosmesis from baseline to 36 mo for PBI v WBI. Separate analyses were done for CTX and non-CTX pts, controlling for axillary dissection. Each comparison used α=0.0125. Planned sample size was 964. Results: From 3-23-05 to 5-27-09, 975 pts were enrolled in the PRO study; 950 had follow-up data. 504 did not receive CTX and 446 received CTX. In non-CTX pts, PBI had less fatigue (p=0.011) and did not meet criteria for cosmesis equivalence (97.5% CI, -0.02 to 0.22; ∆=0.20). In CTX pts, PBI had worse fatigue (p=0.011) and equivalent cosmesis to WBI (97.5% CI, -0.09 to 0.21; ∆=0.24). In both groups, PBI pts reported less pain at end of tx. In non-CTX pts, PBI had more pain at 36 mo but in CTX pts, there was no difference. Convenience of care and treatment related symptom outcomes will be presented. Conclusions: In non-CTX pts, PBI is more convenient with less fatigue and slightly poorer cosmesis at 36 mo. Cosmesis was equivalent at 36 mo in CTX pts. Support: U10CA180868, -180822, UG1CA189867. Clinical trial information: NCT00103181.

Abstract GS4-04: Primary results of NSABP B-39/RTOG 0413 (NRG Oncology): A randomized phase III study of conventional whole breast irradiation (WBI) versus partial breast irradiation (PBI) for women with stage 0, I, or II breast cancer

Background: Conventional WBI after lumpectomy for early-stage breast cancer decreases ipsilateral breast tumor recurrence (IBTR), yielding comparable results to mastectomy. Accelerated PBI appears effective in reducing IBTR by treating only the tumor bed area. As the majority of IBTR occur at or in the vicinity of the tumor bed, we hypothesized that PBI would be as effective as WBI in controlling IBTR. The primary aim of NSABP B-39/RTOG 0413 was to determine if PBI provides equivalent local tumor control post lumpectomy compared to WBI in pts with early-stage breast cancer. The equivalency test was based on a 50% margin of increase in the hazard ratio (HR=1.5). Secondary endpoints included: overall survival (OS), recurrence-free interval (RFI), distant disease-free interval (DDFI), and toxicity.

Methods: Eligible pts had lumpectomy with histologically-free margins and 0-3 positive axillary nodes. Pts were stratified by stage, menopausal status, hormone receptor status, and intent to receive chemotherapy and then randomized to PBI or WBI. PBI was 10 fractions of 3.4-3.85 Gy, given twice daily with either brachytherapy or 3D external beam radiation. WBI was 50 Gy in 2 Gy fractions given daily with a sequential boost to the surgical cavity. Follow-up was every 6 mos for 5 yrs and then annually. All analyses were by intent-to-treat.

Results: From 3-21-05 to 4-16-13, 4216 pts were randomized: 2107 PBI; 2109 WBI. 61% were postmenopausal; 81% were hormone receptor-positive; 29% intended to receive chemotherapy. Stage distribution was: DCIS, 24%; invasive pN0, 65%; invasive pN1, 10%. As of 7-31-18, median follow-up was 10.2 yrs. There were 161 IBTRs as first events: 90 PBI v 71 WBI (HR 1.22; 90%CI 0.94-1.58). Per protocol-defined margin, to declare PBI and WBI equivalent regarding IBTR risk, the 90% CI for the observed HR had to lie entirely between 0.667 and 1.5. The percent of pts IBTR-free at 10 yrs was 95.2% PBI v 95.9% WBI. A statistically significant difference in the 10-yr RFI rate favored WBI (91.9% PBI v 93.4% WBI; HR 1.32; 95%CI 1.04-1.68; p=0.02). No statistically significant differences existed between PBI and WBI in DDFI (HR 1.31; 95%CI 0.91-1.91; p=0.15), OS (HR 1.10; 95%CI 0.90-1.35; p=0.35), or DFS (HR 1.12; 95%CI 0.98-1.29; p=0.11). Grade 3 toxicity was 9.6% PBI v 7.1% WBI, and grade 4-5 toxicity was 0.5% v 0.3%, respectively.

Discussion: PBI did not meet the criteria for equivalence to WBI in controlling IBTR based on the upper limit of the hazard ratio confidence interval. However, the absolute difference in 10-yr rate of IBTR was <1% (4.8% PBI v 4.1% WBI). The risk of an RFI event was statistically significantly higher for PBI compared to WBI, but the absolute difference in 10-yr RFI rate was also small (8.1% PBI v 6.6% WBI). DDFI, OS, and DFS were not statistically different for PBI v WBI. Grade 3-5 toxicities, although low, were more common for PBI than WBI. The trial population was heterogeneous, ranging from Stage 0-2 breast cancer, and outcome by risk categories are being analyzed.

Support: U10CA180868, -180822, UG1CA189867.

Citation Format: Vicini FA, Cecchini RS, White JR, Julian TB, Arthur DW, Rabinovitch RA, Kuske RR, Parda DS, Ganz PA, Scheier MF, Winter KA, Paik S, Kuerer HM, Vallow LA, Pierce LJ, Mamounas EP, Costantino JP, Bear HD, Germaine I, Gustafson G, Grossheim L, Petersen IA, Hudes RS, Curran, Jr. WJ, Wolmark N. Primary results of NSABP B-39/RTOG 0413 (NRG Oncology): A randomized phase III study of conventional whole breast irradiation (WBI) versus partial breast irradiation (PBI) for women with stage 0, I, or II breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS4-04.

Locoregional recurrence by molecular subtype after multicatheter interstitial accelerated partial breast irradiation: Results from the Pooled Registry Of Multicatheter Interstitial Sites research group

PURPOSE

To determine in breast tumor recurrence (IBTR) and regional nodal recurrence (RNR) rates for women treated with multicatheter interstitial accelerated partial breast irradiation.

METHODS AND MATERIALS

Data from five institutions were collected for patients treated from 1992 to 2013. We report outcomes of 582 breast cancers with ≥1 year of followup. Molecular subtype approximation was performed using estrogen receptor, progesterone receptor, Her2, and grade. The Kaplan-Meier method was used to calculate overall survival, IBTR, RNR, and distant recurrence rates. Univariate and multivariate Cox proportional hazard models were performed to estimate risks of IBTR and RNR.

RESULTS

With a median followup time of 5.4 years, the 5-year IBTR rate was 4.7% overall, 3.5% for Luminal A, 4.1% for Luminal B, 5.2% for Luminal Her2, 13.3% for Her2, and 11.3% for triple-negative breast cancer. Positive surgical margins and high grade were associated with increased risk for IBTR, as was Her2 subtype in comparison with Luminal A subtype. Other individual subtypes comparisons did not show a significant difference. Analysis of Luminal A vs. all other subtypes demonstrated lower IBTR risk for Luminal A (5-year IBTR 3.5% vs. 7.3%, p = 0.02). The 5-year RNR rate was 2.1% overall, 0.3% for Luminal A, 4.6% for Luminal B, 2.6% for Luminal Her2, 34.5% for Her2, and 2.3% for triple-negative breast cancer. RNR risk was higher for women with Her2 compared to the other four subtypes and for Luminal B compared to Luminal A subtype.

CONCLUSIONS

Molecular subtype influences IBTR and RNR rates in women treated with multicatheter interstitial accelerated partial breast irradiation.

Use of a 3-dimensional lumpectomy marker for targeting interstitial accelerated partial breast irradiation (APBI)

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Background: APBI via high-dose-rate (HDR) interstitial catheter implants is an effective, highly customizable method of delivering radiotherapy in breast cancer patients. The technique is amenable to challenging anatomy such as pendulous and/or very small breasts, augmented breasts or superficial lumpectomy sites. The challenge for any APBI technique is identification of the lumpectomy cavity, which can be difficult to visualize after surgery due to post-surgical changes or tissue mobilization for oncoplastic closure. In the past we have used x-ray contrast injected into the cavity to facilitate the radiographic visualization of the cavity or individual clips. A new 3-D tissue marker (BioZorb, Focal Therapeutics, Inc.) has recently been used by surgeons to mark the area of the lumpectomy cavity at greatest risk for recurrence. In effect this acts as a communication tool to help guide the radiation oncologist for treatment planning and delivery. We examined this device for target volume localization in 15 patients receiving interstitial HDR APBI. Methods: The marker mimicking the tumor size was surgically sutured at the base of the lumpectomy cavity in 15 patients with T1T2N0N1 breast cancer with a variety of closure techniques. The clinical target volume (CTV) was taken as the 3-D outline made by the six embedded titanium markers and a 2 cm margin expanded around that structure (the planning target volume, PTV). Multiple interstitial catheters were spaced 1.5 cm apart within the PTV and 34 Gy was delivered in 10 fractions delivered over 5 treatment days. Results: The marker/CTV was easily visualized on CT images, without clips or injected contrast, making catheter insertion and planning more efficient, easier, and reproducible. The CTV volume was small (12.5 +/- 8.7cc; mean +/- SD, range 4.4–33.4cc) as was the PTV (137 +/- 60cc; mean +/- SD, range 75–327cc), relative to typical HDR APBI implants. Conclusions: The technique facilitated identification of the lumpectomy cavity in all patients treated regardless of surgical closure technique. The unambiguous margin demarcation facilitated target contouring and reproducibility for APBI.

Outcomes for APBI with strut-based brachytherapy: First 100 accrued patients (5-year median follow-up)

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Background: The SAVI Collaborative Research Group (SCRG), was created to study the long-term outcomes of women receiving accelerated partial breast irradiation (APBI) using strut-based applicators. The outcomes for the first 100 accrued patients in the study are reported. Methods: Patients for this subset analysis weretaken as the initial 100 treated across all participating sites. Median follow-up of this cohort was 56.3 months at the time of the abstract. Patients were treated with APBI using the strut-based brachytherapy device with conventional dose and fractionation (3.4 Gy x 10 fx, BID). Treatment planning goals for the planning target volume were a V90>90%, V150<50 cc, and V200<20 cc. Patients were followed regularly by their radiation oncologist and outcomes were graded based on the CTCAE v3.0 (common terminology criteria for adverse events, version 3.0). Recurrence (raw and actuarial) rates were also calculated based on the follow up. Cosmesis was graded using the Harvard Scale. Results: 75 patients had invasive disease and 25 had ductal carcinoma in situ. The median age was 60.5 yrs (range 40-85 yrs), with 84% post-menopausal. Median tumor size was 10.0 mm (range 0.7-35 mm) with 92% being estrogen receptor positive. 65% of patients had at least one round of hormone therapy and 7% had chemotherapy. All patients completed APBI as planned with no serious adverse events. All patients met the dosimetric criteria. Good/excellent cosmesis was seen in >94% of subjects at all times of follow up (6-60 months). The 5-yr actuarial rates for TR/MM were 2.2%, 1.5% and 4.2% for all subjects, invasive and DCIS subgroups, respectively. The 5-yr actuarial rates for IBTR were 3.3%, 3.0% and 4.2% for all subjects, invasive and DCIS subgroups, respectively. Conclusions: For these initially treated 100 patients with a median 5 years of follow up, strut-based brachytherapy appears to be a well-tolerated, effective treatment with low rates of toxicities and local control as good as other brachytherapy APBI methods.

Locoregional recurrence risk for women with various molecular subtypes of breast cancer treated with multicatheter interstitial accelerated partial-breast irradiation: Results from Pooled Registry of Multicatheter Interstitial Sites (PROMIS)

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Background: This study was performed to determine in breast tumor recurrence (IBTR) and regional nodal recurrence (RNR) rates for women with different subtypes of invasive ductal breast cancer treated with multicatheter interstitial accelerated partial breast irradiation (mAPBI). Methods: Data from 5 institutions was collected for patients treated from 1992-2013. We report the outcomes of 821 women with 830 breast cancers, all with ≥ 1 year of follow-up after completion of mAPBI. Molecular subtype analysis was performed for 582 women in whom ER, PR, Her-2, and grade were known. The Kaplan-Meier method was used to calculate overall survival (OS), IBTR and RNR. A univariate proportional hazard model was performed to estimate the risk of IBTR based upon molecular subtype, age, grade, N-stage, T-stage, margin status, tumor size, dose rate, endocrine therapy, and chemotherapy. Results: The median age of our patient cohort was 60 years. 50.0% (n = 415) of women had luminal A, 6.9% (n = 57) luminal B, 5.7% (n = 47) luminal Her-2, 1.8% (n = 15) Her-2, and 5.8% (n = 48) triple negative breast cancer (TNBC); an additional 29.8% (n = 248) could not be subtyped. With a median follow-up time of 6.5 years, the 5-year OS of our patient cohort was 94.8%. The 5-year IBTR was 3.5% for luminal A, 4.1% for luminal B, 5.1% for luminal Her-2, 13.3% for Her-2, 11.3% for TNBC, and 1.7% for non-subtyped women. Positive surgical margins and high grade correlated with risk for IBTR; molecular subtype and other variables did not. The 5-year RNR rates were 0.3% for luminal A, 4.6% for luminal B, 2.6% for luminal Her-2, 34.5% for Her-2, and 2.3% for TNBC. RNR risk was significantly higher for women with Her-2 compared to the other 4 subtypes. In addition, risk of RNR was significantly higher for women with luminal B compared to those of luminal A. Conclusions: Women with Her-2 and luminal B breast cancer may have higher RNR but not IBTR risk after mAPBI, as compared with women with luminal A subtype. Further follow-up, correlation with use of trastuzumab, and comparison of outcomes with whole breast irradiation will be valuable.

Toxicity and cosmesis after oncoplastic surgery and interstitial brachytherapy

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Background: Oncoplastic surgery fuses breast cancer surgical and reconstructive techniques, both simple and complex. Following sculpting and removing the appropriate malignancy, tissue rearrangement is utilized to minimize the dead space. PBI with brachytherapy provides excellent tumor control in this population. This study investigates cosmetic outcome and toxicity in select stage 0, 1, and 2 breast cancers treated by a single breast surgeon and radiation oncologist. Methods: 140 women were treated between May 2010 and December 2013 with breast conservation, sentinel node biopsy (SNB), and interstitial brachytherapy. Selection criteria included women of any age, any subtype, tumor size less than < 3 cm, N0 or N1mic, with excision margins > 1 mm. Strict modified Harvard cosmesis scale was used by direct examination by the surgeon, not photos. Toxicity was judged by the surgeon at the time of each follow-up, using the CTCAE scale, version 4. Median follow-up is 2 years. Results: Two patients were lost to follow-up. There were no in-breast and 1 axillary recurrence. Grade 2 or higher toxicities were seen in 10 patients (7.2%, one of whom had Lupus), and only 1 lasted beyond a year. Toxicity included 1 transient breast edema, 1 late mastitis at one year, 1 grade 4 (0.7%), 0 grade 3, 5 grade 2 (3.6%), and 7 grade 1 fat necrosis, 3 grade 2 fibrosis (2.2%), and only 1 transient arm lymphedema (all patients had SNB). Cosmesis was judged as poor in 1 (0.7%), fair in 2 (1.4%), good in 19 (14%), and excellent in 116 (84%). Pockmarks were visible on casual examination in 8% after one year. Conclusions: Oncoplastic surgery combined with sentinel node mapping and interstitial brachytherapy has resulted in low toxicity (7.2%) and high rates of acceptable cosmesis (98% good/excellent), as scored by a single surgeon with strict criteria at each follow-up visit. No conclusions about tumor control will be made until this cohort has mature follow-up.

Abstract P5-14-06: Outcomes in 500 patients from a large, retrospective study of APBI with a strut-based breast brachytherapy applicator

Purpose/Objectives:

The SAVI Collaborative Research Group (SCRG) is a coalition of 14 institutions who have retrospectively compiled a large database of APBI patients treated with a strut-based brachytherapy device (SAVI). This report details the findings of statistical correlations between numerous dosimetric variables and cosmetic outcome.

Materials/Methods:

The SCRG study enrolled 1005 patients. A subset of patients with complete dosimetry and more than 1 year of follow-up by a radiation oncologist were analyzed for toxicity, cosmesis and recurrence/survival. Dosimetric parameters were tabulated for patients, including: V90, V95, V100, V150, V200, skin spacing (skin-bridge), maximum skin dose, tumor size, PTV-Eval volume and applicator size (model). Toxicity (e.g., telangiectasia, fibrosis, fat necrosis, seroma) were graded by physicians for patients with at least 1 year of follow-up (up to 6 years) using the CTCAE v3 Scale and fat necrosis using a simplified CTCAE scale (Grade 1 asymptomatic but seen on imaging, grade 2 symptomatic without intervention, & grade 3 required intervention).

Results:

Median follow up in this cohort was 29.2 months (range 2.4 to 72.2 months). Follow up was &gt;2 yr and &gt;3 yr for 323 and 191 subjects, respectively. Overall, in 500 subjects the late toxicity (grade ≥2) rates were less than 5% during follow up: telangiectasia 1.0%, fibrosis 4.1%, seroma 2.9% and fat necrosis 0.6%. Cosmesis was reported at various post-APBI follow-up visits following treatment completion (6, 12, 24, 36, 48 & 60+ months). For the 6 and 12 month intervals, 98% (n = 122) and 97% (n = 262) were reported excellent or good (E/G), respectively. At 24, 36, 48 and 60 month intervals, the E/G rates were 93% (n = 184), 90% (n = 98), 100% (n = 41) and 94% (n = 15), respectively. The raw rates of ipsilateral breast tumor recurrence (IBTR) and TR/MM were 1.6% (n = 8) and 1.2% (n = 6), respectively, in 500 patients with &gt;1 year of follow up. The 1- and 2-year actuarial rates of overall survival and disease-free survival were: 1-year, 99.6% & 99.4%, resp. and 2-year, 99.2% & 96.7%.

Conclusions:

APBI treatment with the strut-based applicators was well-tolerated, demonstrated low toxicity rates, favorable cosmetic outcomes and excellent local control over the follow-up to date. Patients with challenging breast anatomy were successfully treated with strut-based devices.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-14-06.

Accelerated partial-breast irradiation using strut-based brachytherapy in ductal carcinoma in situ patients: A report on 321 patients with median 25-month follow-up

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Background: Limited data are available on the treatment of ductal carcinoma in situ (DCIS) with accelerated partial breast irradiation (APBI). The American Society for Radiation Oncology (ASTRO) consensus guidelines on APBI classify patients with DCIS as “cautionary”. We present the largest series of DCIS patients reported to date treated with APBI using strut-based brachytherapy. Methods: The SAVI Collaborative Research Group (SCRG) database was used to identify APBI patients with DCIS at 15 institutions treated with strut-based brachytherapy. All patients had a histologic diagnosis of DCIS and received monotherapy APBI (34 Gy in 10 fractions). Data on patient age and margin status, implant dosimetry, device size, disease status and toxicity in this population were analyzed. Results: From 2007-2011, 321 patients (322 breasts) with DCIS received APBI using strut-based brachytherapy. Patient ages ranged from 40-88 with a median age of 62. 51 patients were under 50 years of age. Detailed dosimetry data were reported on 245 patients. Long-term follow up was available on 221 breasts (median F/U = 25 months). Sixty patients have been followed for >3 years. Skin spacing was a challenge in a significant number of patients including 52 with skin spacing ≤ 5mm and 20 with skin spacing ≤ 3mm. Median maximum skin dose in those patient groups were 87% and 84% of prescription dose (PD), respectively. Overall reported dosimetry (n=245) was excellent: median percent of target volume receiving 90% PD was 96.9%, median maximum skin dose was 83.2%, V150% and V200% (volume at 150% and 200% PD) were 25.2 cc and 12.7 cc respectively. The ipsilateral recurrence rate was 2.2% (1.1% TR/MM). Late toxicity (grade ≥ 2) was low: hyperpigmentation = 0.0%, telangiectasias =1.4%, seroma = 3.2%, and fat necrosis in 1.8%. Conclusions: APBI using strut-based brachytherapy appears to be an effective treatment for patients with DCIS with acceptably low ipsilateral breast recurrence rates and low rates of late toxicity. 52 patients in our series had skin spacing 5 mm or less. APBI using brachytherapy may not have been possible for these women with other single-entry devices.

Accelerated partial breast irradiation using a strut-based brachytherapy device: A multi-institutional initial report on acute and late toxicity with greater than 24-month follow-up

149

Background: Accelerated partial breast irradiation (APBI) is commonly used in early-stage breast cancer. The SAVI Collaborative Research Group is a multi-institutional group created to study outcomes in patients who received APBI utilizing strut-based brachytherapy. This analysis reports the acute and late toxicities for patients with greater than 2-year follow-up (F/U) from this study. Methods: 904 APBI patients (ductal carcinoma in situ [n=267] or invasive breast cancer [n=637]), received HDR brachytherapy (34 Gy in 10 fractions) using the SAVI device (Cianna Medical). Patients with dosimetry and documented follow-up were evaluated within 6 weeks of treatment for early adverse events (AEs), and at 1 year, 2 years, and beyond for late AEs. Dosimetric parameters were evaluated with respect to toxicity and will be presented. Results: In 212 patients (median age 62.9 years, range 40-88) all with follow-up greater than 24 months, the median tumor size was 12mm. As of last follow-up (>24 months) cumulative rates of erythema and hyperpigmentation of grade 2 or higher were 1.4% and 0.5%. The incidence of grade 2 or higher telangiectasia, seroma and fat necrosis were 2.8%, 2.8%, and 0.5% respectively. Conclusions: Adverse events for APBI with SAVI are low in incidence, low in grade and compare favorably to other HDR APBI methods.

Long-term outcome from RTOG 9517: A phase I/II study of accelerated partial breast irradiation (APBI) with mulitcatheter brachytherapy (MCT) following lumpectomy for early-stage breast cancer

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Background: Comparison of APBI to whole breast irradiation post lumpectomy for breast conservation is ongoing in phase III trials. However, APBI has gained acceptance in clinical practice despite relatively limited long-term data. RTOG 9517 studied MCT, one of the earliest methods of APBI, and can uniquely provide long-term cancer outcomes. Methods: Eligibility was stage I/II unifocal breast cancer <3cm, invasive non-lobular histology without EIC, negative surgical margins, and 0-3 positive axillary nodes; no extracapsular extension. The target volume was the lumpectomy cavity plus a 2 cm radial and 1 cm ant/post margin. Low Dose Rate (LDR), 45 Gy in 3.5-5 day, or High Dose Rate (HDR) 34 Gy in 10 BID fractions over 5 days was delivered. A rapid dosimetry review was done to assure dose delivery per protocol. Systemic therapy was per physician’s discretion. The primary endpoint was HDR and LDR MCT reproducibility. This analysis focuses on ipsilateral breast failure (IBF), contralateral breast cancer events (CBE), regional (RF) and distant failure (DF) (cumulative incidence) disease-free (DFS), relapse-free (RFS), and overall survival (OS), (Kaplan-Meier). Results: The median follow up is 12.1 years (yr). 100 patients were accrued from 1997-2000; 98 were evaluable; 65 HDR and 33 LDR MCT. Median age was 62; 88% had T1 tumors; 12% T2; 81% p N0, 19% pN1; 77% ER and/or PR +; 19% ER - and PR -; 33 % received adjuvant chemotherapy and 64% antiendocrine therapy. There have been 6 IBF for a 10 yr rate of 6.2%; 2 IBF were outside the APBI field. There were 5 total RF for a 10 yr rate of 5.2%, respectively. There have been 5 CBE for a 10 yr rate of 4.2%. Failure patterns were: 4 isolated IBF, 1 isolated RF, 8 DF only, 1 IBF+RF, 1 IBF+RF+DF, 1 RF+CBE, 1 RF+DF, 3 CBE, and 1 CBE+DF (21 total failures). Eleven patients have developed DF; 8 have died of breast cancer, 22 have died from other causes. The 10 yr DFS, RFS and OS are 69.8%, 71.9%, and 78.0%, respectively. Conclusions: This multi-institutional phase II trial studying MCT-APBI continues to report durable local regional cancer control rates with long term follow-up. Supported by NCI U10 grants CA21661 and CA37422.

A Phase II trial of brachytherapy alone after lumpectomy for select breast cancer: tumor control and survival outcomes of RTOG 95-17

PURPOSE

Radiation Therapy Oncology Group 95-17 is a prospective Phase II cooperative group trial of accelerated partial breast irradiation (APBI) alone using multicatheter brachytherapy after lumpectomy in select early-stage breast cancers. Tumor control and survival outcomes are reported.

METHODS AND MATERIALS

Eligibility criteria included Stage I/II breast carcinoma confirmed to be <3 cm, unifocal, invasive nonlobular histology with zero to three positive axillary nodes without extracapsular extension. APBI treatment was delivered with either low-dose-rate (LDR) (45 Gy in 3.5-5 days) or high-dose-rate (HDR) brachytherapy (34 Gy in 10 twice-daily fractions over 5 days). End points evaluated included in-breast control, regional control, mastectomy-free rate, mastectomy-free survival, disease-free survival, and overall survival. The study was designed to analyze the HDR and LDR groups separately and without comparison.

RESULTS

Between 1997 and 2000, 100 patients were accrued and 99 were eligible; 66 treated with HDR brachytherapy and 33 treated with LDR brachytherapy. Eighty-seven patients had T1 lesions and 12 had T2 lesions. Seventy-nine were pathologically N0 and 20 were N1. Median follow-up in the HDR group is 6.14 years with the 5-year estimates of in-breast, regional, and contralateral failure rates of 3%, 5%, and 2%, respectively. The LDR group experienced similar results with a median follow-up of 6.22 years. The 5-year estimates of in-breast, regional, and contralateral failure rates of 6%, 0%, and 6%, respectively.

CONCLUSION

Patients treated with multicatheter partial breast brachytherapy in this trial experienced excellent in-breast control rates and overall outcome that compare with reports from APBI studies with similar extended follow-up.

Dose specification and quality assurance of radiation therapy oncology group protocol 95-17; a cooperative group study of iridium-192 breast implants as sole therapy

PURPOSE

The Radiation Therapy Oncology Group (RTOG) protocol 95-17 was a Phase I/II trial to evaluate multicatheter brachytherapy as the sole method of adjuvant breast radiotherapy for Stage I/II breast carcinoma after breast-conserving surgery. Low- or high-dose-rate sources were allowed. Dose prescription and treatment evaluation were based on recommendations in the International Commission on Radiation Units and Measurements (ICRU), Report 58 and included the parameters mean central dose (MCD), average peripheral dose, dose homogeneity index (DHI), and the dimensions of the low- and high-dose regions.

METHODS AND MATERIALS

Three levels of quality assurance were implemented: (1) credentialing of institutions was required before entering patients into the study; (2) rapid review of each treatment plan was conducted before treatment; and (3) retrospective review was performed by the Radiological Physics Center in conjunction with the study chairman and RTOG dosimetry staff.

RESULTS

Credentialing focused on the accuracy of dose calculation algorithm and compliance with protocol guidelines. Rapid review was designed to identify and correct deviations from the protocol before treatment. The retrospective review involved recalculation of dosimetry parameters and review of dose distributions to evaluate the treatment. Specifying both central and peripheral doses resulted in uniform dose distributions, with a mean dose homogeneity index of 0.83 +/- 0.06.

CONCLUSIONS

Vigorous quality assurance resulted in a high-quality study with few deviations; only 4 of 100 patients were judged as representing minor variations from protocol, and no patient was judged as representing major deviation. This study should be considered a model for quality assurance of future trials.

Phase II trial of brachytherapy alone after lumpectomy for select breast cancer: toxicity analysis of RTOG 95-17

PURPOSE

Accelerated partial breast irradiation (APBI) can be delivered with brachytherapy within 4-5 days compared with 5-6 weeks for conventional whole breast external beam radiotherapy. Radiation Therapy Oncology Group 95-17 is the first prospective phase I-II cooperative group trial of APBI alone after lumpectomy in select patients with breast cancer. The toxicity rates are reported for low-dose-rate (LDR) and high-dose-rate (HDR) APBI on this trial.

METHODS AND MATERIALS

The inclusion criteria for this study included invasive nonlobular tumors < or =3 cm after lumpectomy with negative surgical margins and axillary dissection with zero to three positive axillary nodes without extracapsular extension. The patients were treated with either LDR APBI (45 Gy in 3.5-5 days) or HDR APBI (34 Gy in 10 twice-daily fractions within 5 days). Chemotherapy (> or =2 weeks after APBI) and/or tamoxifen could be given at the discretion of the treating physicians.

RESULTS

Between August 1997 and March 2000, 100 women were enrolled in this study, and 99 were evaluated. Of the 99 women, 33 were treated with LDR and 66 with HDR APBI. The median follow-up for all patients was 2.7 years (range, 0.6-4.4 years) and was 2.9 years for LDR and 2.7 years for HDR patients. Toxicities attributed to APBI included erythema, edema, tenderness, pain, and infection. Of the 66 patients treated with HDR APBI, 2 (3%) had Grade 3 or 4 toxicity. Of the 33 patients treated with LDR, 3 (9%) had Grade 3 or 4 toxicity during brachytherapy. Late toxicities included skin thickening, fibrosis, breast tenderness, and telangiectasias. No patient experienced late Grade 4 toxicity; the rate of Grade 3 toxicity was 18% for the LDR and 4% for the HDR groups.

CONCLUSION

Acute and late toxicity for this invasive breast radiation technique was modest and acceptable. Patients receiving chemotherapy, a nonprotocol therapy, had a greater rate of Grade 3 toxicity. The study design did not allow for this to be tested statistically.

3D CT–based high-dose-rate breast brachytherapy implants: treatment planning and quality assurance

PURPOSE

Although accelerated partial breast irradiation (APBI) as the sole radiation modality after lumpectomy has shown promising results for select breast cancer patients, published experiences thus far have provided limited information on treatment planning methodology and quality assurance measures. A novel three-dimensional computed tomography (CT)-based treatment planning method for accurate delineation and geometric coverage of the target volume is presented. A correlation between treatment volume and irradiation time has also been studied for quality assurance purposes.

METHODS AND MATERIALS

Between May 2002 and January 2003, 50 consecutive patients underwent an image-guided interstitial implant followed by CT-based treatment planning and were subsequently treated with APBI with a high-dose-rate (HDR) brachytherapy remote afterloader. Target volume was defined as the lumpectomy cavity +2 cm margin modified to >/=5 mm to the skin surface. Catheter reconstruction, geometric optimization, and manual adjustment of irradiation time were done to optimally cover the target volume while minimizing hot spots. Dose homogeneity index (DHI) and percent of target volume receiving 100% of the prescription dose (32 Gy in 8 fractions or 34 Gy in 10 fractions) was determined. Additionally, the correlation between the treatment volume and irradiation time, source strength, and dose was then analyzed for manual verification of the HDR computer calculation.

RESULTS

In all cases, the lumpectomy cavity was covered 100%. Target volume coverage was excellent with a median of 96%, and DHI had a median value of 0.7. For each plan, source strength times the treatment time for every unit of prescribed dose had an excellent agreement of +/-7% to the Manchester volume implant table corrected for modern units.

CONCLUSIONS

CT-based treatment planning allowed excellent visualization of the lumpectomy cavity and normal structures, thereby improving target volume delineation and optimal coverage, relative to conventional orthogonal film dosimetry. Using the Manchester volume implant table calculated irradiation time can be used as quality assurance for the HDR computed time. Thus dosimetric quality assurance and adequate target volume coverage can be concurrently confirmed, allowing prospective evaluation and optimization of implants.

Initial clinical experience with the MammoSite breast brachytherapy applicator in women with early-stage breast cancer treated with breast-conserving therapy

PURPOSE

We present the results of the initial clinical testing of the MammoSite balloon breast brachytherapy applicator in women with early-stage breast cancer treated with breast-conserving therapy.

METHODS AND MATERIALS

Seventy patients were enrolled in a multicenter prospective trial testing the applicator for safety and performance. Fifty-four patients were implanted, and 43 patients were ultimately eligible for and received brachytherapy as the sole radiation modality after lumpectomy. Patients were staged T1N0M0 with negative pathologic margins and age >45 years. A dose of 34 Gy was delivered in 10 fractions over 5 days prescribed to 1 cm from the applicator surface using 192Ir high-dose-rate brachytherapy. A minimum skin-to-balloon surface distance of 5 mm was required for treatment. Device performance, complications, and cosmesis were assessed.

RESULTS

Computed tomography imaging post-balloon inflation showed 8, 14, and 21 patients with 5-6 mm, 7-9 mm, and >10 mm of skin spacing, respectively. Two patients were explanted because of inadequate skin spacing and 7 because of suboptimal conformance of the surgical cavity to the applicator balloon. One patient was explanted because of positive nodal status and another because of age. The most common side effects related to device placement included mild erythema, drainage, pain, and echymosis. No severe side effects related to implantation, brachytherapy, or explantation occurred. Side effects related to radiation therapy were generally mild with erythema, pain, and dry desquamation being the most common. At 1 month, 88% of patients were evaluated as having good-to-excellent cosmetic results.

CONCLUSIONS

The MammoSite balloon breast brachytherapy applicator performed well clinically. All eligible patients completed treatment. Side effects were mild to moderate and self-limiting. Skin-balloon surface distance and balloon-cavity conformance were the main factors limiting the initial use of the device.

Accelerated partial breast irradiation: an updated report from the American Brachytherapy Society

Logistical barriers of time and travel created by the conventional six-week course of radiotherapy prevent many women from pursuing breast conservation treatment. For the past 12 years, Accelerated Partial Breast Irradiation (APBI) has been investigated as a potential alternative treatment approach in women with early stage breast cancer. The ability to complete treatment in five days has the potential to provide additional women with the option of breast conservation. The validity of this APBI is supported in the study of in-breast recurrence patterns, pathologic data and the clinical treatment experience. The review of the recent data on contemporary APBI reveals that patient selection criteria and brachytherapy quality assurance are clearly critical components and necessary to assure a successful treatment outcome. This updated report from the American Brachytherapy Society on Accelerated Partial Breast Irradiation reviews the appropriate background data supporting this treatment approach with conclusions regarding patient selection criteria and treatment delivery.

Accelerated partial breast irradiation

Logistical barriers of time and travel created by the conventional six week course of radiotherapy prevent many women from pursuing breast conservation treatment. For the past 12 years, Accelerated Partial Breast Irradiation (APBI) has been investigated as a potential alternative treatment approach in women with early stage breast cancer. The ability to complete treatment in five days has the potential to provide additional women with the option of breast conservation. The validity of this APBI is supported in the study of in-breast recurrence patterns, pathologic data and the clinical treatment experience. The review of the recent data on contemporary APBI reveals that patient selection criteria and brachytherapy quality assurance are clearly critical components and necessary to assure a successful treatment outcome. This updated report from the American Brachytherapy Society on Accelerated Partial Breast Irradiation reviews the appropriate background data supporting this treatment approach with conclusions regarding patient selection criteria and treatment delivery.

Postmastectomy radiotherapy: clinical practice guidelines of the American Society of Clinical Oncology

OBJECTIVE

To determine indications for the use of postmastectomy radiotherapy (PMRT) for patients with invasive breast cancer with involved axillary lymph nodes or locally advanced disease who receive systemic therapy. These guidelines are intended for use in the care of patients outside of clinical trials.

POTENTIAL INTERVENTION

The benefits and risks of PMRT in such patients, as well as subgroups of these patients, were considered. The details of the PMRT technique were also evaluated.

OUTCOMES

The outcomes considered included freedom from local-regional recurrence, survival (disease-free and overall), and long-term toxicity.

EVIDENCE

An expert multidisciplinary panel reviewed pertinent information from the published literature through July 2000; certain investigators were contacted for more recent and, in some cases, unpublished information. A computerized search was performed of MEDLINE data; directed searches based on the bibliographies of primary articles were also performed.

VALUES

Levels of evidence and guideline grades were assigned by the Panel using standard criteria. A "recommendation" was made when level I or II evidence was available and there was consensus as to its meaning. A "suggestion" was made based on level III, IV, or V evidence and there was consensus as to its meaning. Areas of clinical importance were pointed out where guidelines could not be formulated due to insufficient evidence or lack of consensus.

RECOMMENDATIONS

The recommendations, suggestions, and expert opinions of the Panel are described in this article.

VALIDATION

Seven outside reviewers, the American Society of Clinical Oncology (ASCO) Health Services Research Committee members, and the ASCO Board of Directors reviewed this document.

Brachytherapy in the treatment of breast cancer

Whole-breast external-beam radiation therapy (EBRT) involves a 6-week course of fractionated treatments. In contrast, brachytherapy can be completed in a 4- to 5-day treatment course. Because of this shortened time frame, there has been interest in breast brachytherapy as a sole modality after lumpectomy. The American Brachytherapy Society (ABS) has issued guidelines specifically for the use of brachytherapy in breast carcinoma. In these guidelines, the ABS addresses important areas of controversy related to the indications, execution, and evaluation of breast implants when utilized in the following settings: as the sole treatment modality following lumpectomy, as an alternative to a 6-week course of EBRT following lumpectomy, as a boost following whole-breast irradiation, and for the treatment of local recurrences following breast-conservation treatment. The ABS recommends a precise definition and meticulous delineation of the clinical target volume. In addition, the Society recommends the routine use of dose-volume histograms and a dose-homogeneity index as tools to ensure reproducible brachytherapy and to allow interinstitutional comparisons. Brachytherapy as a sole modality is currently considered investigational and should be performed in the context of a controlled clinical trial. Practitioners and cooperative groups are encouraged to use these guidelines to formulate treatment and dose-reporting policies, but responsibility for medical decisions ultimately rests with the treating radiation oncologist.

The influence of young age and positive family history of breast cancer on the prognosis of ductal carcinoma in situ treated by excision with or without radiation therapy or by mastectomy

BACKGROUND

Several recent studies have investigated the influence of family history on the progression of DCIS patients treated by tylectomy and radiation therapy. Since three treatment strategies have been used for DCIS at our institution, we evaluated the influence of family history and young age on outcome by treatment method.

METHODS

Between 1/1/82 and 12/31/92, 128 patients were treated for DCIS by mastectomy (n = 50, 39%), tylectomy alone (n = 43, 34%), and tylectomy with radiation therapy (n = 35, 27%). Median follow-up is 8.7 years. Thirty-nine patients had a positive family history of breast cancer; 26 in a mother, sister, or daughter (first-degree relative); and 26 in a grandmother, aunt, or cousin (second-degree relative). Thirteen patients had a positive family history in both first- and second-degree relatives.

RESULTS

Six women developed a recurrence in the treated breast; all of these were initially treated with tylectomy alone. There were no recurrences in the mastectomy group or the tylectomy patients treated with postoperative radiation therapy. Patients with a positive family history had a 10.3% local recurrence rate (LRR), vs. a 2.3% LRR in patients with a negative family history (p = 0.05). Four of 44 patients (9.1%) 50 years of age or younger recurred, compared to two of 84 patients (2.4%) over the age of 50 (p = 0.10). Fifteen patients had both a positive family history and were 50 years of age or younger. Among these women, the recurrence rate was 20%. Women in this group treated by lesionectomy alone had a LRR of 38% (3 of 8).

CONCLUSION

The most important determinant of outcome was the selection of treatment modality, with all of the recurrences occurring in the tylectomy alone group. In addition to treatment method, a positive family history significantly influenced LRR in patients treated by tylectomy, especially in women 50 years of age or younger. These results suggest that DCIS patients, particularly premenopausal women with a positive family history, benefit from treatment of the entire breast, and raise concerns about treating patients with a possible genetic susceptibility to breast cancer with tylectomy alone.

Long-term results of wide-field brachytherapy as the sole method of radiation therapy after segmental mastectomy for T(is,1,2) breast cancer

BACKGROUND

We hypothesized that wide-field brachytherapy (BRT) after margin negative excision would result in complication rates, local recurrence rates, and cosmesis scores equivalent to external beam radiotherapy (ERT).

METHODS

Patients with T(is,1,2) tumors less than or equal to 4 cm, 0 to 3 positive axillary nodes, and negative inked surgical margins were entered prospectively into BRT phase I/II trial. Patients who met the eligibility criteria for BRT but were treated with ERT during the same time period were retrospectively identified as controls. A blinded panel of healthcare professionals graded cosmetic outcome.

RESULTS

Fifty patients with 51 breast cancers received BRT from January 1992 to October 1993. We identified 94 patients eligible for BRT but concurrently treated with ERT. At a median follow-up of 75 months, the two groups were similar for grade III treatment toxicities, local/regional recurrence rates, and cosmesis scores.

CONCLUSIONS

For selected breast cancer patients undergoing breast-conserving therapy, BRT is an attractive alternative to ERT.

The role of postmastectomy radiation in the treatment of early stage breast cancer: back to the future

Oncologists once downplayed the adjuvant role of radiotherapy after mastectomy. A decade ago, lacking a survival benefit, studies demonstrating late fatal myocardial infarctions nearly put a stop to any referrals of postoperative high-risk women to radiation oncology. The potential survival benefits of adjuvant radiotherapy may be overshadowed by inadequate technique leading to late cardiac deaths. Is it possible to cover the chest wall, internal mammary lymph chain, supraclavicular, and, where indicated, the axillary nodes and keep the dose to the coronary arteries and the lung to well within tolerance? A modern five-field comprehensive technique can deliver less cardiac and lung irradiation than the standard three-field technique, i.e. supraclavicular field matched to broad tangential fields. Linear accelerators with 4 megavolt (MV) to 6 MV photons, a full spectrum (6 MV to 20 MV) of electron energies, and meticulous computerized treatment planning based on multiple computed tomography planes allow an experienced physics/dosimetry team to treat all target sites while wrapping the dose around critical normal tissues.Whether to offer postmastectomy radiation to women with one to three positive nodes after adjuvant chemotherapy treatment has been the subject of intense discussion since the publication of two major randomized prospective trials. Although before these studies radiotherapy after mastectomy was an established treatment for women with four or more positive axillary nodes, existing data did not justify its use in patients with less extensive nodal involvement. Now, with results from these studies showing improved survival after radiotherapy in all node-positive premenopausal and perimenopausal women, with perhaps its greatest benefit in women with 1-3 positive nodes, practice patterns are again shifting toward strong consideration of treatment in women with less tumor nodal involvement.

Adjuvant irradiation after mastectomy in women with one to three positive axillary nodes: then no; now yes

The decision whether to offer women with one to three positive nodes postmastectomy radiation after adjuvant chemotherapy has been the subject of intense discussion since the publication of two major randomized prospective trials. Although radiotherapy after mastectomy was an established treatment for women with four or more positive axillary nodes, before these studies, existing data did not justify its use in patients with less extensive nodal involvement. Now with results from these studies showing improved survival after radiotherapy in all node-positive premenopausal and perimenopausal women, with perhaps its greatest benefit in women with one to three positive nodes, practice patterns are again shifting toward strong consideration of treatment in women with less tumor involvement. The arguments supporting this new treatment philosophy are presented.