A Phase II trial of brachytherapy alone after lumpectomy for select breast cancer: tumor control and survival outcomes of RTOG 95-17.
ABSTRACT 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.
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.
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.
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.
Article: High-dose-rate brachytherapy alone versus whole breast radiotherapy with or without tumor bed boost after breast-conserving surgery: seven-year results of a comparative study.[show abstract] [hide abstract]
ABSTRACT: To report the 7-year results of a prospective study of accelerated partial breast irradiation (APBI) using interstitial high-dose-rate brachytherapy and compare the treatment results with those achieved by standard, whole breast radiotherapy (WBRT), with or without a tumor bed boost (TBB). Between 1996 and 1998, 45 prospectively selected patients with T1N0-N1mi (single nodal micrometastasis), nonlobular breast cancer without the presence of an extensive intraductal component and with negative surgical margins were treated with APBI using interstitial high-dose-rate implants. A total dose of 30.3 Gy (n = 8) and 36.4 Gy (n = 37) in seven fractions within 4 days was delivered to the tumor bed plus a 1-2-cm margin. During the same period, 80 patients, who met the eligibility criteria for APBI but who were treated with 50 Gy WBRT with (n = 36) or without (n = 44) a 10-16-Gy TBB, were selected as controls. The median follow-up for the APBI and control groups was 81 and 83 months, respectively. Local control, relapse-free survival, cancer-specific survival, late side effects, and cosmetic results were assessed. The crude rate of total ipsilateral breast failure was 6.7% (3 of 45), 11.4% (5 of 44), and 8.3% (3 of 36) for patients treated with APBI, WBRT, and WBRT + TBB, respectively. The differences in the 5- and 7-year actuarial rates of ipsilateral breast recurrence were not statistically significant among patients treated with APBI (4.4% and 9.0%), WBRT (4.7% and 14.8%), and WBRT + TBB (5.7% and 9.5%). No statistically significant difference in either the 7-year probability of relapse-free survival (79.8%, 73.5%, and 77.7% for APBI, WBRT, and WBRT + TBB, respectively) or cancer-specific survival (93.3%, 92.9%, and 93.9% for APBI, WBRT, and WBRT + TBB, respectively) was found. The 7-year actuarial elsewhere breast failure rate was 9.0% in the APBI group and 8.3% in the control group (p = 0.80). The rate of excellent/good cosmetic results was 84.4% in the APBI group and 68.3% in the control group (p = 0.04). The corresponding rates of asymptomatic fat necrosis were 20.0% and 20.6%. Symptomatic fat necrosis occurred in 1 patient (2.2%) treated with APBI. The incidence of Grade 2 or worse late radiation side effects was similar for both groups (26.7% vs. 28.6%). Accelerated partial breast irradiation using interstitial high-dose-rate implants, with proper patient selection and quality assurance, yields similar 7-year results to those achieved with standard breast-conserving therapy. APBI does not increase the risk of elsewhere breast failures.International Journal of Radiation OncologyBiologyPhysics 12/2004; 60(4):1173-81. · 4.11 Impact Factor