Four-year clinical update from a prospective trial of accelerated partial breast intensity-modulated radiotherapy (APBIMRT).

This prospective Phase II single-arm study gathered data on the use of intensity-modulated radiotherapy (IMRT) to deliver accelerated partial breast irradiation (APBI). Four-year efficacy, cosmesis, and toxicity results are presented. Between February 2004 and September 2007, 136 consecutive patients with Stage 0/I breast cancer and negative margins ≥0.2 cm were treated on protocol. Patients received 38.5 Gy in 10 equal fractions delivered twice daily. Breast pain and cosmesis were rated by patient, and cosmesis was additionally evaluated by physician per Radiation Therapy Oncology Group (RTOG) criteria. The National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE v3.0) was used to grade toxicities. 136 patients (140 breasts) with median follow-up of 53.1 months (range, 8.9-83.2) were evaluated. Population characteristics included median age of 61.9 years and Tis (13.6 %), T1a (18.6 %), T1b (36.4 %), and T1c (31.4 %). Kaplan-Meier estimates at 4 years: ipsilateral breast tumor recurrence 0.7 %; contralateral breast failure 0 %; distant failure 0.9 %; overall survival 96.8 %; and cancer-specific survival 100 %. At last follow-up, patients and physicians rated cosmesis as excellent/good in 88.2 and 90.5 %, respectively; patients rated breast pain as none/mild in 97.0 %. Other observations included edema (1.4 %), telangiectasia (3.6 %), five cases of grade 1 radiation recall (3.6 %), and two cases of rib fractures (1.4 %). This analysis represents the largest cohort and longest follow-up of APBI utilizing IMRT reported to date. Four-year results continue to demonstrate excellent local control, survival, cosmetic results, and toxicity profile.

A prospective Phase III trial evaluating patient self-reported pain and cosmesis in accelerated partial breast irradiation utilizing 3-D versus intensity-modulated radiotherapy.

PURPOSE/OBJECTIVE: The primary objective is to examine patient self-assessment of breast pain and cosmesis between three-dimensional (3D-CRT) versus intensity-modulated radiotherapy (IMRT). The secondary objective is to evaluate any relationship of treatment planning conformality of both cohorts to patient-assessed pain. Assessments were performed at interim 12, 24, 36, and 48 months with a final 5-year assessment. MATERIALS/METHODS: In total, 656 patients (3D-CRT n = 328; IMRT n = 328) were randomly assigned to either IMRT or 3D-CRT accelerated partial breast radiotherapy to 38.5 Gy in 10 BID 3.85 Gy fractions. RESULTS: Median follow-up was 3 years. Multivariate analysis showed that pain severity significantly decreased from baseline to the 12-month follow-up visit (<0.001 for both 3D-CRT and IMRT) in each cohort. There was significantly less pain at 2 (p = 0.002) and 3 years (0.045) in the IMRT arm versus the 3D-CRT arm when compared to the baseline pain level. There was no difference in patient-assessed cosmesis at any follow-up point; however, although MD-assessed cosmesis showed no difference from years 1 to 4, there was significantly better cosmesis for 3D-CRT versus IMRT (p = 0.047) at 5 years. There was a significant correlation between a maximum pain score and an increase in the CI100 (indicating less conformity) in the IMRT cohort (p < 0.01) and in the IMRT subgroup when the CI100 was ≤0.37 cohort arm (p = 0.01). CONCLUSION: In the analysis of our primary objective we found that at 2 years, IMRT resulted in more interval improvement in breast pain after baseline when compared to patients treated with 3D-CRT planning. As seen in our secondary analysis, this may be due to the ability of IMRT to achieve higher conformality (as evidenced by lower CI values) resulting in less fibrosis. There were no differences in patient-assessed cosmesis or MD-assessed cosmesis for years 1-4; however, physician-assessed 5-year cosmesis was better with 3D-CRT.

Accelerated partial-breast intensity-modulated radiotherapy results in improved dose distribution when compared with three-dimensional treatment-planning techniques.

PURPOSE: To compare dose distribution and normal tissue sparing in partial-breast treatment using three-dimensional conformal radiotherapy (3D-CRT) vs. intensity-modulated radiotherapy (IMRT). METHODS AND MATERIALS: Sixty-three patients with Tis-1N0M0 breast cancer were treated on a Phase II prospective accelerated partial-breast IMRT protocol at two facilities between April 2004 and January 2006. Fifty-six patients had data sets sufficient to adequately contour all structures. These cases were subsequently replanned with 3D-CRT techniques using the same contours, to compare the dose distribution patterns of 3D-CRT vs. IMRT. RESULTS: The average planning target volume (PTV) to ipsilateral breast (IB) ratio was 24% (range, 7-58%). The average volume of IB receiving 25%, 50%, 75%, and 100% of the prescribed dose was 4.0%, 5.0%, 5.5%, and 10.5% less with IMRT than with 3D (p < 0.01). The dose reduction to normal breast was further improved in the subset of patients whose PTV to IB ratio was >25%, and in patients with contoured breast volume <750 cm(3). No difference was detected in delivery to the lumpectomy cavity or clinical target volume. The PTV volume receiving 95% of the dose was higher in the 3D conformal plans (p < 0.01), but no significant difference was observed in the PTV volume receiving 90% (p = 0.17). The irradiated heart and lung volumes were small with both techniques but also favored IMRT. CONCLUSIONS: In T1N0 patients treated with external beam partial-breast radiotherapy, IMRT improves normal tissue sparing in the ipsilateral breast compared with 3DRT, without compromising dose delivery to the lumpectomy cavity and clinical target volume.

External beam accelerated partial breast irradiation yields favorable outcomes in patients with prior breast augmentation.

PURPOSE: To report outcomes in breast cancer patients with prior breast augmentation treated with external beam accelerated partial breast irradiation (EB-APBI) utilizing intensity-modulated radiotherapy or 3-dimensional conformal radiotherapy, both with IGRT. MATERIALS AND METHODS: Sixteen stage 0/1 breast cancer patients with previous elective bilateral augmentation were treated post-lumpectomy on institutional EB-APBI trials (01185132 and 01185145 on clinicaltrials.gov). Patients received 38.5 Gy in 10 fractions over five consecutive days. Breast/chest wall pain and cosmesis were rated by patient; cosmesis was additionally evaluated by physician per RTOG criteria. RESULTS: The median follow-up from accelerated partial breast irradiation (APBI) completion was 23.9 months (range, 1.2-58.6). Little to no change in cosmesis or pain from baseline was reported. Cosmetic outcomes at last follow-up were judged by patients as excellent/good in 81.2% (13/16), and by physicians as excellent/good in 93.8% (15/16). Ten patients (62.5%) reported no breast/chest wall pain, five (31.2%) reported mild pain, and one (6.2%) reported moderate pain. All patients remain disease free at last follow-up. The median ipsilateral breast, planning target volume (PTV), and implant volumes were 614, 57, and 333 cm(3). The median ratios of PTV/ipsilateral breast volume (implant excluded) and PTV/total volume (implant included) were 9 and 6%. CONCLUSION: These 16 breast cancer cases with prior bilateral augmentation treated with EB-APBI demonstrate favorable clinical outcomes. Further exploration of EB-APBI as a treatment option for this patient population is warranted.