Prone Accelerated Partial Breast Irradiation After Breast-Conserving Surgery: Five-year Results of 100 Patients

Abstract

Purpose To report the 5-year results of a prospective trial of three-dimensional conformal external beam radiotherapy (3D-CRT) to deliver accelerated partial breast irradiation in the prone position (P-APBI). Methods Post-menopausal patients with Stage I breast cancer with non palpable <2 cm tumors, negative margins, and negative nodes, positive hormonal receptors, and no extensive intraductal component (EIC) were eligible. The trial was offered only once eligible patients had refused to undergo standard whole-breast radiotherapy. Patients were simulated and treated on a dedicated table for prone set-up. The 3D-CRT delivered was 30 Gy in five 6 Gy/daily fractions over 10 days with port film verification at each treatment. Ipsilateral breast, ipsilateral nodal, contralateral breast, and distant failure (IBF, INF, CBF, DF) were estimated using the cumulative incidence method. Disease-free, overall, and cancer-specific survival (DFS, OS, CSS) were recorded. Results One hundred patients accrued to this IRB- approved prospective trial, one with bilateral breast cancer. One patient withdrew consent after simulation and another elected to interrupt radiotherapy after receiving two treatments. Ninety-eight patients are evaluable for toxicity and, in one case, both breasts were treated with PBI. Median patient age was 68 years (range 53–88 years); in 55% the tumor size was <1 cm. All patients had hormonal receptor positive cancers: 87% underwent adjuvant anti-hormonal therapy. At a median follow-up of 64 months (range, 2–125 months), there was one local recurrence (1% IBF) and one contralateral breast cancer (1% CBF). There were no deaths due to breast cancer by 5 years. Grade 3 late toxicities occurred in 2 patients (1 breast edema, 1 transient breast pain). Cosmesis was rated good/excellent in 89% of patients with at least 36 months follow-up. Conclusions Five-year efficacy and toxicity of 3D-CRT to deliver prone-PBI are comparable to other experiences with similar follow-up.

Accelerated Partial Breast Irradiation: Executive summary for the update of an ASTRO Evidence-Based Consensus Statement

“…29,36,37 However, other clinical series of APBI delivered with 3D-CRT or IMRT reported acceptable cosmetic outcomes. 9,[38][39][40][41][42][43][44][45] These conflicting studies raise the hypothesis that subtle variations in planning techniques and/or dose constraints may substantially modify the therapeutic ratio of EBRT-based APBI. [46][47][48] In light of ongoing research, particularly the National Surgical Adjuvant Breast and Bowel Project B-39/RTOG 0413 trial, 5 which has yet to report cosmetic outcomes for patients treated with 3D-CRT APBI, the task force opted not to make a specific recommendation either for or against the use of EBRT-based APBI at this time.…”

The Influence of Treatment Position (Prone vs. Supine) on Clip Displacement, Seroma, Tumor Bed and Partial Breast Target Volumes: Comparative Study

“…To overcome the integral dose problem large variety of techniques using multiple directions with non-coplanar beams exist as well [17][18][19][20]. To date only the NYU group treated large cohort of PBI patients with mini-tangents [7]. However they use seroma based target volume definition and reduced CTV-PTV margin that required by the supine RTOG trial 0413 [21].…”

“…PBI offers decreased overall treatment time and reduced dose delivery to uninvolved portion of the breast and adjacent organs at risk [3][4][5][6]. PBI has been already introduced in prone (Pr) position [7,8]. Formenti et al have reported comparable 5-year efficacy, cosmetics, and toxicity of prone three-dimensional conformal external beam radiation therapy to other forms of PBI [7].…”

“…PBI has been already introduced in prone (Pr) position [7,8]. Formenti et al have reported comparable 5-year efficacy, cosmetics, and toxicity of prone three-dimensional conformal external beam radiation therapy to other forms of PBI [7].…”

GammaPod—A new device dedicated for stereotactic radiotherapy of breast cancer

“…26 Combined with MRI and/or CT to assess tumor extent, GammaPod has the potential to accurately deliver high radiation dose to the gross tumor and its micro extensions. Breathing motion should have little effect on the geometrical accuracy because the patient is treated in prone position 10 and the skin of the breast is immobilized by the vacuum-assisted breast cup.…”