A Single Weekly Tumor Bed Boost is Comparable to Daily Boost Breast Radiotherapy

Summary

A weekly concomitant boost to the tumor bed during prone breast radiotherapy had comparable efficacy but a trend toward more satisfactory cosmetic outcomes than did daily boost therapy, according to data from a prospective randomized trial comparing 2 schedules of adjuvant radiotherapy.

  • Radiology
  • Oncology Clinical Trials
  • Breast Cancer
  • Radiation Therapy
  • Radiology
  • Oncology Clinical Trials
  • Breast Cancer
  • Oncology
  • Radiation Therapy

A weekly concomitant boost to the tumor bed during prone breast radiotherapy had comparable efficacy but a trend toward more satisfactory cosmetic outcomes than did daily boost therapy, according to Benjamin Cooper, MD, New York University Radiation Oncology, New York, New York, USA, who presented data from a prospective randomized trial comparing 2 schedules of adjuvant radiotherapy.

A preliminary study demonstrated the safety of prone breast radiotherapy with daily boost radiation. The majority of radiation treatment schedules require a weekend break from therapy, when potential tumor repopulation could occur. The current study investigated an alternate adjuvant therapy schedule with a single weekly boost before the weekend break to combat this repopulation.

A total of 400 patients with stage 0 to II breast cancer were randomly assigned to either a tumor bed boost of 0.5 Gy delivered daily (arm 1) or an equivalent boost of 2 Gy delivered once every Friday (arm 2). Both groups received weeklong intensity-modulated radiation therapy of 40.5 Gy in 15 fractions of the whole breast. All patients had previous partial mastectomy with negative margins and were stratified according to previous chemotherapy and menopause status.

At a median follow-up of 40 months, there were no differences in recurrence-free survival between the 2 arms (98% vs 97%; log-rank P = .7). There were no mortalities in either arm due to breast cancer. There were 1 local and 2 distant recurrences in arm 1. There were 3 local and 1 distant recurrences in arm 2. General patient and tumor characteristics were similar in both groups at this time point. Descriptions of appearance outcomes from 280 patients showed a trend that more women in arm 2 reported good or excellent cosmesis than those in arm 1 (88% vs 80%; P = .08; Table 1).

Table 1.

Patient-Reported Cosmetic Outcomes, No. (%)

The authors concluded that, at this very early time point, there were no differences in clinical outcomes or safety, based on the schedule of concomitant therapy. However, the cosmetic results trended toward superiority in the once-weekly boost, which may be preferable for treatment.

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