Projecting changes in breast treatment delivery in the hypofractionated future

Summary: Advancements in radiation therapy for breast cancer allow clinicians to utilize hypofractionated treatment schedules with equivalent oncologic and cosmetic outcomes compared to longer fractionation schemes. Well-designed clinical trials have the potential to significantly reduce the number of fractions delivered in a day-to-day clinic. We evaluated the projected impact that these hypofractionated treatment schedules would have on day-to-day clinical operations. We completed a retrospective chart review of patients seen between July and December 2022 at a tertiary multi-disciplinary accredited breast center. Patient and tumor characteristics, as well as radiation treatment and number of fractions, were recorded. The impact of FAST Forward (whole breast, no boost), RTOG 1005 (whole breast with boost), NSABP B-51 (omission, 5 fractions, or 15 fractions whole breast with pN0), and RT CHARM (16 fractions) were projected and compared to the number of fractions patients received. To project the number of fractions, we evaluated each patient and identified the appropriate clinical trial for a more hypofractionated regimen. For example, a 15-fraction whole breast patient treated without a boost would be eligible for FAST Forward and assigned 5 fractions, if a boost was necessary then the patient was assigned 15 fractions per RTOG 1005. A 30-fraction regional nodal patient would qualify for RT Charm and receive 16 fractions. Given the nuance and evolving data on omission of radiation therapy in early stage, favorable lumpectomy patients, no additional patients were omitted that received whole breast irradiation. We performed simple calculations to estimate the percent change in fractions delivered. We evaluated 152 patients, seen in a multi-disciplinary clinic over 6 months, 117 patients had early-stage disease (pTis-pT2N0) and 35 had node-positive disease. Thirty-five patients underwent mastectomy with no indications for additional radiation. In total, 1971 fractions of therapy were delivered with 49 patients avoiding radiation. A total of 68 received whole breast irradiation, and 35 were treated with standard fractionated regional nodal irradiation (Table 1). When applying the clinical trial criteria above to our patients, the number of fractions projected dropped to 1241, a 37% decrease from the current volume. In our study, the number of fractions for breast radiotherapy declined. It should be noted that these clinical trials have demonstrated excellent clinical and cosmetic outcomes that are more convenient for patients. This modeling argues in favor of a diagnosis-based reimbursement model rather than a fee-for-service/fraction to preserve the financial stability of many radiation oncology practices. Andrew Simpson, n/a (Presenting Author) - University of Alabama at Birmingham; Samuel Hayworth, MS4 (Co-Author) - University of Alabama Birmingham; Drexel H. Boggs, MD (Co-Author) - University of Alabama Birmingham; Kimberly Keene, MD (Co-Author) - University of Alabama Birmingham; Markus Bredel, MD (Co-Author) - University of Miami; Chris Dobelbower, MD (Co-Author) - University of Alabama Birmingham; Catherine Parker, MD (Co-Author) - University of Alabama Birmingham; Erica Stringer-Reasor, MD (Co-Author) - University of Alabama Birmingham; Michael Soike, MD (Co-Author) - University of Alabama Birmingham