A cost comparison analysis of partial versus whole-breast irradiation after breast-conserving surgery for early-stage breast cancer.

PURPOSE: To assess, if and for whom, there are cost savings associated with alternate breast radiotherapy (RT) techniques when compared with the conventional external beam-based whole-breast RT with a boost (WBRT-B).

METHODS AND MATERIALS: Treatment planning and delivery utilization data were modeled for eight different breast RT techniques: (1) WBRT-B: 60 Gy in 30 fractions; (2) WBRT: 50 Gy in 25 fractions; (3) WBRT-accelerated (AC): 42.5 Gy in 16 fractions; (4) WBRT-intensity-modulated RT (IMRT): 60 Gy in 30 fractions; (5) accelerated partial breast irradiation (APBI)-IC, MammoSite: 34 Gy in 10 twice-daily fractions; (6) APBI-IT, HDR interstitial: 34 Gy in 10 twice-daily fractions; (7) APBI three-dimensional conformal RT (3D-CRT): 38.5 Gy in 10 twice-daily fractions; or (8) APBI-IMRT: 38.5 Gy in 10 twice-daily fractions. Costs incurred by payer (i.e., direct medical costs; 2003 Medicare Fee Schedule) and patient (i.e., direct nonmedical costs; time and travel) were estimated. Total societal costs were then calculated for each treatment approach.

RESULTS: Not all efforts to reduce overall treatment time result in total cost savings. The least expensive partial breast-based RT approaches were the external beam techniques (APBI-3D-CRT, APBI-IMRT). Any reduced cost to patients for the HDR brachytherapy-based APBI regimens were overshadowed by substantial increases in cost to payers, resulting in higher total societal costs; the cost of HDR treatment delivery was primarily responsible for the increased direct medical cost. For the whole breast-based RT approaches, treating without a boost (WBRT) or with WBRT-AC reduced total costs. Overall, WBRT-AC was the least costly of all the regimens, in terms of costs to society; APBI approaches, in general, were favored over whole-breast techniques when only considering costs to patients.

CONCLUSIONS: Based on societal cost considerations, WBRT-AC appears to be the preferred approach. If one were to pursue a partial-breast RT regimen to minimize patient costs, it would be more advantageous from a societal perspective to pursue external beam-based approaches such as APBI-3D-CRT or APBI-IMRT in lieu of the brachytherapy-based regimens.