I. J. Radiation Oncology d Biology d Physics
Volume 75, Number 3, Supplement, 2009
Breast Brachytherapy in the United States: Utilization Patterns in Older Patients after Breast-conserving Surgery
G. L. Smith, Y. Xu, T. A. Buchholz, B. D. Smith, S. H. Giordano, Y. T. Shih University of Texas M. D. Anderson Cancer Center, Houston, TX Purpose/Objective(s): The role of brachytherapy as the sole radiation treatment modality after breast-conserving surgery (BCS) for early-stage invasive breast cancer is unclear. Though initial studies of treatment efficacy are promising, randomized Phase III data have yet to mature, and the ideal patient subgroup to receive brachytherapy alone remains controversial. Brachytherapy use alone after BCS in the community setting is ongoing, but its actual frequency of use has not been previously studied. Additionally, the clinical and nonclinical factors influencing its use are unknown. We sought to characterize patterns and predictors of breast brachytherapy use in a retrospective, population-based study of older women treated with BCS. Materials/Methods: We used a nationwide database of Medicare beneficiaries (age $65) with private supplemental insurance (MarketScan Medicare Supplemental). Claims codes identified patients treated with BCS followed by brachytherapy alone vs. external beam radiotherapy for an incident breast cancer diagnosed between 2001 and 2006. Patients who received brachytherapy as boost were excluded (\1% of study population). Logistic regression modeled predictors of brachytherapy use alone, including demographic, clinical, socioeconomic, and provider variables. Odds ratios (OR) .1 indicate increased use of brachytherapy. Results: In our cohort of 6,854 women, mean age was 74 ± 6. Frequency of brachytherapy use alone increased over time (\1% in 2001, 1% in 2002, 3% in 2003, 5% in 2004, 8% in 2005, and 10% in 2006; p\ 0.001), with 89% of brachytherapy patients receiving balloon-based treatment by 2006. On adjusted analysis, treatment year remained a significant predictor of brachytherapy use alone (p \0.001). Additionally, brachytherapy use alone was more likely in women who had lymph node-negative disease (OR, 2.04; 95% CI, 1.12–3.73), did not receive chemotherapy (OR, 1.77; 95% CI, 1.07–2.94), or received an axillary surgery (OR, 1.71; 95% CI, 1.22– 2.40). Nonclinical factors also affected utilization, including non-HMO insurance (OR, 1.80; 95% CI, 1.25–2.61); or residence in metropolitan areas (OR, 1.79; 95% CI, 1.12–2.86), areas with a low density of radiation oncologists (OR, 1.87; 95% CI, 1.16–3.04), or high density of surgeons (OR, 1.70; 95% CI, 1.02–2.82). Patients living in the West, Midwest, and South were more likely to receive brachytherapy alone compared to the Northeast (OR, 3.48; 95% CI, 1.89–6.39; 1.70, 0.96–3.02; 2.547, 1.38–4.43, respectively). Conclusions: Despite ongoing debate, breast brachytherapy is being used as sole radiation treatment after BCS with increasing frequency across much of the United States. Along with clinical factors, socioeconomic, geographic, and provider characteristics strongly influence utilization. Author Disclosure: G.L. Smith, None; Y. Xu, None; T.A. Buchholz, None; B.D. Smith, None; S.H. Giordano, None; Y.T. Shih, None.
Patient Preferences and Physician Practice Patterns Regarding Breast Radiotherapy
D. J. Hoopes1, D. Kaziska2, D. Weed3, B. D. Smith4, E. R. Hale1, P. A. Johnstone3 Wright-Patterson Medical Center, Wright-Patterson Air Force Base, OH, 2Air Force Institute of Technology, Wright-Patterson Air Force Base, OH, 3Indiana University School of Medicine, Indianapolis, IN, 4Wilford Hall Medical Center, Lackland Air Force Base, TX 1
Purpose/Objective(s): Current strategies for breast radiotherapy (RT) following breast conservation surgery differ in total treatment time, volume treated, invasive vs. noninvasive nature, and the level of supporting evidence. There is a paucity of literature describing patient preferences for breast RT strategies and little information on physician practice patterns. Materials/Methods: Using a reliable and valid instrument, we conducted a cross-sectional mail-based survey of 5,000 randomlyselected women at risk for breast cancer (undergoing mammography) in military-health-care systems in Ohio and Texas, as well as a large integrated medical system in Indiana. A total of 2,150 randomly-selected United States physician-members of ASTRO were also surveyed using a mail/fax strategy. Results: To date, 1,735 women (35%) and 363 physicians (17%) have responded. Patient treatment preferences by fractionation/volume scheme were as follows: shortened whole-breast RT (S-WBRT, e.g., 4,256 cGy in 16 fractions) 62%, partial breast irradiation (PBI) 28%, and conventional whole-breast RT (C-WBRT) 10%. By comparison, 82% of physicians use C-WBRT for more than 2/3 of women and 56% never use S-WBRT. When evaluating various PBI strategies, 62% of women preferred external beam PBI vs. 38% who would prefer brachytherapy PBI. By comparison, 37% of physicians offer external beam PBI, 54% offer MammoSite or similar PBI, and 10% offer interstitial catheter PBI. A total of 71% of women would prefer once-daily RT over 10 days vs. twice-daily RT over 5 days. Fifty-five percent of physicians do not offer PBI as part of a clinical trial and less than 30% of women treated with PBI are enrolled on trial. Seventy-six percent of physicians listed clinical trial data as the most important factor when selecting a breast RT regimen. The 95% confidence interval is \ ± 2.4% for all patient items and \ ± 5.2% for all physician items. Conclusions: The majority of women surveyed would prefer S-WBRT over PBI and conventional RT while, despite level I evidence supporting S-WBRT, a minority of physicians offer S-WBRT. There is also a discrepancy between women’s preferences for PBI modality (EBRT PBI favored over MammoSite) and type of PBI currently offered by United States physicians. The majority of PBI is not performed as part of a clinical trial. Once-daily PBI strategies are preferred by women and merit future study. Further analysis, including factors influencing patient/physician preferences, is ongoing. Author Disclosure: D.J. Hoopes, None; D. Kaziska, None; D. Weed, None; B.D. Smith, None; E.R. Hale, None; P.A. Johnstone, None.
Role of Regional Nodal Irradiation in Breast Cancer Patients with Pathologic-negative Lymph Node after Neoadjuvant Chemotherapy and Conservative Surgery
C. Daveau, D. Stevens, E. Brain, O. Berges, M. Gardner, S. Villette, P. Moisson, B. De la Lande, A. Labib, R. Le Scodan Centre Rene´ Huguenin, St.-Cloud, France Purpose/Objective(s): The value of lymph node irradiation (LNI) for breast cancer (BC) patients with pathologic N0 status (pN0) after neoadjuvant chemotherapy (NAC) and breast-conservative surgery (BCS) is unknown. We compared the outcomes of pN0 patients following NAC and BCS who received breast radiotherapy (BRT) with or without LNI.