2982 - Impact of Insurance-Mandated 3DCRT vs. VMAT Comparisons on Treatment Delays in Breast Cancer Radiation Therapy: Evaluating an Adaptive Planning Algorithm

03:00pm - 04:00pm PT

Hall F

Screen: 17

POSTER

Presenter(s)

Jino Park, MD - University of California Irvine, Orange, CA

J. Park¹, C. Hui², J. G. Bazan Jr³, and E. Healy¹; ¹Department of Radiation Oncology, University of California - Irvine, Orange, CA, ²University of California - Irvine, Irvine, CA, ³Department of Radiation Oncology, City of Hope National Medical Center, Duarte, CA

Purpose/Objective(s):

For breast cancer patients requiring comprehensive regional nodal irradiation (RNI), treatment planning is complex and presents dosimetric challenges that often necessitate VMAT to meet OAR constraints. However, many insurance policies mandate comparison 3DCRT plans to justify use of VMAT, increasing provider and administrative workload and potentially delaying treatments. This study investigates treatment delays caused by insurance-mandated comparison plans for breast cancer patients, with a secondary objective of identifying clinical predictors of VMAT need. Additionally, we examine the role of an adaptive treatment planning algorithm (TPA) in our institutional workflow.

Materials/Methods:

Electronic health records of patients receiving chest wall or breast and RNI (undissected axilla, supraclavicular nodes, and internal mammary nodes in the first three intercostal spaces) at a single institution under one breast radiation oncologist from January 2022 to December 2024 were retrospectively reviewed. A previously published adaptive TPA was utilized, where all target volumes were prospectively contoured, with 3DCRT attempted first and VMAT used only if OAR constraints were not met. Collected data included time from authorization submission to approval (auth approval time), time from treatment decision to start (TDS), time from treatment decision to simulation (TDSim), and clinical factors such as implant reconstruction status, laterality, and planned boost. Statistical analyses included Student’s t-test, Pearson’s ?² test, and multivariate logistic regression.

Results:

Of 97 patients, 5 were excluded due to prolonged TDS unrelated to institutional workflow (e.g., hospitalization, patient-driven delays). Among 92 patients, 74% (68/92) were treated with 3DCRT, and 26% (24/92) required VMAT. Auth approval time was significantly longer for VMAT (median 33.5 vs. 9 days for 3DCRT), but TDS was similar (38.5 vs. 36 days, p=0.43). The minimal TDS difference is attributed to the adaptive TPA, which facilitated timely simulations with 3DCRT authorization. Patients with implant reconstruction were significantly more likely to require VMAT (54% [13/24] vs. 25% [17/68], ?² p<0.05). Left-sided treatment showed a numerical but non-significant correlation with VMAT need (75% VMAT vs. 56% 3DCRT, ?² p=0.16). Boost requirement was not associated with VMAT use (33% VMAT vs. 38% 3DCRT, ?² p=0.86). On multivariate analysis, implant status remained an independent predictor of VMAT (OR 3.6, CI 1.6–9.2).

Conclusion:

Patients undergoing chest wall or breast and RNI with complex anatomy requiring VMAT experience significant insurance approval delays. Treatment delays can be mitigated by an adaptive TPA, but increased provider and administrative workload remains a concern. Insurance companies should consider eliminating mandatory 3DCRT vs. VMAT comparison plans for patients with implant reconstruction or left breast/chest wall+RNI radiation.