Prospective Evaluation of Limited-Stage Small Cell Lung Cancer Radiotherapy Fractionation Regimen Usage and Acute Toxicity in a Large Statewide Quality Collaborative
Allen SG, Dragovic AF, Yin HM, Bryant AK, Paximadis PA, Matuszak MM, Schipper MJ, Dess RT, Hayman JA, Dominello MM, Kestin LL, Movsas B, Jolly S, and Bergsma DP. Prospective Evaluation of Limited-Stage Small Cell Lung Cancer Radiotherapy Fractionation Regimen Usage and Acute Toxicity in a Large Statewide Quality Collaborative. Pract Radiat Oncol 2023.
Pract Radiat Oncol
PURPOSE: National guidelines on limited stage small cell lung cancer (LS-SCLC) treatment give preference to a hyperfractionated regimen of 45 Gy/30 fractions delivered twice-daily, however use of this regimen is uncommon compared to once-daily regimens. The purpose of this study was to characterize the LS-SCLC fractionation regimens used throughout a statewide collaborative, analyze patient and treatment factors associated with these regimens, and describe real-world acute toxicity profiles of once- and twice-daily RT regimens.
METHODS AND MATERIALS: Demographic, clinical, and treatment data along with physician toxicity and patient-reported outcomes were prospectively collected by 29 institutions within the [quality consortium] between 2012 and 2021 for patients with LS-SCLC. We modeled the influence of RT fractionation and other patient-level variables clustered by treatment site on the odds of a treatment break specifically due to toxicity with multilevel logistic regression. Common Terminology Criteria for Adverse Events, version 4.0, incident Grade 2 or worse toxicity was longitudinally compared between regimens.
RESULTS: There were 78 patients (15.6% overall) treated with twice-daily RT and 421 patients treated with once-daily RT. Patients receiving twice-daily RT were more likely to be married/living with someone (65% vs 51%, p=0.019) and to have no major comorbidities (24% vs 10%, p=0.017). Once-daily RT fractionation toxicity peaked during RT and twice-daily toxicity peaked within 1 month after RT. After stratifying by treatment site and adjusting for patient-level variables, once-daily treated patients had a 4.11 (95% confidence interval 1.31-12.87) higher odds of treatment break specifically due to toxicity than twice-daily treated patients.
CONCLUSION: Hyperfractionation for LS-SCLC remains infrequently prescribed despite the lack of evidence demonstrating superior efficacy or lower toxicity of once-daily RT. With peak acute toxicity after RT and lower likelihood of a treatment break with twice-daily fractionation in real-word practice, providers may start utilizing hyperfractionated RT more frequently.
ePub ahead of print