Radiation Dose and Fractionation for Limited-stage Small-cell Lung Cancer: Survey of US Radiation Oncologists on Practice Patterns

Background: Thoracic radiotherapy (TRT) with concurrent chemotherapy is standard for limited-stage small-cell lung cancer (LS-SCLC). However, the optimal dosing and fractionation remain unclear. The National Comprehensive Cancer Network guidelines have recommended either 45 Gy delivered twice daily (BID) or 60 to 70 Gy delivered once daily (QD). However, the current practice patterns among US radiation oncologists are unknown. Materials and Methods: We surveyed US radiation oncologists using an institutional review board-approved questionnaire. The questions covered demographic data, self-rated knowledge of key trials, and treatment recommendations. Results: We received 309 responses from radiation oncologists. Of the 309 radiation oncologists, 60% preferred TRT QD and 76% acknowledged QD to be more common in their practice. The respondents in academic settings were more likely to endorse BID treatment by both preference (P =.001) and actual practice (P =.009). The concordance between preferring QD and administering QD in practice was 100%. In contrast, 40% of respondents who preferred BID actually administered QD more often. Also, 15% of physicians would be unwilling to switch from QD to BID and 3% would be unwilling to switch from BID to QD, even on patient request. Most respondents (88%) recommended a dose of 45 Gy for BID treatment. For QD treatment, the division was greater, with 54% recommending 60 Gy, 30% recommending 63 to 66 Gy, and 10% recommending 70 Gy. Conclusion: Substantial variation exists in how US radiation oncologists approach TRT dosing and fractionation for LS-SCLC. Three quarters of our respondents reported administering TRT QD most often. The most common doses were 60 Gy QD and 45 Gy BID. The results of the present survey have provided the most up-to-date information on US practice patterns for LS-SCLC.