A retrospective study of hypofractionated radiotherapy for small cell lung cancer

Purpose: Hypofractionated radiotherapy (HypoRT) shows the superiority in cancer treatment because of its high biological equivalent dose. This retrospective study aims to evaluate the toxicity and efficacy of HypoRT on small cell lung cancer (SCLC). Methods: : Medical records of SCLC patients between July 2018 and October 2019 were collected. All patients treated with chemotherapy plus HypoRT (PTV: 30 Gy/10F, PGTV: 45 Gy/10F) were eligible for analysis. The chemotherapy was performed for a total of 4-6 cycles by using Etoposide plus Cisplatin or Carboplatin in peri-radiotherapy phase. Meanwhile, indexes including in-field recurrence rate (ifRR), in-field relapse-free survival (ifRFS) and overall survival (OS) were calculated. Results: : Medical data of 30 patients were eligible for analysis. Male to female ratio was 19: 11. The median age was 64 (range from 46 to 75 years old, 95% CI: 52.5-83.75). The median follow-up time was 15 months (range from 1 to 19 months). In follow-up period, either radiation esophagitis or radiation pneumonitis of grade 3 occurred in 6.7% of the patients (2/30). The incidences of severe hematologic toxicities (grade 3/4) including leukopenia, granulocytopenia, thrombocytopenia and anemia were 33.3%, 66.7%, 26.7% and 16.7%, respectively. The ifRR post-HypoRT was 6.7% (2/30) with a median ifRFS of 15 months (rang from 1 to 19 months, 95% CI: 11.25-18.75) and a median OS of 15 months (range from 1 to 19, 95% CI: 11.25-18.75). Conclusion: HypoRT can be tolerated by most of enrolled patients, and HypoRT exhibits its efficacy in controlling SCLC tumors.