Incidence and Treatment Outcome of Radiation Pneumonitis in Patients With Limited-stage Small Cell Lung Cancer Treated With Concurrent Accelerated Hyperfractionated Radiation Therapy and Chemotherapy

Kosei Doshita; Yuya Tabuchi; Hirotsugu Kenmotsu; Shota Omori; Takanori Kawabata; Hiroaki Kodama; Naoya Nishioka; Eriko Miyawaki; Yuko Iida; Nobuaki Mamesaya; Haruki Kobayashi; Ryo Ko; Kazushige Wakuda; Akira Ono; Tateaki Naito; Haruyasu Murakami; Keita Mori; Hideyuki Harada; Takeshi Kaneko; Toshiaki Takahashi

doi:10.1016/j.adro.2022.101129

Incidence and Treatment Outcome of Radiation Pneumonitis in Patients With Limited-stage Small Cell Lung Cancer Treated With Concurrent Accelerated Hyperfractionated Radiation Therapy and Chemotherapy

Adv Radiat Oncol. 2022 Nov 23;8(2):101129. doi: 10.1016/j.adro.2022.101129. eCollection 2023 Mar-Apr.

Authors

Kosei Doshita^{1

2}, Yuya Tabuchi³, Hirotsugu Kenmotsu¹, Shota Omori¹, Takanori Kawabata⁴, Hiroaki Kodama¹, Naoya Nishioka¹, Eriko Miyawaki¹, Yuko Iida¹, Nobuaki Mamesaya¹, Haruki Kobayashi¹, Ryo Ko¹, Kazushige Wakuda¹, Akira Ono¹, Tateaki Naito¹, Haruyasu Murakami¹, Keita Mori⁴, Hideyuki Harada³, Takeshi Kaneko², Toshiaki Takahashi¹

Affiliations

¹ Division of Thoracic Oncology, Shizuoka Cancer Center, Nagaizumi-cho Sunto-gun, Shizuoka, Japan.
² Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan.
³ Radiation and Proton Therapy Center, Shizuoka Cancer Center, Nagaizumi-cho Suntou-gun, Shizuoka, Japan.
⁴ Clinical Research Center, Shizuoka Cancer Center, Nagaizumi-cho Sunto-gun, Shizuoka, Japan.

Abstract

Purpose: This study aimed to clarify the characteristics of and evaluate the risk factors for radiation pneumonitis (RP) induced by chemoradiation therapy (CRT) using accelerated hyperfractionated (AHF) radiation therapy (RT) in patients with limited-stage small cell lung cancer (LS-SCLC).

Methods and materials: Between September 2002 and February 2018, 125 patients with LS-SCLC were treated with early concurrent CRT using AHF-RT. Chemotherapy was comprised of carboplatin/cisplatin with etoposide. RT was administered twice daily (45 Gy/30 fractions). We collected data regarding onset and treatment outcomes for RP, and analyzed the relationship between RP and total lung dose-volume histogram findings. Uni- and multivariate analyses were performed to assess patient- and treatment-related factors for grade ≥2 RP.

Results: The median age of patients was 65 years, and 73.6% of participants were men. In addition, 20% and 80.0% of participants presented with disease stage II and III, respectively. The median follow-up time was 73.1 months. Grades 1, 2, and 3 RP were observed in 69, 17, and 12 patients, respectively. Grades 4 to 5 RP were not observed. RP was treated with corticosteroids in patients with grade ≥2 RP, without recurrence. The median time from initiation of RT to onset of RP was 147 days. Three patients developed RP within 59 days, 6 within 60 to 89 days, 16 within 90 to 119 days, 29 within 120 to 149 days, 24 within 150 to 179 days, and 20 within ≥180 days. Among the dose-volume histogram parameters, the percentage of lung volume receiving >30 Gy (V₃₀) was most strongly related to the incidence of grade ≥2 RP, and the optimal threshold to predict RP incidence was V₃₀ ≥20%. On multivariate analysis, V₃₀ ≥20% was an independent risk factor for grade ≥2 RP.

Conclusions: The incidence of grade ≥2 RP correlated strongly with a V₃₀ of ≥20%. Contrarily, the onset of RP induced by concurrent CRT using AHF-RT may occur later. RP is manageable in patients with LS-SCLC.