Dose-volume parameters predict radiation pneumonitis after induction chemoradiotherapy followed by surgery for non-small cell lung cancer: a retrospective analysis

• Main Authors: Kuniaki Katsui, Takeshi Ogata, Kenta Watanabe, Norihisa Katayama, Junichi Soh, Masahiro Kuroda, Katsuyuki Kiura, Yoshinobu Maeda, Shinichi Toyooka, Susumu Kanazawa
• Format: Article
• Language: English
• Published: BMC 2019-11-01
• Series: BMC Cancer
• Subjects: Radiation pneumonitis; Mean lung dose; Lower lobe; Induction chemoradiotherapy; Non-small cell lung cancer
• Online Access: http://link.springer.com/article/10.1186/s12885-019-6359-9

Abstract Background The relationship between lung dose-volume histogram (DVH) parameters and radiation pneumonitis (RP) associated with induction concurrent chemoradiotherapy (CCRT) followed by surgery in patients with non-small cell lung cancer (NSCLC) is unclear, particularly when concerning irradiation of the whole lung prior to resection. We performed this study to identify factors associated with grade ≥ 2 RP in such patients. Methods Patients who received induction CCRT (chemotherapy: cisplatin and docetaxel; radiotherapy: 46 Gy/23 fractions) between May 2003 and May 2017 were reviewed. The mean lung dose (MLD) and the percentage of the lung volume that received ≥5 Gy (V5) and ≥ 20 Gy (V20) were calculated. Factors associated with the development of grade ≥ 2 RP were analyzed. Results One hundred and eight patients were included in this study, 34 (31.5%) of whom experienced grade ≥ 2 RP. A V20 ≥ 21%, an MLD ≥10 Gy, and a lower lobe tumor location were significant predictors of grade ≥ 2 RP on univariate analysis (p = 0.007, 0.002, and 0.004, respectively). Moreover, an MLD ≥10 Gy and lower lobe location were significant predictors of grade ≥ 2 RP on multivariate analysis (p = 0.026 and 0.0043, respectively). The cumulative incidence rates of grade ≥ 2 RP at 6 months were 15.7 and 45.6% in patients with MLDs < 10 Gy and ≥ 10 Gy, respectively, and were 23.5 and 55.6% in patients with upper/middle lobe- vs. lower lobe-located tumors, respectively. Conclusions MLD and lower lobe location were predictors of grade ≥ 2 RP in patients who received induction CCRT. It is necessary to reduce the MLD to the greatest extent possible to prevent the occurrence of this adverse event.