Yongmei Liu1, Weili Wang2, Kevin Shiue3, Huan Yao2, Alberto Cerra-Franco3, Ronald H Shapiro4, Ke Colin Huang3, Douglas Vile3, Mark Langer3, Gordon Watson3, Greg Bartlett3, Huisi Ai3, Francis Sheski5, Jian-Yue Jin2, Rich Zellars3, Pingfu Fu6, Tim Lautenschlaeger3, Feng-Ming Spring Kong7. 1. Department of Thoracic Oncology, West China Hospital, Sichuan University, Chengdu, China; Department of Radiation Oncology, Indiana University School of Medicine and Indiana University Health, Indianapolis, USA. 2. Department of Radiation Oncology, University Hospitals/Seidman Cancer Center and Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, USA. 3. Department of Radiation Oncology, Indiana University School of Medicine and Indiana University Health, Indianapolis, USA. 4. Department of Radiation Oncology, Indiana University School of Medicine and Indiana University Health, Indianapolis, USA; Department of Radiation Oncology, Richard L. Roudebush VAMC, Indianapolis, USA. 5. Department of Pulmonary Medicine, Indiana University School of Medicine, Indianapolis, USA. 6. Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine, Cleveland, USA. 7. Department of Radiation Oncology, University Hospitals/Seidman Cancer Center and Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, USA; Department of Clinical Oncology, Hong Kong University Shenzhen Hospital, and Hong Kong University, Hong Kong, China. Electronic address: kong0001@hku.hk.
Abstract
BACKGROUND AND PURPOSE: Radiation pneumonitis (RP) can be a potential fatal toxicity of stereotactic body radiation therapy (SBRT) for medically inoperable non-small cell lung cancer (NSCLC). This study aimed to examine the risk factors that predict RP and explore dosimetric tolerance for safe practice in a large institutional series of NSCLC patients. MATERIALS AND METHODS: Patients with early-stage and locally recurrent NSCLC who received lung SBRT between 2002 and 2015 formed the study population. The primary endpoint was grade 2 or above radiation pneumonitis (RP2). Lungs were re-contoured consistently by one radiation oncologist according to the RTOG atlas for organs at risk. Dosimetric factors were computed consistently with exclusion of gross tumor volume of either ipsilateral, contralateral, or total lungs. RESULTS: A total of 339 patients were eligible. With a median follow-up of 47 months, RP2 was recorded in 10% patients. History of respiratory comorbidity, previous thoracic radiation, right lung location, mean lung doses of total or ipsilateral lung, and total lung volume receiving 20 Gy were all significantly associated with the risk of RP2. The dosimetric parameters of contralateral lung, including mean dose and volume receiving more than 5, 10, and 20 Gy, were not significantly associated with RP2 (ps > 0.05). A model of combining significant clinical and dosimetric factors had a predictive accuracy AUC of 0.76. According to this model, RP2 can be limited to <10% should the patient have no previous lung radiation and the mean dose of total and ipsilateral lungs be kept less than 6 Gy and 20 Gy, respectively. CONCLUSION: Dosimetric factors of total or ipsilateral lung together with important clinical factors were significant risk factors for symptomatic radiation pneumonitis after SBRT. Constraining mean lung dose can limit clinically significant lung toxicity.
BACKGROUND AND PURPOSE:Radiation pneumonitis (RP) can be a potential fatal toxicity of stereotactic body radiation therapy (SBRT) for medically inoperable non-small cell lung cancer (NSCLC). This study aimed to examine the risk factors that predict RP and explore dosimetric tolerance for safe practice in a large institutional series of NSCLCpatients. MATERIALS AND METHODS:Patients with early-stage and locally recurrent NSCLC who received lung SBRT between 2002 and 2015 formed the study population. The primary endpoint was grade 2 or above radiation pneumonitis (RP2). Lungs were re-contoured consistently by one radiation oncologist according to the RTOG atlas for organs at risk. Dosimetric factors were computed consistently with exclusion of gross tumor volume of either ipsilateral, contralateral, or total lungs. RESULTS: A total of 339 patients were eligible. With a median follow-up of 47 months, RP2 was recorded in 10% patients. History of respiratory comorbidity, previous thoracic radiation, right lung location, mean lung doses of total or ipsilateral lung, and total lung volume receiving 20 Gy were all significantly associated with the risk of RP2. The dosimetric parameters of contralateral lung, including mean dose and volume receiving more than 5, 10, and 20 Gy, were not significantly associated with RP2 (ps > 0.05). A model of combining significant clinical and dosimetric factors had a predictive accuracy AUC of 0.76. According to this model, RP2 can be limited to <10% should the patient have no previous lung radiation and the mean dose of total and ipsilateral lungs be kept less than 6 Gy and 20 Gy, respectively. CONCLUSION: Dosimetric factors of total or ipsilateral lung together with important clinical factors were significant risk factors for symptomatic radiation pneumonitis after SBRT. Constraining mean lung dose can limit clinically significant lung toxicity.
Authors: Laura Cella; Serena Monti; Maria Thor; Andreas Rimner; Joseph O Deasy; Giuseppe Palma Journal: Cancers (Basel) Date: 2021-07-25 Impact factor: 6.639