Purpose: Chest wall pain is an uncommon but bothersome late complication following lung stereotacticbody radiation therapy. Despite numerous studies investigating predictors of chest wall pain, no clearconsensus has been established for a chest wall constraint. The aim of our study was to investigate factorsrelated to chest wall pain in a homogeneous group of patients treated at our institution.
Patients and methods: All 122 patients were treated with the same stereotactic body radiation therapyregimen of 48 Gy in three fractions, seen for at least 6 months of follow-up, and planned with heterogene-ity correction. Chest wall pain was scored according to the Common Terminology Criteria for AdverseEvents classification v3.0. Patient (age, sex, diabetes, osteoporosis), tumour (planning target volume, vol-ume of the overlapping region between planning target volume and chest wall) and chest wall dosimetricparameters (volumes receiving at least 30, 40, and 50 Gy, the minimal doses received by the highest irra-diated 1, 2, and 5 cm3, and maximum dose) were collected. The correlation between chest wall pain(grade 2 or higher) and the different parameters was evaluated using univariate and multivariate logisticregression.
Results: Median follow-up was 18 months (range: 6–56 months). Twelve patients out of 122 developedchest wall pain of any grade (seven with grade 1, three with grade 2 and two with grade 3 pain). Inunivariate analysis, only the volume receiving 30 Gy or more (P = 0.034) and the volume of the overlappingregion between the planning target volume and chest wall (P = 0.038) significantly predicted chest wallpain, but these variables were later proved non-significant in multivariate regression.
Conclusions: Our analysis could not find any correlation between the studied parameters and chestwall pain. Considering our present study and the wide range of differing results from the literature, areasonable conclusion is that a constraint for chest wall pain is yet to be defined.