Adaptive lung radiotherapy in the era of immunotherapy: A single center retrospective study

Purpose: Treatment for locally advanced non-small cell lung cancer (NSCLC) consists of concurrent chemoradiation followed by immunotherapy. Though this combination has been shown to have a benefit in both progression-free survival and overall survival, treatment is often limited the development pneumonitis. One way mitigate toxicity through adaptive radiation therapy (ART), which does not currently standardized implementation clinical practice.Materials Methods: A single center retrospective review patients with stage III or oligometastatic IV NSCLC who were treated subsequent immunotherapy from 2015-2020 was performed. Patients stratified based on having one more offline adapted plans. The aim study evaluate association between dose volume histogram (DVH) values common toxicities experienced during treatment, including pneumonitis esophagitis.Results: 25 included final analysis, 10 plans (AP) 15 non-adapted (NAP). Mean age at onset 74 years. most histology adenocarcinoma (N=13). Five pneumonitis, 2 AP 3 NAP. Mann-Whitney U test GTV sizes (346.2 +/- 269.7 cm3) NAP (153.1 99.6 significant (P=0.019). Multiple linear regression analysis adjustment covariates versus plan adaptation (P = 0.106) esophagitis (P=0.59) did demonstrate difference non-adaptive patients.Conclusion: Despite similar groups, size than double compared NAP, suggesting that techniques provide method larger target volumes be without an observed rates. These results suggest ART may role mitigating experience warrants further investigation.