Single Institution Experience of Proton and Photon-based Postoperative Radiation Therapy for Non–small-cell Lung Cancer

Abstract

Postoperative radiation therapy (PORT) for non-small-cell lung cancer remains controversial and is associated with elevated cardiopulmonary toxicity. Recent advances in PORT techniques including proton beam therapy (PBT) may improve toxicity. We evaluated 136 patients treated with PORT at our institution. PBT resulted in improved heart and lung sparing with reduced toxicity rates. Proton-based PORT should be evaluated prospectively. Introduction: Postoperative radiation therapy (PORT) for non-small-cell lung cancer remains controversial with studies showing no overall survival (OS) benefit in the setting of excessive cardiopulmonary toxicity. Proton beam therapy (PBT) can potentially reduce toxicity with improved organ-at-r isk spar ing. We evaluated outcomes of PORT patients treated with PBT and intensity-modulated radiation therapy (IMRT). Materials and Methods: This is a retrospective review of 136 PORT patients (61 PBT, 75 IMRT) treated from 2003 to 2016. A Kaplan-Meier analysis was performed to assess oncologic outcomes. A Cox regression was conducted to identify associated factors. Total toxicity burden (TTB) was defined as grade ≥ 2 pneumonitis, cardiac, or esophageal toxicity. Results:

Imaging Strategies in Proton Therapy for Thoracic Tumors: A Mini Review

“…( 33 ) describes the expected future roles of PET/CT for thoracic tumors. In the free-breathing cases, the gross tumor volume (GTV) is often defined based on all available clinical information in the average intensity projection reconstruction images derived from all breathing phases of the 4D-CT ( 19 – 21 , 25 , 34 ). The plan is then generated on an averaged 4D-CTs with possible density overwrites.…”

Role of Adjuvant Radiotherapy in Non-Small Cell Lung Cancer—A Review

“…The use of protons may be another step towards reducing RT-induced toxicity. Small retrospective series showed there were significantly lower RT doses to surrounding organs at risk (heart, lungs) with proton-based PORT [ 76 , 77 , 78 , 79 ]. In the monocentric retrospective review of Boyce-Fappiano et al [ 78 ], the improved sparing of the heart and lung with the use of proton beam PORT was associated with improved OS.…”

“…Small retrospective series showed there were significantly lower RT doses to surrounding organs at risk (heart, lungs) with proton-based PORT [ 76 , 77 , 78 , 79 ]. In the monocentric retrospective review of Boyce-Fappiano et al [ 78 ], the improved sparing of the heart and lung with the use of proton beam PORT was associated with improved OS. Multicenter studies randomizing patients to PORT with proton therapy versus photon therapy, including a cardiopulmonary toxicity endpoint, would be a good approach to understanding the potential benefits of proton therapy.…”

Dosimetry, Efficacy, Safety, and Cost-Effectiveness of Proton Therapy for Non-Small Cell Lung Cancer

“…Eight patients (15.1%) with grade 3 toxicities occurred (two esophagitis, three dermatitis, and four pulmonary toxicities). Postoperative radiation therapy for 136 patients (61 proton therapy, 75 IMRT) was reported by Boyce-Fappiano et al [68], and it was found that the organat-risk (OAR) was more spared with proton therapy compared with IMRT, including the heart (mean 2.0 vs. 7.4 Gy, p < 0.01; V 30Gy 2.6% vs. 10.7%, p < 0.01) and lung (mean 7.9 vs. 10.4 Gy; p = 0.042; V 5Gy 23.4% vs. 42.1%, p < 0.01; V 10Gy 20.4% vs. 29.6%, p < 0.01). The total toxicity was also significantly reduced (OR, 0.35; p = 0.017), including cardiac toxicity (14.7% for IMRT vs. 4.9% for proton therapy, p = 1.09) and grade ≥ 2 pneumonitis (17.0% for IMRT and 4.9% for proton therapy, p = 0.104).…”