Pre-Operative Contralateral Radiation Lung Dose is Associated with Post-Operative Pulmonary Toxicity in Patients with Locally-Advanced Non-Small Cell Lung Cancer Treated with Trimodality Therapy

Publication date: Available online 31 January 2018
Source:Practical Radiation Oncology
Author(s): Wenji Guo, Xuan Hui, Salem Alfaifi, Lori Anderson, Scott Robertson, Russell Hales, Chen Hu, Todd McNutt, Stephen Broderick, Jarushka Naidoo, Richard Battafarano, Stephen Yang, K. Ranh Voong
PurposeIn patients with non-small cell lung cancer (NSCLC) who undergo trimodality therapy (chemoradiation followed by surgical resection), it is unknown whether limiting pre-operative radiation dose to the uninvolved lung reduces post-surgical morbidity. This study evaluated whether radiation fall-off dose parameters to the contralateral lung, that is unaffected by NSCLC, are associated with post-operative complications in NSCLC patients treated with trimodality therapy.Methods and materialsWe retrospectively reviewed NSCLC patients who underwent trimodality therapy between March 2008-October 2016, with available restored digital radiation plans. Fischer's exact test was used to assess associations between patient and treatment characteristics and the development of treatment-related toxicity. Spearman's rank correlation was used to measure the strength of association between dosimetric parameters.ResultsForty-six patients were identified who received trimodality therapy with intensity modulated radiation (median 59.4 Gy, range 45-70) and concurrent platinum doublet chemotherapy, followed by surgical resection. The median age was 64.9 years (range 45.6-81.6 years). The median follow-up time was 1.9 years (range 0.3-8.4 years). Twenty-four (52.2%) patients developed any grade pulmonary toxicity and 14 (30.4%) patients developed grade 2+ pulmonary toxicity. There was an increased incidence of any grade pulmonary toxicity in patients with contralateral lung V20≥7% compared to <7% (90%, n=9 versus 41.7%, n=15; p=0.01). Similarly, contralateral lung V10≥20% was associated with an increased rate of any grade pulmonary toxicity compared to V10<20% (80%, n=12 versus 38.7%, n=12; p=0.01). Pneumonectomy/bilobectomy was associated with grade 2+ pulmonary toxicity (p=0.04).ConclusionsPatients who received a higher radiation fall-off dose volume parameter (V20≥7% and V10≥20%) to the contralateral uninvolved lung had a higher incidence of any grade post-operative pulmonary toxicity. Limiting radiation fall-off dose to the uninvolved lung may be an important modifiable radiation parameter in limiting post-operative toxicity in trimodality patients.



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