Thoracic Vertebral Body Irradiation Contributes to Hematologic Toxicity During Chemoradiation Therapy for Non-Small Cell Lung Cancer

Abstract

Purpose/Objective(s)Hematological toxicity (HT) commonly occurs with definitive chemoradiation therapy (CRT) for non-small cell lung cancer (NSCLC), with both therapies contributing to the decline in blood counts. Since the most common toxicities precluding chemotherapy delivery are neutropenia and leukopenia, we sought to determine the dose volume histogram (DVH) constraints that correlate with decline in WBC/ granulocytes due to thoracic vertebral (TV) body irradiation during CRT.Materials/MethodsFifty-two patients with NSCLC treated with definitive concurrent carboplatin-paclitaxel and RT were included. Patients who missed CRT for reasons other than neutropenia or received colony-stimulating factors were excluded. HT was scored using the Common Terminology Criteria for Adverse Events version 4.0. TV was contoured from T1-T10 vertebrae on 4DCT simulation scans. DVH data was collected for TV V10-V60 (TVV) in increments of 10, TVV5, and mean vertebral dose (MVD). A DVH parameter of Vx was defined as the percentage of organ receiving x Gy of radiation. Normality was assessed with Shapiro Wilks test. Univariate linear regression and t-tests were performed to identify associations between neutropenia, lymphopenia, anemia, and thrombocytopenia nadirs, and DVH parameters. β represents the change in ANC in k/μL for every 1 unit increase in DVH parameter.ResultsPoster Viewing Abstracts 3103; Table 1VV60VV50VV40VV30VV20VV10VV5MVDGranulocyteβ0.080.006-0.02-0.02-0.02-0.009-0.006-0.04p-value0.210.800.110.040.120.380.570.14WBCβ0.07-0.002-0.02-0.03-0.02-0.01-0.01-0.04p-value0.220.930.080.010.060.240.330.06 Open table in a new tab ConclusionHT is associated with greater RT doses to the TV during definitive CRT for NSCLC. Better sparing of the TV during RT may decrease HT and additional investigation into the topic is needed. Purpose/Objective(s)Hematological toxicity (HT) commonly occurs with definitive chemoradiation therapy (CRT) for non-small cell lung cancer (NSCLC), with both therapies contributing to the decline in blood counts. Since the most common toxicities precluding chemotherapy delivery are neutropenia and leukopenia, we sought to determine the dose volume histogram (DVH) constraints that correlate with decline in WBC/ granulocytes due to thoracic vertebral (TV) body irradiation during CRT. Hematological toxicity (HT) commonly occurs with definitive chemoradiation therapy (CRT) for non-small cell lung cancer (NSCLC), with both therapies contributing to the decline in blood counts. Since the most common toxicities precluding chemotherapy delivery are neutropenia and leukopenia, we sought to determine the dose volume histogram (DVH) constraints that correlate with decline in WBC/ granulocytes due to thoracic vertebral (TV) body irradiation during CRT. Materials/MethodsFifty-two patients with NSCLC treated with definitive concurrent carboplatin-paclitaxel and RT were included. Patients who missed CRT for reasons other than neutropenia or received colony-stimulating factors were excluded. HT was scored using the Common Terminology Criteria for Adverse Events version 4.0. TV was contoured from T1-T10 vertebrae on 4DCT simulation scans. DVH data was collected for TV V10-V60 (TVV) in increments of 10, TVV5, and mean vertebral dose (MVD). A DVH parameter of Vx was defined as the percentage of organ receiving x Gy of radiation. Normality was assessed with Shapiro Wilks test. Univariate linear regression and t-tests were performed to identify associations between neutropenia, lymphopenia, anemia, and thrombocytopenia nadirs, and DVH parameters. β represents the change in ANC in k/μL for every 1 unit increase in DVH parameter. Fifty-two patients with NSCLC treated with definitive concurrent carboplatin-paclitaxel and RT were included. Patients who missed CRT for reasons other than neutropenia or received colony-stimulating factors were excluded. HT was scored using the Common Terminology Criteria for Adverse Events version 4.0. TV was contoured from T1-T10 vertebrae on 4DCT simulation scans. DVH data was collected for TV V10-V60 (TVV) in increments of 10, TVV5, and mean vertebral dose (MVD). A DVH parameter of Vx was defined as the percentage of organ receiving x Gy of radiation. Normality was assessed with Shapiro Wilks test. Univariate linear regression and t-tests were performed to identify associations between neutropenia, lymphopenia, anemia, and thrombocytopenia nadirs, and DVH parameters. β represents the change in ANC in k/μL for every 1 unit increase in DVH parameter. ResultsPoster Viewing Abstracts 3103; Table 1VV60VV50VV40VV30VV20VV10VV5MVDGranulocyteβ0.080.006-0.02-0.02-0.02-0.009-0.006-0.04p-value0.210.800.110.040.120.380.570.14WBCβ0.07-0.002-0.02-0.03-0.02-0.01-0.01-0.04p-value0.220.930.080.010.060.240.330.06 Open table in a new tab ConclusionHT is associated with greater RT doses to the TV during definitive CRT for NSCLC. Better sparing of the TV during RT may decrease HT and additional investigation into the topic is needed. HT is associated with greater RT doses to the TV during definitive CRT for NSCLC. Better sparing of the TV during RT may decrease HT and additional investigation into the topic is needed.