title: Late-Course Adaptive Adjustment Based on Metabolic Tumor Volume Changes during Radiotherapy May Reduce Radiation Toxicity in Patients with Non-Small Cell Lung Cancer.
abstract: To reduce the high risk of radiation toxicity and enhance the quality of life of patients with non-small cell lung cancer (NSCLC), we quantified the metabolic tumor volumes (MTVs) from baseline to the late-course of radiotherapy (RT) by fluorodeoxyglucose positron emission tomography computerized tomography (FDG PET-CT) and discussed the potential benefit of late-course adaptive plans rather than original plans by dose volume histogram (DVH) comparisons. Seventeen patients with stage II-III NSCLC who were treated with definitive conventionally fractionated RT were eligible for this prospective study. FDG PET-CT scans were acquired within 1 week before RT (pre-RT) and at approximately two-thirds of the total dose during-RT (approximately 40 Gy). MTVs were taken as gross tumor volumes (GTVs) that included the primary tumor and any involved hilar or mediastinal lymph nodes. An original plan based on the baseline MTVs and adaptive plans based on observations during-RT MTVs were generated for each patient. The DVHs for lung, heart, esophagus and spinal cord were compared between the original plans and composite plans at 66 Gy. At the time of approximately 40 Gy during-RT, MTVs were significantly reduced in patients with NSCLC (pre-RT 136.2±82.3 ml vs. during-RT 64.7±68.0 ml, p = 0.001). The composite plan of the original plan at 40 Gy plus the adaptive plan at 26 Gy resulted in better DVHs for all the organs at risk that were evaluated compared to the original plan at 66 Gy (p<0.05), including V5, V10, V15, V20, V25, V30 and the mean dose of total lung, V10, V20, V30, V40, V50, V60 and the mean dose of heart, V35, V40, V50, V55, V60, the maximum dose and mean dose of the esophagus, and the maximum dose of the spinal-cord. PET-MTVs were reduced significantly at the time of approximately 40 Gy during-RT. Late course adaptive radiotherapy may be an effective way to reduce the dose volume to the organs at risk, thus reducing radiation toxicity in patients with NSCLC.
authors.affiliation: School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, Jinan, Shandong, China.|Department of Radiation Oncology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong, China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Xiao
authors.affiliation: Department of Radiation Oncology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.affiliation: Department of Radiation Oncology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong, China.
authors.forename: Guifang
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Oncology, Linyi Cancer Hospital, Linyi, Shandong, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Oncology, Jining Infectious Diseases Hospital, Jining, Shandong, China.
authors.forename: Song
authors.initials: S
authors.lastname: Gao
authors.affiliation: Department of Radiology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Fu
authors.affiliation: Department of Radiation Oncology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong, China.
authors.forename: Suzhen
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong, China.
authors.forename: Qingxi
authors.initials: Q
authors.lastname: Yu
authors.affiliation: Department of Radiation Oncology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong, China.
authors.forename: Jinming
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Radiation Oncology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong, China.|Shandong Academy of Medical Sciences, Jinan, Shandong, China.
authors.forename: Shuanghu
authors.initials: S
authors.lastname: Yuan
mesh_terms: D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D011788:Quality of Life; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D016896:Treatment Outcome; D047368:Tumor Burden