Open AccessMetabolic tumor volume and conformal radiotherapy based on prognostic PET/CT for treatment of nasopharyngeal carcinoma
Author(s) -
Zhaodong Fei,
Chuanben Chen,
Yingying Huang,
Xianxin Qiu,
Yi Li,
Li Li,
Taojun Chen
Publication year - 2019
Publication title -
medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.59
H-Index - 148
eISSN - 1536-5964
pISSN - 0025-7974
DOI - 10.1097/md.0000000000016327
Subject(s) - medicine , nasopharyngeal carcinoma , nuclear medicine , radiation therapy , positron emission tomography , standardized uptake value , primary tumor , receiver operating characteristic , radiology , oncology , metastasis , cancer
For patients with nasopharyngeal carcinoma (NPC), prognostic indicators to customize subsequent biologically conformal radiation therapy may be obtained via 2-(fluorine-18)-fluoro-2-deoxy-D-glucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT). This retrospective study assessed the prognostic significance and feasibility of conformal radiotherapy for NPC, based on 18 F-FDG PET/CT. Eighty-two patients with NPC underwent 18 F-FDG PET/CT prior to intensity-modulated radiation therapy (IMRT). The maximum standardized uptake value (SUV max ) and metabolic tumor volume (MTV) of the primary tumor were measured, with MTV x based on absolute SUV x values ≥ specific threshold x on each axial image. The cut-off SUV max and MTV values for predicting 3-year progression-free survival (PFS) were calculated according to a receiver operating characteristic curve. Assessed were correlations between SUV max and MTV and between threshold x and MTV x , and the MTV percentage of the primary tumor volume at threshold x . The SUV max and MTV were positively associated, as were MTV and primary tumor volume. Primary tumor volume, SUV max , and MTV were significant predictors of survival. The 3-year PFS rates for SUV max ≤8.20 and >8.20 were 91.1% and 73.0%, respectively ( P = .027). With furthermore analysis, patients having tumor with smaller MTV had higher 3-year PFS than patients having tumor with larger MTV. The 3-year PFS rate was inversely related to MTV. SUV max and MTV, derived by PET/CT, are important for assessing prognosis and planning radiotherapy for patients with NPC. Small MTV indicated better 3-year PFS compared with large MTV. For the best therapeutic effect, MTV 4.0 was the best subvolume to determine radiotherapy boost.