Metabolic tumor volume and conformal radiotherapy based on prognostic PET/CT for treatment of nasopharyngeal carcinoma

Abstract

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.

Effectiveness and cost-effectiveness analysis of nimotuzumab for the radiotherapy of locoregionally advanced nasopharyngeal carcinoma

“…Chemotherapy, including CCRT and IC, were repeated every 3 weeks. Radiotherapy was administered simultaneously with the first cycle of concurrent chemotherapy [13].…”

Differences among [18F]FDG PET-derived parameters in lung cancer produced by three software packages

“…Other authors suggest that MTV is a prognostic factor for local control (LC) and overall survival (OS) in patients with early-stage NSCLC 46 . MTV is also widely used for assessing gross tumour volume in radiotherapy planning not only in lung cancer patients but also in patients with other cancers 47 ; therefore, based on our study, it is reasonable to assess patients on workstations with the same software to avoid under- or overestimating the results.…”

Prognostic Factors for Overall Survival in Nasopharyngeal Cancer and Implication for TNM Staging by UICC: A Systematic Review of the Literature

“…Among the 15 studies on FDG-PET included in the current review, most evaluated the maximum SUV (SUV max ), either alone (n = 11) ( 100 – 103 , 105 – 108 , 110 , 112 , 113 ); some also proposed other metabolic parameters, such as metabolic tumor volume (MTV; n = 1) ( 99 ) or TLG (n = 2) ( 104 , 111 ) ( Supplementary Table 6 ). A single study further evaluated the difference in prognosis between PET-CT-guided dose-painting intensity-modulated radiation therapy (IMRT) and CT-based IMRT ( 109 ).…”