Pretreatment Photopenia on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography Scans Predicts Poor Prognosis in Nasopharyngeal Cancer Patients Undergoing Concurrent Chemoradiotherapy

Abstract

Objectives. To investigate the influence of pretreatment primary tumor or nodal photopenia (PP) on <sup>18</sup>F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT), an indicator of tumor ischemia, on survival results of nasopharyngeal cancers (NPCs) treated with concurrent chemoradiotherapy (C-CRT).Methods. The pre-C-CRT FDG PET-CT scans of 104 patients with NPC (cT1-4 N0-3 M0) were retrospectively examined to determine the presence of PP (PP+). Our primary endpoint was the influence of PP+ on overall survival (OS), while the progression-free survival (PFS) and locoregional PFS (LRPFS) constituted the secondary endpoints.Results. The PP+ was detected in 29 (27.9%): nine (8.7%), seven (6.7%), and 13 (12.5%) in the primary tumor alone, primary tumor plus neck nodes, and neck nodes alone, respectively. Because the PP+ cases were small by count per location, all comparative analyses were performed according to overall PP+/ PP– status instead of per detected site. At a median follow-up of 67.8 months (range, 9 to 130 months), the median survival times were not reached (NR) for the entire population, while 5-year OS, LRPFS, and PFS rates were 73.3%, 68.2%, and 63.4%, respectively. Comparatively the PP+ patients exhibited significantly poorer median OS (49.8 months vs. NR, <i>P</i><0.001), LRPFS (40.7 months vs. NR, <i>P</i>=0.001), and PFS (31.8 months vs. NR, <i>P</i>=0.002) durations than their PP– counterparts. Furthermore, the PP+ retained its independent prognostic significance in multivariate analysis (<i>P</i><0.001).Conclusion. Present results uncovered the pre-C-CRT PP as an independent predictor of poor prognosis for NPC patients, which underscore the requirement for the fortification of the local and systemic treatments in hypoxic NPCs.

Pretreatment Metabolic Tumor Volume of Primary Tumor and Total Lesion Glycolysis of Lymph Nodes are Predictive in Nasopharyngeal Cancer

“…Many studies have shown that the higher SUVmax, MTV, and TLG values are associated with worse treatment outcomes (10). There are few studies showing the meaning of parameters derived from PET for locally advanced NPC patients (11)(12)(13). More studies that evaluate the significance of PET-derived parameters concerning disease prognosis are needed.…”