PET/CT-guided dose-painting versus CT-based intensity modulated radiation therapy in locoregional advanced nasopharyngeal carcinoma

Abstract

BackgroundThe effect of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT)-guided dose-painting intensity-modulated radiation therapy (IMRT) in locoregionally advanced nasopharyngeal carcinoma (NPC) is unclear. This study aimed to assess the efficacy and toxicity of such combination.MethodsFrom 2012 to 2014, 213 patients with stage III-IVB NPC received chemoradiotherapy by PET/CT-guided DP-IMRT (group A, n = 101) or CT-based IMRT (group B, n = 112). In group A, subvolume GTVnx-PET (gross tumor volume of nasopharynx in PET images) was defined within GTVnx (gross tumor volume of nasopharynx) as the SUV50%max isocontour; the dose to GTVnx-PET was escalated to DT 75.2 Gy/32 and 77.55 Gy/33 Fx, respectively, for patients with T1-2 and T3-4 disease, respectively. In group B, PGTVnx was irradiated at DT 70.4–72.6 Gy/32–33 Fx in 2.2 Gy per fraction.ResultsComplete response rates were 99.0% (100/101) and 92.9% (104/112) in groups A and B, respectively (P = 0.037). Compared with CT-based IMRT, FDG-PET/CT guided DP-IMRT significantly improved 3-year local failure-free survival (LFFS, 98.8% vs. 91.3%; P = 0.032), locoregional failure-free survival (LRFFS, 97.2 vs. 91.2%; P = 0.049), distant metastasis-free survival (DMFS, 92.9% vs. 87.4%; P = 0.041), disease free survival (DFS, 87.9% vs. 82.4%; P = 0.02), and overall survival (OS, 91.8% vs. 82.6%; P = 0.049). No statistically significant differences in acute and late toxic effects were observed. Multivariate analysis showed that dose painting (PET/CT-guided DP-IMRT vs CT-based IMRT without DP) was a significant independent prognostic factor for LFFS and DFS.ConclusionFDG-PET/CT guided DP-IMRT plus chemotherapy is associated with a considerable survival benefit, without increasing toxicity in patients with locoregional advanced NPC. Further randomized trials are needed to fully assess the role of PET/CT-guided DP-IMRT.

Clinical value of a plasma Epstein–Barr virus DNA assay in the diagnosis of recurrent or metastatic nasopharyngeal carcinoma: a meta-analysis

“…PET/CT, as a functional imaging examination, can reflect local tissue metabolism and identify abnormal changes after radiotherapy such as scarring, fibrosis, or tumor recurrence in the diagnosis of the recurrence or metastasis of NPC in patients [48,49]. In addition, PET can be used to determine the correlation between the differentiation degree of NPC through SUV, which could help to confirm the pathological classification of patients who cannot obtain a pathological diagnosis [50]. Nonetheless, local chronic mucosal ulcers, granulomatous tissue, inflammatory changes, and radioactive osteomyelitis formed after radiotherapy inevitably lead to FP results [51].…”

MR‐guided simulation is superior than FDG/PET‐guided simulation for local control in nasopharyngeal cancer patients treated with intensity‐modulated radiotherapy

“…In the subgroup analysis of the same study, for OS in NPCs, PET/CT‐simulation was not superior to CT‐simulation, whereas PET/CT‐simulation was superior to CT‐simulation in terms of locoregional control rates 21 . In another study of patients treated with IMRT, the researchers achieved a higher dose density in tumor tissue with PET/CT guided therapy, and achieved a better locoregional recurrence‐free survival, distant metastasis‐free survival, disease‐free survival, and overall survival 22 . In the NPCs, both PET/CT‐guided simulation (with or without immobilization equipment) and MR‐guided simulation (with or without immobilization equipment) are widely used by radiotherapy planning systems for better GTV identification in the worldwide.…”

“…21 In another study of patients treated with IMRT, the researchers achieved a higher dose density in tumor tissue with PET/CT guided therapy, and achieved a better locoregional recurrencefree survival, distant metastasis-free survival, disease-free survival, and overall survival. 22 In the NPCs, both PET/CT-guided simulation Abbreviations: DMFS: distant metastasis-free survival; LRFS: local recurrence-free survival OS: overall survival, RRFS: regional recurrence-free survival, HR: hazard ratio, CI: confidence interval. patient number, and not being a standardized delineation of targeted volume in PET/CT imaging in the literature.…”

Prognostic value of baseline [18F]-fluorodeoxyglucose positron emission tomography parameters MTV, TLG and asphericity in an international multicenter cohort of nasopharyngeal carcinoma patients

“…A recent publication with 213 NPC patients retrospectively investigated two groups of patients: one group of 101 patients received a PET based radiation dose escalation with about 12% increased radiation dose, while 112 patients received standard curative radiation doses. This PET boost approach improved LRC, FFDM and OS of patients [37]. This study is limited by the retrospective (non-randomized) design; however, improvement in patient outcome by a PET based treatment individualization could be demonstrated consistently for different endpoints in a comparably large patient sample.…”