Use of 18F-FDG PET/MRI as an Initial Staging Procedure for Nasopharyngeal Carcinoma

Abstract

Background: Compared with the conventional work-up (CWU) including computed tomography (CT) of the chest and abdomen, MRI of the head and neck, and skeletal scintigraphy, positron emission tomography (PET)/MRI might improve diagnostic accuracy, shorten the work-up time, and reduce false-positive (FP) findings in patients with nasopharyngeal carcinoma (NPC). However, evidence of cost-effectiveness is needed for the adoption of PET/MRI for the initial staging in NPC.

Purpose: To evaluate the cost-effectiveness and clinical value of PET/MRI as an initial staging procedure for NPC.

Study type: Retrospective cohort cost effectiveness study.

Subjects: Three hundred forty-three patients with a median age of 51 (13-81) years underwent PET/MRI before treatment (the PET/MRI group) and the remaining 677 patients with a median age of 55 (15-95) years only underwent CWU (the CWU group). There were 80 (23.3%) females and 193 (28.5%) females in the PET/MRI and CWU groups, respectively.

Field strength/sequence: 3-T integrated PET/MRI system, diffusion-weighted echo-planar imaging (b = 0 and 1000 s/mm² ) and [18F] fluorodeoxyglucose PET.

Assessment: The primary end point was the FP rate. Costs were determined as issued in 2021 by the Medical Insurance Administration Bureau of Zhejiang, China.

Statistical tests: Incremental cost effectiveness ratio (ICER) measured cost of using PET/MRI per percent of patients who avoided a FP. A P-value <0.05 was considered statistically significant.

Results: For the whole group, the de novo metastatic disease rate was 5.2% (53/1020). A total of 187 patients with FP results were observed. Significantly more patients with FP results were observed in the CWU group compared to the PET/MRI group (25.6% vs. 4.1%). The ICER was $54 for each percent of patients avoiding a FP finding.

Data conclusion: Compared with CWU, PET/MRI may reduce the FP risk. Furthermore, PET/MRI may be cost-effective as an initial staging procedure for NPC.

Evidence level: 3 TECHNICAL EFFICACY: Stage 6.

Keywords: PET; cost-effectiveness analysis; nasopharyngeal carcinoma; tumor staging.