A PET-based nomogram for oropharyngeal cancers.

Area of Science:

• Oncology
• Nuclear Medicine
• Radiotherapy

Background:

• Locally advanced oropharyngeal cancer (LAOC) requires effective prognostic tools for treatment planning.
• Current prognostic factors for LAOC may not fully capture treatment response and survival outcomes.
• Positron Emission Tomography with Fluorodeoxyglucose (PET-FDG) offers insights into tumor metabolism.

Purpose of the Study:

• To identify PET-FDG parameters predicting overall survival (OS) in LAOC patients.
• To develop and validate a prognostic scoring system for LAOC based on PET-FDG.
• To assess the performance of the PET-FDG score against established prognostic factors.

Main Methods:

• A training cohort (n=76) of LAOC patients treated with definitive radiotherapy (RT) underwent PET-FDG imaging.
• A predictive model for locoregional control (LRC) and OS was built using PET-FDG parameters.
• A validation cohort (n=46) of LAOC patients was used to test the developed nomogram and scoring system.

Main Results:

• Metabolic tumor volume (MTV) of the primary tumor and lymph nodes were independent predictors of LRC and OS.
• The PET-FDG-based predictive score identified two distinct risk groups with significantly different median OS (42 vs. 14 months in training, not reached vs. 26 months in validation).
• The PET-based nomogram demonstrated robust performance and good calibration between predicted and observed OS.

Conclusions:

• A novel PET-FDG-based nomogram and scoring system can effectively predict survival in LAOC patients.
• This PET-based prognostic tool showed superior performance compared to classical prognostic factors.
• The validated scoring system offers a robust method for risk stratification in LAOC treated with definitive RT.