Multi-modality imaging parameters that predict rapid tumor regression in head and neck radiotherapy

Area of Science:

• Oncology
• Radiotherapy
• Medical Imaging

Background:

• Tumor volume regression during radiotherapy indicates patient-specific treatment response.
• Human papilloma virus (HPV)-associated oropharyngeal carcinoma requires precise treatment monitoring.
• Multimodality imaging (MMI) offers potential for predicting treatment outcomes.

Purpose of the Study:

• To identify pre-treatment MMI metrics predicting rapid tumor regression.
• To evaluate the predictive value of PET, MRI, and CT in HPV+ oropharyngeal carcinoma.
• To correlate imaging findings with tumor volume changes during radiotherapy.

Main Methods:

• Acquired pre-treatment FDG PET-CT, DW-MRI, and intra-treatment MRI in 72 patients.
• Delineated nodal gross tumor volumes to measure intra-treatment volume changes.
• Computed and correlated pre-treatment PET SUV, CT HU, and DW-MRI metrics with volume loss.

Main Results:

• Baseline FDG SUVmean, CT HUmean, and DW-MRI Dmean significantly correlated with volume loss.
• FDG PET-CT SUVmean was a significant predictor of volume loss in multivariate analysis (p=0.01).
• SUVmean showed significant correlations in a separate validation cohort (N=64).

Conclusions:

• Multiple pre-treatment imaging metrics correlate with rapid tumor volume loss.
• FDG PET-CT SUVmean is a significant predictor of tumor regression.
• Pre-treatment FDG PET-CT SUVmean can guide personalized radiotherapy for HPV+ oropharyngeal carcinoma.