Benefits from ¹⁸F-FDG PET-CT-Based Radiotherapy Planning in Stage III Non-Small-Cell Lung Cancer: A Prospective...

Area of Science:

• Oncology
• Radiotherapy
• Medical Imaging

Background:

• Lung cancer is a leading cause of cancer mortality globally.
• Accurate radiotherapy (RT) planning is crucial for treating inoperable non-metastatic lung cancer.
• Conventional CT-based planning may lack precision in defining tumor and nodal disease margins.

Purpose of the Study:

• To investigate the utility of ¹⁸F-FDG PET-CT imaging in RT planning for lung cancer.
• To assess the impact of PET-CT on target volume delineation for primary, nodal, and metastatic disease.
• To evaluate PET-CT's role in overall therapeutic strategy adjustments.

Main Methods:

• Prospective single-center study involving 34 patients with locally advanced non-small-cell lung carcinoma (NSCLC).
• Patients underwent ¹⁸F-FDG PET-CT-based RT simulation.
• Two RT plans were created: one CT-based, the other PET-CT-based, with analysis of planning target volumes (PTVs) and adjustments.

Main Results:

• PET-CT detected distant metastases in 20.6% of patients, altering therapeutic plans in 11.8%.
• RT planning was modified in 76.5% of patients, clarifying malignancy in atelectatic areas.
• Nodal involvement was redefined in 8.8% of cases, and additional involved nodes were identified in 35.3%, necessitating dose escalation. PTV changes occurred in a significant proportion of patients (p < 0.0001).

Conclusions:

• ¹⁸F-FDG PET-CT enhances RT planning by precisely defining tumor and nodal volumes.
• The imaging modality identifies previously undetected lesions and guides necessary dose adaptations.
• Further long-term studies are needed to confirm improvements in locoregional control and survival.