Radiotherapy for Post-Chemotherapy Residual Mass in Advanced Seminoma: A Fluorodeoxyglucose Positron Emission...

Area of Science:

• Oncology
• Nuclear Medicine
• Radiotherapy

Background:

• Management of post-chemotherapy residual masses in classical seminoma lacks consensus.
• Fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) can detect viable disease in residual masses.
• FDG PET-CT may help tailor therapy for seminoma patients.

Purpose of the Study:

• To evaluate if FDG PET-CT can identify patients who benefit from locoregional radiotherapy.
• To assess the diagnostic accuracy of FDG PET-CT in detecting viable disease.
• To compare survival outcomes between different risk groups based on FDG PET-CT findings.

Main Methods:

• Retrospective analysis of advanced classical seminoma patients treated with chemotherapy.
• Stratification into low risk (SUVmax <3) and high risk (SUVmax ≥3) groups based on FDG PET-CT.
• Subgroup analysis for a very high risk group (residual nodal size ≥3 cm and SUVmax ≥3).

Main Results:

• Sixty-nine patients were analyzed; 48 observed, 21 received radiotherapy.
• Locoregional failure rates were 0% in the radiotherapy group vs. 30% in the observation group for the very high risk subgroup (P=0.059).
• Benefit in locoregional control did not translate to improved overall survival.

Conclusions:

• A tailored, FDG PET-based risk-adapted treatment approach refines management of post-chemotherapy residual masses in seminoma.
• Radiotherapy appears beneficial for patients with post-chemotherapy residual mass SUVmax ≥3.
• FDG PET-CT aids in selecting seminoma patients for risk-adapted radiotherapy.