Outcomes of Patients Treated With RCHOP With a PET-Adapted Approach for Consolidative Radiotherapy: A Retrospective...

Area of Science:

• Oncology
• Hematology
• Radiotherapy

Background:

• Consolidative radiotherapy (CRT) following CHOP-based chemotherapy was standard for primary mediastinal B cell lymphoma (PMBCL) before rituximab.
• Overtreatment with CRT raises concerns about long-term toxicity, especially in the rituximab era where immunochemotherapy may suffice.
• Positron emission tomography (PET) can identify patients unlikely to benefit from CRT.

Purpose of the Study:

• To assess the use of CRT and survival outcomes in PMBCL patients treated between 2003 and 2020.
• To evaluate the role of PET scans in guiding CRT decisions for PMBCL.
• To determine if CRT can be safely omitted in select PMBCL patients.

Main Methods:

• Retrospective review of 43 PMBCL patients treated at the Royal Marsden Hospital.
• Analysis of CRT administration, survival rates (event-free and overall), and relapse patterns.
• Assessment of PET scan results in relation to CRT decisions and outcomes.

Main Results:

• 95% of patients received R-CHOP; CRT was administered to only 5 patients.
• Five-year event-free survival was 79%, and 5-year overall survival was 88%.
• Seven of 9 PET-positive patients (DS4) did not receive CRT and showed no mediastinal relapse with serial PET monitoring.

Conclusions:

• CRT may be omitted in PMBCL patients with negative end-of-treatment PET scans.
• Careful observation and serial PET scans may obviate the need for CRT even in PET-positive patients.
• This approach can help reduce treatment-related toxicity in PMBCL management.