Retroperitoneal node biopsy in paratesticular rhabdomyosarcoma

Area of Science:

• Pediatric Oncology
• Surgical Oncology
• Medical Imaging

Background:

• Paratesticular rhabdomyosarcoma (PT RMS) requires accurate staging for treatment planning.
• Retroperitoneal lymph node (RPLN) involvement is a critical prognostic factor.
• Assessing RPLN involvement guides the need for adjuvant therapies like x-ray therapy (XRT).

Purpose of the Study:

• To compare clinical node evaluation (CNE) with pathological node evaluation (PNE) in staging PT RMS.
• To evaluate predictors of relapse and survival in PT RMS patients.
• To determine the efficacy of RPLN dissection and subsequent treatment in preventing recurrence.

Main Methods:

• Retrospective analysis of 121 Intergroup Rhabdomyosarcoma Study (IRS) III patients with nonmetastatic PT RMS.
• Clinical node evaluation using computed tomography (CT) or sonogram.
• Pathological node evaluation via lymphadenectomy or biopsy.
• Postoperative chemotherapy (vincristine, actinomycin D) and RPLN XRT for positive nodes.

Main Results:

• 81% of patients had clinically negative nodes (cN0); 14% of these had pathologically positive nodes (pN1).
• 94% of clinically positive nodes (cN1) were pathologically positive (pN1).
• 5-year survival was 91% overall, 96% for cN0, and 69% for cN1 (P < .001).
• RPLN relapse occurred in only 2 patients; both initially had cN0 disease.

Conclusions:

• Clinical node evaluation has limitations in detecting RPLN involvement in PT RMS (sensitivity 57%).
• Pathological node evaluation is crucial for accurate staging.
• RPLN recurrence is uncommon with appropriate regional XRT and chemotherapy, even with initial nodal involvement.