The Pelvic Rosetta Classification Project: An Interdisciplinary Proposal for a Lymph Node Map of the Pelvis in...

Area of Science:

• Urology
• Radiology
• Medical Imaging

Background:

• Accurate staging of prostate cancer relies on precise lymph node assessment.
• Interdisciplinary communication between radiologists and urologists can be challenging in pelvic lymph node mapping.

Purpose of the Study:

• To develop and validate the Pelvic Rosetta Classification (PRC), an interdisciplinary, landmark-based pelvic lymph node map for prostate cancer.
• To enhance communication and consistency in reporting pelvic lymph node status.

Main Methods:

• Development of a landmark-based lymph node map (PRC) through expert consensus meetings.
• Validation through contouring lymph node areas (LNAs) on patient imaging and assigning PET/CT-positive lesions.
• Interrater reliability assessed using Fleiss κ.

Main Results:

• Defined 8 pelvic and 4 extrapelvic LNAs using consistent anatomic landmarks.
• Achieved strong expert consensus for well-defined LNAs, moderate overall agreement (κ = 0.53) during validation.
• Identified discrepancies primarily at borders between LNAs; final map and 3D model approved by experts.

Conclusions:

• The Pelvic Rosetta Classification demonstrates fair reproducibility and validity for prostate cancer lymph node mapping.
• Further external validation is necessary to confirm its impact on interdisciplinary communication and patient treatment outcomes.