Fifty Shades of PSMA-Avid Rib Lesions: A Comprehensive Review

Area of Science:

• Nuclear Medicine
• Oncology
• Radiology

Background:

• Prostate-specific membrane antigen (PSMA)-targeted imaging is crucial for detecting prostate cancer (PCa) metastases.
• Unspecific bone uptake (UBU) in ribs on PSMA PET/CT poses diagnostic challenges.
• Differentiating true metastases from benign mimics in PCa patients is essential.

Purpose of the Study:

• To synthesize evidence on PSMA-avid rib lesions in PCa.
• To propose a structured approach for differentiating true metastases from benign mimics.
• To enhance the accuracy of PCa staging and clinical decision-making.

Main Methods:

• Comprehensive literature search across major databases (PubMed, EMBASE, Scopus, Web of Science).
• Extraction and analysis of data on uptake intensity, CT features, lesion characteristics, tracer type, and patient risk factors.
• Development of a clinical decision tree based on extracted variables.

Main Results:

• Solitary rib lesions are often benign, especially in low-risk patients or anterior/lateral locations.
• Metastatic lesions are more likely multiple, show cortical destruction, high uptake, and correlate with elevated PSA or Gleason score.
• ¹⁸F-PSMA-1007 shows higher UBU in ribs than ⁶⁸Ga-PSMA-11.

Conclusions:

• Accurate interpretation of PSMA-avid rib lesions requires a multimodal approach.
• The proposed diagnostic decision tree aids in differentiating benign from metastatic lesions.
• Further validation of rib-specific findings is needed for personalized treatment strategies.