PSMA-Guided MDT Shows Promise in Oligometastatic RCC

Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) has demonstrated significantly better results over conventional imaging for the direction of metastasis-directed therapy (MDT) for oligometastatic renal cell carcinoma (RCC). A recent proof-of-concept study has further evaluated the efficacy of PSMA-guided MDT for oligometastatic RCC.

Researchers utilized a PET/CT database to gain insight on patients with oligometastatic RCC who had MDT between 2014 and 2020. From a search of 3,095 PSMA PET/CT scans, 83 patients with RCC were identified, and 34 had received MDT to 60 sites.

The primary end point of the study was progression-free survival (PFS), and secondary end points included freedom from local progression, freedom from change in systemic therapy strategy, and overall survival (OS).

Synchronous metastatic disease was present in 6 patients (18%), and the median number of metastases was 1 (interquartile range, 1-2). The common sites of metastasis included bone (19; 32%) and lung (19; 32%). Radiation therapy was used to treat 56 metastases (93%); stereotactic ablative body radiotherapy and conventional radiotherapy were used to treat 38 and 18 metastases, respectively. Four patients (7%) underwent surgery.

The rates of 1-, 3-, and 5-year freedom from local progression were 94% (95% CI, 85%-98%), 85% (95% CI, 69%- 94%), and 85% (95% CI, 69%-94%), respectively. The 1-, 3-, and 5-year OS rates were 88% (95% CI, 71%-95%), 71% (95% CI, 52%-84%), and 64% (95% CI, 45%-79%), respectively.

Rates of PFS were 47% (95% CI, 30%-63%) at 1 year, 26% (95% CI, 13%-42%) at 3 years, and 8% (95% CI, 2%-22%) at 5 years. Freedom from change in systemic therapy strategy was 76% (95% CI, 57%-87%) at 1 year, 65% (95% CI, 45%-79%) at 3 years, and 43% (95% CI, 19%-65%) at 5 years.

This study shows that PSMA-guided MDT can provide durable outcomes for oligometastatic RCC, even at an extended rate of 5 years. PSMA PET/CT can be used to select appropriate patients for MDT and improve outcomes.