Radiopharmaceutical Use in Stereotactic Radiation Shows Promise in Delaying Prostate Cancer Progression

Recent clinical research indicates that incorporating radiopharmaceutical therapy into stereotactic radiation treatments can significantly extend the period before prostate cancer progresses, especially in cases with limited metastases. The phase II LUNAR trial, the first of its kind, demonstrated that patients with oligometastatic prostate cancer—where cancer has spread to a few sites—experienced longer progression-free survival when they received a targeted radiopharmaceutical prior to high-precision radiation.

This innovative approach involves administering a PSMA-targeted radiopharmaceutical, such as ¹⁷⁷Lu-PNT2002, which delivers radiation directly to cancer cells expressing prostate-specific membrane antigen. The study enrolled 92 patients with hormone-sensitive, oligometastatic prostate cancer, randomizing them to receive either stereotactic body radiation therapy (SBRT) alone or combined with the radiopharmaceutical. Over a median follow-up of 22 months, the combination group showed a median progression-free survival of 18 months versus 7 months for the SBRT-only group, highlighting a substantial benefit.

Furthermore, patients receiving the radiopharmaceutical experienced a delay in the need for hormone therapy by approximately 10 months. The study also noted that the addition of radioligand therapy did not increase severe side effects, with manageable mild to moderate adverse events. This suggests a safe and effective way to prolong disease control and improve quality of life.

Leading the research, Dr. Amar U. Kishan emphasized that pairing systemic radiopharmaceuticals with localized radiation can target microscopic disease hidden beyond the reach of conventional imaging. While current treatments like PSA testing and advanced imaging detect visible tumors, microscopic disease often remains undetected, contributing to recurrence.

These findings propose that integrating radiopharmaceuticals earlier in the treatment of prostate cancer might help delay or even prevent disease progression, reducing reliance on treatments like androgen deprivation therapy, which come with notable side effects. However, the radiopharmaceutical used in this study is still investigational and primarily available within clinical trials.

The results support the evolving role of targeted radiation strategies in managing oligometastatic prostate cancer and highlight the need for ongoing research to optimize dosing, sequencing, and combination therapies to further improve patient outcomes.