Evaluating the effectiveness and safety a second radiation therapy in patients with prostate cancer.

This study investigated the effectiveness and safety of re-irradiation in the treatment of patients with relapsed prostate cancer (PCa). The data showed that the use of re-irradiation in these patients was associated with good outcomes and low toxicity.

Radiotherapy (RT) is an effective treatment for localized prostate cancer (PCa). There are many different types of RT used to treat PCa. Brachytherapy (BT) is a type of RT that uses a radioactive implant device into the cancer tissue. It slowly releases radiation and kills cancer cells over time. Stereotactic body radiation therapy (SBRT) is a special type of RT that uses a high dose of radiation and targets a specific area from different angles. This technique precisely kills the cancer cells while reducing the damage to healthy tissues. External beam radiation therapy (EBRT) is another type of RT which involves directing high-energy rays from outside the body at the tumor site to kill cancer cells.

Despite these accurate RT treatments, nearly one-third of the patients experience relapse. Re-irradiation (Re-I) involves repeat administration of RT to a previously exposed region of the body. There are very few studies investigating the effectiveness and safety of Re-I after relapse of previously irradiated PCa.

This study analyzed the results of 38 studies that involved 1194 patients with PCa. Patients in these studies underwent Re-I treatment after relapse of PCa. BT was the most used Re-I technique (27 studies), followed by SBRT (9 studies), and EBRT (2 studies). The average follow-up time was 30 months from Re-I.

The overall survival (OS) rate was 97.9% at 2 years and 87.5% at 4 years. Biochemical failure (BF) was also evaluated. If, after treatment, the prostate-specific antigen (PSA: a protein made by cells of the prostate gland that increases in PCa) levels increased by 0.2 ng/ml from the lowest value it was considered as evidence of BF. The BF rate was 24% at 2 years and 35.6% at 4 years.

1.3% of the patients experienced immediate severe side-effects and 8.7% of patients experienced late side effects. Most side effects were urinary and genital.

This study concluded that Re-I resulted in high rates of overall survival with low levels of toxicities in patients with relapsed PCa.

The studies reviewed had a short follow-up period. A longer follow-up period is necessary to evaluate the long-term effectiveness and safety of Re-I for PCa.