Comparing whole-pelvis vs prostate only radiotherapy in patients with high-risk prostate cancer

This study compared the use of radiotherapy for prostate cancer in two areas: the prostate only, or the whole pelvis. The results showed that, for high-risk patients, radiotherapy of the whole pelvis improved patient outcomes.

For patients with medium or high-risk prostate cancer, the standard treatment is radiotherapy (RT) with hormone therapy. There are many types of RT. Common types of RT used for high-risk prostate cancer is high beam RT (HBRT) and high-dose-rate (HDR) brachytherapy (BT). HDR-BT is important for controlling the tumor. It involves implanting a radioactive device into the tumor to stop tumor growth and kill the cancer cells. 

Before prostate cancer develops into a more aggressive form and spreads to other areas of the body, small amounts of cells can move to lymph nodes nearby, in the pelvis. Whether giving RT to the whole pelvis, instead of the prostate alone reduces the risk of cancer cells spreading and improves patients’ outcomes, is still unknown.

This study included 812 patients with medium- or high-risk prostate cancer. They were split into two groups. One group received whole pelvis RT (WPRT) and one group received prostate only RT (PORT). All patients also received HDR-BT. Hormone therapy was also given before and after RT. Participants were followed up for an average of 4.7 years. 

Overall, significantly more patients in the WPRT group were alive at 5 years without cancer progressing (89%) compared to those in the PORT group (81%). Also, significantly more patients with high-risk disease given WPRT were alive at 5 years without cancer progressing (84%) compared to those treated with PORT (77%). 

The overall survival rate was similar between the 2 groups at 5 years (94% with WPRT vs 93% with PORT).

Significantly more patients in the WPRT group had short-term genital and urinary side effects compared to PORT.  Slightly more patients in the WPRT group had short-term bowel-related side effects compared to the PORT group. However, no differences were reported in long-term side toxic effects between groups. 

This study showed that WPRT combined with HDR-BT improves survival without cancer progression in patients with high-risk prostate cancer. 

Patients were not randomly assigned to each treatment group. This might have influenced the results.