The effects and benefits of radiation treatment in prostate cancer

The authors aimed to review existing evidence on the safety and effectiveness of hypofractionation in prostate cancer.

Radiation involves directing a beam of radiation at the site of the tumor with the aim of killing cancer cells present. Hypofractionation is a type of radiation therapy that involves receiving large, daily doses of radiation for a shorter period of time than standard radiation, in the hope of targeting the cancer cells while minimizing the damage to normal cells. Radiation is measured in gray (Gy) and the amount of radiation used will vary depending on the severity of the cancer.

The aim of this study was to review safety and effect of hypofractionation in prostate cancer patients.

This study evaluated two groups, patients who received moderate hypofractionation (lower radiation doses given but higher overall amount of radiation is received) and patients who received extreme hypofractionation (higher radiation doses given but lower overall amount of radiation is received).

6 patient groups received moderate fractionation with a follow-up of 4.3 to 7.5 years. Group 1  and 2 received low overall amounts of radiation which resulted in poor 5-year biochemical control rates (prostate specific antigen [PSA – protein elevated in the presence of prostate cancer] levels increased after treatment) of between 40-53%. Groups 3, 4, 5 and 6 received high overall amounts of radiation which resulted in 5-year biochemical control rates of over 80% and low toxic side-effects experienced in the urinary system and stomach of 2-20%.

11 patients groups received extreme fractionation with a follow-up of 18 months to 4.6 years. In the largest group of 515 patients, patients with low-risk cancer (tumor cannot be felt by a doctor and PSA levels are low) had a 5-year biochemical control rate of 98%. Toxic side-effects were moderate to extreme that targeted the urinary system, bowel and rectum. This was directly linked with the total radiation used, where patients who received higher radiation levels experienced more severe toxic side-effects compared to patients who received lower overall radiation. Patients exposed to higher amounts of overall radiation experienced erectile dysfunction. From the 515 patients, 23% of men experienced a drop in sexual functioning after 12 months of treatment, comparable to existing research on standard radiation treatment.

The authors conclude that though 5-year biochemical control rates after hypofractionated radiation are promising, further data is needed to determine long-term side-effects and safety in patients.

Results presented in this study cannot be widely applied as they are still involved in clinical trials. 

If you are considering radiation treatment for prostate cancer please consult your doctor for potential risks and benefits.