Evaluating treatment outcomes of hypofractionated stereotactic radiotherapy in patients with brain metastases.

This study investigated the optimal doses of hypofractionated stereotactic radiation therapy (HSRT) for patients with brain metastases (BM). The data showed that a HSRT dose of 30 Gy or higher delivered in 5 daily fractions was safe and effective in these patients.

Stereotactic radiosurgery (SRS) is commonly used in patients with BM. SRS can directly target the tumor in the brain, rather than targeting the whole brain. SRS uses high-energy radiation to kill cancer cells by damaging their DNA. SRS is delivered in a single fraction and is useful for small intact BM.

HSRT is an option for treating larger BM (greater than 3 cm). HSRT uses higher doses of radiation in a shorter period of time and targets a specific area from different angles. However, there are few studies investigating the different doses of HSRT and their treatment outcomes in patients with BM.

This study involved 220 patients with BM from lung, breast cancer, or melanoma. Patients were treated with HSRT. 70% of patients had more than one BM. Patients were given an average total dose of 30 Gy in 5 fractions. The average follow-up time was 10.8 months.

23.8% of patients experienced local failure (reappearance of the cancer in and around the original site treated) in 12 months. The average time to local failure was 8.5 months. The risk of local failure at 1 year was lower for patients who received a radiation dose larger than 30 Gy (19%) compared to less than 30 Gy (33%). Patients who received a total dose of less than 30 Gy were 1.68 times more likely to experience local failure than those who received a total dose larger than 30 Gy. 

15.6% of patients experienced damage to the brain tissue related to radiation therapy.

This study concluded that a HSRT dose of 30 Gy or more delivered in 5 daily fractions was safe and effective in patients with BM.

This study had a small number of participants. The study looked back in time at medical records. Patients had multiple types of cancer and received different types of cancer treatments. This might have influenced the results.