Role of stereotactic body radiotherapy in patients with positive margins after rectal cancer surgery

This study investigated the role of stereotactic body radiotherapy (SBRT) in patients with positive margins (when the cancer is not totally removed) after chemotherapy, radiation therapy and rectal surgery. Researchers suggested that SBRT is an effective and safe treatment option.

Chemotherapy and radiation therapy (CRT) followed by surgery has made a significant impact in reducing post-surgery positive margins in rectal cancer. However, 5-15% of patients may still have positive margins and local recurrences (when the cancer comes back) resulting in poorer survival. The best treatment option for positive margins after CRT and surgery is unclear.

SBRT delivers high doses of radiation at very precise targets. Prior studies suggested SBRT as an efficient treatment method. However it is not clear if SBRT is as efficient in patients that already underwent radiation therapy. 

The objective of this study was to evaluate the role of SBRT in rectal cancer patients with positive margins who underwent CRT and surgery.

This study included information about 7 patients who underwent CRT and surgery and were treated with SBRT for positive margins. The average follow-up was 23.5 months. Follow-up included CT imaging (X-ray computed tomography) at 1 month after treatment and 3-6 months after. Overall survival, recurrence rates and toxicity (negative effects) were evaluated.

1-year overall survival was 100% and 2-year overall survival was 71%. 1-year survival without recurrence was 71% and 2-year survival without recurrences was 57%.

6 out of 7 patients experienced fatigue following SBRT, and 2 patients had diarrhea treated with medication. 

This study determined that SBRT is an efficient and safe treatment option for positive margins after rectal cancer CRT and surgery.

This was a very small, initial study. Further studies with larger patient populations are required.