Re-irradiation Therapy of Locally Recurrent Rectal Cancer With Carbon Ion

A Prospective Phase II Clinical Study of Carbon Ion Re-irradiation in Unresectable Locally Recurrent Rectal Cancer

Prospective phase II clinical study aim to explore the clinical outcome of patients with unresectable locally recurrent rectal cancer (LRRC) treated with re-irradiation by carbon ion radiotherapy (CIRT)

Inclusion Criteria:

• 1) pathologically confirmed rectal adenocarcinoma (including mucinous adenocarcinoma and signet-ring cell carcinoma) and LRRC confirmed by biopsy or clinical diagnosis,
• 2) received a radical operation for their primary tumor and regional lymph nodes,
• 3) received chemo-radiation or radiation in pelvic before CIRT,
• 4) received re-irradiation by CIRT after their pelvic radiotherapy.

Exclusion Criteria:

• 1) received more than once prior radiotherapy in the same treatment field,
• 2) time to the last radiotherapy was <1 year,
• 3) space between the lesion to organ at risk (OARs) (bladder or digestive tract) was too close (<5 mm).