Study of High-Dose-Rate Endorectal Brachytherapy (HDRBT) in the Treatment of Locally Advanced Low Rectal Cancer

This research is being done to see how effective high-dose rate endorectal brachytherapy (HDRBT) is in treating cancer of the lowest part of the bowel (rectum). In this study we want to try to decrease side effects and shorten the course of radiation treatment for patients with cancer of their rectum by using a high-dose rate endorectal brachytherapy (HDRBT). This is a different form of radiation than what is normally given. With HDRBT, the radiation is given through an applicator placed into the bowel next to the tumor. The radiation is directed at the tumor and a small area around it.

This study is a pilot study open to patients with clinical stage T2N1 or T3N0-1 resectable rectal cancer. The investigational tool being evaluated is high-dose endorectal brachytherapy (HDRBT) which is an FDA approved method to administer endoluminal radiation for low rectal cancer. This study assumes that the rate of pathological response to HDRBT will be similar to historical controls (conventional neoadjuvant chemoradiation). All patients will receive postoperative standard 5-FU based chemotherapy (at the discretion of the medical oncologist). The clinical response will be assessed with endoscopic/ultrasound, pelvic MRI and FDG-PET/CT. In addition, tissue and serum will be collected to evaluate for biological predictors of response to therapy. The endpoints of this study include adverse events (gastrointestinal toxicity), quality of life as measured by the QLQ-C30, and tumor regression/response.

Inclusion Criteria:

• Patients with histologically confirmed adenocarcinoma of the rectum
• Able to undergo local staging of the rectal tumor performed by MRI and/or EUS demonstrating a T2N1 or T3N0-1 tumor
• ECOG performance status of 0 or 1
• Participants are willing to undergo initial therapy and if needed subsequent therapy prior to resection at Johns Hopkins Medical Institutions
• English as a primary language in order to complete the quality of life questionnaires

Exclusion Criteria:

• Patients with tumors >12 cm from the anal verge.
• Near obstructing or bulky tumors which will not allow application of the endorectal probe
• Patients with distant metastatic disease
• Any pelvic lymph nodes outside of the mesorectum (iliac or inguinal)
• Prior history of radiation therapy to the pelvis
• Prior history of chemotherapy for rectal cancer
• Active connective tissue disease such as scleroderma or Crohn's disease