watch and wait management on rectal cancer patients using new swift local therapy

Conditions: Rectal Cancer; Comorbidities and Coexisting Conditions; Inoperable Disease; Brachytherapy

Summary: within our institution, the principal investigator have acquired expertise in endorectal brachytherapy, a localized treatment for colorectal cancer. until now a modality which uses an endorectal applicator has been used, which has certain limitations. in the context of this study, a new applicator will be used which is already approved by health canada for endorectal brachytherapy, thereby improving the participant's quality of life and optimizing treatment time.

the main goal of this study is to treat patients using external beam radiotherapy followed by endorectal brachytherapy using a new applicator. validating the feasibility of this new applicator, assessing the treatment time required when using it, the necessary workload required and ultimately avoid the need for surgery are our main priorities. currently, this option is still experimental, although several patients have been treated with this method during the last ten years. in this pilot study, 45 patients will be recruited, whom have medical conditions (co-morbidities) that make surgery very difficult, or patients that are refusing surgery.

Eligibility criteria:
inclusion criteria: * patients with histologic diagnosis by proctoscopic biopsy of invasive rectal adenocarcinoma will be considered for entry in this study. * patient in whom the diagnosis of invasive rectal cancer has been obtained by incisional biopsy (surgical or endoscopic biopsy) that the majority of the tumor has not been removed . * the tumor should be either palpable by clinical rectal exam or accessible via a rigid proctoscope, and its proximal border should be located no more than 15 cm from the anal verge. * rectal cancer clinically stage as t2-t3 n1+ by mri or endoscopic ultrasound. * tumor of 5 cm or less length, non obstructive * patient is not suitable for surgery nor chemotherapy due to medical conditions * patient must consent to be in the study and consent form must be signed, witnessed and dated prior to registration . * patients must be accessible geographically for follow up. * adults older than 18 years of age exclusion criteria: * patient with malignant rectal tumors other than adenocarcinoma, i.e, sarcoma, lymphoma, carcinoid, squamous cell, cloacogenic, etc. * patient who demonstrate prior to randomization, evidence of free perforation, as manifested by free fluid in the abdomen. * patient who are curable by standard of care with either surgery or eligible for the morpheus study. * patient who have received any previous therapy (radiation , chemotherapy) for rectal cancer. * patient whose tumor is fixed by clinical examination to surrounding structures, precluding the possibility of adequate surgical resection even with pelvic exenteration. * patient with a performance status of 3 or 4. * patient with tumor involving the anal canal. * patient who are pregnant at the time of randomization. * patient with psychiatric or addictive disorders that would preclude obtaining informed consent. * patient who have multiple primary tumors involving both the colon and rectum that would preclude them from being classified as having only rectal cancer.