Study of the Value of the PET/CT in Evaluating the Response of Distal Rectal Cancer to Neoadjuvant Chemoradiation Therapy
Patients with distal rectal adenocarcinoma will be submitted to an initial whole body PET/CT
prior to the preoperative chemoradiation therapy with 5-fluorouracil and 5040 cGy. Six weeks
and 12 weeks after the preoperative treatment is finished the PET/CT will be repeated. At 1
and at 2 years after preoperative treatment is concluded another PET/CT will be performed.
The colorectal surgeon evaluating the response to chemoradiation therapy will be blinded to
the results of the PET/CT, as the radiologist will be blinded to the response assessment.
PET/CT results will not be used to determine treatment strategy, unless metastatic disease
or other disease is diagnosed. Patients with a complete clinical response at 8 weeks will be
rigorously followed while patients with an incomplete clinical response at 8 weeks will be
submitted to radical surgery. PET/CT results will be compared to current radiological
studies and final pathological reports.
Allocation: Non-Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Double Blind (Investigator, Outcomes Assessor), Primary Purpose: Diagnostic
PET/CT specificity and sensitivity for tumor response
Response assesment at 6 and 8 weeks following neoadjuvant therapy
Angelita Habr-Gama, MD, PhD
University of São Paulo School of Medicine - Department of Gastroenterology
Brazil: National Committee of Ethics in Research