The management of resectable rectal cancer continues to be guided by clinical trials and advances in technique. Although surgical advances including total mesorectal excision continue to decrease rates of local recurrence, the management of locally advanced disease (T3-T4 or N+) benefits from a multimodality approach including neoadjuvant concomitant chemotherapy and radiation. Circumferential resection margin, which can be determined preoperatively via MRI, is prognostic. Toxicity associated with radiation therapy is decreased by placing the patient in the prone position on a belly board, however for patients who cannot tolerate prone positioning, IMRT decreases the volume of normal tissue irradiated. The use of IMRT requires knowledge of the patterns of spreads and anatomy. Clinical trials demonstrate high variability in target delineation without specific guidance demonstrating the need for peer review and the use of a consensus atlas. Concomitant with radiation, fluorouracil based chemotherapy remains the standard, and although toxicity is decreased with continuous infusion fluorouracil, oral capecitabine is non-inferior to the continuous infusion regimen. Additional chemotherapeutic agents, including oxaliplatin, continue to be investigated, however currently should only be utilized on clinical trials as increased toxicity and no definitive benefit has been demonstrated in clinical trials.
The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every two years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.
Oncology | Radiology
Jones et al. Radiation Oncology 2012, 7:161