In 2003, Cancer Care Ontario (CCO) established a small working panel, the Diagnostic Imaging Panel, consisting of medical, radiation, and surgical oncologists; diagnostic radiologists; and methodologists, to review guidelines published during the last five years on the use of cross-sectional imaging in oncology. After examining documents from nineteen guideline developers, the panel concluded that the available guidelines did not focus on the particular issues of interest here. Therefore, the panel decided to review the primary research and develop recommendations for Ontario on the use of computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound for the initial staging, assessment of tumour response during active treatment, and follow-up for patients with six types of cancer: lymphoma, breast cancer, colorectal cancer, prostate cancer, lung cancer, and ovarian cancer. The potential utility of the different imaging technologies may vary across disease sites. The working group developing the recommendations for lung cancer agreed that the use of ultrasound in this type of cancer is limited currently and would not be considered. In contrast, bone scans are commonly used to detect metastatic disease in lung cancer and, although not within the scope of this report, may be a topic for a future report.
A systematic review of the literature identified few randomized studies to provide guidance on the use of cross-sectional imaging in the management of patients with cancer; therefore, it was decided to also include cohort studies and case series reports in the evidence review and incorporate expert opinion in the development of the recommendations. The initial selection and summary of relevant evidence was completed by methodologists at the Program in Evidence-Based Care in consultation with the clinical experts from the Diagnostic Imaging Panel.
The systematic reviews served as the evidentiary foundation to inform the deliberation of clinical experts. Formal and informal consultations with radiologists was facilitated by Dr. Anne Keller, diagnostic imaging representative of the CCO Clinical Council, and undertaken with members who participated in the provincial MRI and CT Wait Times Strategy Expert Panel and the CCO Diagnostic Imaging Panel. In addition, consultations with oncologists were undertaken, mainly through the relevant disease site groups of CCO's Program in Evidence-Based Care. The recommendations, which are presented in the format developed by the Canadian Association of Radiologists, emerged through these consultations.