Is diagnostic review of radiotherapy-planning CT scans important in the conformal therapy era?

OBJECTIVE. Detailed CT scans are often acquired during the radiotherapy pla nning process. This study was performed to determine the incidence of impor tant benign and cancer-related CT findings on these scans. SUBJECTS AND METHODS. From December 1998 to December 2000, 162 radiotherapy patients who were to be treated curatively underwent treatment planning CT scans on a helical scanner in the radiology department at Washington Hospi tal, Fremont, CA. Ali CT scans were prospectively interpreted relative to d iagnoses, and reports were dictated for the medical records. The diagnostic reports and records on all patients were reviewed to determine the inciden ce of previously unknown benign or cancer-related findings, the impacts of such findings on treatment, and the need for additional radiologic studies or procedures on the basis of the CT interpretations. RESULTS. Incidental benign findings were noted for 32 patients (20%). Poten tially important benign findings were noted fox three patients: two with an eurysms and one with a possible deep vein thrombosis. Potentially cancer-re lated findings were reported in 20 patients: a single liver lesion (four pa tients), multiple liver lesions (two patients), possible or probable lympha denopathy (I I patients), abnormal soft tissue (one patient), a small-bowel obstruction (one patient), and a breast mass (one patient). After reviewin g prior diagnostic studies and obtaining additional recommended studies, th e physicians found that only three of the previously unknown findings requi red further investigation: two aneurysms, which did not require near-term t reatment, and one metastatic neck node. CONCLUSION. Routine diagnostic interpretation of radiotherapy planning scan s resulted in few important medical findings and changed patient care for l ess than 1 % of the patients.