"Patients received too much radiation dose from CT exams during their postoperative follow-up period, usually five years," noted Dr. Seung Ho Kim, PhD, from Haeundae Paik Hospital and Inje University College of Medicine in Busan. "According to a recent study, the cumulative radiation dose was over 60 mSv in cases of stomach cancer."
The current study examined 79 consecutive patients who had undergone surgical resection for stomach cancer. They had undergone standard-dose CT follow-up every six months, but the last study was acquired at half the normal dose (120 kVp, 100 mAs). Several sets of images were reconstructed separately using ASIR blending (0%, 30%, 50%, and 70%) and were reviewed by two radiologists for noise, sharpness, artifact, and acceptability. The best images used 30% or 50% ASIR blending.
"Half-dose CT scans can be applied to the oncology field, particularly to postoperative follow-up CT of gastrointestinal malignancy such as colorectal cancer," Kim said.