Looking for appropriateness in follow-up CT of oncologic patients: Results from a cross-sectional study

Purpose: The objective of this study was to assess the inappropriateness rate of oncological follow-up CT examinations. Methods: Out of 7.000 oncology patients referred for follow-up CT examinations between March and October 2022, a random sample of 10 % was included. Radiology residents assessed the appropriateness using the Italian Society of Medical Oncology (AIOM) guidelines, supervised by senior radiologists. Association between inap-propriateness and clinical variables was investigated and variables influencing inappropriateness were analyzed through a binary logistic regression. Results: Three-hundred-eighty-eight examinations (56.1 %) were consistent with AIOM guidelines. An additional 100 (14.5 %) examinations did not follow the recommended schedule but were nevertheless considered appropriate because of suspected recurrence/progression (10.7 %) or adverse event requiring imaging assess-ment (3.8 %). Two-hundred-four (29.4 %) examinations were rated as inappropriate. Inappropriateness causes were as follows: CT not included in the relevant guideline (n = 47); CT extended to additional anatomical regions (n = 59); CT requested at a shorter time-interval (n = 98). No statistically significant difference was found in age, sex, scan region, and primary cancer between appropriate and inappropriate examinations. The only variable significantly associated with inappropriateness was being referred by a specific hospital unit named "unit 2" in the study (p = 0.009), which was demonstrated to be the only appropriateness independent predictor (OR 1.952). Conclusion: This study shows that majority of oncological patients referred for follow-up CT follows standard guidelines. However, a non-negligible proportion was rated as inappropriate, mainly due to the shorter time -interval. No clinical variable was associated with inappropriateness, except for referral by a specific hospital unit.