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

The objective of this study was to assess the inappropriateness rate of oncological follow-up CT examinations. 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 inappropriateness and clinical variables was investigated and variables influencing inappropriateness were analyzed through a binary logistic regression. 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 assessment (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). 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.