PB2259 SIGNIFICANCE OF INCIDENTAL FINDINGS DETECTED ON PET‐CT SCANS PERFORMED IN HAEMATO‐ONCOLOGY: A SINGLE CENTRE EXPERIENCE

Background: PET‐CTs scans are commonly used in haematological malignancies to stage disease and assess response to therapy. It is not uncommon for PET‐CT to reveal incidental findings, the significance of which is unclear. Aims: This study aimed to determine how common incidental findings are in patients with haematological malignancies, and assess the outcome of the investigations into these findings. Methods: Reports from 212 patients who had a PET‐CT scan reviewed at the departmental haematology‐radiology meeting of the Beatson Oncology Centre, Glasgow, Scotland between May 2015 and May 2018 were reviewed retrospectively. All scans were undertaken at the same site, the West of Scotland PET Centre. For each incidental finding, follow up, diagnosis and outcome was then reviewed. 57% (n = 121) of patients were male and the median age was 57 years. The majority of patients (93%, n = 196) underwent the PET‐CT scan due to underlying lymphoma, 122 (43%) of these were Non‐Hodgkin and 74 (35%) with Hodgkin lymphoma,16 of the patients had underlying myeloma or other suspected malignancies. Results: The study found that 13% (n = 28) of patients that underwent PET‐CT scanning had an incidental finding. The majority of these findings (82%, n = 23) were investigated further. No significant abnormal finding was revealed through further investigation for 43% (n = 10). A pathological finding was found in 57% (n = 13) of scans. Of these 69% (n = 9) had a pre‐malignant or malignant diagnosis: 2 adenocarcinomas and 4 precancerous polyps in the colon and 3 Thy3a in the thyroid. The remaining 4 were benign pathologies including gastric reflux, benign adenomas and a fistula. The incidental findings were in a variety of anatomical sites, the most common being the colon (n = 15 findings), followed by the thyroid (n = 4). Regarding outcome patients with pre‐malignant polyps and adenocarcinomas underwent complete surgical excision, with no disease remaining post operatively. No patient had evidence of progression / relapse of the incidental finding at time of follow up. Summary/Conclusion: Incidental findings on PET‐CT were shown to occur commonly in patients with haematological malignancies. Follow up of these incidental findings is indicated, and appropriate, as it often results in the diagnosis of a treatable, pathological condition. Further investigation in patients with haematological malignancy is particularly important in view of the potential high survival rate from the underlying haematological cancer.