ECE2021 Audio Eposter Presentations Late Breaking (114 abstracts)
1Changi General Hospital, Singapore, Singapore; 2Mount Elizabeth Novena Hospital, Singapore, Singapore; 3Singapore General Hospital, Singapore, Singapore; 4National University Hospital, Singapore, Singapore; 5Tan Tock Seng Hospital, Singapore, Singapore; 6Ng Teng Fong General Hospital, Singapore, Singapore; 7Khoo Teck Puat Hospital, Singapore, Singapore; 8Sengkang General Hospital, Singapore, Singapore; 9National University of Singapore, Singapore, Singapore
Introduction
Unilateral PA can be cured with unilateral adrenalectomy. Adrenal vein sampling (AVS) is the current reference test to identify unilateral PA, but it is invasive and technically-difficult. 11C-metomidate PET-CT offers a non-invasive alternative to AVS. We compared the accuracy of AVS and PET-CT in identifying patients with unilateral surgically-curable PA.
Methods
In this prospective multi-centre clinical trial, patients with confirmed PA underwent both AVS and 11C-metomidate PET-CT. All results were reviewed at a multi-disciplinary meeting to decide on the final diagnosis and treatment. Primary outcome was the accuracy of each diagnostic test compared to biochemical cure of PA post-surgery as defined by Primary Aldosteronism Surgery Outcomes (PASO) criteria. Secondary outcome was the accuracy of each diagnostic test compared to the final diagnosis (ClinicalTrials.gov: NCT03990701).
Results
25 patients were recruited, and all patients had a successful AVS procedure, and 11C-metomidate PET-CT. Final diagnosis was unilateral in 22 patients, bilateral in two patients, and indeterminate in one patient due to discordant lateralization on AVS and PET-CT. 20 of 22 patients with unilateral PA underwent surgery, and all were biochemically cured six months post-surgery. For the primary outcome, sensitivity of AVS was 15/20 (75%), and PET-CT was 16/20 (80%). For the secondary outcome, the sensitivity and specificity of AVS was 15/22 (68.2%) and 2/2 (100%), and PET-CT was 18/22 (81.9%) and 2/2 (100%), respectively. Six patients had PET lateralization without AVS lateralization, of which four patients had AVS lateralization ratios between 2.83.5, while two had bilateral low aldosterone levels on AVS. Three patients had AVS lateralization without PET lateralization. There were no differences in clinical outcomes (blood pressure) using PASO criteria between patients identified on PET-CT and those with AVS. Patients with higher PET lateralization ratios also had higher AVS lateralization ratios, and higher peripheral aldosterone levels during AVS, but similar aldosterone and cortisol levels during PET-CT, compared to those with lower PET lateralization ratios.
Conclusion
11C-metomidate PET-CT performs comparably with AVS in identifying unilateral PA and can also identify patients not currently detected with AVS. Being non-invasive and non-operator dependent, it may allow identification of more patients with unilateral surgically-curable PA.