Comparison between PSMA PET/CT and MRI for Characterizing Hepatocellular carcinoma: A Real-World Study

Abstract

Prostate specific membrane antigen (PSMA) is expressed by hepatocellular carcinoma (HCC). PSMA PET/CT has potential as an imaging agent for the detection of HCC including early diagnosis and monitoring for recurrence following surgical resection. This study aims to compare PSMA PET to standard surveillance imaging in the detection of HCC. Patients with suspected or treated HCC were prospectively recruited from a tertiary hospital outpatient clinic. In addition to routine surveillance imaging as recommended by the multidisciplinary team, a PSMA PET/CT was performed. Imaging and clinical characteristics were compared over a follow-up period of up to 12 months. In a cohort of 19 patients with known HCC or suspected recurrent HCC, PSMA PET/CT had similar efficacy to MRI for the detection of HCC, with a sensitivity of 91% and a specificity of 70% and sensitivity of 87% and a specificity of 73% for PSMA PET/CT and MRI, respectively. PSMA PET/CT had a higher negative predictive value of 90%. In this relatively large single centre study, PSMA is shown to have promising equivalence in performance and its role should be further evaluated in multi-centre prospective trials.

Keywords: Hepatocellular carcinoma; PSMA PET/CT; liver.

Figure 1

Interquartile SUVmax ranges for lesions considered suspicious based on PSMA, compared with average normal liver SUVmax. The blue dots are outliers.

Figure 2

Representative imaging of a lesion suspicious for recurrence and metastatic spread of HCC on PSMA PET. Case details: 58-year-old male of Asian ethnicity with previous resection of HCC in 2019. (A) low dose CT, (B) fused PET PSMA and low does CT, (C) PSMA PET, (D) contrast-enhanced CT, (E) MIP PSMA PET image. There is a hypodense fluid attenuation area within the right liver adjacent to surgical clips representing a known seroma/biloma. Ultrasound guided biopsy of the PSMA avid lesion in hepatic segment 7 confirmed HCC. The patient was commenced on lenvatanib therapy with PSMA avid-likely bony metastatic disease in the right proximal humerus, T5 vertebral body and left 3rd rib anterolaterally. The liver lesion was non-enhancing on contrast-enhanced CT.