Clinical value of 18F-FDG PET/CT imaging for detecting immune related adverse events of the combined immunotherapy in hepatobiliary carcinoma / 中华核医学与分子影像杂志

ABSTRACT

Objective:To investigate the capability of 18F-FDG PET/CT imaging in monitoring combined immunotherapy response and detecting immune related adverse events (irAEs) in patients with advanced hepatobiliary carcinoma. Methods:From August 2018 to July 2019, 21 patients (14 males, 7 females, age (58.5±10.0) years) with advanced hepatobiliary carcinoma routinely underwent 66 18F-FDG PET/CT examinations in Peking Union Medical College Hospital. SUV max, the occurrence time and symptoms of irAEs were obtained and analyzed. Therapy response (complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), progressive metabolic disease (PMD)) was evaluated according to PET response criteria in solid tumors (PERCIST). Results:(1) Clinical results. Twenty-two irAEs occurred in 16 patients, while were not found in 5 patients. Six organs were involved, including thyroiditis(8), colitis(5), pneumonitis(4), rash(2), hepatitis(2), myositis and fasciitis(1). The appearance time of each irAEs were (103.0±58.0), (141.6±103.5), 34.0(6.0, 308.8), 9 and 117, 62 and 67, and 87 d after therapy, respectively. PET/CT detected all pneumonitis and myositis and fasciitis, but no rash and hepatitis were found. For colitis and thyroiditis, PET/CT detected 4 and 6 times respectively. (2) PET/CT signs of irAEs. Except thyroiditis, all irAEs lesions exhibited exudative changes in CT and high-avidity in PET. SUV max of the lesions were 9.0(7.9, 17.6) (colitis), 7.1±3.2 (thyroiditis), 5.3 and 8.6 (pneumonitis), 4.1 (myositis and fasciitis), respectively. (3) Therapy assessment. Among 21 patients, there were 7 for PMR, 9 for SMD, 5 for PMD, which were 7, 8, 1 in patients with irAEs and 0, 1, 4 in patients without irAEs. Conclusions:Patients with advanced hepatobiliary carcinoma can benefit from combined immunotherapy. 18F-FDG PET/CT can be used to evaluate the efficacy of immunotherapy by detecting the changes of tumor lesions and the occurrence of irAEs simultaneously. However, it is necessary to use CT to distinguish tumor progression from irAEs.