One Versus Up-to-5 Lesion Measurements for Response Assessment by PERCIST in Patients with Lung Cancer

• Published in: Nuclear medicine and molecular imaging Vol. 55; no. 3; pp. 123 - 129
• Main Authors: Kwon, Soo Jin, O, Joo Hyun, Yoo, Ie Ryung
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01.06.2021; Springer Nature B.V; 대한핵의학회
• Subjects: Cardiology; Classification; Computed tomography; Correlation coefficients; Emission analysis; Fluorine; Fluorine isotopes; Imaging; Lesions; Lung cancer; Medicine; Medicine & Public Health; Metabolic disorders; Nuclear Medicine; Oncology; Original; Original Article; Orthopedics; Outliers (statistics); Positron emission; Radiology; Tomography; 방사선과학; Response assessment; Lung cancer; PET/CT; PERCIST
• ISSN: 1869-3474; 1869-3482
• DOI: 10.1007/s13139-021-00697-4

Purpose The optimal number of lesions to measure for response assessment from fluorine-18 fluorodeoxyglucose ( 18 F-FDG) positron emission tomography (PET)/computed tomography (CT) is not validated for lung cancer. We compared 1 lesion and up-to-5 lesion measurements for response assessment in lung cancer per PET Response Criteria in Solid Tumors (PERCIST). Methods Patients with lung cancer with pre- and post-treatment PET/CT images were included. The standard uptake value corrected for lean body mass (SUL peak ) of up-to-5 hottest target lesions was measured at each time point. The percent changes of SUL peak of the single hottest lesion and the sum of up-to-5 hottest lesions were computed. Pearson correlation coefficient evaluated the strength of association between the percent changes of SUL peak values from the 1 lesion and up-to-5 lesion analyses. Response categories were complete metabolic response (CMR) with no perceptible lesion; partial metabolic response (PMR), stable metabolic disease (SMD), or progressive metabolic disease (PMD) using the threshold of 30% and 0.8 unit change in SUL peak ; and unequivocal new lesion meant PMD. The concordance for response categorization was assessed by kappa statistics. Results A total of 40 patients (25 non-small cell lung cancer; 15 small cell lung cancer) were analyzed, all with 18 F-FDG-avid lung cancer. Average of 3 target lesions were measured for up-to-5 lesion analysis. Pearson’s r was 0.74 ( P  < 0.001) and increased to 0.96 ( P  < 0.001) when two outliers were excluded. Response categorization with 1 lesion and up-to-5 lesion analyses was concordant in 37 patients (92.5%, weighted kappa = 0.89). Conclusion Analyzing 1 lesion and up-to-5 lesions for response assessment by PERCIST showed high concordance in patients with lung cancer.