Diagnostic accuracy of 11C-methionine PET in detecting neuropathologically confirmed recurrent brain tumor after radiation therapy

• Published in: Annals of nuclear medicine Vol. 32; no. 2; pp. 132 - 141
• Main Authors: Kits, Annika, Martin, Heather, Sanchez-Crespo, Alejandro, Delgado, Anna F.
• Format: Journal Article
• Language: English
• Published: Tokyo Springer Japan 01.02.2018; Springer Nature B.V
• Subjects: Brain; Brain cancer; Brain tumors; Cortex (frontal); Diagnostic systems; Imaging; Injuries; Injury analysis; Mastectomy; Medical diagnosis; Medicin och hälsovetenskap; Medicine; Medicine & Public Health; Meningioma; Metastases; Methionine; Nuclear Medicine; Original Article; Patients; Positron emission; Positron emission tomography; Radiation; Radiation effects; Radiation injuries; Radiation therapy; Radiology; Sensitivity; Thermal analysis; Tomography; Tumors; Radiation injury; C-methionine PET; Gamma-knife surgery; Brain tumor recurrence; Radiosurgery
• ISSN: 0914-7187; 1864-6433; 1864-6433
• DOI: 10.1007/s12149-017-1227-7

Objective This study aims to determine the diagnostic test accuracy (DTA) of 11 C-methionine (MET) PET in the discrimination between recurrent tumor and radiation-induced injury in neuropathologically confirmed cases. Methods A retrospective cohort of 30 patients with previously irradiated intracranial tumors (23 gliomas, 6 metastases, and 1 meningioma) was included. All patients underwent a preoperative MET PET and postoperative neuropathological analysis. Maximum and mean standardized uptake values (SUV) were obtained in the lesion, in the contralateral mirror region, and in the contralateral frontal cortex. Lesion-to-background SUV ratios (SUR mirror and SUR cortex) were then calculated. The Mann–Whitney U test was used to evaluate differences in SUV ratios between confirmed recurrent tumor and radiation injury. DTA was determined through receiver operating characteristic (ROC) analysis. Results Twenty-one patients had recurrent tumor and nine had radiation injury. The area under the ROC curve (AUC) was 0.89 for SUR max mirror and 0.88 for SUR max cortex. The mean (SD) of SUR max mirror was 2.37 (0.58) in tumor recurrence and 1.57 (0.40) in radiation necrosis ( P  ≤ 0.001). The corresponding values for SUR max cortex were 2.13 (0.50) and 1.45 (0.37) ( P  = 0.001). Clinically relevant cutoffs were SUR max mirror ≥ 1.99 giving a specificity of 100% for tumor recurrence with a sensitivity of 76% and SUR max cortex ≥ 1.58 giving a sensitivity and specificity of 90 and 78%, respectively. Conclusions Based on neuropathologically confirmed cases, the DTA of SUR max mirror and SUR max cortex from 11 C-methionine PET was high when discriminating recurrent tumor from radiation injury.