PT - JOURNAL ARTICLE AU - Yasuo Iwadate AU - Natsuki Shinozaki AU - Tomoo Matsutani AU - Yoshio Uchino AU - Naokatsu Saeki TI - Molecular imaging of 1p/19q deletion in oligodendroglial tumours with <sup>11</sup>C-methionine positron emission tomography AID - 10.1136/jnnp-2015-311516 DP - 2016 Sep 01 TA - Journal of Neurology, Neurosurgery &amp; Psychiatry PG - 1016--1021 VI - 87 IP - 9 4099 - http://jnnp.bmj.com/content/87/9/1016.short 4100 - http://jnnp.bmj.com/content/87/9/1016.full SO - J Neurol Neurosurg Psychiatry2016 Sep 01; 87 AB - Objective Chromosome 1p/19q deletion is an established prognostic and predictive marker in the WHO grade III oligodendroglial tumours (OT). To estimate the genetic status preoperatively, the authors investigated the correlation between the uptake of 11C-methionine in positron emission tomography (PET) and the 1p/19q status in grades II and III OT.Methods We retrospectively reviewed 144 patients with gliomas who received 11C-methionine PET. 66 cases with grades II–III oligodendrogliomas or oligoastrocytomas underwent fluorescence in situ hybridisation to determine the 1p/19q status. The tissue uptake of 11C-methionine was expressed as the ratio of the maximum standardised uptake value (SUVmax) in tumour areas to the mean SUV (SUVmean) in the contralateral normal brain (tumour-to-normal tissue (T/N) ratio).Results The T/N ratio in 11C-methionine PET was significantly higher in grade III OT than in grade II tumours. The mean T/N ratio of the grade II tumours without 1p/19q deletion was significantly higher than that of the grade II tumours with 1p/19q deletion (mean 2.67 vs 1.94, respectively; p=0.0457). In grade III tumours, the mean T/N ratio of the tumours without 1p/19q deletion was also significantly higher than that of the tumours with 1p/19q deletion (mean 4.83 vs 3.49, respectively; p=0.0261). The rate of IDH1 mutation was lower and the rate of contrast enhancement on MRIs was higher in the 1p/19q non-deleted OT than those with 1p/19q deletion, which may contribute to the high T/N ratio.Conclusions Among suspected OT, 11C-methionine PET may help us preoperatively discriminate tumours with and without 1p/19q deletion.