Correlation of DOTATOC Uptake and Pathologic Grade in Neuroendocrine Tumors

Abstract

Objectives 68Gallium (Ga)–DOTATOC is a somatostatin analog used to detect neuroendocrine tumors (NETs). Ki-67 proliferation index (Ki-67 PI) has been established as a prognostic factor in NETs. We aimed to evaluate whether a correlation exists between Ki-67 PI and somatostatin receptor positron emission tomography (SSTR-PET) uptake. Methods We retrospectively reviewed 238 DOTATOC PET scans between 2014 and 2016. Patients were excluded if DOTATOC PET was performed more than 365 days from the date of biopsy. Maximum standardized uptake values (SUVmax) of SSTR-PET from biopsied lesions were measured and correlated with Ki-67 PI using the Pearson correlation coefficient. Results Among 110 lesions from 90 patients, DOTATOC PET had 92.7% sensitivity and 100% specificity (102 true positives, 8 false negatives) for detection of NETs. Among 63 lesions from 54 patients with Ki-67 PI available, there were 27 grade 1 lesions [median Ki-67 PI, 1.0%; interquartile range (IQR), 1.0–2.0], 30 grade 2 lesions (median, Ki-67 PI 7.5%; IQR, 5–10), and 6 grade 3 lesions (median Ki-67 PI, 30%; IQR, 26–34). There was a correlation between Ki-67 PI and SUVmax (r 2 = −0.3, P = 0.018). Conclusions Our analysis demonstrates an inverse correlation between Ki-67 PI and SUVmax in NETs. Somatostatin receptor–PET provides additional information that can help guide management of NETs.

A [68Ga]Ga-DOTANOC PET/CT Radiomic Model for Non-Invasive Prediction of Tumour Grade in Pancreatic Neuroendocrine Tumours

“…Although commonly used in clinical practise, it may be affected by the amount of image noise [ 24 ]. A correlation between SUVmax values and SSTR expression [ 4 , 5 ] was reported, but no reference values were indicated to differentiate G1 from G2 tumours. However, our results showed that SUVmax is not effective in discriminating G1 and G2 tumours.…”

“…To date, most papers have correlated the easily accessible 68Ga-DOTApeptides PET/CT maximum standardised uptake value (SUVmax) of a given lesion with its pathological grade [ 3 , 4 , 5 ]. However, the SUVmax corresponds to a single voxel measure and therefore it may not take into account potential heterogeneity of the whole lesion.…”

Digestive Well-Differentiated Grade 3 Neuroendocrine Tumors: Current Management and Future Directions

“…In Velayoudom-Céphise et al [ 6 ] and Heetfeld et al [ 3 ] studies, patients with NET G-3 showed significantly more positive SRI than those with NEC ( p = 0.03 and 0.001 respectively). In a recent work, six NET G-3 lesions showed positive 68 Ga-DOTATOC PET-CT uptake, and a negative correlation was found between Ki-67 index and SUVmax values in the whole NET population evaluated (r = −0.3; p = 0.018) [ 47 ]. Regarding 18 F-FDG PET-CT, data are even more scarce ( Table 2 ).…”

Somatostatinoma: Beyond neurofibromatosis type 1 (Review)

“…SSAs such as octreotide or lanrerotide exhibit both tumour and hormonal control (30,37). In addition to SSAs, PRRT like 177 Lu-DOTATATE may improve the poor survival while thyosine kinase inhibitors express a certain response (38). However, the current standard management is still far from optimal.…”