MRI‐based nomogram estimates the risk of recurrence of primary nonmetastatic pancreatic neuroendocrine tumors after curative resection

Abstract

Background Accurate estimation of the recurrence of pancreatic neuroendocrine tumors help with prognosis, guide follow‐up, and avoid futile treatments. Purpose To investigate whether MRI features could preoperatively estimate the recurrence of pancreatic neuroendocrine tumors (PNETs) and to refine a novel prognostic model through developing a nomogram incorporating various MRI features. Study Type Retrospective. Population In all, 81 patients with clinicopathologically confirmed nonmetastatic PNETs. Field Strength/Sequences 1.5 T MR, including T1‐weighted, T2‐weighted, and diffusion‐weighted imaging sequences. Assessment Qualitative and quantitative MRI features of PNET were assessed by three experienced radiologists. Statistical Tests Uni‐ and multivariable analyses for recurrence‐free survival (RFS) were evaluated using a Cox proportional hazards model. The MRI‐based nomogram was then designed based on multivariable logistic analysis in our study and the performance of the nomogram was validated according to C‐index, calibration, and decision curve analyses. Results MRI features, including tumor size (hazard ratio [HR]: 14.131; P = 0.034), enhancement pattern (HR: 21.821, P = 0.032), and the apparent diffusion coefficient (ADC) values (HR: 0.055, P = 0.038) were significant independent predictors of RFS at multivariable analysis. The performance of the nomogram incorporating various MRI features (with a C‐index of 0.910) was improved compared with that based on tumor size, enhancement pattern, and ADC alone (with C‐index values of 0.672, 0.851, and 0.809, respectively). The calibration curve of the nomogram exhibited perfect consistency between estimation and observation at 0.5, 1, and 2 years after surgery. The decision curve showed that a nomogram incorporating three features had more favorable clinical predictive usefulness than any single feature. Data Conclusion MRI features can be considered effective recurrence predictors for PNETs after surgery. The preliminary nomogram incorporating various MRI features could assess the risk of recurrence in PNETs and may be used to optimize individual treatment strategies. Level of Evidence: 4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:397–409.

Imaging of Pancreatic Neuroendocrine Neoplasms

“…A large meta-analysis showed a pooled sensitivity and specificity for ADC in distinguishing G3 from G1/G2 of 0.93 (95% CI, 0.66-0.99) and 0.92 (95% CI, 0.86-0.95), respectively [83]. Moreover, tumor size, enhancement pattern and ADC value are independent prognostic factors for recurrence after curative resection of panNENs [84]. Some studies showed that SUV max values on 68 Ga-DOTATATE seem to have an inverse relationship with Ki-67.…”

Preoperative prediction of lymph node metastasis in nonfunctioning pancreatic neuroendocrine tumors from clinical and MRI features: a multicenter study

“…However, these variables are mainly based on postoperative pathological results. As a noninvasive imaging modality, magnetic resonance imaging (MRI) plays a crucial role in detecting and staging PNETs as well as evaluating biological behavior of the tumors [16][17][18][19]. Anatomic and functional parameters of MRI have been used as predictors for tumor grade, recurrence, and outcomes after surgery [20][21][22].…”

The prognostic nomogram including MRI for locally advanced prostate cancer treated by radical prostatectomy

“…Multiparametric magnetic resonance imaging (mp-MRI) is widely used in PCa patients before surgery as a noninvasive imaging modality, which have shown effective as a recurrence predictor in many kinds of solid tumor after surgery included PCa. [9][10][11] However, it has not been applied to predict the clinical outcomes of LAPC patients treated by surgery. Therefore, the aim of our study was to find out prognostic factors related to BCR and clarify the nomogram including MRI in estimating the biochemical progression-free survival (bPFS) in LAPC patients.…”

“…Multiparametric magnetic resonance imaging (mp‐MRI) is widely used in PCa patients before surgery as a noninvasive imaging modality, which have shown effective as a recurrence predictor in many kinds of solid tumor after surgery included PCa 9–11 . However, it has not been applied to predict the clinical outcomes of LAPC patients treated by surgery.…”