3D prostate gland uptake of 18F-choline - association with overall survival in patients with hormone-naïve prostate cancer
Artikel i vetenskaplig tidskrift, 2017

Objectives: To develop a completely automated method to quantify prostate gland uptake of 18F-choline in PET/CT images and to study the relationship between this measure, clinical data and overall survival in patients with prostate cancer.
Methods: An automated method for segmentation of the prostate gland in CT images was developed using a training group of 100 patients who had undergone PET/CT scanning. The algorithms were trained based on the manual segmentations of the prostate gland in the 100 CT scans performed by a single radiologist. A multi-atlas-based method was used applied for automated segmentation of the prostate gland. Each of a subset of the training images was registered separately to the test image. By applying the resulting transformations to the manual delineations a rough segmentation of the test image was obtained. This segmentation was refined using a random-forest classifier and the final segmentation was obtained with graph cuts. Voxels in the 18F-choline PET scans having a standard uptake value (SUV) >2.65 and localized in the prostate gland in the corresponding CT scan were defined as abnormal. Automated calculation of the following five PET measurements was performed: The maximal SUV within the prostate gland - SUVmax The average SUV within the abnormal part of the prostate gland - SUVmean The volume of abnormal uptake within the prostate gland - VOL The product SUVmean x VOL defined as Total Lesion Uptake - TLU The fraction of the prostate with abnormal uptake related to the whole volume of the prostate gland - FRAC The automated quantification method was retrospectively applied to a separate test group of 46 prostate cancer patients, aged 53-94 years, who had undergone 18F-choline PET/CT. These patients have previously been selected for a study aiming to compare whole-body bone scans, 18F-choline-PET/CT and 18F-NaF PET/CT with magnetic resonance imaging. The study entry criteria were biopsy-proven prostate cancer, a positive whole-body bone scan consistent with bone metastases, and no history of androgen deprivation. The association between the automated PET measurements, age, PSA, Gleason score and overall survival was evaluated using a univariate Cox proportional hazards regression model. Kaplan-Meier estimates were used to estimate the survival difference between patients with values above and below the median value for all variables analyzed.
Results: The fraction of the prostate with abnormal uptake related to the whole volume of the prostate gland - FRAC and age were significantly associated with overall survival (Table) while PSA, Gleason score and other PET measurements were not. The patients with a FRAC above the median value (58.2%) had a significantly shorter median survival time than patients with a value below the median value (2.8 years vs. 5.5 years; p=0.04), see Figure.
Conclusion: A completely automated method of quantifying 18F-choline PET uptake in the prostate gland yielded a measure of disease extent that was significantly associated with overall survival in patients with hormone-naïve prostate cancer. The method can also be applied to PET/CT scans with other tracers such as FDG or PSMA-targeted agents. It is our hope that these preliminary data will inspire further evaluation of this type of objective quantification of PET/CT scans.

Författare

May Sadik

Sahlgrenska universitetssjukhuset

Eirini Polymeri

Sahlgrenska universitetssjukhuset

Reza Kaboteh

Sahlgrenska universitetssjukhuset

Olof Enqvist

Chalmers, Signaler och system, Signalbehandling och medicinsk teknik, Digitala bildsystem och bildanalys

Frida Fejne

Chalmers, Signaler och system, Signalbehandling och medicinsk teknik, Digitala bildsystem och bildanalys

Fredrik Kahl

Chalmers, Signaler och system, Signalbehandling och medicinsk teknik, Digitala bildsystem och bildanalys

Mattias Ohlsson

Lunds universitet

Elin Trägårdh

Skånes universitetssjukhus (SUS)

Jane Angel Simonsen

Odense Universitetshospital

Mads Poulsen

Odense Universitetshospital

Poul Flemming Høilund-Carlsen

Odense Universitetshospital

Lars Edenbrandt

Sahlgrenska universitetssjukhuset

Journal of Nuclear Medicine

0161-5505 (ISSN)

Vol. 58 supplement 1 544-

Ämneskategorier

Radiologi och bildbehandling

Medicinsk bildbehandling

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Senast uppdaterat

2022-04-04