Detection of Aggressive Primary Prostate Cancer with ¹¹C-Choline PET/CT Using Multimodality Fusion Techniques

Abstract

The aim of the study was to assess whether 11 C-choline PET/CT could identify high-risk primary adenocarcinoma of the prostate. Methods: 11 C-choline PET/CT and transpelvic MRI were performed in 14 patients with untreated localized primary adenocarcinoma of the prostate, followed by radical prostatectomy as a form of primary monotherapy within 14 d of in vivo imaging. To allow accurate coregistration of whole-mount histology with in vivo imaging, additional ex vivo MR images of the prostatectomy specimen were obtained. Nonlinear 3-dimensional image deformations were used for registrations of PET/CT, MRI, and histology. Volumes of interest from tumor and benign tissue were defined on the basis of histology and were transferred into coregistered 11 C-choline PET/CT volumes to calculate the mean (T (mean) /B) and maximum (T (max) /B) ratio of tumor to benign prostate background. On the basis of MIB-1/Ki-67 expression in tumor tissues represented on a tissue microarray, we assessed whether 11 C-choline uptake correlated with local Gleason score and tumor proliferation. Results: Histology confirmed 42 tumor nodules with Gleason scores between 3 1 2 and 4 1 4, with volumes ranging from 0.03 to 12.6 cm 3 . T (mean) /B (P , 0.01) and T (max) /B (P , 0.001) ratios were significantly increased in highGleason score ($4 1 3) lesions versus 3 1 4 and lower disease but failed to distinguish between 3 1 4 disease versus 3 1 3 and lower. T (mean) /B and T (max) /B ratios were significantly increased in tumors with an MIB-1/Ki-67 labeling index greater than or equal to 5% (P , 0.01). Conclusion: On the basis of our preliminary data using ratios of tumor to benign prostate background, 11 C-choline preferentially identified aggressive primary prostate cancer.

11C-choline PET/MRI for Characterization of Primary High-Risk Prostate Cancer: Correlations between Positron Emission Tomography Imaging Parameters and Clinical Features

“…PET imaging parameters showed significant correlations with PSA level, and both MTV and PSA level were significant predictors of distant metastasis. However, the maximum SUV, mean SUV, MTV, and UVP did not show a correlation with the Gleason score, as previous studies indicated [9,15]. Further, we included texture-based quantification in our study to determine whether tumor metabolic heterogeneity was correlated with the Gleason score.…”

Preclinical Evaluation of 11C-Sarcosine as a Substrate of Proton-Coupled Amino Acid Transporters and First Human Application in Prostate Cancer

“…11 C-choline and 18 F-fluorocholine are widely used PET radiotracers for prostate cancer imaging (9,20), but also 11 C-methionine and 11 C-acetate PET have been successfully tested for this indication (32,33). 11 C-choline is known to be rapidly transported into human cancers, including prostate cancer.…”

“…11 C-choline and 18 F-fluorocholine are widely used PET radiopharmaceuticals for imaging of prostate cancer, particularly in the setting of prostate cancer recurrence (7). At primary staging, 11 C-choline preferentially identifies intermediateand high-risk (i.e., clinically significant) prostate cancer, whereas low-risk lesions are typically not visualized (8,9). However, choline radiotracers are limited because of commonly observed increased retention in nodular benign prostatic hyperplasia (10) as well as unsatisfactory accuracy for nodal metastatic disease in initial staging (11).…”

Prostate cancer imaging

“…Also, lesion detection by anatomical MRI increases with Gleason grade, favouring detection of more aggressive disease stages even when lesion size is small [21]. On the other hand, the metabolic signature of lesions identified by 11 C-choline PET may also have prognostic value related to cancer aggressiveness [22]. Thus one would hope that the combination of both as a single examination (without the need for image fusion) may improve clinical staging by aiding in the identification of significant disease earlier than possible with MRI or PET/CT alone.…”