Spine metastases in prostate cancer: comparison of technetium-99m-MDP whole-body bone scintigraphy, [¹⁸F]choline positron emission tomography(PET)/computed tomography (CT) and [¹⁸F]NaF PET/CT

Abstract

Objective

To compare the diagnostic accuracy of the following imaging techniques in the detection of spine metastases, using magnetic resonance imaging (MRI) as a reference: whole-body bone scintigraphy (WBS) with technetium-99m-MDP, [18F]-sodium fluoride (NaF) positron emission tomography (PET)/computed tomography (CT) and [¹⁸F]-fluoromethylcholine (FCH) PET/CT.

Patients and Methods

The study entry criteria were biopsy-proven prostate cancer, a positive WBS consistent with bone metastases, and no history of androgen deprivation. Within 30 days of informed consent, trial scans were performed in random order. Scans were interpreted blindly for the purpose of a lesion-based analysis. The primary target variable was bone lesion (malignant/benign) and the ‘gold standard’ was MRI.

Results

A total of 50 men were recruited between May 2009 and March 2012. Their mean age was 73 years, their median PSA level was 84 ng/mL, and the mean Gleason score of the tumours was 7.7. A total of 46 patients underwent all four scans, while four missed one PET/CT scan. A total of 526 bone lesions were found in the 50 men: 363 malignant and 163 non-malignant according to MRI. Sensitivity, specificity, positive and negative predictive values and accuracy were: WBS: 51, 82, 86, 43 and 61%; NaF-PET/CT: 93, 54, 82, 78 and 81%; and FCH-PET/CT: 85, 91, 95, 75 and 87%, respectively.

Conclusions

We found that FCH-PET/CT and NaF-PET/CT were superior to WBS with regard to detection of prostate cancer bone metastases within the spine. The present results call into question the use of WBS as the method of choice in patients with hormone-naïve prostate cancer.