Dynamic contrast-enhanced MRI for prostate cancer localization

Abstract

Radiotherapy dose escalation improves tumour control in prostate cancer but with increased toxicity. Boosting focal tumour only may allow dose escalation with acceptable toxicity. Intensity-modulated radiotherapy can deliver this, but visualization of the tumour remains limiting. CT or conventional MRI techniques are poor at localizing tumour, but dynamic contrast-enhanced MRI (DCE-MRI) may be superior. 18 patients with prostate cancer had T(2) weighted (T2W) and DCE-MRI prior to prostatectomy. The prostate was sectioned meticulously so as to achieve accurate correlation between imaging and pathology. The accuracy of DCE-MRI for cancer detection was calculated by a pixel-by-pixel correlation of quantitative DCE-MRI parameter maps and pathology. In addition, a radiologist interpreted the DCE-MRI and T2W images. The location of tumour on imaging was compared with histology, and the accuracy of DCE-MRI and T2W images was then compared. Pixel-by-pixel comparison of quantitative parameter maps showed a significant difference between the benign peripheral zone and tumour for the parameters K(trans), v(e) and k(ep). Calculation of areas under the receiver operating characteristic curve showed that the pharmacokinetic parameters were only "fair" discriminators between cancer and benign gland. Interpretation of DCE-MRI and T2W images by a radiologist showed DCE-MRI to be more sensitive than T2W images for tumour localization (50% vs 21%; p = 0.006) and similarly specific (85% vs 81%; p = 0.593). The superior sensitivity of DCE-MRI compared with T2W images, together with its high specificity, is arguably sufficient for its use in guiding radiotherapy boosts in prostate cancer.

A Giant Thoracic Duct Cyst as the Cause of Abdomen Pain: A Case Report and Review of the Literature

“…29) Also Zätterstrom et al followed a 55 year old male with cervical cystic dilatation and widened intrathoracic duct for 25 years without intervention. 15) In both of these cases the cysts underwent remission. Therefore while symptomatic lesions should be resected, it is better to simply follow up in asymptomatic patients with confirmed diagnosis over time.…”

Practical aspects of prostate MRI: hardware and software considerations, protocols, and patient preparation

“…DCE takes advantage of the unique characteristics associated with the abnormal tumor vasculature to assess aggressiveness of the disease. The usefulness of DCE in detecting, localizing, and staging prostate cancer is well documented in literature [58,[86][87][88][89][90]. Additionally, several studies have reported promising findings on the utility of DCE parameters in discriminating prostate cancer based on aggressiveness of the disease [91,92].…”

“…The final approach to analyzing DCE images aims to estimate physiologically interpretable, kinetic parameters by fitting pharmacokinetic models to the enhancement curves [88,113,114]. The most common is the two-compartment model.…”

MRI in Diagnosis of Prostate Carcinoma

“…Research found that, for one radiologist using a commercial software, DCE-MRI resulted in superior tumour localization compared with T2W scans. They have demonstrated that tumours appear to have different enhancement property to benign peripheral zone and according to ROC analysis, this may results in a diagnostic test which would be considered of fairly discriminatory value by conventionally accepted criteria (17) . Sung Y.S et al studied the importance of computer-aided diagnosis for prostate carcinoma detection on dynamic contrast-enhanced MRI (DCE-MRI).…”