Magnetic resonance spectroscopy imaging-directed transrectal ultrasound biopsy increases prostate cancer detection in men with prostate-specific antigen between 4-10 ng/mL and normal digital rectal examination

Objectives: To evaluate the ability of magnetic resonance spectroscopic imaging to improve prostate cancer detection rate. Methods: A retrospective analysis was carried out of 278 men with prostate-specific antigen in the range of 4–10 ng/mL and normal digital rectal examination who underwent transrectal ultrasound-guided prostate biopsy. Outcomes were compared between men who had a standard biopsy versus those who also underwent a prebiopsy magnetic resonance spectroscopic imaging. Men with an abnormal voxel on magnetic resonance spectroscopic imaging had standard transrectal ultrasound biopsies plus biopsies directed to the abnormal voxels. Results: The study group (n = 140) and control group (n = 138) were similar in baseline parameters, such as mean age, prostate size and mean prostate-specific antigen. The overall cancer detection in the magnetic resonance spectroscopic imaging positive group (24.4%) was more than double that of the control group (10.1%). On comparing the magnetic resonance spectroscopic imaging results with the transrectal ultrasound biopsy findings, magnetic resonance spectroscopic imaging had 95.6% sensitivity, 41.9% specificity, a positive predictive value of 24.4%, a negative predictive value of 98% and an accuracy of 51.4%. Conclusions: Magnetic resonance spectroscopic imaging-directed transrectal ultrasound biopsy increases the cancer detection rate compared with standard transrectal ultrasound biopsy in patients with normal digital rectal examination and elevated prostate-specific antigen in the range of 4–10 ng/mL

Potential of diffusion weighted imaging (DWI) in the characterization of malignant, benign and healthy breast tissues and molecular subtypes of breast cancer

The role of apparent diffusion coefficient (ADC) in the diagnosis of breast cancer and its association with molecular biomarkers was investigated in 259 patients with breast cancer, 67 with benign pathology and 54 healthy volunteers using diffusion-weighted imaging (DWI) at 1.5 T. In 59 breast cancer patients, dynamic contrast enhanced MRI (DCEMRI) was also acquired. Mean ADC of malignant lesions was significantly lower (1.02 ± 0.17 x 10-3 mm2/s) compared to benign (1.57 ± 0.26 x 10-3 mm2/s) and healthy (1.78 ± 0.13 x 10-3 mm2/s) breast tissues. A cut-off ADC value of 1.23 x 10-3 mm2/s (sensitivity 92.5%; specificity 91.1%; AUC 0.96) to differentiate malignant from benign diseases was arrived by ROC analysis. In 10/59 breast cancer patients, indeterminate DCE curve was seen while their ADC value showed as positive for malignancy implying the potential of the addition of DWI in increasing the specificity of DCEMRI data. Further, the association of ADC with the tumor volume, stage, hormonal receptors [estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor (HER2)] and menopausal status was investigated. A significant difference was seen in tumor volume between breast cancer patients of stages IIA and IIIA; IIB and IIIA; and IIB and III (B + C) (p<0.05). A statistically significant lower ADC and a lower tumor volume was seen in patients with early (n=52) compared to those with locally advanced breast cancer (n=207). No association was found in ADC and tumor volume with the menopausal status. Breast cancers with ER-, PR- and triple negative (TN) status showed a significantly larger tumor volume compared to ER+, PR+ and non-triple negative (nTN) cancers, respectively. Also, TN cancers showed a significantly higher ADC compared to ER+, PR+ and nTN cancers. Patients with ER- and TN cancers were of younger age compared to those with ER+ and nTN cancers. The present study demonstrated that ADC may increase the diagnostic specificity of DCEMRI and aid in treatment management in a clinical setting. Additionally, it provides an insight into characterization of molecular types of breast cancer and may serve as an indicator of metabolic reprogramming underlying tumor proliferation