Diffusion-weighted magnetic resonance imaging in management of bladder cancer, particularly with multimodal bladder-sparing strategy

Bladder-sparing strategy for muscle-invasive bladdercancer(MIBC) is increasingly demanded instead ofradical cystectomy plus urinary diversion. Multimodaltherapeutic approaches consisting of transurethralresection, chemotherapy, radiotherapy and/or partialcystectomy improve patients' quality of life by preserv-ing their native bladder and sexual function withoutcompromising oncological outcomes. Because a favor-able response to chemoradiotherapy(CRT) is a prereq-uisite for successful bladder preservation, predictingand monitoring therapeutic response is an essentialpart of this approach. Diffusion-weighted magneticresonance imaging(DW-MRI) is a functional imagingtechnique increasingly applied to various types of can-cers. Contrast in this imaging technique derives fromdifferences in the motion of water molecules among tissues and this information is useful in assessing the biological behavior of cancers. Promising results in pre-dicting and monitoring the response to CRT have been reported in several types of cancers. Recently, growing evidence has emerged showing that DW-MRI can serve as an imaging biomarker in the management of blad-der cancer. The qualitative analysis of DW-MRI can be applied to detecting cancerous lesion and monitoring the response to CRT. Furthermore, the potential role of quantitative analysis by evaluating apparent diffu-sion coefficient values has been shown in character-izing bladder cancer for biological aggressiveness and sensitivity to CRT. DW-MRI is a potentially useful tool for the management of bladder cancer, particularly in multimodal bladder-sparing approaches for MIBC.

A novel equation and nomogram including body weight for estimating prostate volumes in men with biopsy-proven benign prostatic hyperplasia

Anthropometric measurements, e.g., body weight （BW）, body mass index （BMI）, as well as serum prostate-specific antigen （PSA） and percent-free PSA （%fPSA） have been shown to have positive correlations with total prostate volume （TPV）. We developed an equation and nomogram for estimating TPV, incorporating these predictors in men with benign prostatic hyperplasia （BPH）. A total of 1852 men, including 1113 at Tokyo Medical and Dental University （TMDU） Hospital as a training set and 739 at Cancer Institute Hospital （CIH） as a validation set, with PSA levels of up to 20 ng m1-1, who underwent extended prostate biopsy and were proved to have BPH, were enrolled in this study. We developed an equation for continuously coded TPV and a logistic regression-based nomogram for estimating a TPV grater than 40 mh Predictive accuracy and performance characteristics were assessed using an area under the receiver operating characteristics curve （AUC） and calibration plots. The final linear regression model indicated age, PSA, %fPSA and BW as independent predictors of continuously coded TPV. For predictions in the training set, the multiple correlation coefficient was increased from 0.38 for PSA alone to 0.60 in the final model. We developed a novel nomogram incorporating age, PSA, %fPSA and BW for estimating TPV greater than 40 mh External validation confirmed its predictive accuracy, with AUC value of 0.764. Calibration plots showed good agreement between predicted probability and observed proportion. In conclusion, TPV can be easily estimated using these four independent predictors.