A Contemporary Report of Low-Dose-Rate Brachytherapy for Prostate Cancer Using MRI for Risk Stratification: Disease Outcomes and Patient-Reported Quality of Life.

PURPOSE: We examined a prospective consecutive cohort of low dose rate (LDR) brachytherapy for prostate cancer to evaluate the efficacy of monotherapy for unfavorable-intermediate risk (UIR) disease, and explore factors associated with toxicity and quality of life (QOL). METHODS: 149 men with prostate cancer, including 114 staged with MRI, received Iodine-125 brachytherapy alone (144-145 Gy) or following external beam radiation therapy (110 Gy; EBRT). Patient-reported QOL was assessed by the Expanded Prostate Index Composite (EPIC) survey, and genitourinary (GU) and gastrointestinal (GI) toxicity were prospectively recorded (CTC v4.0). Global QOL scores were assessed for decline greater than the minimum clinically important difference (MCID). Univariate analysis (UVA) was performed, with 30-day post-implant dosimetry covariates stratified into quartiles. Median follow-up was 63 mo. RESULTS: Men with NCCN low (n = 42) or favorable-intermediate risk (n = 37) disease were treated with brachytherapy alone, while most with high-risk disease had combined EBRT (n = 17 of 18). Men with UIR disease (n = 52) were selected for monotherapy (n = 42) based on clinical factors and MRI findings. Freedom from biochemical failure-7 yr was 98%. Of 37 men with MRI treated with monotherapy for UIR disease, all 36 men without extraprostatic extension were controlled. Late Grade 2+/3+ toxicity occurred in 55/3% for GU and 8/2% for GI, respectively. Fifty men were sexually active at baseline and had 2 yr sexual data; 37 (74%) remained active at 2 yr. Global scores for urinary incontinence (UC), urinary irritation/obstruction (UIO), bowel function, and sexual function (SF) showed decreases greater than the MCID (p < 0.05) in UC at 2 mo, UIO at 2 and 6 mo, and SF at 2-24 mo, and >5 yr. Analysis did not reveal any significant associations with any examined rectal or urethral dosimetry for late toxicity or QOL. CONCLUSION: Disease outcomes and patient-reported QOL support LDR brachytherapy, including monotherapy for UIR disease.

PI-RADS score is associated with biochemical control and distant metastasis in men with intermediate-risk and high-risk prostate cancer treated with radiation therapy.

BACKGROUND: Novel methods of risk stratification are needed for men with prostate cancer. The Prostate Imaging Reporting and Data System (PI-RADS) uses multiparametric MRI (mpMRI) to assign a score indicating the likelihood of clinically significant prostate cancer. We evaluated pretreatment mpMRI findings, including PI-RADS score, as a marker for outcome in patients treated with primary radiation therapy (RT). METHODS: One hundred and twenty-three men, 64% and 36% of whom had National Comprehensive Cancer Network (NCCN) intermediate-risk and high-risk disease, respectively, underwent mpMRI prior to RT. PI-RADS score and size of the largest nodule were analyzed with respect to freedom from biochemical failure (FFBF) and freedom from distant metastasis. RESULTS: A PI-RADS score of ≤3, 4, or 5 was defined in 7%, 49%, and 44%; with a median nodule size of 0, 8, and 18 mm, respectively (P < 0.001). Median follow-up was 67 months. Men with PI-RADS ≤ 3, 4, or 5 disease had 7-year FFBF of 100%, 92%, and 65% (P = 0.002), and a 7-year freedom from distant metastasis of 100%, 100%, and 82%, respectively (P = 0.014). PI-RADS (Hazard Ratio 5.4 for PI-RADS 5 vs. 4, P = 0.006) remained associated with FFBF when controlling for NCCN risk category (P = 0.063) and receipt of androgen deprivation therapy (P = 0.535). Nodule size was also associated with FFBF (Hazard Ratio 1.08 per mm, P < 0.001) after controlling for NCCN risk category (P = 0.156) and receipt of androgen deprivation therapy (P = 0.776). CONCLUSION: mpMRI findings, including PI-RADS score and nodule size, may improve risk stratification in men treated with primary RT.

Pretreatment multiparametric MRI is independently associated with biochemical outcome in men treated with radiation therapy for prostate cancer.

PURPOSE: The purpose of this study was to investigate the utility of pre-treatment multiparametric magnetic resonance imaging (mpMRI) in a modern cohort of intermediate and high-risk prostate cancer patients treated with primary radiotherapy. METHODS AND MATERIALS: One hundred twenty three men with National Comprehensive Cancer Network (NCCN) intermediate or high-risk prostate cancer were treated with primary EBRT and/or brachytherapy and had evaluable pre-treatment mpMRI with endorectal coil. Images were assessed for the presence of radiographic extraprostatic extension (rEPE), seminal vesicle invasion (rSVI), lymph node involvement (LNI), sextant involvement, and largest axial tumor diameter. Imaging characteristics were analyzed along with clinical risk factors against freedom from biochemical failure (FFBF). Median follow-up time was 50 months. RESULTS: Fourteen (11%) men developed biochemical failure. The 5-year FFBF was 94% in intermediate-risk patients and 82% in high-risk patients (p < 0.01). mpMRI findings including rEPE (29% vs. 66%, p < 0.01), rSVI (6% vs. 25%, p < 0.01), LNI (1% vs. 30%, p < 0.01), and largest axial tumor size> 15 mm (27% vs. 48%, p = 0.02) were identified in men with intermediate vs. high risk prostate cancer, respectively. mpMRI features associated with 5-y FFBF biochemical failure on univariate analysis included rEPE (80% vs 98%), rSVI (55% vs. 96%), LNI (65% vs. 93%), and largest axial tumor size >15mm (81% vs. 94%, all p < 0.01). Men without any high risk MRI finding had a 5-y FFBF of 100% vs. 81% (p < 0.01). Adverse imaging features (HR 8.9, p < 0.01) were independently associated with biochemical failure in a bivariate model analyzed alongside clinical risk category (HR 3.2, p = 0.04). CONCLUSIONS: Pre-treatment mpMRI findings are strongly associated with biochemical outcomes in a modern cohort of intermediate and high-risk patients treated with primary radiotherapy. mpMRI may aid risk stratification beyond clinical risk factors in men treated with radiation therapy; further study is warranted to better understand how mpMRI can be used to individualize therapy.

Fully automated MR liver volumetry using watershed segmentation coupled with active contouring.

PURPOSE: Our purpose is to develop a fully automated scheme for liver volume measurement in abdominal MR images, without requiring any user input or interaction. METHODS: The proposed scheme is fully automatic for liver volumetry from 3D abdominal MR images, and it consists of three main stages: preprocessing, rough liver shape generation, and liver extraction. The preprocessing stage reduced noise and enhanced the liver boundaries in 3D abdominal MR images. The rough liver shape was revealed fully automatically by using the watershed segmentation, thresholding transform, morphological operations, and statistical properties of the liver. An active contour model was applied to refine the rough liver shape to precisely obtain the liver boundaries. The liver volumes calculated by the proposed scheme were compared to the "gold standard" references which were estimated by an expert abdominal radiologist. RESULTS: The liver volumes computed by using our developed scheme excellently agreed (Intra-class correlation coefficient was 0.94) with the "gold standard" manual volumes by the radiologist in the evaluation with 27 cases from multiple medical centers. The running time was 8.4 min per case on average. CONCLUSIONS: We developed a fully automated liver volumetry scheme in MR, which does not require any interaction by users. It was evaluated with cases from multiple medical centers. The liver volumetry performance of our developed system was comparable to that of the gold standard manual volumetry, and it saved radiologists' time for manual liver volumetry of 24.7 min per case.

Indications and selection of MR enterography vs. MR enteroclysis with emphasis on patients who need small bowel MRI and general anaesthesia: results of a survey.

AIMS: To survey the perceived indications for magnetic resonance imaging of the small bowel (MRE) by experts, when MR enteroclysis (MREc) or MR enterography (MREg) may be chosen, and to determine how the approach to MRE is modified when general anaesthesia (GA) is required. MATERIALS AND METHODS: Selected opinion leaders in MRE completed a questionnaire that included clinical indications (MREg or MREc), specifics regarding administration of enteral contrast, and how the technique is altered to accommodate GA. RESULTS: Fourteen responded. Only the diagnosis and follow-up of Crohn's disease were considered by over 80 % as a valid MRE indication. The remaining indications ranged between 35.7 % for diagnosis of caeliac disease and unknown sources of gastrointestinal bleeding to 78.6 % for motility disorders. The majority chose MREg over MREc for all indications (from 100 % for follow-up of caeliac disease to 57.7 % for tumour diagnosis). Fifty per cent of responders had needed to consider MRE under GA. The most commonly recommended procedural change was MRI without enteral distention. Three had experience with intubation under GA (MREc modification). CONCLUSION: Views were variable. Requests for MRE under GA are not uncommon. Presently most opinion leaders suggest standard abdominal MRI when GA is required. MAIN MESSAGES: • Experts are using MRE for various indications. • Requests for MRE under general anaesthesia are not uncommon. • Some radiologists employ MREc under general anaesthesia; others do not distend the small bowel.

Evaluation of the prostate bed for local recurrence after radical prostatectomy using endorectal magnetic resonance imaging.

PURPOSE: To summarize the results of a 4-year period in which endorectal magnetic resonance imaging (MRI) was considered for all men referred for salvage radiation therapy (RT) at a single academic center; to describe the incidence and location of locally recurrent disease in a contemporary cohort of men with biochemical failure after radical prostatectomy (RP), and to identify prognostic variables associated with MRI findings in order to define which patients may have the highest yield of the study. METHODS AND MATERIALS: Between 2007 and 2011, 88 men without clinically palpable disease underwent eMRI for detectable prostate-specific antigen (PSA) after RP. The median interval between RP and eMRI was 32 months (interquartile range, 14-57 months), and the median PSA level was 0.30 ng/mL (interquartile range, 0.19-0.72 ng/mL). Magnetic resonance imaging scans consisting of T2-weighted, diffusion-weighted, and dynamic contrast-enhanced imaging were evaluated for features consistent with local recurrence. The prostate bed was scored from 0-4, whereby 0 was definitely normal, 1 probably normal, 2 indeterminate, 3 probably abnormal, and 4 definitely abnormal. Local recurrence was defined as having a score of 3-4. RESULTS: Local recurrence was identified in 21 men (24%). Abnormalities were best appreciated on T2-weighted axial images (90%) as focal hypointense lesions. Recurrence locations were perianastomotic (67%) or retrovesical (33%). The only risk factor associated with local recurrence was PSA; recurrence was seen in 37% of men with PSA >0.3 ng/mL vs 13% if PSA ≤0.3 ng/mL (P<.01). The median volume of recurrence was 0.26 cm(3) and was directly associated with PSA (r=0.5, P=.02). The correlation between MRI-based tumor volume and PSA was even stronger in men with positive margins (r=0.8, P<.01). CONCLUSIONS: Endorectal MRI can define areas of local recurrence after RP in a minority of men without clinical evidence of disease, with yield related to PSA. Further study is necessary to determine whether eMRI can improve patient selection and success of salvage RT.