Prostate Region Research Articles

A Point Says a Lot: An Interactive Segmentation Method for MR Prostate via One-Point Labeling.

In this paper, we investigate if the MR prostate segmentation performance could be improved, by only providing one-point labeling information in the prostate region. To achieve this goal, by asking the physician to first click one point inside the prostate region, we present a novel segmentation method by simultaneously integrating the boundary detection results and the patch-based prediction. Particularly, since the clicked point belongs to the prostate, we first generate the location-prior maps, with two basic assumptions: (1) a point closer to the clicked point should be with higher probability to be the prostate voxel, (2) a point separated by more boundaries to the clicked point, will have lower chance to be the prostate voxel. We perform the Canny edge detector and obtain two location-prior maps from horizontal and vertical directions, respectively. Then, the obtained location-prior maps along with the original MR images are fed into a multi-channel fully convolutional network to conduct the patch-based prediction. With the obtained prostate-likelihood map, we employ a level-set method to achieve the final segmentation. We evaluate the performance of our method on 22 MR images collected from 22 different patients, with the manual delineation provided as the ground truth for evaluation. The experimental results not only show the promising performance of our method but also demonstrate the one-point labeling could largely enhance the results when a pure patch-based prediction fails.

Prostatitis and Benign Prostatic Hyperplasia among Monks/Friars Aged 45-70 Presented at Unth Enugu state, Nigeria Between 2008-2013

The present work was undertaken to study the prevalence of prostatitis and Benign prostatic Hyperplasia (BPH) among male nuns aged 45-70 years presented at the University of Nigeria Teaching Hospital (UNTH) Ituku/Ozalla, Enugu between 2008-2013. A total of thirty (30) paraffin processed Benign Prostatic Hyperplasia and prostatitis tissue biopsies were used. These samples were obtained by medical experts from patients who had been diagnosed of BPH and prostatitis between the years 2008-2013. Two (2) thin sections (5 μ) were obtained from each paraffin block of BPH and prostatitis and stained with Haematoxylin and Eosin (H&E). The results obtained showed that they were higher prevalence of BPH (62.34%) to prostatitis (37.80%) in UNTH from the year 2008-2013. It was also observed that the occurrence of these diseases is mostly dependent on the age of individual. The increased prevalence rate of 62.24% was seen mostly amongst monks which show significant result (p<0.05) between the ages 51-70 years while the incidence rate of prostatitis in UNTH under the period of study mostly among the monks studied is 37.80% seen among the monks/friar between 45-50 years. Also, the various morphological alterations seen in the examined diseased prostate tissues state included the presence of inflammatory cells, prostatic acini, corpora amalycae, prostatic region, hyperplastic cyst and fibromuscular region. In conclusion, the occurrence of BPH and prostatitis depend on the age of the individual.

Poster ‐ 10: QA of Ultrasound Images for Prostate Brachytherapy

Purpose:The current QA protocol of ultrasound systems used in prostate brachytherapy (TG128) addresses geometrical verifications, but the scope of evaluation of image quality is limited. We recognized importance of the latter in routine practice, and designed a protocol for QA of the images.Methods:Images of an ultrasound prostate phantom (CIRS053) were collected with BK Flex Focus 400. The images were saved as bmp after adjusting the gain to 50% for consistent results. Mean pixel values and signal to noise ratio were inspected in the representative sections of the phantom, including the mock prostate and the unechoic medium. Constancy of these numbers over a one year period was looked at.Results:The typical intensity in the mock prostate region in the transverse images ranged between 95 and 118 (out of 256), and the signal to noise was about 10. The intensity in the urethra region was about 170±40, and the unechoic medium was 2±2. The mean and the signal to noise ratio remained almost unchanged after a year, while the signal in the unechoic medium increased to about 7±4. Similar values were obtained in the sagittal images.Conclusions:The image analysis discussed above allows quick evaluation of constancy of the image quality. This may be also useful in troubleshooting image‐quality problems during routine exams, which might not be due to deterioration of the US system, but other reasons, e.g. variations in tissue properties or air being trapped between the probe and the anatomy.

Morphophysiology and ultrastructure of the male reproductive accessory glands of the bats Carollia perspicillata, Glossophaga soricina and Phyllostomus discolor (Chiroptera: Phyllostomidae)

The male reproductive accessory glands (RAGs) are important organs that contribute to the secretion of different substances that composed the ejaculate. Despite this important function, their composition, anatomy and function vary widely between species. Thus, the RAGs of three species of phyllostomid bats were morphologically and ultrastructurally characterized and compared in this study. The RAGs of the three analyzed species are composed of a prostate and a pair of bulbourethral glands (BG). In all species, the prostate is composed of three well-defined regions (ventral, dorsolateral and dorsal regions). The ventral region showed an atypical epithelium (undefined) with no obvious cellular limits and a holocrine PAS-positive secretion. The dorsolateral region of Carollia perspicillata and Phyllostomus discolor showed a pseudostratified cubic morphology, and that from Glossophaga soricina had a columnar morphology endowed with cytoplasmic projections and stereocilia. The dorsal region of the three analyzed species is composed of a pseudostratified columnar epithelium endowed with stereocilia; however, G. soricina also presented cytoplasmic projections in the apical portions of the secretory cells similar to those in the dorsolateral region. The BG of the three analyzed species are composed of a pseudostratified columnar epithelium including basal and PAS-positive secretory cells. In conclusion, this study morphologically and ultrastructurally characterized the RAGs of three species of phyllostomid bats, demonstrating the presence of a novel third prostatic region in species of this family. The results also showed the absence of seminal vesicles and ampullary glands, and better characterized the holocrine pattern of the prostatic ventral region, which is unique to bats.

MRI to CT Prostate Registration for Improved Targeting in Cancer External Beam Radiotherapy.

External radiotherapy is a major clinical treatment for localized prostate cancer. Currently, computed tomography (CT) is used to delineate the prostate and to plan the radiotherapy treatment. However, CT images suffer from a poor soft-tissue contrast and do not allow an accurate organ delineation. On the contrary, magnetic resonance imaging (MRI) provides rich details and high soft-tissue contrast, allowing tumor detection. Thus, the intraindividual propagation of MRI delineations toward the planning CT may improve tumor targeting. In this paper, we introduce a new method to propagate MRI prostate delineations to the planning CT. In the first step, a random forest classification is performed to coarsely detect the prostate in the CT images, yielding a prostate probability membership for each voxel and a prostate hard segmentation. Then, the registration is performed using a new similarity metric which maximizes the probability and the collinearity between the normals of the manual registration (MR) existing contour and the contour resulting from the CT classification. The first study on synthetic data was performed to analyze the influence of the metric parameters with different levels of noise. Then, the method was also evaluated on real MR-CT data using manual alignments and intraprostatic fiducial markers and compared to a classically used mutual information (MI) approach. The proposed metric outperformed MI by 7% in terms of Dice score coefficient, by 3.14 mm the Hausdorff distance, and 2.13 mm the markers position errors. Finally, the impact of registration uncertainties on the treatment planning was evaluated, demonstrating the potential advantage of the proposed approach in a clinical setup to define a precise target.

SU‐F‐J‐34: Automatic Target‐Based Patient Positioning Framework for Image‐Guided Radiotherapy in Prostate Cancer Treatment

Purpose:Current image‐guided radiotherapy (IGRT) procedure is bonebased patient positioning, followed by subjective manual correction using cone beam computed tomography (CBCT). This procedure might cause the misalignment of the patient positioning. Automatic target‐based patient positioning systems achieve the better reproducibility of patient setup. Our aim of this study was to develop an automatic target‐based patient positioning framework for IGRT with CBCT images in prostate cancer treatment.Methods:Seventy‐three CBCT images of 10 patients and 24 planning CT images with digital imaging and communications in medicine for radiotherapy (DICOM‐RT) structures were used for this study. Our proposed framework started from the generation of probabilistic atlases of bone and prostate from 24 planning CT images and prostate contours, which were made in the treatment planning. Next, the gray‐scale histograms of CBCT values within CTV regions in the planning CT images were obtained as the occurrence probability of the CBCT values. Then, CBCT images were registered to the atlases using a rigid registration with mutual information. Finally, prostate regions were estimated by applying the Bayesian inference to CBCT images with the probabilistic atlases and CBCT value occurrence probability. The proposed framework was evaluated by calculating the Euclidean distance of errors between two centroids of prostate regions determined by our method and ground truths of manual delineations by a radiation oncologist and a medical physicist on CBCT images for 10 patients.Results:The average Euclidean distance between the centroids of extracted prostate regions determined by our proposed method and ground truths was 4.4 mm. The average errors for each direction were 1.8 mm in anteroposterior direction, 0.6 mm in lateral direction and 2.1 mm in craniocaudal direction.Conclusion:Our proposed framework based on probabilistic atlases and Bayesian inference might be feasible to automatically determine prostate regions on CBCT images.

SU-F-R-28: Correction of FCh-PET Bladder Uptake Using Virtual Sinograms and Investigation of Its Impact On the Quantification of Prostate Textural Characteristics

Purpose: Textural biomarkers as a tool for quantifying intratumoral heterogeneity hold great promise for diagnosis and early assessment of treatment response in prostate cancer. However, spill-in counts from the bladder uptake are suspected to have an impact on the textural measurements of the prostate volume. This work proposes a correction method for the FCh-PET bladder uptake and investigates its impact on intraprostatic textural properties. Methods: Two patients with PC received pre-treatment dynamic FCh-PET scans reconstructed at four time points (interval: 2 min), for which prostate and bladder contours were obtained. Projection bins affected by bladder uptake were determined by forward-projection. For each time point and axial position, virtual sinograms were obtained and affected bins replaced by a weighted combination of original values and values interpolated using cubic spline from non-affected bins of the current and adjacent projection angles. The process was optimized using a genetic algorithm in terms of minimization of the root-mean-square error (RMSE) within the bladder between the corrected dynamic time point volume and a reference initial uptake volume. Finally, the impact of the bladder uptake correction on the prostate region was investigated using two standard SUV metrics (1) and three texture metrics (2): 1) SUVmax, SUVmean; 2) Contrast, Homogeneity, Coarseness. Results: Without bladder uptake correction, SUVmax and SUVmean were on average overestimated in the prostate by 0%, 0%, 33.2%, 51.2%, and 3.6%, 6.0%, 2.9%, 3.2%, for each time point respectively. Contrast varied by −9.1%, −6.7%, +40.4%, +107.7%, and Homogeneity and Coarseness by +4.5%, +1.8%, −8.8%, −14.8% and +1.0%, +0.5%, −9.5%, +0.9%. Conclusion: We proposed a method for FCh-PET bladder uptake correction and showed an impact on the quantification of the prostate signal. This method achieved a large reduction of intra-prostatic SUVmax while minimizing the impact on SUVmean. Further investigation is necessary to interpret changes in textural features. SL acknowledges partial support by the CREATE Medical Physics Research Training Network grant of the Natural Sciences and Engineering Research Council (Grant number: 432290).

TH‐CD‐207A‐12: Impacts of Inter‐ and Intra‐Fractional Organ Motion for High‐Risk Prostate Cancer Stereotactic Body Radiation Therapy

Purpose:We are conducting a clinical trial on stereotactic body radiation therapy (SBRT) for high‐risk prostate cancer. Doses to three targets, prostate, intra‐prostatic lesion, and pelvic lymph node (PLN) region, are escalated to three different levels via simultaneous integrated boost technique. Inter‐/intra‐fractional organ motions deteriorate planned dose distribution. This study aims at developing a dose reconstruction system to comprehensively understand the impacts of organ motion in our clinical trial.Methods:A 4D dose reconstruction system has been developed for this study. Using a GPU‐based Monte‐Carlo dose engine and delivery log file, the system is able to reconstruct dose on static or dynamic anatomy. For prostate and intra‐prostatic targets, intra‐fractional motion is the main concern. Motion trajectory acquired from Calypso in previously treated SBRT patients were used to perform 4D dose reconstructions. For pelvic target, inter‐fractional motion is one concern. Eight patients, each with four cone beam CTs, were used to derive fractional motion. The delivered dose was reconstructed on the deformed anatomy. Dosimetric parameters for delivered dose distributions of the three targets were extracted and compared with planned levels.Results:For prostate intra‐fractional motion, the mean 3D motion amplitude during beam delivery ranged from 1.5mm to 5.0mm and the average among all patients was 2.61mm. Inter‐fractional motion for the PLN target was more significant. The average amplitude among patients was 4mm with the largest amplitude up to 9.6mm. The D95% deviation from planned level for prostate PTVs and GTVs are on average less than&lt;0.1% and this deviation for intra‐prostatic lesion PTVs and GTVs were more prominent. The dose at PLN was significantly affected with D95% reduced by up to 44%.Conclusion:Intra‐/inter‐fractional organ motion is a concern for high‐risk prostate SBRT, particularly for the PLN target. Our dose reconstruction approach can also serve as the basis to guide treatment adaptation.

Influence of the contrast agents on treatment planning dose calculations of prostate and rectal cancers

AimThe aim of the present study is to quantify differences in dose calculations caused by using CA and determine if the resulting differences are clinically significant. BackgroundThe influence of contrast agents (CA) on radiation dose calculations must be taken into account in treatment planning. Materials and methodsEleven patients with pelvic cancers were included in this study and two sets of CTs were taken for each patient (without and with CA) in the same position and coordinates. Both sets of images were transferred to the DosiSoft ISOgray treatment planning system for contouring and calculating the dose distribution and monitor units (MUs) with Collapsed Cone and Superposition algorithms, respectively. All plans were generated on pre-contrast CT and subsequently copied to the post-contrast CT. Radiation dose calculations from the two sets of CTs were compared using a paired sample t-test. ResultsThe results showed a statistically insignificant difference between pre- and post-contrast CT treatment plans for target volume and OARs (p>0.05), except bladder organ in the prostate region (p<0.05) but the relative mean dose and MU differences were less than 2% in any patient for 18MV photon beam. ConclusionsTreatment planning on contrasted images generally showed a lower radiation dose to both target volume and OARs than plans on non-contrasted images. The results of this research showed that the small radiation dose differences between the plans for the CT scans with and without CA seem to be clinically insignificant; therefore, contrast-enhanced CT can be used for both target delineation and treatment planning of prostate and rectal cancers.

MP79-19 IMPACT OF INTRINSIC AND EXTRINSIC FACTORS ON THE DETECTION RATE OF THE PET TRACER FLUCICLOVINE (18F) IN BIOCHEMICAL RELAPSE OF PROSTATE CANCER: A MULTI-INSTITUTIONAL EXPERIENCE

You have accessJournal of UrologyProstate Cancer: Staging II1 Apr 2016MP79-19 IMPACT OF INTRINSIC AND EXTRINSIC FACTORS ON THE DETECTION RATE OF THE PET TRACER FLUCICLOVINE (18F) IN BIOCHEMICAL RELAPSE OF PROSTATE CANCER: A MULTI-INSTITUTIONAL EXPERIENCE Trond Veld Bogsrud, Cristina Nanni, Peter Nieh, Lucia Zanoni, Tore Bach-Gansmo, H Sletten, K Koren, Jesse Kieboom, Albert Chau, Penny Ward, Mark Goodman, Stefano Fanti, David Schuster, and Frode Willoch Trond Veld BogsrudTrond Veld Bogsrud More articles by this author , Cristina NanniCristina Nanni More articles by this author , Peter NiehPeter Nieh More articles by this author , Lucia ZanoniLucia Zanoni More articles by this author , Tore Bach-GansmoTore Bach-Gansmo More articles by this author , H SlettenH Sletten More articles by this author , K KorenK Koren More articles by this author , Jesse KieboomJesse Kieboom More articles by this author , Albert ChauAlbert Chau More articles by this author , Penny WardPenny Ward More articles by this author , Mark GoodmanMark Goodman More articles by this author , Stefano FantiStefano Fanti More articles by this author , David SchusterDavid Schuster More articles by this author , and Frode WillochFrode Willoch More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.2017AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Study BED001 retrospectively pooled and analysed data from an open access program in Oslo, Norway and 2 prospective studies conducted at Emory University, Atlanta, GA and Ospedale St'Orsola, Bologna Italy. This analysis evaluates the impact of intrinsic and extrinsic factors on fluciclovine (18F) PET-CT scan detection rate (DR) in a biochemical relapse (BR) cohort. Diagnostic performance compared to histology and clinical follow-up is reported separately. METHODS Data from 596 BR patients who underwent fluciclovine (18F) PET-CT scanning were subjected to subgroup analyses to evaluate the impact of: PSA at time of scanning, age, weight, race, prior treatment, Gleason and D'Amico risk scores on scan DR at a subject and region level. RESULTS BED001 was conducted in accordance with ICH GCP and the Declaration of Helsinki. Overall, fluciclovine (18F) PET-CT scanning detected sites of recurrence in 68% (403/595) of patients. The influence of baseline PSA value (by quartile) on DR is summarized below. The DR, at Subject level, was 41.4% for patients in the 1st quartile compared to >75% for those in the 3rd and 4th quartiles. DR at region level was 14% (PSA <0.79 ng/mL) compared to >50% (PSA >2.03 ng/mL) in the Prostate region (P), and 31% compared to 45-59% in the Extra-Prostatic region (E-P). Subgroup analyses to report performance against the other factors above will also be presented. CONCLUSIONS Results suggest that fluciclovine (18F) PET-CT is effective for visualising locations of prostate cancer relapse across a wide range of PSA values, including PSA <1ng/mL, with a Detection Rate proportional to PSA. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e1041-e1042 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Trond Veld Bogsrud More articles by this author Cristina Nanni More articles by this author Peter Nieh More articles by this author Lucia Zanoni More articles by this author Tore Bach-Gansmo More articles by this author H Sletten More articles by this author K Koren More articles by this author Jesse Kieboom More articles by this author Albert Chau More articles by this author Penny Ward More articles by this author Mark Goodman More articles by this author Stefano Fanti More articles by this author David Schuster More articles by this author Frode Willoch More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

The effects of castration followed testosterone supplementation in prostatic complex of Artibeus planirostris (Chiroptera: Phyllostomidae).

The prostatic complex (ventral and dorsal regions) of Artibeus planirostris exhibits seasonal variations throughout the year. Circulating testosterone was correlated with prostate weight, showing an increase from autumn to summer, with the highest peak in summer corresponding to the largest breeding season. This indicates that the level of serum testosterone influences variations in both testicular and prostatic weights. Serum testosterone levels seem to be closely related to the different responses of these glands throughout the year. The castration (consequent suppression of testosterone) and subsequent hormone supplementation may elucidate the relationship of these two glandular types with testosterone. Thus, the aim of this study was to evaluate the effect of castration and the testosterone supplementation in the male prostatic complex of A. planirostris. The results indicated that both prostatic regions were affected by the ablation of testosterone, presenting a decrease in cell proliferation and an increase in apoptosis. Similarly, the prostate was responsive to hormonal supplementation, having a recovery of the active morphophysiological pattern with testosterone supplementation. However, data have shown that the ventral region was more sensitive to changes in testosterone than the dorsal, presenting greater cell renewal.

In vivo imaging of prostate cancer using an anti-PSMA scFv fragment as a probe.

We aimed to evaluate a fluorescent-labeled single chain variable fragment (scFv) of the anti-PSMA antibody as a specific probe for the detection of prostate cancer by in vivo fluorescence imaging. An orthotopic model of prostate cancer was generated by injecting LNCaP cells into the prostate lobe. ScFvD2B, a high affinity anti-PSMA antibody fragment, was labeled using a near-infrared fluorophore to generate a specific imaging probe (X770-scFvD2B). PSMA-unrelated scFv-X770 was used as a control. Probes were injected intravenously into mice with prostate tumors and fluorescence was monitored in vivo by fluorescence molecular tomography (FMT). In vitro assays showed that X770-scFvD2B specifically bound to PSMA and was internalized in PSMA-expressing LNCaP cells. After intravenous injection, X770-scFvD2B was detected in vivo by FMT in the prostate region. On excised prostates the scFv probe co-localized with the cancer cells and was found in PSMA-expressing cells. The PSMA-unrelated scFv used as a control did not label the prostate cancer cells. Our data demonstrate that scFvD2B is a high affinity contrast agent for in vivo detection of PSMA-expressing cells in the prostate. NIR-labeled scFvD2B could thus be further developed as a clinical probe for imaging-guided targeted biopsies.

In vivo MRI based prostate cancer localization with random forests and auto-context model

Prostate cancer is one of the major causes of cancer death for men. Magnetic resonance (MR) imaging is being increasingly used as an important modality to localize prostate cancer. Therefore, localizing prostate cancer in MRI with automated detection methods has become an active area of research. Many methods have been proposed for this task. However, most of previous methods focused on identifying cancer only in the peripheral zone (PZ), or classifying suspicious cancer ROIs into benign tissue and cancer tissue. Few works have been done on developing a fully automatic method for cancer localization in the entire prostate region, including central gland (CG) and transition zone (TZ). In this paper, we propose a novel learning-based multi-source integration framework to directly localize prostate cancer regions from in vivo MRI. We employ random forests to effectively integrate features from multi-source images together for cancer localization. Here, multi-source images include initially the multi-parametric MRIs (i.e., T2, DWI, and dADC) and later also the iteratively-estimated and refined tissue probability map of prostate cancer. Experimental results on 26 real patient data show that our method can accurately localize cancerous sections. The higher section-based evaluation (SBE), combined with the ROC analysis result of individual patients, shows that the proposed method is promising for in vivo MRI based prostate cancer localization, which can be used for guiding prostate biopsy, targeting the tumor in focal therapy planning, triage and follow-up of patients with active surveillance, as well as the decision making in treatment selection. The common ROC analysis with the AUC value of 0.832 and also the ROI-based ROC analysis with the AUC value of 0.883 both illustrate the effectiveness of our proposed method.

Antenatally Diagnosed Posterior Urethral Valve: A Case Report

Posterior urethral valve (PUV) are the most common congenital obstructive lesion of the urethra and a common cause of obstructive uropathy in infancy. Clinical presentation depends on the severity of the obstruction. In case of severe obstruction, the diagnosis is usually made antenatally. Here, we present a case of antenatally diagnosed PUV of a fetus of a lady in her 9th month of pregnancy with mild lower abdominal pain for several hours. On ultrasound (US) examination, we found 36.5±2 weeks of pregnancy with mild to moderate oligohydramnios. Fetal urinary bladder was over distended; both the kidneys were grossly hydronephrotic and PUV like echo lucent area was seen at the prostatic region (Key hole sign). Emergency caesarian section (CS) was done and US of the baby showed typical US finding of PUV. The prognosis of antenatal diagnosis of PUV in early pregnancy is poor. But in this case due to the late onset of symptoms and as immediate necessary steps were taken, the baby was totally cured. This case was reported to aware about importance of antenatal anomaly scan and to share our experience.&#x0D; CBMJ 2016 January: Vol. 05 No. 01 P: 42-45

Bacterial emphysematous prostatic abscess – A case report

s / Urological Science 26 (2015) 301e310 310 Materials and Methods: An 82 years old female patient presented to the Emergency Department with feeling unwell, pyrexia, gross hematuria, nausea and abdominal pain. She gave a history of type 2 Diabetes mellitus with regular follow-up in our hospital. A large right renal mass was detected near 4 years ago. However, she and family refused operation since then due to old age. On examination she looked weakness. A mass was palpable in the right upper quadrant and lumbar region. Liver and spleen were not palpable. There were no signs of peritonitis. Her pulse rate was 121/minute, BP 189/104 and temp 39.3 degree. She had blood tests in the Emergency Department which revealed the following: Hb 15.6 g/dL, WBC 11,400 and platelets 202,000. Electrolytes were as follows: Na 136 mmol/ litre, K 3.3 mmol/litre, BUN: 12, creatinine: 0.8, blood sugar: 213. Chest X ray showed 1) Mild coarse and crowding lung markings, some infiltration in bilateral lungs; but no focal active lung lesion. 2) Borderline cardiomegaly and mild tortuosity of aorta with some calcified atheroma plaques of aortic arch wall.. The patient had ultrasound scanwhich showed mass in the right kidney. Computerised tomography (CT) scan image of abdomen showed anterior upper pole tumor 9.5 x 12 x9.0 cm in size with heterogeneous enhancement and area of necrosis. Extension to perirenal fat and renal sinus fat but not Gerota fascia. Positron emission tomography (PET) revealed: 1. F-18 FDG avid lesion in the left thyroid, malignancy should be considered. 2. Right paraaortic lymph node metastases should be considered. She underwent right-side radical nephrectomy after full staging procedures and appropriate investigations. NDP32: BACTERIAL EMPHYSEMATOUS PROSTATIC ABSCESS e A CASE REPORT Chih-Cheng Lu, Wen-Chou Fan. Division of Urology, Department of Surgery, Chi Mei Medical Center, Liouying, Tainan, Taiwan Purpose: We present a case of emphysematous prostatic infection complicated with multiple organs abscess by Klebsiella pneumoniae. Materials and Methods: A 47 year-old male patient suffered from uncontrolled diabetes. Four days before admission, he had fever and general weakness. He visited our emergent department after empirical treatment at local clinic. After admission, intensive care was given due to diabetic ketoacidosis and septic shock. Although multiple drains for liver and lung, spiking fever persisted. Sequential CT showed air and abscess in the prostate region. Urgent transurethral prostate incision was done to drain the abscess. Afterwards, the general condition became stable. He was discharged with oral antibiotics and antidiabetic drugs. After one year followup, the patient kept uneventful condition with tight diabetic control. Conclusion: Emphysematous prostatic abscess is an unusual acute disease with high morbidity and mortality. The predisposing factors include diabetes mellitus, hepatic cirrhosis, and intravesical obstruction. CT provides a good tool for immediate diagnosis. Treatment of prostatic abscess includes parenteral antibiotics and abscess drainage. Transperineal needle aspiration, transrectal needle aspiration, open perineal incision, and transurethral resection or unroofing are available routes for drainage.

The influence of prostatic anatomy and neurotrophins on basal prostate epithelial progenitor cells.

Based on findings of surface marker, protein screens as well as the postulated near-urethral location of the prostate stem cell niche, we were interested whether androgen ablation, distinct anatomic regions within the prostate or neurotrophins have an influence on basal prostate epithelial progenitor cells (PESCs). Microdissection of the prostate, enzymatic digestion, and preparation of single cells was performed from murine and human prostates. Adult PESC marker expressions were compared between a group of C57BL/6 mice and a separate group of castrated C57BL/6 mice. Surface markers CD13/CD271 on human prostate epithelial progenitor cells were evaluated by FACS analyses in cells cultured under novel stem cell conditions. The effect of neurotrophins NGF, NT3, and BDNF were evaluated with respect to their influence on proliferation and activation of human basal PESCs in vitro. We demonstrate the highest percentage of CD49f+ and Trop2+ expressing cells in the urethra near prostatic regions of WT mice (Trop2+ proximal: 10% vs. distal to the urethra: 3%, P < 0.001). While a marked increase of Trop2 expressing cells can be measured both in the proximal and distal prostatic regions after castration, the most prominent increase in Trop2+ cells can be measured in the prostatic tissue distant to the urethra. Furthermore, we demonstrate that the proportion of syndecan-1 expressing cells greatly increases in the regions proximal to the urethra after castration (WT: 5% vs. castrated: 40%). We identified heterogeneous CD13 and nerve growth factor receptor (p75(NGFR), CD271) expression on CD49f(+)/TROP2(high) human basal PESCs. Addition of the neurotrophins NT3, BDNF, and NGF to the stem cell media led to a marked temporary increase in the proliferation of human basal PESCs. Our results in mice support the model, in which the proximal urethral region contains the prostate stem cell niche while a stronger androgen-dependent regulation of adult prostate stem cells can be found in the peripheral prostatic tissue. Neutrophin signaling via nerve growth factor receptor is possibly involved in human prostate stem cell homeostasis.

A learning-based CT prostate segmentation method via joint transductive feature selection and regression

In recent years, there has been a great interest in prostate segmentation, which is an important and challenging task for CT image guided radiotherapy. In this paper, a learning-based segmentation method via joint transductive feature selection and transductive regression is presented, which incorporates the physician׳s simple manual specification (only taking a few seconds), to aid accurate segmentation, especially for the case with large irregular prostate motion. More specifically, for the current treatment image, experienced physician is first allowed to manually assign the labels for a small subset of prostate and non-prostate voxels, especially in the first and last slices of the prostate regions. Then, the proposed method follows the two step: in prostate-likelihood estimation step, two novel algorithms, tLasso and wLapRLS, will be sequentially employed for transductive feature selection and transductive regression, respectively, aiming to generate the prostate-likelihood map. In multi-atlases based label fusion step, the final segmentation result will be obtained according to the corresponding prostate-likelihood map and the previous images of the same patient. The proposed method has been substantially evaluated on a real prostate CT dataset including 24 patients with 330 CT images, and compared with several state-of-the-art methods. Experimental results show that the proposed method outperforms the state-of-the-arts in terms of higher Dice ratio, higher true positive fraction, and lower centroid distances. Also, the results demonstrate that simple manual specification can help improve the segmentation performance, which is clinically feasible in real practice.

Magnitude of observer error using cone beam CT for prostate interfraction motion estimation: effect of reducing scan length or increasing exposure.

Objective:Cone beam CT (CBCT) enables soft-tissue registration to planning CT for position verification in radiotherapy. The aim of this study was to determine the interobserver error (IOE) in prostate position verification using a standard CBCT protocol, and the effect of reducing CBCT scan length or increasing exposure, compared with standard imaging protocol.Methods:CBCT images were acquired using a novel 7 cm length image with standard exposure (1644 mAs) at Fraction 1 (7), standard 12 cm length image (1644 mAs) at Fraction 2 (12) and a 7 cm length image with higher exposure (2632 mAs) at Fraction 3 (7H) on 31 patients receiving radiotherapy for prostate cancer. Eight observers (two clinicians and six radiographers) registered the images. Guidelines and training were provided. The means of the IOEs were compared using a Kruzkal–Wallis test. Levene's test was used to test for differences in the variances of the IOEs and the independent prostate position.Results:No significant difference was found between the IOEs of each image protocol in any direction. Mean absolute IOE was the greatest in the anteroposterior direction. Standard deviation (SD) of the IOE was the least in the left–right direction for each of the three image protocols. The SD of the IOE was significantly less than the independent prostate motion in the anterior–posterior (AP) direction only (1.8 and 3.0 mm, respectively: p = 0.017). IOEs were within 1 SD of the independent prostate motion in 95%, 77% and 96% of the images in the RL, SI and AP direction.Conclusion:Reducing CBCT scan length and increasing exposure did not have a significant effect on IOEs. To reduce imaging dose, a reduction in CBCT scan length could be considered without increasing the uncertainty in prostate registration. Precision of CBCT verification of prostate radiotherapy is affected by IOE and should be quantified prior to implementation.Advances in knowledge:This study shows the importance of quantifying the magnitude of IOEs prior to CBCT implementation.

Tomographie conique quotidienne pour les traitements pelviens et prostatiques : étude interobservateurs

PurposeThis work evaluated the interobserver variability in cone beam computed tomography (CBCT) registration for prostate cancers treated with intensity-modulated radiotherapy. Material and methodsTwelve technologists realized 286 CBCT/CT registrations (bone registration followed by prostate to prostate registration). The registration results were compared to those obtained by two radiation oncologists (reference). Each technologist reported the shifts calculated by the software in all three axes. A statistical analysis allowed us to calculate the minimum threshold under which 95% of the observers found similar values. A variance analysis followed by the post hoc test were used to find differences in interobserver registration variability and determine whether any individual users performed registrations which differed significantly from those of the other users. ResultsThe registration differences compared to the reference in the three directions in terms of 95th percentile are: 2.1mm left–right, 3.5mm target–gun, 7.3mm anterior–posterior. In the posterior direction, 4% of the observers have found differences superior to 8mm, margin used in routine without the use of a daily CBCT. The variance test revealed a P-value <0.05 only for target–gun and for all observers there was no significant difference compared to the reference. ConclusionThis study confirmed the interest of a 3D tissue registration for prostate treatments. The registration study showed a good interobserver reproducibility. This showed the importance of a daily CBCT/CT registration in prostate treatment with the possibility of a planning target volume margin reduction in the three directions. An evaluation of a partial delegation of registration to technologists should be done by the radiation oncologists.

Accuracy of dose planning for prostate radiotherapy in the presence of metallic implants evaluated by electron spin resonance dosimetry.

Radiotherapy is one of the main approaches to cure prostate cancer, and its success depends on the accuracy of dose planning. A complicating factor is the presence of a metallic prosthesis in the femur and pelvis, which is becoming more common in elderly populations. The goal of this work was to perform dose measurements to check the accuracy of radiotherapy treatment planning under these complicated conditions. To accomplish this, a scale phantom of an adult pelvic region was used with alanine dosimeters inserted in the prostate region. This phantom was irradiated according to the planned treatment under the following three conditions: with two metallic prostheses in the region of the femur head, with only one prosthesis, and without any prostheses. The combined relative standard uncertainty of dose measurement by electron spin resonance (ESR)/alanine was 5.05%, whereas the combined relative standard uncertainty of the applied dose was 3.35%, resulting in a combined relative standard uncertainty of the whole process of 6.06%. The ESR dosimetry indicated that there was no difference (P>0.05, ANOVA) in dosage between the planned dose and treatments. The results are in the range of the planned dose, within the combined relative uncertainty, demonstrating that the treatment-planning system compensates for the effects caused by the presence of femur and hip metal prostheses.