Rate Brachytherapy For Prostate Cancer Research Articles

Clinical Efficacy and Openness to New Challenges of Low Dose Rate Brachytherapy for Prostate Cancer.

Over a century ago, low-dose-rate (LDR) brachytherapy was introduced to treat prostate cancer (PCa). Since then, it has been widely applied worldwide, including in East Asia. LDR brachytherapy has been performed in 88 institutes in Japan. Beneficial clinical outcomes of LDR brachytherapy for intermediate-to-high-risk PCa have been demonstrated in large clinical trials. These clinical outcomes were achieved through advances in methods, such as urological precise needle puncture and seed placement, and the quantitative decision making regarding radiological parameters by radiation oncologists. The combined use of LDR brachytherapy with other therapeutic modalities, such as external beam radiation and androgen deprivation therapy, for the clinical risk classification of PCa has led to better anticancer treatment efficacy. In this study, we summarized basic LDR brachytherapy findings that should remain unchanged and be passed down in urology departments. We also discussed the applications of LDR brachytherapy for PCa in various clinical settings, including focal and salvage therapies. In addition, we highlighted technologies associated with brachytherapy that are under development.

A Pilot Study of an Interactive Virtual Tour Tool for Patient Education Prior to Undergoing High-Dose Rate Brachytherapy for Prostate Cancer.

High-dose rate (HDR) brachytherapy for treatment of prostate cancer is an invasive procedure that can be associated with patient anxiety. Patient education regarding the procedure can allow for better informed decision-making while also decreasing anxiety. We sought to develop and assess the utility of an interactive virtual tour tool that portrays a 360-degree view of the HDR brachytherapy patient experience, with the goals of providing patient education, decreasing patient anxiety, and assisting in wayfinding on the procedure day. Using a 360-degree camera, we captured multiple photographs that depicted the various hospital locations that a patient would navigate through on the day of their HDR brachytherapy procedure, including the medical center lobby, pre-operative/post-operative units, and the brachytherapy suite. We then compiled these 360-degree photographs using virtual tour software, to allow users to navigate throughout the locations. We added informational text, spoken audio, and videos associated with key staff, objects, and the brachytherapy procedure that allow the users to interact with and learn about these various components within the virtual tour. This tool was accessible via a website link on a computer, tablet, or smartphone and was provided at the time of consult to patients who were planning to undergo HDR brachytherapy for prostate cancer. A questionnaire assessing the tool's ease of use, educational value, wayfinding utility, and ability to improve anxiety and treatment decision-making was conducted prior to and after their procedure. Preliminary feedback from healthy volunteers is highly positive, with users finding that the tool is easily accessible, user-friendly, improves understanding of HDR brachytherapy, simulates the treatment experience accurately, helps with wayfinding, and has the potential to decrease patient anxiety and increase comfort with the treatment decision. Data from the patient questionnaires are being collected and will be analyzed. A 360-degree virtual tour tool allows for an easily accessible, immersive, and interactive method of patient education on an invasive, anxiety-associated procedure. This has the potential to decrease patient anxiety and improve comfort regarding treatment decision-making. This tool may be applied toward other relatively involved radiotherapy modalities, including gynecologic HDR brachytherapy, respiratory-gated treatments, and CyberKnife stereotactic radiosurgery.

Clinical and treatment characteristics of secondary bladder malignancies following low dose rate brachytherapy for prostate cancer.

To characterize the clinical course and prognosis of bladder malignancies associated with prior prostate brachytherapy SUBJECTS/PATIENTS AND METHODS: We queried our institutional database for patients with bladder cancer (BC) diagnosed between January 2005 and April 2019 who had previously undergone low dose rate (LDR) prostate brachytherapy. Patients diagnosed with BC at least 1 year following LDR prostate brachytherapy with or without external beam radiation therapy were included. Clinical and disease-specific characteristics were abstracted from chart review and survival outcomes were estimated using Kaplan-Meier estimates. We compared the pathologic characteristics and prognosis of secondary BCs in our study cohort to those of BCs diagnosed after prostate cancer managed without radiation reported by the Surveillance, Epidemiology, and End Results (SEER) populational database from 2005 to 2018. Three hundred seventy-five patients were identified with combined diagnosis of prostate cancer and BC, 51 of whom met inclusion criteria in the study cohort. Median times from brachytherapy to BC diagnosis for the study and SEER cohort were 9.5 ± 4.5 and 6.3 ± 4.1 years, respectively. Compared to the SEER cohort, significantly greater proportion of BC from the study cohort presented with high-grade (study: 78.4%, SEER: 52.3%, P = 0.0008) and with MIBC (Study BC 35.3%, SEER BC: 17.5%, P = 0.0009). The study and the SEER cohort had similar 5-year overall survival (study: 67.9%, SEER: 58.0%, P = 0.1099), and 5-year cancer-specific survival (study: 81.0%, SEER: 82.8%, P = 0.5559). The 5-year progression-free survival for the study cohort was 43.7% (95% CI: 28.8-57.7). Compared to bladder cancers following prostate cancer managed without radiation, bladder malignancies following prostate LDR brachytherapy present with higher grade and are more likely to be muscle invasive. Despite the aggressive presenting features of postprostate brachytherapy BC, there were no differences in overall and cancer-specific survival between the groups.

Syndrome of inappropriate secretion of antidiuretic hormone following high dose rate brachytherapy for prostate cancer: a case report

BackgroundThe syndrome of inappropriate secretion of antidiuretic hormone is a disorder characterized by the excess release of antidiuretic hormone and can result in hyponatremia. If managed inappropriately, severe hyponatremia can cause seizures, cerebral edema, and even death. There are various known causes of this inappropriate release of antidiuretic hormone, including malignancy, CNS disorders, and disturbances in the hypothalamic-pituitary-renal axis. However, reports of syndrome of inappropriate secretion of antidiuretic hormone after brachytherapy for prostate cancer are exceedingly rare.Case presentationWe report a case of symptomatic hyponatremia secondary to the inappropriate secretion of antidiuretic hormone after prostate high-dose rate brachytherapy under general anesthesia in a patient with adenocarcinoma of the prostate.ConclusionsIn rare instances, inappropriate secretion of antidiuretic hormone can occur after high-dose rate brachytherapy for prostate cancer. The cause is likely multifactorial, involving pain or discomfort ensuing from the surgical procedure, the general anesthesia or intraoperative drugs administered. However, due to the potential severity of the side effects, timely diagnosis is crucial to ensure prompt, and effective management.

Detection of Failure Patterns Using Advanced Imaging in Patients With Biochemical Recurrence Following Low Dose Rate Brachytherapy for Prostate Cancer

Low dose rate (LDR) brachytherapy alone or with external beam radiation (EBRT) results in excellent rates of biochemical control in patients (pts) with prostate cancer (PCa). Understanding failure patterns in pts with biochemical recurrence (BCR) may inform implant technique or pt selection. The primary objective of this study was to describe locations of recurrence on multiparametric MRI (mpMRI) and prostate specific membrane antigen (PSMA) imaging in pts with BCR after LDR brachytherapy.Pts with BCR after definitive LDR (± EBRT, ± androgen deprivation therapy (ADT)) referred for IRB approved imaging protocols were included. All pts underwent 3T mpMRI (T2 weighted, dynamic contrast-enhanced, and diffusion-weighted imaging) prospectively reviewed by prostate-dedicated radiologists. A subset of pts underwent PSMA-PET/CT imaging. Pathologic confirmation was obtained unless contraindicated. Prostate lesions were categorized as left (L)/right (R)/midline (ML); transitional zone (TZ)/peripheral zone (PZ); apical/mid/base; and anterior/posterior/central. Locations of recurrence (prostate, seminal vesicles (SV), lymph nodes (LN) and distant metastases (DM)) were recorded and reported descriptively.Between Jan 2011 and Feb 2021, 57 pts with BCR after LDR underwent prostate mpMRI. Treatment was LDR (n = 39) or EBRT + LDR (n = 18), ± ADT (n = 12). At time of LDR, initial Gleason score was ≤6 (n = 29), 7 (n = 19), 8-9 (n = 8), unknown (n = 1) and median PSA was 6 ng/mL (3.4-49). Of dosimetry available (n = 27), 2 had D90 < 90%. Median time from LDR to mpMRI was 6.7 yrs (0.8-18.3). At time of mpMRI, median pt age was 68 yrs (51-85), median PSA was 5.64 ng/mL (0.17-37.47). Lesions (n = 67) in the prostate/SV were detected in 45/57 pts on mpMRI, with a median lesion size of 1.2 cm (0.3-3.6). SV involvement was present in 20/45 patients with mpMRI detected lesions. Locations of mpMRI prostate lesions were L (n = 19) vs R (n = 16) vs ML (n = 15); TZ (n = 22) vs PZ (n = 14); apical (n = 17) vs mid (n = 25) vs base (n = 23); and anterior (n = 13) vs posterior (n = 0) vs central (n = 8). In pts with PSMA (n = 32), 31 had uptake in the prostate (n = 16, 14 detected on mpMRI) and SV (n = 12, 10 detected on mpMRI). One pt had uptake in the prostate+SV detected only on PSMA. Extraprostatic uptake on PSMA included LN (n = 15), DM (n = 5) and penile bulb (n = 1). Of 37 pts who had prostate/SV biopsy, tumor recurrence was confirmed in 31 (prostate (n = 25) and SV (n = 12)). Three of 6 pts with negative biopsy had no lesion on mpMRI. SV recurrence (imaging ± biopsy) occurred in 18/39 pts with LDR alone and in 5/18 with LDR + EBRT.In this cohort of pts with BCR following LDR, the predominant locations of local recurrence were in the anterior/central TZ and SV. PSMA corroborated the majority of mpMRI findings and often demonstrated LN and DM. These findings may inform LDR technique and impact patient selection or pre-treatment imaging evaluation; and should be confirmed in larger subsets and correlated with post-implant dosimetry.

PD-0809 4-year PSA to predict relapse risk after low dose rate brachytherapy for prostate cancer

PD-0809 4-year PSA to predict relapse risk after low dose rate brachytherapy for prostate cancer

Design of the novel ThermoBrachy applicators enabling simultaneous interstitial hyperthermia and high dose rate brachytherapy

Objective: In High Dose Rate Brachytherapy for prostate cancer there is a need for a new way of increasing cancer cell kill in combination with a stable dose to the organs at risk. In this study, we propose a novel ThermoBrachy applicator that offers the unique ability to apply interstitial hyperthermia while simultaneously serving as an afterloading catheter for high dose rate brachytherapy for prostate cancer. This approach achieves a higher thermal enhancement ratio than in sequential application of radiation and hyperthermia and has the potential to decrease the overall treatment time. Methods: The new applicator uses the principle of capacitively coupled electrodes. We performed a proof of concept experiment to demostrate the feasibility of the proposed applicator. Moreover, we used electromagnetic and thermal simulations to evaluate the power needs and temperature homogeneity in different tissues. Furthermore we investigated whether dynamic phase and amplitude adaptation can be used to improve longitudinal temperature control. Results: Simulations demonstrate that the electrodes achieve good temperature homogeneity in a homogenous phantom when following current applicator spacing guidelines. Furthermore, we demonstrate that dynamic phase and amplitude adaptation provides a great advancement for further adaptability of the heating pattern. Conclusions: This newly designed ThermoBrachy applicator has the potential to revise the interest in interstitial thermobrachytherapy, since the simultaneous application of radiation and hyperthermia enables maximum thermal enhancement and provides maximum efficiency for patient and organization.

The Hare and Tortoise: A Nursing Perspective on Two Workflows for High Dose Rate Brachytherapy for Prostate Cancer

The Hare and Tortoise: A Nursing Perspective on Two Workflows for High Dose Rate Brachytherapy for Prostate Cancer

Clinical and Treatment Characteristics of Secondary Bladder Malignancies following Low Dose Rate Brachytherapy for Prostate Cancer

Clinical and Treatment Characteristics of Secondary Bladder Malignancies following Low Dose Rate Brachytherapy for Prostate Cancer

Clinical and Treatment Characteristics of Secondary Rectal and Anal Malignancies following Low Dose Rate Brachytherapy for Prostate Cancer

Clinical and Treatment Characteristics of Secondary Rectal and Anal Malignancies following Low Dose Rate Brachytherapy for Prostate Cancer

Coverage of the external prostatic region by the hybrid method compared with the conventional method of prostate low-dose-rate brachytherapy: A randomized controlled study.

To compare the dose evaluation parameters between conventional (using loose seed alone) and hybrid (using loose seeds in combination with stranded seeds) low-dose rate brachytherapy for prostate cancer. Between 2014 and July 2016, a total of 219 patients who underwent low-dose rate brachytherapy were enrolled in a randomized controlled trial (trial number: UMIN 000012780). Patients were randomized and allocated to two groups (conventional method vs hybrid method). Post-dosimetric parameters (%D90, minimal percentage of the dose received by 90% of the prostate gland; V100, percentage of the prostate volume receiving 100% of the prescribed minimal peripheral dose; V150, percentage of the prostate volume receiving 150% of the prescribed minimal peripheral dose; %UD30, minimal percentage of the dose received by 30% of the urethra; R100, rectal volume [mL] receiving 100% of the prescribed dose) calculated at 1month after seed implantation by computed tomography scan were compared between the two groups, as well as the post-dosimetric parameters using the planning target volume of the prostate+5-mm margin. Regarding dose evaluation parameters, the prostate dose (%D90, V100, V150) and the urethral dose (%UD30) were not significantly different between the two groups, whereas V100 (+5-mm margin) and %D90 (+5-mm margin) were significantly higher in the hybrid method group compared with the conventional method group (P<0.001). The present randomized study shows that the hybrid method of low-dose rate brachytherapy can achieve a higher coverage of the periprostatic region compared with the conventional method while maintaining an acceptable level of urethral and rectal doses.

Evaluation of the urethral α/β ratio and tissue repair half-time for iodine-125 prostate brachytherapy with or without supplemental external beam radiotherapy

PurposeTo assess the correlation between postimplant dosimetric quantifiers and the genitourinary (GU) toxicity of low-dose rate brachytherapy for prostate cancer. Methods and MaterialsThe minimum urethral dose (UD10, 30, and 90) and the percent volume of the urethra receiving the prescription dose (V100, V150) were calculated from the postimplant dose-volume histograms of 182 patients. We then calculated various urethral biologically equivalent doses (uBEDs) using different values of the α/β ratio and tissue repair half-time (t1/2) and examined the correlations with GU toxicity. ResultsCommon dosimetric quantifiers, such as UD90 (brachytherapy) + UD50 (external beam radiotherapy), showed no correlation with Grade ≥ 2 GU toxicity. There was a significant correlation between Grade ≥2 GU toxicity and uBED when the α/β value was 0.5 or 1 Gy and t1/2 was 0.5–2.5 h. An uBED (α/β = 1.0, t1/2 = 0.5) had the largest hazard ratio for GU toxicity, and it was also significantly correlated with Grade ≥ 2 GU toxicity according to multivariate analysis. ConclusionsWe observed a significant correlation of uBED with GU toxicity when α/β was 0.5 or 1.0 Gy and t1/2 was 0.5–2.5 h. As the simple formula we used has not been verified in basic experiments, more data are needed to validate our results.

Exploring the Impact of External Urethral Length on Acute Urinary Toxicity in Patients Undergoing High Dose Rate Brachytherapy for Prostate Cancer

The pre-operative and post-operative length of the external urethra sphincter (EUS) in patients undergoing radical prostatectomy has previously been reported to correlate with urinary incontinence. We aimed to determine if external urethral length impacts rates of urinary incontinence in patients undergoing high dose rate (HDR) brachytherapy. We performed a retrospective cohort study of patients with localized prostate cancer treated with MRI-based HDR brachytherapy monotherapy on a prospectively maintained database of prostate HDR patients treated from 2017-2018. Patients were treated with 13.5 Gy in 2 fractions delivered 1-2 weeks apart. CT images were used for catheter identification, and a T2 weighted MRI was obtained after the implant for target and normal structure delineation. The planning target volume (PTV) consisted of the prostate with an asymmetric expansion of 0-5 mm, with inclusion of the proximal seminal vesicles. Expanded Prostate Cancer Composite - 26 (EPIC-26) was evaluated at baseline, 1 month, 3 months, 6 months, then every 6 months thereafter. Linear mixed effects models were used to estimate mean EPIC-26 scores, International Prostate Symptom Score (IPSS) scores, and CTCAE v.5.0 genitourinary and gastrointestinal toxicity over time based on EUS length which was dichotomized as ≤ (short) or > (long) than the median. During analysis, changes were also classified as minimal clinically important difference (MCID). 46 patients were treated with definitive HDR using MRI-based planning, including 1 NCCN high risk , 32 intermediate risk, and 13 low risk patients. Median follow up was 4.18 months. The median EUS length was 1.7 cm (range 0.5-2.35 cm). There was no difference in baseline mean EPIC-26 scores in any domains. For the Urinary Incontinence domain, baseline mean scores were similar for short and long EUS (87.79 vs. 91.42; p=0.96). Patients with a short EUS had a greater decline in Urinary Incontinence mean scores at 1 month (72.51 vs. 83.59), 3 months (73.16 vs. 92.59), and 6 months (76.47 vs. 93.01), meeting MCID at all time points after treatment, although this was only marginally significantly associated with EPIC-26 urinary incontinence scores (p=0.05). EUS length was not associated with other EPIC-26 scores, changes in IPSS scores, or acute GU or GI toxicity. In concordance with surgical literature, shorter EUS length may be associated with acute urinary incontinence outcomes as assessed by EPIC-26 scores, however our series is limited by short follow-up and small sample size. Further research is required to validate our findings and, if so, may guide discussion with patients in the future regarding risks and benefits of brachytherapy.

Changes in apparent diffusion coefficient radiomics features during dose-painted radiotherapy and high dose rate brachytherapy for prostate cancer.

Background and purposeDose escalation has improved cancer outcomes for patients with localized prostate cancer. Targeting subprostatic tumor regions for dose intensification may further improve outcomes. Apparent Diffusion Coefficient (ADC) maps may enable early radiation response assessment and dose adaptation. This study was a proof-of-principle investigation of early changes in ADC radiomics features for patients undergoing radiotherapy with dose escalation to the gross tumor volume (GTV).Materials and methodsFifty-nine patients were enrolled on a prospective tumor dose-escalation trial. Multi-parametric MRI was performed at baseline and week six, corresponding to the time of peak ADC change. GTV and prostate contours were deformably registered between baseline and week six T2-weighted images, and applied to ADC maps, to account for diminished image contrast post-EBRT and possible differences in prostate gland volume, shape, and orientation. A total of 101 radiomics features were tested for significant change post-EBRT using two-tailed Student’s t-test. All ADC features of the prostate and GTV volumes were correlated using Pearson’s coefficient (p < 0.00008, based on Bonferroni correction).ResultsADC feature extraction was insensitive to b = 0 s/mm2 exclusion, and to gradient non-linearity bias. GTV presented predominant changes in first-order features, particularly 10Percentile, and prostate volumes presented predominant changes in second-order features. Changes in both first and second-order features of GTV and prostate ROIs were strongly correlated.ConclusionsOur data confirmed significant changes in numerous GTV and prostate features assessed from ADC and T2-weighted images during radiotherapy; all of which may be potential biomarkers of early radiation response.

High dose rate brachytherapy for prostate cancer: A prospective toxicity evaluation of a one day schedule including two 13.5 Gy fractions

Background and purposeHigh dose-rate (HDR) brachytherapy (BT) provides a highly conformal method of dose delivery to the prostate. The purpose of this study is to prospectively determine the toxicity of the treatment protocol of 13.5 Gy × 2 fractions. Materials and methodsFrom 2010 through 2017, 119 patients with low (71%) or intermediate-risk prostate cancer were prospectively treated in a single institute with HDR-BT at 13.5 Gy × 2 fractions within one day. Median follow-up time was 4.4 years. ResultsActuarial rates of no biochemical evidence of disease, overall survival and metastasis-free survival for all patients were 96%,98% and 98%, respectively. The cumulative incidence of acute grade 2 and 3 genitourinary (GU) toxicity was 9% and 2%, respectively. The corresponding incidences of late GU toxicity were 18% and 1%. No grade ≥4 of either type of toxicity was detected. Multivariate analysis showed that having higher international prostate symptom score (IPSS; P = 0.041) or higher V200 (P = 0.013) was associated with a higher risk of experiencing any grade of acute GU toxicity. In addition, patients having a higher IPSS (P = 0.019) or a higher V150 (P = 0.033) were associated with a higher grade >1 acute GU toxicity. ConclusionsThe findings of this study show that HDR-BT 13.5 Gy × 2 as monotherapy was safe and effective for prostate cancer patients with low-intermediate risk.

Changes in Apparent Diffusion Coefficient of the Dominant Tumor During Dose-Painted Radiation Therapy and High Dose Rate Brachytherapy for Prostate Cancer

Dose escalation has successfully improved cancer outcomes for patients with localized prostate cancer. Targeting subprostatic regions of tumor burden for dose-intensification may further improve tumor control and reduce dose to surrounding normal tissues. Quantitative MRI may provide a clinically useful evaluation of early radiation response to enable the adaptation of dose. Our objective is to determine whether the ADC derived from diffusion-weighted imaging (DWI) of prostate tumors may be used as a biomarker for evaluation of early radiation response and dose adaptation. Patients with biopsy proven prostate adenocarcinoma visualized on MRI prior to radiotherapy were recruited to participate in a prospective trial in which patients received 76 Gy in 38 fractions to the prostate and either an integrated boost (IB) (19 Gy/38#) or an HDR boost (10 Gy/1#) to the dominant tumor. Patients underwent endorectal coil multiparametric MRI (3T Verio, Siemens) at baseline and during week 6 of treatment. ADC was calculated from in-line processing of DWI (b values of 0, 100, 600, and 1000 s/mm2). Dominant tumors, prostate, and common reference points were defined on the baseline T2 weighted (T2w) image (Pinnacle). The prostate and common reference points were again defined on the week 6 T2w image. Deformable registration (Morpheus) was applied to the baseline prostate and reference contours to guide segmentation of the tumor volumes (no longer clearly visible) in the week 6 ADC maps. Volume of interest (VOI) voxel based histogram analysis of mean, skewness, and kurtosis were used to assess ADC response. Of 80 enrolled patients, the first 17 were analyzed. 8 patients received IB and 9 patients received HDR. Tumor volumes were small (baseline mean 2.0 cm3, 95% CI 1.6-2.9 cm3). For all 17 patients, there was a statistically significant increase in tumor ADC from baseline (mean 1.12x10-3 mm2/s, 95% CI 1.04-1.19 x10-3 mm2/s) to week 6 of treatment (mean 1.34x10-3 mm2/s, 95% CI 1.29-1.39 x10-3 mm2/s, p<0.001). Tumor ADC kurtosis increased significantly from 3.1 to 4.0 (95% CI 2.7-3.6 at baseline, 3.3-4.8 at week 6, p=0.04). Mean tumor ADC increased by 24.5% (95% CI 10-39%) in the IB-VMAT arm and 20% (95% CI 6-34%) in the VMAT+HDR arm (p=0.6). Our preliminary data confirm a statistically significant increase in tumor ADC during radiotherapy, worthy of further investigation. Complete analysis of the study cohort will elucidate relationships between early changes in tumor ADC and subsequent response to treatment.

High dose rate brachytherapy for prostate cancer: Current techniques and applications to varying disease presentations

High dose rate brachytherapy for prostate cancer: Current techniques and applications to varying disease presentations

EP-1771: Low dose rate brachytherapy for prostate cancer: A Brazilian Institution experience

EP-1771: Low dose rate brachytherapy for prostate cancer: A Brazilian Institution experience

A quantitative analysis of two-dimensional manually segmented transrectal ultrasound axial images in planning high dose rate brachytherapy for prostate cancer

Background/Aim. Prostate delineation, pre-planning and catheter implantation procedures, in high-dose rate brachytherapy (HDR-BT), are commonly based on the prostate manually segmented transrectal ultrasound (TRUS) images. The aim of this study was to quantitatively analyze the consistency of prostate capsule delineation, done by a single therapist, prior to each HDR-BT fraction and the changes in the shape of the prostate capsule during HDR-BT, using two dimensional (2D) TRUS axial image. Methods. A group of 16 patients were treated at the Medical System Belgrade Brachytherapy Department with definitive HDRBT. The total applied median dose of 52 Gy was divided into four individual fractions, each fraction being delivered 2? 3 weeks apart. Real time prostate axial visualization and the manual segmentation prior to each fraction were performed using B-K Medical ultrasound. Quantitative analyses, analysis of an area and shape were applied on 2D-TRUS axial images of the prostate. Area analyses were used to calculate the average value of the cross-sectional area of the prostate image. The parameters of the prostate shape, the fractal dimension and the circularity ratio of the prostate capsule contour were estimated at the maximum axial cross section of the prostate image. Results. The sample group consisted of four phases, each phase being performed prior to the first, second, third and fourth HDR-BT fraction, respectively. Statistical analysis showed that during HDR-BT fractions there were no significant differences in the average value of area, as well as in the maximum shape of prostate capsule. Conclusions. Quantitative analysis of TRUS axial prostate segmented images shows a successful capsule delineation in the series of manually segmented TRUS images, and the prostate maximum shape remaining unchanged during HDR-BT fractions.

Needle Migration in High Dose Rate Brachytherapy for Prostate Cancer Evaluated by Serial MRI and Photos

Needle Migration in High Dose Rate Brachytherapy for Prostate Cancer Evaluated by Serial MRI and Photos