High Dose Rate Brachytherapy In Patients Research Articles

Clinical use of high dose-rate brachytherapy in treatment of patients with localized prostate cancer and infravesical obstruction

Background. High dose-rate brachytherapy is a new method of interstitial radiation therapy for treatment of localized prostate cancer. The difference from low dose therapy is temporary implantation of radiation sources with targeted high dose-rate irradiation of the affected organ.Aim. To evaluate 3-year effectiveness and safety of high dose-rate brachytherapy in patients with infravesical obstruction. Materials and methods. Between January of 2017 and December of 2019 at the Central Clinical Hospital “RZD-medicine”, 49 patients (mean age 67.8 ± 7.5 years) with verified prostate cancer diagnosis underwent high dose-rate brachytherapy in the regimen of 2 sessions of 15 Gy with 192Ir source. The inclusion criteria were disease stage ≤сТ2с, Gleason score ≤7. Patients were divided into 2 groups: 1st – patients with incidental prostate cancer (n = 21) who previously (more than 6 months ago, mean time 9.4 ± 2.4 months) underwent transurethral prostatectomy; 2nd – patients with verified prostate cancer (mean prostate volume 56 cm3) and obstructive symptoms without previous transurethral prostatectomy (n = 28).Results. In both groups, no intraoperative complications were observed. In 6 (28 %) patients of the 1st group and 2 patients of the 2nd group, grade II genitourinary toxicity in the form of moderate dysuria and nocturia was observed. Acute gastrointestinal toxicity was observed in 3 (14 %) patients of the 1st group, in the 2nd group such complications were absent. In the 2nd group during the postoperative period after the 2nd session, 4 patients (14 %) experienced acute urinary retention requiring cystostomy.Conclusion. High dose-rate brachytherapy is a safe and effective radical treatment method for patients with localized prostate cancer with obstructive symptoms who have contraindications for surgical treatment.

Effects of Interfraction Dose Variations of Target and Organs at Risk on Clinical Outcomes in High Dose Rate Brachytherapy for Cervical Cancer.

Meeting dose prescription is critical to control tumors in radiation therapy. Interfraction dose variations (IDVs) from the prescribed dose in high dose rate brachytherapy (HDR) would cause the target dose to deviate from the prescription but their clinical effect has not been widely discussed in the literature. Our previous study found that IDVs followed a left-skewed distribution. The clinical effect of the IDVs in 100 cervical cancer HDR patients will be addressed in this paper. An in-house Monte Carlo (MC) program was used to simulate clinical outcomes by convolving published tumor dose response curves with IDV distributions. The optimal dose and probability of risk-free local control (RFLC) were calculated using the utility model. The IDVs were well-fitted by the left-skewed Beta distribution, which caused a 3.99% decrease in local control probability and a 1.80% increase in treatment failure. Utility with respect to IDV uncertainty increased the RFLC probability by 6.70% and predicted an optimal dose range of 83 Gy-91 Gy EQD2. It was also found that a 10 Gy dose escalation would not affect toxicity. In conclusion, HRCTV IDV uncertainty reduced LC probabilities and increased treatment failure rates. A dose escalation may help mitigate such effects.

Reirradiation Options for Previously Irradiated Prostate cancer (RO-PIP): Feasibility study investigating toxicity outcomes following reirradiation with stereotactic body radiotherapy (SBRT) versus high-dose-rate brachytherapy (HDR-BT)

IntroductionRadiotherapy is the most common curative treatment for non-metastatic prostate cancer; however, up to 13% of patients will develop local recurrence within 10 years. Patients can undergo further and potentially...

Automatic segmentation of magnetic resonance images for high-dose-rate cervical cancer brachytherapy using deep learning.

Magnetic resonance (MR) imaging is the gold standard in image-guided brachytherapy (IGBT) due to its superior soft-tissue contrast for target and organs-at-risk (OARs) delineation. Accurate and fast segmentation of MR images are very important for high-quality IGBT treatment planning. The purpose of this work is to implement and evaluate deep learning (DL) models for the automatic segmentation of targets and OARs in MR image-based high-dose-rate (HDR) brachytherapy for cervical cancer. A 2D DL model using residual neural network architecture (ResNet50) was developed to contour the targets (gross tumor volume (GTV), high-risk clinical target volume (HR CTV), and intermediate-risk clinical target volume (IR CTV)) and OARs (bladder, rectum, sigmoid, and small intestine) automatically on axial MR slices of HDR brachytherapy patients. Furthermore, two additional 2D DL models using sagittal and coronal images were also developed. A 2.5D model was generated by combining the outputs from axial, sagittal, and coronal DL models. Similarly, a 2D and 2.5D DL models were also generated for the inception residual neural network (InceptionResNetv2 (InRN)) architecture. The geometric (Dice similarity coefficient (DSCs) and 95th percentile of Hausdorff distance (HD)) and dosimetric accuracy of 2D (axial only) and 2.5D (axial+sagittal+coronal) DL model generated contours were calculated and compared. The mean (range) DSCs of ResNet50 across all contours were 0.674 (0.05-0.96) and 0.715 (0.26-0.96) for the 2D and 2.5D models, respectively. For InRN, these were 0.676 (0.11-0.96) and 0.723 (0.35-0.97) for the 2D and 2.5D models, respectively. The mean HD of ResNet50 across all contours was 15.6mm (1.8-69mm) and 12.1mm (1.7-44mm) for the 2D and 2.5D models, respectively. The similar results for InRN were 15.4mm (2-68mm) and 10.3mm (2.7-39mm) for the 2D and 2.5D models, respectively. The dosimetric parameters (D90) of GTV and HR CTV for manually contoured plans matched better with the 2.5D model (p>0.6) and the results from the 2D model were slightly lower (p<0.08). On the other hand, the IR CTV doses (D90) for all of the models were slightly lower (2D: -1.3 to -1.5Gy and 2.5D: -0.5 to -0.6Gy) and the differences were statistically significant for the 2D model (2D: p<0.000002 and 2.5D: p>0.06). In case of OARs, the 2.5D model segmentations resulted in closer dosimetry than 2D models (2D: p=0.07-0.91 and 2.5D: p=0.16-1.0). The 2.5D DL models outperformed their respective 2D models for the automatic contouring of targets and OARs in MR image-based HDR brachytherapy for cervical cancer. The InceptionResNetv2 model performed slightly better than ResNet50.

A multiobserver study investigating the effectiveness of prostatic multiparametric magnetic resonance imaging to dose escalate corresponding histologic lesions using high-dose-rate brachytherapy

PurposeUsing multiparametric MRI data and the pathologic data from radical prostatectomy specimens, we simulated the treatment planning of dose-escalated high-dose-rate brachytherapy (HDR-BT) to the Multiparametric MRI dominant intraprostatic lesion (mpMRI-DIL) to compare the dose potentially delivered to the pathologically confirmed locations of the high-grade component of the cancer. Methods and MaterialsPathologist-annotated prostatectomy midgland histology sections from 12 patients were registered to preprostatectomy mpMRI scans that were interpreted by four radiologists. To simulate realistic HDR-BT, we registered each observer's mpMRI-DILs and corresponding histology to two transrectal ultrasound images of other HDR-BT patients with a 15-Gy whole-gland prescription. We used clinical inverse planning to escalate the mpMRI-DILs to 20.25 Gy. We compared the dose that the histopathology would have received if treated with standard treatment plans to the dose mpMRI-targeting would have achieved. The histopathology was grouped as high-grade cancer (any Gleason Grade 4 or 5) and low-grade cancer (only Gleason Grade 3). Results212 mpMRI-targeted HDR-BT plans were analyzed. For high-grade histology, the mpMRI-targeted plans achieved significantly higher median [IQR] D98 and D90 values of 18.2 [16.7–19.5] Gy and 19.4 [17.8–20.9] Gy, respectively, in comparison with the standard plans (p = 0.01 and p = 0.003). For low-grade histology, the targeted treatment plans would have resulted in a significantly higher median D90 of 17.0 [16.1–18.4] Gy in comparison with standard plans (p = 0.015); the median D98 was not significantly higher (p = 0.2). ConclusionsIn this retrospective pilot study of 12 patients, mpMRI-based dose escalation led to increased dose to high-grade, but not low-grade, cancer. In our data set, different observers and mpMRI sequences had no substantial effect on dose to histologic cancer.

Outcomes of patients with cervical cancer treated with low- or high-dose rate brachytherapy after concurrent chemoradiation

ObjectiveThe majority of patients with cervical cancer in Ghana present with locally advanced disease. In October 2014, high-dose rate (HDR) brachytherapy was introduced at the National Center for Radiotherapy, Accra...

The clinical impact of removing rectal gas on high-dose-rate brachytherapy dose distributions for gynecologic cancers.

PurposeTo evaluate the impact of gas removal on bladder and rectal doses during intracavitary and interstitial high‐dose‐rate brachytherapy (HDRB) for gynecologic cancers.Material and MethodsFifteen patients treated with definitive external beam radiation followed by HDRB for gynecologic cancers for a total of 21 fractions, presented with a significant amount of rectal gas at initial CT imaging (CTGAS) after implantation. The gas was removed via rectal tubing followed by subsequent scan acquisition (CTCLINICAL), which was used for planning and treatment delivery. To assess the effect of gas removal on dosimetry, both bladder and rectum volumes were recontoured on CTGAS. In order to evaluate the clinical impact on the total Equivalent‐Dose‐in‐2Gy‐fraction (EQD2), each fraction was also replanned to maintain clinically delivered target coverage (HRCTV D90). EQD2 D2cm3 for bladder and rectum were compared between plans. The Wilcoxon signed rank test was performed to evaluate statistically significant differences for all comparisons (P < 0.05).ResultsMean rectum and bladder Dmax, D0.1cm3, D1cm3, D2cm3, and D5cm3 were significantly different between CTGAS and CTCLINICAL. The mean percent increases on CTGAS for bladder were 12.3, 8.4, 9.9, 10.2, and 9.5% respectively and for rectum were 27.0, 19.6, 18.1, 18.5, and 19.4%, respectively. After replanning with CTGAS to maintain HRCTV D90 EQD2, bladder and rectum EQD2 D2 cm3 resulted in significantly higher doses. The mean EQD2 D2 cm3 difference was 2.4 and 4.1 Gy for bladder and rectum, revealing a higher impact of gas removal on rectal DVH.ConclusionRectal gas removal resulted in statistically significant differences for both bladder and rectum. The resulting larger EQD2 D2 cm3 for bladder and rectum demonstrates that if patients were treated without removing gas, target coverage would need to be sacrificed to satisfy the rectum constraints and prevent toxicities. Therefore, this study demonstrates the importance of gas removal for gynecologic HDRB patients.

High-Dose-Rate Brachytherapy for the Treatment of Basal and Squamous Cell Carcinomas on Sensitive Areas of the Face: A Report of Clinical Outcomes and Acute and Subacute Toxicities

PurposeBasal cell and cutaneous squamous cell carcinoma are common malignancies (keratinocyte carcinomas [KCs]). Surgical resection is the standard of care. Radiation using high-dose rate brachytherapy (HDR-BT) may serve as a superior alternative where surgical scars may be of cosmetic concern or in elderly patients with significant comorbidity. We aim to describe the clinical and cosmetic outcomes as well as posttreatment radiation toxicities associated with HDR-BT in patients who were treated for KCs of the face.Methods and MaterialsPatients with KCs treated with HDR-BT from 2015 to 2018 were included in the study. Patient medical records and clinical photos were reviewed at multiple time points: start of treatment, end of treatment, short-term (2 week) follow-up, 3-month follow-up, and if needed at 6 months. Radiation toxicity was graded using the Radiation Therapy Oncology Grading (RTOG) acute toxicity scale. Median (range) toxicity grades at follow-up intervals were calculated. Clinical outcomes including local recurrence were evaluated for all patients.ResultsThe study included 19 patients and 20 KCs. The median radiation dose was 42 Gy (39-42 Gy) over 6 fractions. The median toxicity at completion of treatment was RTOG grade 2 (85% of patients). At short-term follow-up, 50% of patients (n = 10) improved to RTOG grade 1 (0-2). At 3 months, 70% of patients (n = 14) had RTOG grade 0, and by 6 months, 100% of patients (n = 18) had RTOG grade 0. No RTOG grade 3 or higher skin toxicity was observed. With a median follow-up of 7.2 months (range, 1.3-54.4 months), the local recurrence-free survival was 95%.ConclusionsWe demonstrate that HDR-BT can be used as definitive treatment of KCs of the face with excellent cosmetic outcomes and local control. Acute and subacute skin toxicities were most commonly RTOG grade 2 or less with resolution of patient’s skin toxicity by 3 months.

Single dose high-dose rate (HDR) brachytherapy (BT) as monotherapy for localised prostate cancer: Early results of a UK national cohort study

BackgroundHDR brachytherapy alone is effective for the treatment of localised prostate cancer when given in 2–4 or more fractions. Single dose treatment has been explored in small cohort studies to date. This paper reports a large patient population with localised prostate cancer treated with single dose HDR brachytherapy delivering 19 Gy providing early outcome data from this approach. Patients and methodsSeven centres across the UK collaborated in this national protocol to deliver 19 Gy to the PTV defined by the prostate capsule and a 3 mm expansion with clearly defined planning constraints for the urethra and rectum. Entry criteria allowed all risk groups provided PSA ≤40 µg/L and staging investigations were negative for metastases. The primary end point was biochemical relapse free survival (bRFS) defined using the Phoenix definition. Toxicity was measured using CTCAE v4.0. ResultsA total of 441 patients were entered with median follow up 26 months (range 2–56). Median age was 73 (range 54–84) and 10% were low risk, 65% intermediate risk and 25% high risk. ADT was received by 37.6% overall and 90% of high risk patients for a median period of 6 months. Three year bRFS was overall 88%: this was 100% in low risk, 86% in intermediate risk and 75% in high risk. Only Gleason score was an independent predictor of bRFS. Relapse in 25 patients was assessed radiologically and occurred in the prostate in 15 of these, 11 of whom had localised prostate relapse only. Acute toxicity was low with no grade 3 or 4 events; there were two cases of late urinary stricture and two grade 3 late rectal events. ConclusionThis is the largest cohort of single dose HDR brachytherapy patients treated with a single dose published to date. It shows that with 19 Gy there is 100% bRFS at 3 years in low risk patients but results in intermediate and high risk groups are less encouraging falling to 86% and 75% at 3 years with relapse predominantly in the prostate. Limited by the short follow up period of this study, the long-term outcomes of this single dose HDR approach remains uncertain. It is important to have close ongoing surveillance of this cohort as the data matures.

Brachytherapy in head and neck malignancies: Indian Brachytherapy Society (IBS) recommendations and guidelines.

PurposeBrachytherapy (BT) forms major treatment modality in squamous cell carcinoma of head and neck cancers (HNC). However, there is a dearth of literature and guidelines for the use in various indications. High-dose-rate brachytherapy (HDR-BT) in Indian scenario is an important treatment modality, and the recommendations in this guidelines aim to provide the necessary recommendations for the use of HDR-BT for uniform application across the country in patients with HNC.Material and methodsA panel consisting of members of the Indian Brachytherapy Society (IBS), based on their clinical experience was invited. The process involved defining important steps, precautions, target volumes and indications, thorough literature review, and discussion with fellow members. The guidelines were established and formulated the recommendations for HDR-BT based on available evidences and individual experience for sites, relevant to Indian settings.ResultsThe IBS recommends the use of HDR brachytherapy as a part of treatment of head and neck tumors. The scope of these guidelines and recommendations included practical suggestions, ensuring efficient use of brachytherapy treatment as radical with external beam radiotherapy (EBRT) boost, palliative and adjuvant as definitive, or re-radiation as salvage for HNC in India. The IBS has made specific site-wise recommendations for previously untreated and recurrent HNC patients on their selection criteria, implant techniques, target volume definition, and HDR treatment parameters, such as time, dose rate, total dose, and fractionation schedules. Limited experience exists with HDR-BT in patients with head and neck cancers in India and across the globe.ConclusionsIBS provided a consensus statement and guidelines for the head and neck brachytherapy and believed that these recommendations will overcome the fear of practicing radiation oncologists. This should generate interest amongst students and will help radiation oncologists all across the country to use the art of brachytherapy carefully in HNC patients, with better curative and salvage options.

Concurrent chemoradiotherapy for cervical cancer in a single institution: High-dose rate brachytherapy vs helical tomotherapy

Objective: We reviewed our experience and evaluated the results of helical tomotherapy (HT) compared the disease outcome with that of high-dose rate brachytherapy in patients with cervical cancer. Methods: Total 114 patients who have been treated with concurrent chemoradiotherapy(CCRT) for newly diagnosed cervical cancer from 2008 to 2017 were retrospectively reviewed. Radiotherapy was given as a combination of whole pelvic external beam RT (EBRT) followed by high-dose rate brachytherapy(BT) or helical tomotherapy(HT). Results: We extracted selected population using propensity score matching with 1:1 ratio. After adjustment for age, BMI, radiation dose, prior surgery, clinical stage and histologic type, there was no significantly different parameter between two groups. The overall survival was poorer in BT group compared to HT group (median survival 17.5 months after BT vs 30 months after HT, log rank p=0. 034). 4-year survival rates were 74.2% in brachytherapy group and 100% in tomotherapy group. But the progression free survival was not different between two groups(p=0.270). 1-year and 2-year progression-free rates were 85.3% and 76.3% in BT group, but those were 87.0% and 58.9% in HT group. In univariate analysis, there was no significant risk factor for overall survival. But in PFS, stage was the only significant risk factor for recurrence. In multivariate analysis, clinical stage was still significant risk factor after adjusting for the other clinical parameters. Conclusion: HT could be a feasible option for CCRT in patients with cervical cancer with appropriate indications. Further studies with delicate design and larger number from multicenter with long follow up period are warranted to confirm the significance of benefit of HT in concurrent chemoradiotherapy in the field of cervical cancer.

Predicting Deliverability for Nasobiliary High Dose Rate Brachytherapy Patients: A Retrospective Evaluation of Patient Catheter Curvature and Comparison with QA Results

Nasobiliary high dose rate brachytherapy has recently emerged as a minimally invasive option to escalate the radiation boost for liver transplant eligible cholangiocarcinoma patients. However, depending upon patient anatomy, the force on the source wire that is required to navigate the long and tortuous nasobiliary pathway may exceed the capability of the HDR afterloader’s source drive motor. The purpose of this study was to determine whether it is possible to anticipate treatment deliverability problems using a measurement of the patient’s catheter curvature. Toward this goal, we performed a retrospective analysis to measure the catheter curvatures for previously treated nasobiliary HDR patients. We provide a comparison of this clinical data with Results from a previously published custom quality assurance (QA) device [1] as well as the manufacturer’s specifications for the smallest recommended catheter radius of curvature.

MRI guided focal HDR brachytherapy for localized prostate cancer: Toxicity, biochemical outcome and quality of life

PurposeTo describe toxicity, biochemical outcome and quality of life after MRI guided focal high dose rate brachytherapy (HDR-BT) in a single fraction of 19 Gy for localized prostate cancer. Materials and methodsBetween May 2013 and April 2016, 30 patients were treated by MRI-guided focal HDR-BT. Patients with visible tumour on MRI were included. All patients were ≥65 years, T-stage <T3, Gleason ≤7, PSA <10 ng/mL and IPSS <15. Focal irradiation was delivered in a single fraction of 19 Gy to the D95 of the clinical target volume. Toxicity was reported using the Common Terminology Criteria for Adverse Events version 4. Biochemical failure was defined according to the Phoenix criteria and quality of life was measured using validated questionnaires. ResultsMedian follow up was 24 months. One patient developed a grade 2 and 3 GU toxicity after treatment. In the other 29 patients, no grade 2 or higher perioperative complications occurred. Five patients developed a biochemical recurrence. For all measured time points, there was no statistically significant deterioration in quality of life. ConclusionFocal MRI guided HDR-BT confers low toxicity rates and maintains quality of life. Biochemical recurrence is rather high, 5 patients developed a biochemical recurrence according to the Phoenix definition. Longer evaluation of these patients is necessary and caution is warranted before implementing focal HDR-BT in patients with localized prostate cancer.

Hypofractionated external beam radiation therapy in combination with HDR boost for localized prostate cancer: Quality of life outcomes.

62 Background: There is limited data to support the use of hypofractionated external beam radiation (HypoF) in combination with high dose rate brachytherapy (HDR). We report our quality of life (QOL) outcomes when treating intermediate (IR) and high risk (HR) prostate cancer patients with external beam radiation (EBRT) plus HDR. Methods: The charts of 54 patients with localized adenocarcinoma of the prostate treated with standard fractionation (SF) or HypoF EBRT plus HDR boost at a single institution between 2012 and 2015 were reviewed. All patients completed the American Urological Association Symptom Score (AUASS) and Expanded Prostate Index for Prostate Cancer – Clinical Practice (EPIC-CP) quality of life assessments prior to treatment and completed at least one follow-up survey. Linear mixed models were performed to test whether there was any significant change over time for each outcome and to detect whether there was any significant difference in each outcome between the different treatments. Results: Thirty-eight patients were treated with SF and 16 with HypoF. Median age at treatment was 68 years (range 55-82 years). Median follow-up for the cohort was 22.2 months (range 1.57-50.60 months). A majority of patients had clinical T1c disease (n = 35), Gleason score of 7 (n = 35), and a PSA &lt; 10 (n = 39). Thirty-one patients had NCCN IR, and 23 had HR disease. There was no significant difference in AUA score (p = 0.98), incontinence and urinary irritation/obstruction scores (p = 0.81 and p = 0.62, respectively), and rectal toxicity (p = 0.97) between the two dosing groups over time, or at any discrete time point. Likewise, sexual function, vitality score, and QOL scores were not significantly different between the dose groups over time (p = 0.59, p = 0.37, and p = 0.71, respectively). All QOL categories, except sexual function, trended toward baseline with increasing time from intervention. Conclusions: Our study suggests HypoF EBRT can be delivered in combination with HDR for patients with IR and HR adenocarcinoma of the prostate without increasing toxicity compared to SF with an HDR boost. This has important implications in terms of patient convenience and resource utilization.

Hypofractionated external beam radiation therapy in combination with HDR boost for localized prostate cancer: patient reported quality of life outcomes.

PurposeThere is limited data to support the use of hypofractionated external beam radiation (HypoF) in combination with high-dose-rate brachytherapy (HDR). We report our quality of life (QOL) outcomes when treating intermediate and high-risk prostate cancer patients with external beam radiation (EBRT) plus HDR.Material and methodsThe charts of 54 patients with localized adenocarcinoma of the prostate treated with standard fractionation (SF) or HypoF EBRT plus HDR boost at a single institution between 2012 and 2015 were reviewed. All patients completed the American Urological Association Symptom Score (AUASS) and Expanded Prostate Index for Prostate Cancer – Clinical Practice (EPIC-CP) quality of life assessments prior to treatment and completed at least one follow-up survey. Linear mixed models were performed to test for significant changes and differences in each outcome over time.ResultsThere was no significant difference in AUA score (p = 0.98), incontinence (urge) and urinary irritation/obstruction scores (p = 0.81 and p = 0.62, respectively), and bowel QOL (p = 0.97) between the two dosing groups over time or at any discrete time point. For both groups, AUA scores peaked at 0-2 months before improving. Likewise, sexual function, vitality score, and QOL scores were also not significantly different between the dose groups over time (p = 0.59, p = 0.37, and p = 0.71, respectively). All QOL categories, except sexual function, trended toward baseline with increasing time from intervention.ConclusionsOur study suggests HypoF EBRT can be delivered in combination with HDR for patients with ntermediate-risk and high-risk adenocarcinoma of the prostate without increasing toxicity compared to SF with an HDR boost.

Health-related quality of life changes due to high-dose rate brachytherapy, low-dose rate brachytherapy, or intensity-modulated radiation therapy for prostate cancer.

72 Background: To compare urinary, bowel, and sexual health-related quality of life (HRQOL) changes due to high-dose rate (HDR) brachytherapy, low-dose rate (LDR) brachytherapy, or intensity modulated radiation therapy (IMRT) monotherapy for prostate cancer. Methods: Between January 2002 and September 2013, 413 low-risk or favorable intermediate-risk prostate cancer patients were treated with HDR brachytherapy monotherapy to 2,700-2,800 cGy in two fractions (n=85), iodine-125 LDR brachytherapy monotherapy to 14,500 cGy in one fraction (n=249), or IMRT monotherapy to 7,400-8,100 cGy in 37-45 fractions (n=79) without pelvic lymph node irradiation. No androgen deprivation therapy was given. Patients used an International Prostate Symptoms Score questionnaire, an Expanded Prostate cancer Index Composite-26 bowel questionnaire, and a Sexual Health Inventory for Men questionnaire to assess their urinary, bowel, and sexual HRQOL, respectively, pre-treatment and at 1, 3, 6, 9, 12, and 18 months post-treatment. Results: Median follow-up was 32 months. HDR brachytherapy and IMRT patients had significantly less deterioration in their urinary HRQOL than LDR brachytherapy patients at 1 and 3 months post-irradiation. The only significant decrease in bowel HRQOL between the groups was seen 18 months following treatment, at which point IMRT patients had a slight, but significant, deterioration in their bowel HRQOL compared with HDR and LDR brachytherapy patients. HDR brachytherapy patients had worse sexual HRQOL than both LDR brachytherapy and IMRT patients following treatment. Conclusions: IMRT and HDR brachytherapy cause less severe acute worsening of urinary HRQOL than LDR brachytherapy. However, IMRT causes a slight, but significant, worsening of bowel HRQOL compared with HDR and LDR brachytherapy.

Health-related quality-of-life changes due to high-dose-rate brachytherapy, low-dose-rate brachytherapy, or intensity-modulated radiation therapy for prostate cancer

To compare urinary, bowel, and sexual health-related quality-of-life (HRQOL) changes due to high-dose-rate (HDR) brachytherapy, low-dose-rate (LDR) brachytherapy, or intensity-modulated radiation therapy (IMRT) monotherapy for prostate cancer. Between January 2002 and September 2013, 413 low-risk or favorable intermediate-risk prostate cancer patients were treated with HDR brachytherapy monotherapy to 2700-2800 cGy in two fractions (n = 85), iodine-125 LDR brachytherapy monotherapy to 14,500 cGy in one fraction (n = 249), or IMRT monotherapy to 7400-8100 cGy in 37-45 fractions (n = 79) without pelvic lymph node irradiation. No androgen deprivation therapy was given. Patients used an international prostate symptoms score questionnaire, an expanded prostate cancer index composite-26 bowel questionnaire, and a sexual health inventory for men questionnaire to assess their urinary, bowel, and sexual HRQOL, respectively, pretreatment and at 1, 3, 6, 9, 12, and 18 months posttreatment. Median follow-up was 32 months. HDR brachytherapy and IMRT patients had significantly less deterioration in their urinary HRQOL than LDR brachytherapy patients at 1 and 3 months after irradiation. The only significant decrease in bowel HRQOL between the groups was seen 18 months after treatment, at which point IMRT patients had a slight, but significant, deterioration in their bowel HRQOL compared with HDR and LDR brachytherapy patients. HDR brachytherapy patients had worse sexual HRQOL than both LDR brachytherapy and IMRT patients after treatment. IMRT and HDR brachytherapy cause less severe acute worsening of urinary HRQOL than LDR brachytherapy. However, IMRT causes a slight, but significant, worsening of bowel HRQOL compared with HDR and LDR brachytherapy.

SU‐C‐16A‐01: In Vivo Source Position Verification in High Dose Rate (HDR) Prostate Brachytherapy Using a Flat Panel Imager: Initial Clinical Experience

Purpose:We report our initial clinical experience with a novel position‐sensitive source‐tracking system based on a flat panel imager. The system has been trialled with 4 prostate HDR brachytherapy patients (8 treatment fractions) in this initial study.Methods:The flat panel imaging system was mounted under a customised carbon fibre couch top assembly (Figure 1). Three gold fiducial markers were implanted into the prostate of each patient at the time of catheter placement. X‐ray dwell position markers were inserted into three catheters and a radiograph acquired to locate the implant relative to the imaging device. During treatment, as the HDR source dwells were delivered, images were acquired and processed to determine the position of the source in the patient. Source positions measured by the imaging device were compared to the treatment plan for verification of treatment delivery.Results:Measured dwell positions provided verification of relative dwell spacing within and between catheters, in the coronal plane. Measurements were typically within 2.0mm (0.2mm – 3.3mm, s.d. 0.8mm) of the planned positions over 60 dwells (Figure 2). Discrimination between larger dwell intervals and catheter differentiation were clear. This confirms important delivery attributes such as correct transfer tube connection, source step size, relative catheter positions and therefore overall correct plan selection and delivery. The fiducial markers, visible on the radiograph, provided verification of treatment delivery to the correct anatomical location. The absolute position of the dwells was determined by comparing the measured dwell positions with the x‐ray markers from the radiograph, validating the programmed treatment indexer length. The total impact on procedure time was less than 5 minutes.Conclusion:The novel, noninvasive HDR brachytherapy treatment verification system was used clinically with minor impact on workflow. The system allows verification of correct treatment delivery, free of most potential human related errors identified in ICRP 97.This research is supported by funding from the Australian Government Department of Health through Cancer Australia grant no. 616614.

The effects of low- and high-dose-rate brachytherapy on depressive symptoms in prostate cancer patients

To compare the prevalence of depressive symptoms between prostate cancer (PCa) patients who have received low-dose-rate brachytherapy (LDRB) and those receiving high-dose-rate brachytherapy (HDRB). Direct comparisons were made between the prevalence of the DSM-IV-TR symptoms of major depressive disorder (MDD) based upon Zung Self-Rating Depression Scale responses and patients' records on 164 PCa patients from Queensland, Australia. HDRB patients had significantly greater frequency of self-reported symptoms of crying (or feeling like it) (MDD criterion 1), and restlessness and inability to sit still (MDD criterion 5), and a nonsignificant trend towards more frequent fatigue (MDD criterion 7). There was no significant association between fatigue and having received hormone therapy. These three MDD symptoms, which include one of the two alternative key required symptoms (criterion 1), suggest that HDRB PCa patients may present with clinically significantly different depression profiles from their peers who receive LDRB. Treatment choices need to be focused upon possible serotonergic dysfunction as well as somatic complaints of depression. The presence of subsyndromal depression in HDRB patients also warrants consideration.

SU-E-J-94: Investigating the Use of Deformable Algorithms to Register MR Images Acquired with and Without an Endo-Rectal Coil.

Magnetic resonance spectroscopic imaging (MRSI) can identify the dominant intraprostatic lesion, which can then be boosted using high-dose rate (HDR) brachytherapy. MRSI requires the use of an endo-rectal coil, which deforms the prostate. We investigate the performance of deformable registration algorithms to deform MR images acquired with an endo-rectal coil to images acquired without a coil for HDR brachytherapy planning. This study utilized MR images of five HDR brachytherapy patients acquired with and without an endo-rectal coil during the same MRSI imaging study. The prostate was contoured on each set of 'Coil-In' and 'Coil-Out' MR images by an experienced radiation oncologist. The 'Coil-In' and 'Coil-Out' images were rigidly aligned such that the posterior margins of the prostate were as close as possible without deformation. Variations on a commercially available deformation algorithm using the B-spline method were applied to a volume of interest that surrounded the prostate and excluded as much of the coil and rectum as possible. The Dice similarity index (DSI) was calculated between rigidly registered contours (DSI1), and compared to the DSI calculated between the 'Coil-In' contour and the contour deformed from the 'Coil-Out' image to the 'Coil-In' image (DSI2). The difference was calculated between DSI2 and DSI1, where a positive change in DSI would indicate an improvement in contour agreement over rigid registration of the prostate in the 'Coil-Out' and 'Coil-In' images. The B-spline deformation algorithm designed specifically for MR images was most effective in deforming the 'Coil-Out' to the 'Coil-In' prostate contour with a mean change in DSI of 0.0124 with contrast correction, and 0.0004 without. Out of six algorithms tested, only the MR-specific algorithm produced positive changes in DSI. The accuracy of the deformation algorithm on mapping the internal structures of the prostate between 'Coil-Out' and 'Coil-In' images is under investigation. We acknowledge Velocity for providing the registration software.