Intraoperative Neurovascular Bundle Preservation with Hyaluronic Acid during Radical Brachytherapy for Localized Prostate Cancer: Technique and MicroMosfet In Vivo Dosimetry.

PURPOSE: To evaluate the reduction in the absorbed dose delivered to the neurovascular bundle (NB) in patients with localized prostate cancer treated with only HDR brachytherapy and NB protection with hyaluronic acid (HA) on the side of the prostate to increase the distance from NB to the radioactive sources. METHODS: This is the first published report in the medical literature that studies a new approach to decrease neurovascular bundle toxicity and improve quality of life for patients with prostate cancer treated with radical brachytherapy as monotherapy. Transperineal HA injection on the side of the prostate into the lateral aspect of the prostate fat was used to consistently displace several autonomic fibers and vessels on the lateral wall of the prostate away from radiation sources. RESULTS: When a protection in the form of an HA layer is placed, the reduction effect at the maximum dose is between 46% and 54% (calculated values), which means that the method for protection is highly recommended. The values of the absorbed dose calculated in this project have been compared with the ones given by the treatment planning system. CONCLUSIONS: This newly created space decreases absorbed dose in the NB, calculated with the TPS and measured by microMOSFET due to the thickness of HA.

Characterization of microMOSFET detectors for in vivo dosimetry in high-dose-rate brachytherapy with 192 Ir.

PURPOSE: The objective of this study was to characterize the Best Medical Canada microMOSFET detectors for their application in in vivo dosimetry for high-dose-rate brachytherapy (HDRBT) with 192 Ir. We also developed a mathematical model to correct dependencies under the measurement conditions of these detectors. METHODS: We analyzed the linearity, reproducibility, and interdetector variability and studied the microMOSFET response dependence on temperature, source-detector distance, and angular orientation of the receptor with respect to the source. The correction model was applied to 19 measurements corresponding to five simulated treatments in a custom phantom specifically designed for this purpose. RESULTS: The detectors (high bias applied in all measurements) showed excellent linearity up to 160 Gy. The response dependence on source-detector distance varied by (8.65 ± 0.06)% (k = 1) for distances between 1 and 7 cm, and the variation with temperature was (2.24 ± 0.05)% (k = 1) between 294 and 310 K. The response difference due to angular dependence can reach (10.3 ± 1.3)% (k = 1). For the set of measurements analyzed, regarding angular dependences, the mean difference between administered and measured doses was -4.17% (standard deviation of 3.4%); after application of the proposed correction model, the mean difference was -0.1% (standard deviation of 2.2%). For the treatments analyzed, the average difference between calculations and measures was 4.7% when only the calibration coefficient was used, but it is reduced to 0.9% when the correction model is applied. CONCLUSION: Important response dependencies of microMOSFET detectors used for in vivo dosimetry in HDRBT treatments, especially the angular dependence, can be adequately characterized by a correction model that increases the accuracy of this system in clinical applications.

Focal high-dose-rate brachytherapy for localized prostate cancer: toxicity and preliminary biochemical results.

BACKGROUND: This study aimed to evaluate the outcomes and the toxicity of focal high-dose-rate (HDR) brachytherapy in selected localized prostate cancer patients. METHODS: Fifty patients were treated with focal high-dose-rate brachytherapy between March 2013 and November 2017, representing 5% of the cases treated by our group during this period. Only patients with very limited and localized tumors, according to strict criteria, were selected for the procedure. The prescribed dose for the focal volume was 24 Gy. RESULTS: The treated volume corresponded to a mean value of 32% of the total prostatic volume. The mean focal D90 in our series was 23 Gy (range 16-26 Gy). The mean initial IPSS was 8.2 (range 0-26), at 6 months 7.5 (range 0-23), and at 24 months 6.7 (range 0-18). No acute or late urinary retention was seen. When the ICIQ-SF score was 0 at the end of treatment, it remained nil thereafter at 1 and 2 years for all patients. No intraoperative or perioperative complications occurred. No rectal toxicity was reported after treatment. Of the total patients identified as potent, only three patients had a very slight decrease of the mean IIEF5. The mean initial PSA was 6.9 ng/mL (range 1.9-13.4). At the last follow-up visit, the mean PSA was 3 ng/ml (range 0.48-8.11). CONCLUSION: HDR focal brachytherapy in selected patients with low intermediate-risk prostate cancer could achieve the same satisfactory results in terms of relapse-free survival as conventional whole prostate brachytherapy with less toxicity.

High-dose-rate interstitial brachytherapy as monotherapy in one fraction of 20.5 Gy for the treatment of localized prostate cancer: Toxicity and 6-year biochemical results.

PURPOSE: To evaluate acute and late genitourinary toxicity, the gastrointestinal toxicity, and the long-term biochemical control after high-dose-rate (HDR) monotherapy in one fraction (20.5 Gy). MATERIALS AND METHODS: Between May 2011 and October 2014, 60 consecutive patients with low- and intermediate-risk prostate cancer were treated; the median followup was 51 months (range 30-79). All patients received one implant and one fraction of 20.5 Gy HDR real-time U/S planned with transperineal hyaluronic acid injection into the perirectal. Toxicity was reported according to the Common Toxicity Criteria for Adverse Event, Version 4.0 (CTAE v4.03) by the National Cancer Institute. Biochemical failure was defined according to the "Phoenix definition". RESULTS: Our experience in a single fraction of 20.5 Gy HDR brachytherapy is well-tolerated. No intraoperative or perioperative complications occurred. Grade 1 acute genitourinary toxicity occurred in 36% of patients, Grade 2 or more was not observed, only 1 patient requiring the use of a catheter for 7 days in the immediate postoperative period. No gastrointestinal toxicity was observed. No chronic toxicity has been observed after treatment. Morbidity is practically the same as that obtained with 19 Gy in our previously published article but the actuarial biochemical control was better, 82% (±3%) at 6 years. CONCLUSIONS: A single dose of 20.5 Gy resulted in a low genitourinary morbidity and no gastrointestinal toxicity and achieves good levels of biochemical disease control.

Accelerated partial breast irradiation in a single 18 Gy fraction with high-dose-rate brachytherapy: preliminary results.

PURPOSE: To evaluate the feasibility of acute and chronic toxicity in patients suitable for accelerated partial breast irradiation (APBI) in a single 18 Gy fraction with multicatheter high-dose-rate (HDR) brachytherapy, as well as cosmetic and oncological outcomes. MATERIAL AND METHODS: Between September 2014 and March 2016, twenty consecutive patients with low-risk invasive and ductal carcinoma in situ were treated with interstitial multicatheter HDR brachytherapy in a single 18 Gy fraction. RESULTS: Median age was 63.5 years (range, 51-79). Acute toxicity was observed in seven patients, while the pain during following days and hematoma were seen in four patients. With a median follow-up of 24 months, late toxicity was found in one patient with fat necrosis g2 and fibrosis g2 in another patient. The overall survival (OS) and locoregional control (LC) was 100%. Disease-free survival (DFS) and distant control was 95%. Good to excellent cosmetic outcomes were noted in 80% of patients and fair in 4 patients (20%). CONCLUSIONS: This is the first report in the medical literature that focuses on feasibility and acute and chronic toxicity, with a median follow-up of 24 months (range, 20-40). The protocol is viable and convenient. However, a longer follow-up is needed to know chronic toxicity and oncologic outcomes.

Long-term outcomes in patients younger than 60 years of age treated with brachytherapy for prostate cancer.

PURPOSE: The purpose of the study was to report the outcomes and late toxicities in patients younger than 60 years of age with long-term follow-up treated with low dose rate (LDR) brachytherapy for localized prostate cancer. METHODS: Between January 2000 and December 2009, 270 consecutive patients were treated with favourable localized prostate cancer; the median follow-up was 111 months (range 21-206). All patients received one implant of LDR brachytherapy. Toxicity was reported according to the Common Toxicity Criteria for Adverse Events, Version 4.0 (CTAE v4.02) by the National Cancer Institute. RESULTS: The overall survival according to Kaplan-Meier estimates was 99 (±1%) at 17 years. The 17-year rate for failure in tumour-free survival (TFS) was 97% (±1%), whereas for biochemical control it was 95% (±1%) at 17 years, 97% (±1%) of patients being free of local recurrence. No intraoperative or perioperative complications occurred. Acute genitourinary (GU) grade II toxicity was 4% at 12 months. No other chronic toxicity was observed after treatment. At 6 months, 94% of patients reported no change in bowel function. CONCLUSIONS: LDR brachytherapy provides patients younger than 60 years of age with low and intermediate-risk prostate cancer excellent outcomes and has a low risk of significant long-term GU or gastrointestinal morbidity.

Low-dose-rate brachytherapy for patients with transurethral resection before implantation in prostate cancer. Longterm results.

OBJECTIVES: We analyzed the long-term oncologic outcome for patients with prostate cancer and transurethral resection who were treated using low-dose-rate (LDR) prostate brachytherapy. METHODS AND MATERIALS: From January 2001 to December 2005, 57 consecutive patients were treated with clinically localized prostate cancer. No patients received external beam radiation. All of them underwent LDR prostate brachytherapy. Biochemical failure was defined according to the "Phoenix consensus". Patients were stratified as low and intermediate risk based on The Memorial Sloan Kettering group definition. RESULTS: The median follow-up time for these 57 patients was 104 months. The overall survival according to Kaplan-Meier estimates was 88% (±6%) at 5 years and 77% (±6%) at 12 years. The 5 and 10 years for failure in tumour-free survival (TFS) was 96% and respectively (±2%), whereas for biochemical control was 94% and respectively (±3%) at 5 and 10 years, 98% (±1%) of patients being free of local recurrence. A patient reported incontinence after treatment (1.7%). The chronic genitourinary complains grade I were 7% and grade II, 10%. At six months 94% of patients reported no change in bowel function. CONCLUSIONS: The excellent long-term results and low morbidity presented, as well as the many advantages of prostate brachytherapy over other treatments, demonstrates that brachytherapy is an effective treatment for patients with transurethral resection and clinical organ-confined prostate cancer.

High-dose-rate interstitial brachytherapy as monotherapy in one fraction for the treatment of favorable stage prostate cancer: Toxicity and long-term biochemical results.

BACKGROUND: To evaluate acute and late genitourinary, the gastrointestinal toxicity and the long-term biochemical control after HDR monotherapy in one fraction (19Gy). PATIENTS AND METHODS: Between April 2008 and October 2010, 60 consecutive patients were treated with favorable clinically localized prostate cancer; the median follow-up was 72months (range 32-91). All patients received one implant and one fraction of HDR. Fraction dose was 19Gy. Toxicity was reported according to the Common Toxicity Criteria for Adverse Event, Version 4.0 (CTAE v4.02) by the National Cancer Institute. RESULTS: No intraoperative or perioperative complications occurred. Acute toxicity grade 2 or more was not observed in any patients. No chronic toxicity, such as incontinence, late urinary retention, urethral narrowing, rectal bleeding, anal ulcer and/or rectourethral fistula has been observed after treatment. The overall survival and failure in tumor-free survival (TFS) according to Kaplan-Meier estimates was 90% (±5%) and 88% (±5%) respectively at 6years. The actuarial biochemical control was 66% (±6%) at 6years. CONCLUSIONS: This protocol is feasible and very well tolerated with low genitourinary morbidity, no gastrointestinal toxicity but no the same level of LDR biochemical control at 6years.

Low-dose-rate brachytherapy for patients with transurethral resection before implantation in prostate cancer. Long-term results

ABSTRACT We analyzed the long-term oncologic outcome for patients with prostate cancer and transurethral resection who were treated using low-dose-rate (LDR) prostate brachytherapy. Methods and Materials: From January 2001 to December 2005, 57 consecutive patients were treated with clinically localized prostate cancer. No patients received external beam radiation. All of them underwent LDR prostate brachytherapy. Biochemical failure was defined according to the "Phoenix consensus". Patients were stratified as low and intermediate risk based on The Memorial Sloan Kettering group definition. Results: The median follow-up time for these 57 patients was 104 months. The overall survival according to Kaplan-Meier estimates was 88% (±6%) at 5 years and 77% (±6%) at 12 years. The 5 and 10 years for failure in tumour-free survival (TFS) was 96% and respectively (±2%), whereas for biochemical control was 94% and respectively (±3%) at 5 and 10 years, 98% (±1%) of patients being free of local recurrence. A patient reported incontinence after treatment (1.7%). The chronic genitourinary complains grade I were 7% and grade II, 10%. At six months 94% of patients reported no change in bowel function.Conclusions: The excellent long-term results and low morbidity presented, as well as the many advantages of prostate brachytherapy over other treatments, demonstrates that brachytherapy is an effective treatment for patients with transurethral resection and clinical organ-confined prostate cancer

El análisis modal de fallos y efectos (AMFE) ayuda a aumentar la seguridad en radioterapia / No disponible

Objetivos: A raíz de una incidencia de sobredosis detectada en el servicio de radioterapia, se puso en marcha un proyecto de análisis y eliminación de riesgos para aumentar la seguridad de los pacientes.Material y método: Se aplicó el análisis modal de fallos y efectos (AMFE), un instrumento analítico aplicado en varios hospitales de Estados Unidos. Como exige la metodología, se cuantificaron los riesgos de cada modo de fallo en una escala de 1:1.000 utilizando el índice NPR (número de priorización del riesgo). En una primera fase de mejora, se definió el nivel de actuación como NPR > 100. Se detectaron varios riesgos en los protocolos actuales y se eliminaron todos ellos mediante redefinición de circuitos, controles y verificaciones adicionales, listas de comprobación y auditorias internas, entre otros. Posteriormente, se introdujo un sistema de gestión de la calidad según ISO9001, se definió una serie de indicadores y la dirección se implicó realizando revisiones mensuales de los resultados. Resultados: Se implantaron 100 acciones de mejora. El índice de riesgo calculado después de haber tomado las acciones bajó significativamente y aumentó la seguridad. Las mejoras realizadas aseguran el mantenimiento del grado de seguridad logrado. Conclusiones: La experiencia muestra que se puede identificar objetivamente los riesgos de cada paso que damos y destinar los escasos recursos de que disponemos a los procesos o actividades donde el riesgo es mayor, mediante mejoras metodológicas de nuestros protocolos de trabajo

Objectives: As a result of an adverse event detected at the Radiotherapy Treatment Unit, a safety improvement project was undertaken to analyze and eliminate risks and thus increase patient safety. Material and method: Failure Mode and Effects Analysis (FMEA), ananalytical tool used in many US hospitals, was applied. As required by FMEA, risks of potential failure modes were quantified on a scale of 1 to 1000, using the Risk Priority Number (RPN). In the first improvement phase, an RPN value greater than 100 was consideredto be the limit above which corrective actions should be taken. Several potential failure modes were detected in existing treatment protocols and all the causes of potential failure modes were eliminatedthrough corrective actions that included redefinition of treatment protocols, the creation of new records for existing controls and the addition of new controls, checklists, and internal audits, amongother measures. Subsequently, a quality management system based on ISO9001 was introduced. Process indicators were defined to measure treatment quality, and the results were analyzed on a monthly basis with top management participation.Results: A total of 100 improvement actions were taken. The RPN values calculated after the implementation of the actions were significantly lower, increasing patient safety. The actions taken ensure the maintenance of the achieved safety levels. Conclusions: The experience shows that the risks present in all steps taken can be objectively identified. Through improved procedures, the limited resources available can be allocated to those processes or activities that pose maximum risk