Long-term results with custom-linked iodine-125 seeds and real-time brachytherapy in low- and intermediate-risk prostate cancer.

Purpose: Brachytherapy (BT) with iodine-125 (125I) seeds is effective in low- and intermediate-risk prostate carcinoma, with fewer side effects compared to other techniques, but relapses increase in long-term. In the present paper, 10-year biochemical relapse-free survival (BRFS) results are presented. Material and methods: Between 2007 and 2016, 706 patients were treated with real-time technique using Bard-ProLink™ system. 145 Gy was administered to the prostate with exclusive BT and 108 Gy after 46 Gy of external radiotherapy (EBRT). Androgen deprivation therapy was applied in 19.3% of patients. Results: Median follow-up was 96 months (range, 24-163 months). BRFS at 5 and 10 years was 95% and 91.1%, respectively. For 480 low-risk cases, BRFS at 5 and 10 years was 95.7% and 92.7%, and for 226 intermediate-risk cases, it was 92.7% and 88%, respectively (p < 0.05). With combined treatment of EBRT + BT, 133 cases (59%) of intermediate-risk were treated without differences with exclusive BT. Gleason score 4 + 3 cases dropped to 72.8% at 10 years (p < 0.001), with androgen deprivation therapy (ADT) to 90.9% and without ADT to 66.8%; it was worse if patients had exclusive BT. 10-year BRFS for T1c was 95% compared to 84% for T2 (p < 0.001). Initial prostate specific antigen (PSA) > or < 10 showed no differences. With > 50% biopsy cores positive, it fell to 80% at 10 years (p < 0.001). In 154 patients up to 60 years of age, 10-year BRFS was 97.6%. Urinary complications appeared in 16.9% of cases in exclusive BT vs. 26.1% in EBRT + BT. Grade 2+ urinary late complications were observed in 19.1% and grade 3+ in 5.8% of patients. Rectal toxicity was 4% (2.5% in BT alone and 10.1% in RT + BT), while G3+ was seen in 0.1%. Conclusions: Real-time BT with custom-linked 125I seeds is a very effective long-term treatment in low- and intermediate-risk prostate carcinoma. With Gleason score 4 + 3 or > 50% biopsy cores positive, we recommend combined treatment with additional ADT for 6 months.

Open Source 3D Printed Lung Tumor Movement Simulator for Radiotherapy Quality Assurance.

In OECD (Organization for Economic Co-operation and Development) countries, cancer is one of the main causes of death, lung cancer being one of the most aggressive. There are several techniques for the treatment of lung cancer, among which radiotherapy is one of the most effective and least invasive for the patient. However, it has associated difficulties due to the moving target tumor. It is possible to reduce the side effects of radiotherapy by effectively tracking a tumor and reducing target irradiation margins. This paper presents a custom electromechanical system that follows the movement of a lung tumor. For this purpose, a hysteresis loop of human lung movement during breathing was studied to obtain its characteristic movement equation. The system is controlled by an Arduino, steppers motors and a customized 3D printed mechanism to follow the characteristic human breathing, obtaining an accurate trajectory. The developed device helps the verification of individualized radiation treatment plans and permits the improvement of radiotherapy quality assurance procedures.

Tratamiento no quirúrgico del schwannoma vestibular / Non surgical treatment of vestibular schwannoma

Introducción y objetivos: Valorar los resultados de control local y complicaciones en el tratamiento del schwannoma vestibular tratado con radiaciones. Métodos: Estudio retrospectivo de 194 pacientes diagnosticados de schwannoma vestibular, tratados de manera consecutiva bien con observación o bien con radiaciones (bien radiocirugía o radioterapia esterotáctica fraccionada) de 1997 a 2012. Analizamos el control local de los tumores, así como de las complicaciones secundarias al tratamiento con radiocirugía. Resultados: El 68% (132 tumores) son inferiores a 2 cm es decir grado I-II de la clasificación de Koos, 22 pacientes (13%) con tumores grandes grado IV, el resto (40 pacientes) son grado III. Los tumores relacionados con la neurofibromatosis (NF2) representan el 3,6% (6 tumores en 4 pacientes). El control tumoral para los pacientes tratados con radiaciones es del 97% a 5 años, con un seguimiento mediano de 80,4 meses. Para los tumores grandes el control local es del 91% a 5 años. La supervivencia libre de complicaciones crónicas es del 89% a 5 años. De los 50 tumores a los que se realizó seguimiento, 28 (58%) continúan en seguimiento al no haberse objetivado crecimiento alguno. Conclusiones: La radiación y el seguimiento con RM, dentro de un enfoque multidisciplinar, es una alternativa a la cirugía en el tratamiento del schwannoma vestibular, con un bajo nivel de complicaciones (AU)

Introduction and objectives: To evaluate the results of local control and complications in the treatment of vestibular schwannoma treated with radiation. Methods: A retrospective study of 194 patients diagnosed with vestibular schwannoma, treated consecutively with radiation (either stereotactic radiosurgery or fractionated radiotherapy) from 1997 to 2012. We analyze the local control of tumors, as well as secondary complications to treatment with radiation. Results: A total of 132 (68%) tumors 68% are grade I-II tumors of the Koos classification, 40 (19%) are grade III, and 22 (13%) are grade IV. The tumors associated with neurofibromatosis (NF2), are 3.6% (6 tumors in 4 patients). The tumor control for the overall serie is 97% at 5 years, with a median follow-up of 80.4 months. For large tumors the local control is 91% at 5 years. Free survival of chronic complications is 89% at 5 years. Aditionally, 50 tumors were subjected to regular follow-up with MRI without treatment, and 28 (58%) did not experienced tumor growth. Conclusions: Radiation and follow up with MRI, are an alternative to surgery in the treatment of vestibular schwannoma, with a low level of complications inside of multidisciplinary approach (AU)

Non surgical treatment of vestibular schwannoma.

INTRODUCTION AND OBJECTIVES: To evaluate the results of local control and complications in the treatment of vestibular schwannoma treated with radiation. METHODS: A retrospective study of 194 patients diagnosed with vestibular schwannoma, treated consecutively with radiation (either stereotactic radiosurgery or fractionated radiotherapy) from 1997 to 2012. We analyze the local control of tumors, as well as secondary complications to treatment with radiation. RESULTS: A total of 132 (68%) tumors 68% are grade I-II tumors of the Koos classification, 40 (19%) are grade III, and 22 (13%) are grade IV. The tumors associated with neurofibromatosis (NF2), are 3.6% (6 tumors in 4 patients). The tumor control for the overall serie is 97% at 5 years, with a median follow-up of 80.4 months. For large tumors the local control is 91% at 5 years. Free survival of chronic complications is 89% at 5 years. Additionally, 50 tumors were subjected to regular follow-up with MRI without treatment, and 28 (58%) did not experienced tumor growth. CONCLUSIONS: Radiation and follow up with MRI, are an alternative to surgery in the treatment of vestibular schwannoma, with a low level of complications inside of multidisciplinary approach.

From low-dose-rate to high-dose-rate brachytherapy in lip carcinoma: Equivalent results but fewer complications.

PURPOSE: To compare the use of high-dose-rate (HDR) brachytherapy (BT) in patients with lip carcinoma with a former series previously treated with low-dose-rate (LDR) BT. METHODS AND MATERIALS: Ninety-nine patients treated with LDR-BT were compared with 104 patients treated with HDR-BT. Distribution by stage was 53.5% T1, 15.1% T2, 3.1% T3, and 28.3% T4 for LDR and 52.9% T1, 32.7% T2, 0% T3, and 14.4% T4 for HDR. Some cases with positive or close margins received BT after surgery (34.3% with LDR vs. 16.3% with HDR). Parallel metallic needles were used in 100% of HDR cases and in 76% of LDR cases. Most HDR patients were treated with HDR-BT to a dose of 4.5-5 Gy per fraction prescribed to a 90% isodose, in nine fractions delivered twice daily for 5 days. RESULTS: Median followup was 63 months for LDR-BT and 51 months for HDR-BT. Overall local control for LDR- vs. HDR-BT was 94.9% vs. 95.2%; and 100% vs. 100%, 86.6% vs. 94.1%, and 89.3% vs. 80%, for T1, T2, and T4 stage tumors, respectively. Disease-free survival for LDR vs. HDR was 95.9% vs. 94.2%. Soft tissue necrosis, bone necrosis, and fair-bad cosmesis for LDR vs. HDR was 15.1% vs. 0%, 1% vs. 0%, and 11.1% vs. 0%, respectively. CONCLUSIONS: Treatment with HDR-BT using rigid needles is a simple technique that provides good long-term results with minimal complications. LDR- and HDR-BT are regarded as equally effective in local control and disease-free survival, but fewer complications arise when using HDR-BT.

Ten-year results of a phase II study with a single fraction of high-dose-rate brachytherapy (FAST-boost) after whole breast irradiation in invasive breast carcinoma.

PURPOSE: We present the results of a prospective ten-year follow-up study to prove the effectiveness of a single fraction of 192-Ir high-dose-rate (HDR) brachytherapy (BT) as a boost. PATIENTS AND METHODS: Between 1999 and 2000, 84 consecutive patients with invasive breast carcinoma, with over 4 mm free margins after conservative surgery, were treated. All cases were stages T1-2, except for one case, a stage T3, 81% pN0, 19% pN1-2. Chemotherapy was used in 47% and hormonal therapy in 87%. Whole breast external beam radiotherapy (46 Gy) was followed 1-2 weeks later by an implant with metallic needles. A 7 Gy single dose of HDR BT to the 90% isodose line was delivered on an outpatient basis. Dosimetry was performed theoretically. This technique is called FAST-boost because the whole treatment is delivered in about two hours. RESULTS: With a median follow-up of 120 months, three patients relapsed in the margin of the implant and two in a different quadrant (5/84, 6%). Actuarial local control at five and ten years was 98.5% and 95.6%. Overall survival was 92.7% and 90.2%, and disease-free survival 90.2% and 79.9%. Cosmetic results were good or excellent in 92.5%. CONCLUSIONS: A single-fraction HDR boost with rigid needles (FAST-boost) is a good, quick, simple technique when surgical margins are free.

The use of nomograms in LDR-HDR prostate brachytherapy.

PURPOSE: The common use of nomograms in Low Dose Rate (LDR) permanent prostate brachytherapy (BT) allows to estimate the number of seeds required for an implant. Independent dosimetry verification is recommended for each clinical dosimetry in BT. Also, nomograms can be useful for dose calculation quality assurance and they could be adapted to High Dose Rate (HDR). This work sets nomograms for LDR and HDR prostate-BT implants, which are applied to three different institutions that use different implant techniques. MATERIAL AND METHODS: Patients treated throughout 2010 till April 2011 were considered for this study. This example was chosen to be the representative of the latest implant techniques and to ensure consistency in the planning. A sufficient number of cases for both BT modalities, prescription dose and different work methodology (depending on the institution) were taken into account. The specific nomograms were built using the correlation between the prostate volume and some characteristic parameters of each BT modality, such as the source Air Kerma Strength, number of implanted seeds in LDR or total radiation time in HDR. RESULTS: For each institution and BT modality, nomograms normalized to the prescribed dose were obtained and fitted to a linear function. The parameters of the adjustment show a good agreement between data and the fitting. It should be noted that for each institution these linear function parameters are different, indicating that each centre should construct its own nomograms. CONCLUSIONS: Nomograms for LDR and HDR prostate brachytherapy are simple quality assurance tools, specific for each institution. Nevertheless, their use should be complementary to the necessary independent verification.

A dosimetric study of Leipzig applicators.

PURPOSE: To obtain the absolute dose-rate distribution in liquid water for all six cup-shaped Leipzig applicators by means of an experimentally validated Monte Carlo (MC) code. These six applicators were used in high-dose-rate (HDR) afterloaders with the "classic" and v2 (192)Ir sources. The applicators have an inner diameter of 1, 2, and 3 cm, with the source traveling parallel or perpendicular to the contact surface. METHODS AND MATERIALS: The MC GEANT4 code was used to obtain the dose-rate distribution in liquid water for the six applicators and the two HDR source models. To normalize the applicator output factors, a MC simulation for the "classic" and v2 sources in air was performed to estimate the air-kerma strength. To validate this specific application and to guarantee that realistic source-applicator geometry was considered, an experimental verification procedure was implemented in this study, in accordance with the TG43U1 recommendations. Thermolumniscent dosimeter chips and a parallel plate ionization chamber in a polymethyl methacrylate (PMMA) phantom were used to verify the MC results for the six applicators in a microSelectronHDR afterloader with the "classic" source. Dose-rate distributions dependence on phantom size has been evaluated using two different phantom sizes. RESULTS: Percentage depth dose and off-axis profiles were obtained normalized at a depth of 3 mm along the central axis for both phantom sizes. A table of output factors, normalized to 1 U of source kerma strength at this depth, is presented. The dose measured in the PMMA phantom agrees within experimental uncertainties with the dose obtained by the MC GEANT4 code calculations. The phantom size influence on dose-rate distributions becomes significant at depths greater than 5 cm. CONCLUSIONS: MC-detailed simulation was performed for the Nucletron Leipzig HDR applicators. The matrix data obtained, with a grid separation of 0.5 mm, can be used to build a dataset in a convenient format to model these distributions for routine use with a brachytherapy treatment planning system.

Lip cancer treatment with high dose rate brachytherapy.

We present 39 patients with lip carcinoma treated with HDR, (needles) with 5-5.5 Gy per 8-10 fractions b.i.d. (total dose 40.5-45 Gy). Three-year cause-specific survival and local control are 91 and 88% (95% T1-2, 74% T4, p<0.05). Acute and chronic reactions are like LDR cases. We think that HDR results are equivalent to LDR.