Recommendations of the Spanish Brachytherapy Group of SEOR for HDR endoluminal treatments. Part 1: oesophagus

The endoesophageal brachytherapy technique provides good results in the treatment of oesophageal cancer, when indicated. In a consensus meeting, the Spanish Brachytherapy Group of SEOR and the Spanish Society of Medical Physics (SEFM) agreed on the indications, dose, fractionation schedule, prescription and reporting to be performed in endoesophageal brachytherapy. The results of this consensus are presented here as recommendations for medical practice (AU)

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Recommendations of the Spanish Brachytherapy Group of SEOR for HDR endoluminal treatments. Part 1: Oesophagus.

The endoesophageal brachytherapy technique provides good results in the treatment of oesophageal cancer, when indicated. In a consensus meeting, the Spanish Brachytherapy Group of SEOR and the Spanish Society of Medical Physics (SEFM) agreed on the indications, dose, fractionation schedule, prescription and reporting to be performed in endoesophageal brachytherapy. The results of this consensus are presented here as recommendations for medical practice.

Consensus on treatment of endometrium carcinoma with brachytherapy.

Radiotherapy (RT) is commonly used as adjuvant treatment following hysterectomy and double oophorectomy in endometrial carcinoma. Prophylactic vaginal brachytherapy (BT) is the most common treatment in BT units. The PORTEC and GOG 99 studies have attempted to clarify the indications of BT and postoperative external RT, changing treatment standards. However, prophylactic BT regimens are very varied and there is currently no consensus on how to treat patients in terms of dose per fraction and number of fractions. Moreover, unoperated cases of endometrium are uncommon and there is limited experience in their treatment with BT. The 9th Consensus Meeting of the SEOR and SEFM Brachytherapy Group, held in Malaga on 11 March 2011, was therefore dedicated to "Brachytherapy in Endometrial Carcinoma". This article presents the consensus on treatment of endometrial carcinoma in operated (prophylactic vaginal BT) and unoperated (endouterine BT) patients.

Consensus on treatment of endometrium carcinoma with brachytherapy

Radiotherapy (RT) is commonly used as adjuvant treatment following hysterectomy and double oophorectomy in endometrial carcinoma. Prophylactic vaginal brachytherapy (BT) is the most common treatment in BT units. The PORTEC and GOG 99 studies have attempted to clarify the indications of BT and postoperative external RT, changing treatment standards. However, prophylactic BT regimens are very varied and there is currently no consensus on how to treat patients in terms of dose per fraction and number of fractions. Moreover, unoperated cases of endometrium are uncommon and there is limited experience in their treatment with BT. The 9th Consensus Meeting of the SEOR and SEFM Brachytherapy Group, held in Malaga on 11 March 2011, was therefore dedicated to "Brachytherapy in Endometrial Carcinoma". This article presents the consensus on treatment of endometrial carcinoma in operated (prophylactic vaginal BT) and unoperated (endouterine BT) patients (AU)

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 (AU)

Resultados de implante de semillas de iodo-125 con sistema de preplanificación en 250 pacientes con carcinoma de próstata / Results of 125-Iodine seed implant with preplanning system in 250 patients with prostate cancer

Objetivo: Revisar la experiencia con implantes permanentes de semillas de I-125 en carcinoma de próstata y el resultado a los 8 años de comenzar la técnica. Material y métodos: De 2002 a 2007 hemos realizado 250 implantes con braquiterapia de baja tasa con RapidStrand® y sistema de preplanificación. La edad media fue 68 años (49-78). El PSA medio fue 7,32 (2,31-14,6), 98% T1-T2a, 96% Gleason ≤ 6, 81% de bajo riesgo y 19% de riesgo intermedio (10 de estos últimos recibieron 46 Gy de radioterapia externa). Un 42% recibieron hormonoterapia. Resultados: Con seguimiento medio de 48 meses, 14 pacientes (5,7%) tuvieron recaída bioquímica (RB). En 11 pacientes (4,5%) con teórica RB el PSA descendió espontáneamente sin tratamiento. La supervivencia actuarial sin recaída bioquímica a 5 años fue del 91% (92% bajo riesgo, 86% riesgo intermedio); 92 vs 81% en pacientes con PSA < 10 vs > 10 (p < 0,05). Hubo complicaciones rectales G2 en el 0,6%, sondaje vesical en un 6,5%; el 60% conservaron la función sexual. El V100 medio fue del 89% y el D90 143 Gy. Conclusión: El resultado en carcinoma de próstata de bajo riesgo mediante semillas de Iodo-125es muy bueno con muy pocas complicaciones. Las elevaciones de PSA deberían ser controladas antes de dar tratamiento de rescate (AU)

Introduction: We review the experience with prostate carcinoma patients treated with permanent implants of 125-I seeds and the outcome eight years after the beginning of this technique. Material and methods: From 2002 to 2007 we have performed 250 implants with LDR brachytherapy with RapidStrand® and preplanning system. Mean age was 68 (49-78). Mean PSA was 7.32 (2.31 - 14.6). T1-T2a was the stage in 98%, and Gleason ≤ 6 in 96%. Low risk cases were 81% and intermediate risk 19% (ten of them received 46 Gy EBRT). Hormonal treatment was used in 42%. Results: With a mean follow-up of 48 months, 14 patients (5.7%) showed biochemical failure (BF). Eleven patients (4.5%) with theoretical BF were observed and PSA decreased without treatment. Actuarial PSA relapse-free survival at 5 years was 91%, (92% low risk, 86% intermediate cases), and 92% vs 81% with PSA <10 vs >10 (p < 0.05). Rectum complications were G2 in0 .6%. A urinary catheter was necessary in 6.5%. Sexual function was conserved in 60%. Mean V100 was 89% and D90 143 Gy. Conclusion: The outcome of patients with low risk prostate carcinoma treated with I-125 seed is very good with very low complications rate. Cases with PSA bounces should be controlled before starting a salvage treatment (AU)

[Results of 125-iodine seed implant with preplanning system in 250 patients with prostate cancer]. / Resultados de implante de semillas de iodo-125 con sistema de preplanificación en 250 pacientes con carcinoma de próstata.

INTRODUCTION: We review the experience with prostate carcinoma patients treated with permanent implants of 125-I seeds and the outcome eight years after the beginning of this technique. MATERIAL AND METHODS: From 2002 to 2007 we have performed 250 implants with LDR brachytherapy with RapidStrand(®) and preplanning system. Mean age was 68 (49-78). Mean PSA was 7.32 (2.31 - 14.6). T1-T2a was the stage in 98%, and Gleason ≤ 6 in 96%. Low risk cases were 81% and intermediate risk 19% (ten of them received 46 Gy EBRT). Hormonal treatment was used in 42%. RESULTS: With a mean follow-up of 48 months, 14 patients (5.7%) showed biochemical failure (BF). Eleven patients (4.5%) with theoretical BF were observed and PSA decreased without treatment. Actuarial PSA relapse-free survival at 5 years was 91%, (92% low risk, 86% intermediate cases), and 92% vs 81% with PSA <10 vs >10 (p<0.05). Rectum complications were G2 in 0.6%. A urinary catheter was necessary in 6.5%. Sexual function was conserved in 60%. Mean V100 was 89% and D90 143 Gy. CONCLUSION: The outcome of patients with low risk prostate carcinoma treated with I-125 seed is very good with very low complications rate. Cases with PSA bounces should be controlled before starting a salvage treatment.

Design and evaluation of a HDR skin applicator with flattening filter.

The purposes of this study are: (i) to design field flattening filters for the Leipzig applicators of 2 and 3 cm of inner diameter with the source traveling parallel to the applicator contact surface, which are accessories of the microSelectron-HDR afterloader (Nucletron, Veenendaal, The Netherlands). These filters, made of tungsten, aim to flatten the heterogeneous dose distribution obtained with the Leipzig applicators. (ii) To estimate the dose rate distributions for these Leipzig+filter applicators by means of the Monte Carlo (MC) method. (iii) To experimentally verify these distributions for prototypes of these new applicators, and (iv) to obtain the correspondence factors to measure the output of the applicators by the user using an insert into a well chamber. The MC GEANT4 code has been used to design the filters and to obtain the dose rate distributions in liquid water for the two Leipzig+filter applicators. In order to validate this specific application and to guarantee that realistic source-applicator geometry has been considered, an experimental verification procedure was implemented in this study, in accordance with the updated recommendations of the American Association of Physicists in Medicine Task Group No. 43 U1 Report. Thermoluminescent dosimeters, radiochromic film, and a pin-point ionization chamber in a plastic [polymethylmethacrylate (PMMA)] phantom were used to verify the MC results for the two applicators of a microSelectron-HDR afterloader with the mHDR-v2 source. To verify the output of the Leipzig +filter applicators, correspondence factors were deduced for the well chambers HDR100-plus (Standard Imaging, Inc., Middleton, WI) and TM33004 (PTW, Freiburg, Germany) using a specific insert for both applicators. The doses measured in the PMMA phantom agree within experimental uncertainties with the dose obtained by the MC calculations. Percentage depth dose and off-axis profiles were obtained normalized at a depth of 3 mm along the central applicator axis in a cylindrical 20 x 20 cm water phantom. A table of output factors, normalized to 1 U of source air kerma strength at this depth, is presented. Correspondence factors were obtained for the two well chambers considered. The matrix data obtained in the MC simulation with a grid separation of 0.5 mm has been used to build a data set in a convenient format to model these distributions for routine use with a brachytherapy treatment planning system.

Technique for routine output verification of Leipzig applicators with a well chamber.

The H-type Leipzig applicators are accessories of the microSelectron-HDR system (Nucletron, Veenendaal, The Netherlands) for treatment of superficial malignancies. Recently, the dose rate distributions in liquid water for the whole set of applicators using both source models available for the microSelectron-HDR afterloaders have been obtained by means of the experimentally validated Monte Carlo (MC) code GEANT4. Also an output table (cGy/hU) at 3 mm depth on the applicator central axis was provided. The output verification of these applicators by the user, prior to their clinical use, present practical problems: small detectors such as thermoluminescent dosimeters or parallel-plate ionization chambers are not easily used for verification in a clinical environment as they require a rigid setup with the Leipzig applicator and a phantom. In contrast, well-type ionization chambers are readily available in radiotherapy departments. This study presents a technique based on the HDR1000Plus well chamber (Standar Imaging) measurements with a special insert, which allows the output verification of the H-type Leipzig applicators on a routine basis. This technique defines correspondence factors (CF) between the in water dose rate output of the Leipzig applicators (cGy/hU) obtained with MC and the reading on the well chamber with the special insert, normalized to the HDR calibration factor with the HDR insert and to the source strength. To commission the applicators (with the well chamber and the special insert used), the physicist should check if the CF value agrees with its tabulated values presented in this work. If the differences are within 5% the tabulated output values can be used in clinical dosimetry. This technique allows the output validation of the Leipzig applicators with a well chamber widely used for HDR Ir-192 source strength measurements. It can easily be adapted to other types of well chambers for HDR source output verification.

Monte Carlo evaluation of kerma in an HDR brachytherapy bunker.

In recent years, the use of high dose rate (HDR) after-loader machines has greatly increased due to the shift from traditional Cs-137/Ir-192 low dose rate (LDR) to HDR brachytherapy. The method used to calculate the required concrete and, where appropriate, lead shielding in the door is based on analytical methods provided by documents published by the ICRP, the IAEA and the NCRP. The purpose of this study is to perform a more realistic kerma evaluation at the entrance maze door of an HDR bunker using the Monte Carlo code GEANT4. The Monte Carlo results were validated experimentally. The spectrum at the maze entrance door, obtained with Monte Carlo, has an average energy of about 110 keV, maintaining a similar value along the length of the maze. The comparison of results from the aforementioned values with the Monte Carlo ones shows that results obtained using the albedo coefficient from the ICRP document more closely match those given by the Monte Carlo method, although the maximum value given by MC calculations is 30% greater.