Image-Guided BrachyAblation (IGBA) en hepatocarcinoma: descripción de la técnica y reporte del primer caso en Chile / Image-guided brachyablation for hepatocarcinoma: report of one case

Eighty percent of hepatocarcinomas are inoperable at the moment of diagnosis. Liver transplantation is the treatment of choice in these cases, but local therapies are another alternative. Among these, Image-Guided BrachyAblation is a safe choice. We report a 76-year-old male with a hepatocarcinoma, who was considered inoperable due to the high surgical risk of the patient. A local treatment with Image-Guided BrachyAblation was decided. A brachytherapy needle was placed in the tumor under computed tomography guidance and a 15 Gy single dose was delivered from an Iridium-192 source. The patient had no immediate complications and at one month of follow up he continued without incidents.

Effect of adipose-derived stem cells on radiation-induced acute skin injury in rats / 中南大学学报(医学版)

To investigate the effect of adipose-derived stem cells (ADSCs) on radiation-induced skin injury in SD rats.
 Methods: Radioactive particles 192Ir were used to irradiate the left medial thigh skin of SD rats, and the irradiation dose was at 90 Gy. Then, the rats were randomly allocated into a control group and a treatment group (each n=9). After the irradiation, the control group was injected with 60 μL PBS and the treatment group was injected with 60 μL ADSCs in irradiated skin. The progress of skin damage and healing was observed and photographed every day. Twenty-eighth days after the irradiation, the irradiated skin tissue was taken from the left thigh, and then fixed with formaldehyde fixative solution. At the same time, the skin tissue of the corresponding part of the normal group (n=9) that was not irradiated was also taken. After sampling, embedding and slicing, immunohistochemical staining was used to compare the levels of α-smooth muscle actin (α-SMA), and HE staining was used to compare pathological features of the skin.
 Results: Radioactive particle 192Ir caused the development of III or IV radioactive skin damage. The score of the treatment group was significantly lower than that of the control group. The wounds of the treatment group were basically healed at 28 days, while the ulcer of the control group was unhealed. So, the healing time was shorter in the treatment group. The expression of α-SMA in the skin of the two groups was increased after the radiotherapy. By analyzing the pathological microstructure image, we found that the thickness of epidermis in the control group was greater than that in the treatment group, while the vascular density in the treatment group was greater than that in the control group (all P<0.05).
 Conclusion: Radioactive particles 192Ir can cause skin damage, while the adipose-derived stem cells might alleviate radiation-induced skin injury and promote ulcer healing by promoting angiogenesis.

Role of vaginal pallor reaction in predicting late vaginal stenosis after high-dose-rate brachytherapy in treatment-naive patients with cervical cancer / 부인종양

OBJECTIVE: To assess actual rates of late vaginal stenosis and identify predisposing factors for complications among patients with previously untreated cervical cancer following high-dose-rate brachytherapy. METHODS: We performed longitudinal analyses of 57 patients using the modified Dische score at 6, 12, 18, 24, 36, and 60 months after treatment, which consisted of 15 interstitial brachytherapys and 42 conventional intracavitary brachytherapys, with a median follow-up time of 36 months (range, 6 to 144 months). RESULTS: More than half of the patients developed grade 1 (mild) vaginal stenosis within the first year of follow-up, and grade 2 (97.5%, moderate) to grade 3 (severe) stenosis gradually increased with time. Actual stenosis rates for grade 1, 2, and 3 were 97.5% (95% confidence interval [CI], 92.7 to 97.5), 60.7% (95% CI, 42.2 to 79.3), and 7.4% (95% CI, 0 to 18.4) at 3 years after treatment. Pallor reaction grade 2-3 at 6 months was only a statistically significant predisposing factor for grade 2-3 late vaginal stenosis 3 years or later with a hazard ratio of 3.48 (95% CI, 1.32 to 9.19; p=0.018) by a multivariate Cox proportional hazard model. Patients with grade 0-1 pallor reaction at 6 months showed a grade > or =2 vaginal stenosis rate of 53%, whereas the grade 2-3 pallor reaction group achieved a grade > or =2 vaginal stenosis rate at 3 years at 100% (p=0.001). CONCLUSION: High-dose-rate brachytherapy was associated with high incidence of late vaginal stenosis. Pallor reaction grade 2-3 at 6 months was predictive of late grade 2-3 vaginal stenosis at 3 years after treatment. These findings should prove helpful for patient counseling and preventive intervention.

Dosimetric characterization of a high dose rate 192I source for brachytherapy application using Monte Carlo simulation and benchmarking with thermoluminescent dosimetry

The purpose of this project was to derive the brachytherapy dosimetric functions described by American Association of Physicists in Medicine [AAPM] TG-43 U1 based on high dose rate [192]I sources. The method utilized included both simulation of the designed Polymethyl methacrylate [PMMA] phantom using the Monte Carlo of MCNP4C and benchmarking of the simulation with thermoluminescent [TL] dosimeters. The obtained results for the radial dose function and anisotropy function showed nominal errors of less than 3% between TL measurements and the MCNP4C results. It may be concluded that due to small observed errors and the large uncertainty associated with the high dose gradients near the source point the simulation results can be used for dose estimation

A randomized controlled trial of two chemotherapy regimens (paclitaxel liposome combined with platinum and paclitaxel combined with platinum) in concurrent chemoradiotherapy for cervical carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To compare the efficacy, side effects and influence of two chemotherapy regimens, paclitaxel liposome combined with platinum and paclitaxel combined with platinum, on the survival rate in patients with cervical carcinoma receiving concurrent chemoradiotherapy.</p><p><b>METHODS</b>One hundred and sixty two cases with primary cervical carcinoma diagnosed and treated in the Jiangxi Maternal and Children Hospital between January 2008 and November 2009 were enrolled in this randomized controlled trial. Seventy one cases were included in the paclitaxel group and 91 in the paclitaxel liposome group. The chemotherapy doses were as followings: paclitaxel liposome and paclitaxel 135 mg/m(2); cisplatin 80 mg/m(2) or carboplatin AUC 4 - 6, repeated every 21 days for two or three times. Radical radiotherapy was given to both groups at the same time. The efficacy was evaluated by the tumor regression and the patients were followed-up for six months.</p><p><b>RESULTS</b>The overall response rates of paclitaxel group and paclitaxel liposome group were 90.1% and 89.0%, respectively (P > 0.05). The 1-year cumulative survival rate was 91.4% for the paclitaxel group and 89.2% for the paclitaxel liposom group (P > 0.05). The incidence rate of adverse effects such as rash, gastrointestinal toxicity, bone marrow suppression and muscle/joint pain in the paclitaxel liposome group was significantly lower than that in the paclitaxel group (P < 0.05), while there was no significant difference regarding the hair loss, liver damage, and peripheral neuritis (P > 0.05).</p><p><b>CONCLUSIONS</b>Paclitaxel liposome plus platinum is a safe and effective therapeutic regimen for stage IIa-IV cervical carcinoma. However, the long-term efficacy of this regimen should be further observed.</p>

Analysis of the initial efficacy of nedaplatin combined with megestrol in concurrent chemoradiotherapy for advanced cervical cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the early efficacy of nedaplatin combined with megestrol in concurrent chemoradiotherapy for advanced cervical cancer.</p><p><b>METHODS</b>Forty-two cases of cervical cancer (FIGO IIb to IVa) were divided randomly into two groups: radiotherapy alone (21 cases) and radiation plus chemotherapy (Nedaplatin) group. The same radiotherapy was given to the two groups. Patients of the RT + C group received nedaplatin 30 mg/m2 in intravenous drip infusion once weekly on day 1, for 4 to 5 weeks, and megestrol 160 mg orally every day during the radiation therapy.</p><p><b>RESULTS</b>The early outcome: the complete remission rate was 81.0% and partial remission rate was 19.0% in the RT + C group, significantly better than the CR (38.1%) and PR (42.9%) in the RT group. The 1-year survival rates in the two groups were 100% (21/21) and 81.0% (17/21), respectively, with a significant difference between the two groups (P<0.05).</p><p><b>CONCLUSIONS</b>The combination of nedaplatin and megestrol with concurrent chemoradiotherapy can improve the early outcome of advanced cervical cancer, with somewhat increased but tolerable adverse effects.</p>

Surgical intervention for the central recurrence or persistent local lesion of uterine cervical carcinoma following full-dose radiotherapy / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the results of surgical treatment for central recurrence or persistent local lesion of uterine cervical carcinoma following full-dose radiotherapy.</p><p><b>METHODS</b>Forty-seven patients were diagnosed having central recurrence or persistent local lesion of uterine cervical carcinoma following full-dose radiotherapy. The patients were treated surgically: extrafascial hysterectomy was performed in 37 cases, radical hysterectomy in 7, and modified radical hysterectomy in 3. Their clinicopathological features were retrospectively reviewed.</p><p><b>RESULTS</b>Central recurrence or persistent local lesion was confirmed by pathology in 36 patients, while negative in 11. For patients receiving extrafascial hysterectomy, the median survival time and 5-year survival rate were 22 months and 40.4%, while for radical hysterectomy corresponding figures were 26 months and 40.0%. The mean operation time for the extrafascial hysterectomy and the radical or modified hysterectomy was 2.5 and 3.8 hours, respectively. The mean blood loss was 272.1 and 610.0 ml, respectively. The postoperative morbidity was 21.6% for extrafascial hysterectomy and 70.0% for radical or modified hysterectomy (P = 0.007).</p><p><b>CONCLUSION</b>For some patients with central recurrence or persistent local lesion of uterine cervical carcinoma following full-dose radiotherapy, surgical intervention may achieve long time survival. Extrafascial hysterectomy is a feasible and effective treatment for some selected patients.</p>

Tratamiento con braquiterapia intersticial de alta tasa de dosis: en cáncer de mama precoz / Treatment with high doses interstitial brachytherapy: in early breast cancer

El cáncer representa un problema de salud pública. El cáncer de mama, es una entidad que aumenta su incidencia en el mundo. Esto ha llevado a nuevos enfoques terapéuticos quirúrgicos, químicos y radiantes. En el siguiente trabajo se hace mención del tratamiento con braquiterapia de alta tasa de dosis realizado en el Hospital Universitario de Mérida, en el servicio integral de oncología. Se evaluaron 148 pacientes con cáncer de mama en todos los estadios desde febrero 2007 hasta 30 mayo 2008. Se seleccionaron pacientes estadio I-IIANO MO, se analizaron las pacientes que reunieron los criterios de inclusión. En 19 pacientes (12,8 %) se cumplió braquiterapia intersticial hiperfraccionada con intervalo de 6 horas (800 cGy/día) 4 sesiones (400 cGy por fracción). Dosis total 3200 cGy. Con rango de seguimiento entre 18 meses y 2 meses y un promedio de 10 meses sin evidencia de recaída locorregional.

The breast cancer represents a public health problem. The breast cancer is entities which increase his incidence in the world. These problem do to a creation of new surgery, chemical and radiant therapeutically modes. In these work we mention the high dose brachytherapy tease doses realized in the University Merida Hospital in the integral service of oncology. We evaluated 148 patients with breast cancer disease in all the stage since February 2007 to May30 of 2008. We selected a 148 patients classified stage I-IIANO MO, and analyzed the patients with have inclusion therapeutically criterions. In 19 (12.8 %) patients were underwent to interstitial brachytherapy hyperfraccion with and interval to 6 hours (800 cGy/day) in 4 sessions (400 cGyfor fraction). Total doses applied was 3200 cGy. With a control range between 18 month and 2 month, and average of 10 month without any evidence of loco regional distress.

Desenvolvimento e implantação da calibração de câmaras de ionização tipo poço com fonte de 192Ir de alta taxa de dose no Brasil / Development and implementation of the calibration of ionization chambers well with 192Ir source for high dose rate in Brasil

A utilização da braquiterapia com equipamentos de pós-carga remota com fonte de 192Ir de alta taxa de dose tem aumentado em todo o mundo e no Brasil que conta hoje com 60 equipamentos instalados em Serviços de Radioterapia. A necessidade de se garantir a rastreabilidade da grandeza dosimétrica associada às fontes radioativas à Rede Internacional de Metrologia das Radiações Ionizantes tornou-se evidente e urgente, pois doses altas são aplicadas em pouco tempo ao tumor e qualquer erro na determinação dessa dose pode acarretar muito dano aos pacientes. Na ausência de um padrão dosimétrico estabelecido para o espectro de energia do 192Ir, muitos trabalhos mostraram alternativas para a calibração de fontes de 192Ir de alta taxa de dose com câmaras de ionização tipo dedal e tipo poço. A câmara poço, por ser de uso mais simples e apresentar metodologia reprodutível no ambiente de um Serviço de Radioterapia, passou a ser recomendada por instituições internacionais. Os Serviços de Radioterapia do Brasil que possuem equipamentos de pós-carga remota com fonte de 192Ir de alta taxa de dose utilizam, atualmente, a câmara tipo poço para a dosimetria de suas fontes. Como a calibração desse instrumento ainda é restrita a alguns países do hemisfério norte e a fim de suprir a necessidade do Brasil, este trabalho propõe uma metodologia para a calibração das câmaras poço dos usuários com fonte de 192Ir de alta taxa de dose, rastreada à Rede Internacional de Metrologia das Radiações Ionizantes. No método proposto é utilizada uma câmara dedal, calibrada no LNMRI/IRD/CNEN (rastreado à Rede Internacional de Metrologia das Radiações Ionizantes) em feixe de raios X e 60Co com uma interpolação adequada para a energia do 192Ir. Utiliza-se um sistema de posicionamento dessa câmara e da fonte de 192Ir de um equipamento de pós-carga remota para determinar a grandeza taxa de kerma no ar de referência dessa fonte que é, então, utilizada para calibrar as câmaras tipo poço dos usuários...

The use of brachytherapy with after-loading equipment with remote source of high dose rate 192Ir has increased worldwide and in Brazil, which presents 60 facilities with this equipment nowadays. The need to ensure the traceability of the source dosimetric quantity to the International Ionizing Radiation Metrology Network has become evident and urgent, since high doses values are delivered in a short time to the tumor and any error in the determination of the dose can provoke much damage to patients. In the absence of an established dosimetric standard for the energy spectrum of 192Ir, many studies showed alternative calibration of sources of high dose rate 192Ir, with the ionization thimble or well chamber type. The well type chamber is now recommended by international organisms, because of its simplicity to use and to its reproductibility. Nowadays, it is adopted by all radiotherapy services in Brazil using after-loading equipment with high dose rate 192Ir source. As the calibration of this instrument is still limited to some countries in the northerm hemisphere, in order to enhance the growth of the use of this instrument in Brazil, this paper proposes a methodology for calibration of well chambers of users of high dose rate 192Ir sources, traceable to the International Ionizing Radiation Metrology Network. In the proposed method a thimble chamber is used, calibrated in LNMRI/IRD/CNEN (traceable to the International Ionizing Radiation Metrology Network) in X-ray and 60Co beams with an interpolation for the 192Ir energy. Using a positioning system to hold the chamber and a high dose rate 192Ir source, the quantity reference air kerma rate is determined. This radioactive source is then used to calibrate the user's chambers. The proposed methodology was tested in various radiotherapy services of the country and was also compared to the existing methodology in University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL)...

Resultados da associação de braquiterapia de alta taxa de dose à teleterapia no câncer da próstata / Results of the association of high dose-rate brachytherapy with external beam irradiation in prostate cancer

INTRODUÇÃO: Braquiterapia de alta taxa de dose (BATD) para o câncer de próstata pode ser uma boa opção para escalonamento de dose, como um reforço de dose, associada à radioterapia externa, principalmente se não há disponibilidade de radioterapia tridimensional conformada ou tecnologia mais avançada. OBJETIVOS: Neste trabalho, analisaram-se os resultados e as toxicidades de um reforço de dose com BATD prévio à radioterapia externa convencional ou tridimensional conformada em pacientes portadores de câncer localizado da próstata. Fatores prognósticos relacionados à sobrevida livre de doença, além de toxicidade do tratamento também foram estudados. MÉTODOS: Estudo retrospectivo de 403 pacientes com adenocarcinoma localizado da próstata tratados entre dezembro de 2000 e março de 2004, que receberam 3 esquemas de fracionamento distintos de BATD de acordo com o seu grupo de risco: três frações de 5,5 a 6 Gy, 6 a 6,5 Gy ou 6,5 a 7 Gy, para baixo, médio ou alto risco, respectivamente, em um único implante, no decorrer de 24h de internação. A radioterapia externa convencional ou conformada compreendeu dose de 45 Gy na próstata e vesículas seminais. Foram realizadas análises uni e multivariada para avaliação dos fatores prognósticos relacionados à sobrevida livre de falha bioquímica e toxicidades. RESULTADOS: A idade mediana dos pacientes foi de 68 anos, com PSA médio de 9g/ml, peso prostático médio de 35 cc. Grau histológico de Gleason igual a 6 ocorreu em 43% dos casos, estádio menor do que T2c em 97%, presença de nódulo prostático em 49%; 11% dos pacientes apresentaram história de ressecção transuretral e 16% obstrução urinária prévias. No grupo de baixo risco foram classificados 36.1% dos pacientes, 42.8% no grupo de risco intermediário e 21.1% foram considerados de alto risco. Hormonioterapia neoadjuvante por até 6 meses foi utilizada em 64% dos casos e teleterapia conformada em 19%. O seguimento médio foi de 50 meses (mediano de 48,4 meses), variando de 24 a 113...

INTRODUCTION: high dose-rate brachytherapy (HDR) for prostate cancer may be a nice treatment option for dose escalation as a boost, when associated to external beam irradiation, mainly if 3D conformal or more advanced technology is not available. PURPOSE: this study analyzes the results and toxicities of HDR brachytherapy boost prior to external beam radiotherapy with 2D or 3D conformal irradiation in patients with localized prostate cancer. Prognostic factors associated to overall and disease-free survival, as well as to treatment related toxicity were also studied. METHODS: A retrospective study of 403 patients with localized prostate adenocarcinoma treated between December 2000 and March 2004 was performed. According to the risk group, three fractions of HDR brachytherapy were delivered in the course of 24 hours, with a single implant: 5.5 to 6 Gy per fraction for low risk, 6 to 6.5 Gy per fraction for intermediate risk, and 6.5 to 7 Gy per fraction for high risk patients. The interval between fractions was of at least 6 hours. Conventional 2D or 3D conformal external beam irradiation was delivered to the prostate and seminal vesicles with 25 fractions of 1.8Gy (45Gy), about 2 weeks after brachytherapy. Multivariate analysis was done to evaluate unfavorable prognostic factors for biochemical failure free survival (BFFS). RESULTS: Patients presented a median age of 68 years, mean PSA of 9g/ml, and average prostate weight of 35 cc. Gleason score was equal to 6 in 43% of the cases, and 97% of the cases were at a stage lower than T2c. Prostate nodules were present in 49% of the patients; prior history of transurethral resection or urinary obstruction was present in 11% and 16% of the patients, respectively. There were 36.1% patients in the low risk group, 42.8% in the intermediate, and 21.1% in the high risk groups, respectively. Up to six months of neoadjuvant hormone therapy was used in 64% of the cases. External beam radiation was delivered with 3D...

Endocavitary radiotherapy in carcinoma oesophagus.

Radiation therapy is often used in an attempt to palliate or cure oesophageal neoplasms. However, the radiation tolerance of the normal structures around the oesophagus (heart, lung and spinal cord) restricts the radiation dose that can be delivered. We used a nasogastric catheter to deliver High Dose Intra-luminal Iridium-192 irradiation for carcinoma of the oesophagus using HDR-Varisource machine. This technique for treatment of carcinoma of the oesophagus can help overcome the dose restraints. The external beam radiation dose was about 46 Gy and the intra luminal dose was 5 Gy at 1 cm from central axis. These after loading procedures are simple, fast and accurate and can be used to boost external radiation therapy doses. Since the intra luminal boost delivers a high-localized dose with little side effects, this simple technique should be used to obtain palliation, delay tumour progression, reduce overall treatment time and attempt to improve survival in patients with oesophageal neoplasm. Intra luminal brachytherapy helps achieve good palliation in these neoplasms.

Postoperative radiotherapy with high dose rate iridium 192 mould for prevention of earlobe keloids.

BACKGROUND: A 50% to 80% recurrence rate of earlobe keloids can occur following a simple excision. Many modalities, including radiotherapy, have been suggested to reduce the postoperation recurrence. OBJECTIVE: The aim of the present study was to determine the efficacy of postoperative radiotherapy by a high dose rate Iridium 192 mould in the prevention of earlobe keloids recurrence. MATERIAL AND METHOD: Between March 1999 and March 2003, 22 patients with 24 earlobe keloids were treated by radiotherapy immediately following surgical excision. A dose of 15 Gray in 3 fractions was delivered at a point placed 5 mm from the axis of the Iridium sources. RESULTS: From the 22 patients with 24 keloids who were treated, 15 patients with 16 keloids were followed for a minimum of 6 months. Recurrence occurred in two keloids (12.5%). There were no severe adverse effects. CONCLUSION: Postoperative radiotherapy by high dose rate Iridium 192 mould was an effective prevention of earlobe keloids recurrence. It was well tolerated and did not present any significant side effects.

Effect of jingui shenqi pill on morphology of injured spinal cell apoptosis in rats caused by brachytherapy / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the effect of Jingui Shenqi Pill (JSP) on morphology of spinal cell apoptosis in rats injured by 192Ir irradiation.</p><p><b>METHODS</b>One hundred and twenty rats were randomly divided into four groups: the model group, the JSP group, the prednisone group and the normal group. Corresponding pharmaceutics were given to rats once a day for 14 days respectively. Then except rats in the normal group, the others received 192Ir interstitial irradiation with the dosage of 22 Gy using back-fixing technology. The injured segments of spinal cord were taken out for HE staining, TUNEL examination and observation with electron microscope 8 hrs, 24 hrs and 4 weeks after irradiation.</p><p><b>RESULTS</b>HE staining examination showed no obvious histological change in rats 8 and 24 hrs after irradiation, but pathological changes, as tissue rarefaction and hemorrhage did found in white matter of spinal cord shown by TUNEL 4 weeks later. Electron microscopic examination and TUNEL staining showed that as compared with the model group, the apoptotic index in the JSP and predinisone treated groups was significantly lower (P < 0.01) 8 hrs after radiation, but it showed insignificant difference between groups at the time points of 24 hrs and 4 weeks after radiation (P > 0.05).</p><p><b>CONCLUSION</b>JSP could act against apoptosis of gliocyte in spinal cord of rats in early stage after brachytherapy, indicating that JSP possessing a prednisone-like action.</p>

In-air calibration of an HDR 192Ir brachytherapy source using therapy ion chambers.

The Gammamed Plus 192Ir high dose rate brachytherapy sources were calibrated using the therapy level ionization chambers (0.1 and 0.6 cc) and the well-type chamber. The aim of the present study was to assess the accuracy and suitability of use of the therapy level chambers for in-air calibration of brachytherapy sources in routine clinical practice. In a calibration procedure using therapy ion chambers, the air kerma was measured at several distances from the source in a specially designed jig. The room scatter correction factor was determined by superimposition method based on the inverse square law. Various other correction factors were applied on measured air kerma values at multiple distances and mean value was taken to determine the air kerma strength of the source. The results from four sources, the overall mean deviation between measured and quoted source strength by manufacturers was found -2.04% (N = 18) for well-type chamber. The mean deviation for the 0.6 cc chamber with buildup cap was found -1.48 % (N = 19) and without buildup cap was 0.11% (N = 22). The mean deviation for the 0.1 cc chamber was found -0.24% (N = 27). Result shows that probably the excess ionization in case of 0.6 cc therapy ion chamber without buildup cap was estimated about 2.74% and 1.99% at 10 and 20 cm from the source respectively. Scattered radiation measured by the 0.1 cc and 0.6 cc chamber at 10 cm measurement distance was about 1.1% and 0.33% of the primary radiation respectively. The study concludes that the results obtained with therapy level ionization chambers were extremely reproducible and in good agreement with the results of the well-type ionization chamber and source supplier quoted value. The calibration procedure with therapy ionization chambers is equally competent and suitable for routine calibration of the brachytherapy sources.

Dose uniformity assessment of intraluminal brachytherapy using HDR 192Ir stepping source.

PURPOSE: The aim of this study is to achieve dose uniformity for intraluminal implants by assessment of dose distributions for single catheter generated by using various combinations of source stopping spacing and optimization mode. MATERIALS AND METHODS: A dose distribution was generated using HDR 192Ir stepping source on single straight catheter of fixed length used for Intraluminal brachytherapy. The various combinations of source position spacing and optimization mode were used and these dose distributions were evaluated by using three different parameters. The source position spacings were 0.2, 0.5, 1.0, 1.4, 2.0, 2.5, 3.0 and 3.3 cm. Three different optimization modes that compute the source stopping times along the catheter were used. The parameters used for assessment of dose distributions were statistical analysis of doses to dose reference points, area under natural dose-volume histogram and the dose non-uniformity ratio. RESULTS: None of the combinations of source position spacing and optimization mode was able to generate the desired optimum uniform dose distribution. However in a discrete manner, comparatively higher uniform dose distribution was found with short (0.2 cm) and longer (1.5 to 2.0 cm) source spacing. Optimization mode of Iterative correction was found to be suitable for the single catheter used in intraluminal brachytherapy. CONCLUSION: The applicator dimension and irradiation target volume should be taken in to consideration while selecting either higher or smaller source position spacing for the single catheter intraluminal brachytherapy. The Anisotropy factor of the source has some role in the variation of the dose uniformity over the target volume.

Effect on dose owing to source displacement in coronary endovascular brachytherapy / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effect on the dose distribution of source position displacement with the target region margin in catheter-based 192Ir line source endovascular brachytherapy.</p><p><b>METHOD</b>Dose rate distribution along longitudinal axes was estimated by the formula recommended by AAPM No.60 and No. 43.</p><p><b>RESULTS</b>In the two cases of source displacement (1.1 and 5 mm) doses of target region margin was decreased dramatically (at most 53.9% and 565.8% respectively) were compared to that of no source displacement, and the affected range was 6 mm and 9 mm respectively.</p><p><b>CONCLUSION</b>Source displacement will lead to the decrease of dose in target region margin.</p>

Treatment of keloids by immediat post-operatoire interstitial brachytherapy

Clinically considered as a pathologic scar remaining beyond 12 to 18 months, the keloid is characterised by a high recurrance rate after excision alone [50% - 100%]. Many therapeutic methods were used [Corticotherapy, pressotherapy], with disappointing results. The aim of this paper is to identify that post operative interstitial radiotherapy by iridium 192 [low dose rate] is effective for improving local control of keloids and preventing recurrence. From 1995 to 1998, 14 patients [18 keloids] were treated at the National Institute of Oncology - Rabat - Morocco. The average age is 27 years. The keloid was located on ear lobes in half of the cases. All patients had previously a trauma [injured, surgery]. 3 patients had multiple keloids. 10 patients [70% of cases] had keloid relapse after surgical excision. The treatment consisted of surgical excision followed immediately by brachytherapy with iridium 192. After 41 months of follow-up, we had obtained a good esthetic results in 7 cases [8 keloids]. 4 patients [5 keloids] recurred after an average delay of 14 months. 4 patients [5 keloids] were lost to follow-up

Survival Benefits of Lung Cancer Patients Undergoing Laser and Brachytherapy

We aimed to compare the duration of survival among subjects receiving brachytherapy (BT) in combination with Nd:YAG laser therapy (LT), and those receiving LT or BT alone. The medical records of subjects who received endobronchial treatment for unresectable tracheobronchial malignancies between January 1997 and December 1999 in a single center were reviewed retrospectively. A total of 80 patients were evaluated. The overall symptomatic response rate after treatment was 86.5%. Median survival durations for the LT, BT, and combined therapy (CT) group were 111, 115, and 264 days, respectively. The survival duration was significantly longer in the CT group than in the BT group (p=0.0078), but the difference was not statistically significant between the CT and the LT group. The bronchoscopic finding of endobronchial polypoid lesion was associated with a longer survival time than extraluminal with compression type (p=0.0023) by univariate analysis. Other factors associated with the better prognosis included hemoglobin > or = 12.5 g/dL, serum albumin level > or =37 g/L, and BT dose > or = 15 Gy at 1 cm distance. Of these factors, specific bronchoscopic findings, serum albumin level, CT modality, and dose of BT retained statistical significance in multivariate analysis. In conclusion, combined LT and BT is associated with increased patient survival compared with BT alone. Combined therapy may improve survival time in selected patients with endobronchial malignancies.

Tratamento do câncer do endométrio com braquiterapia de alta taxa de dose / Treatment of endometrium neoplasm with high dose rate brachytherapy

Cento e quatro pacientes com histologia comprovada de carcinoma do endométrio foram tratadas desde a instalaçao da BATD no Departamento, em 1991. A idade mediana foi de 65,5 anos e o seguimento mediano de 38 meses. Noventa e cinco eram pós-menopausadas, sete peri-menopausadas e duas estavam na pré-menopausa. Dezesseis pacientes eram do estádio clínico (pós-cirúrgico) EC IA, sendo cinco com grau de diferenciaçao Gl, oito G2 e três G3. Trinta e quatro pacientes eram do EC IB, dez com grau de diferenciaçao Gl, 18 G2 e seis G3. Vinte e cinco eram do EC IC, sendo nove Gl, nove G2 e sete G3. Seis eram do EC IIA, duas Gl, três G2 e uma G3. Oito eram do EC IIB, uma Gl, três G2 e quatro G3. Nove eram do EC IIIA, duas Gl, cinco G2 e duas G3. Três eram do EC IIIB, sendo duas Gl e uma G2. Uma era EC IIIC G3 e duas eram IVA G3. Dependendo da extensao da doença, a cirurgia consistiu de pan-histerectomia (Histerectomia total mais salpingooforectomia bilateral), pan-histerectomia mais omentectomia ou Wertheim-Meigs. Todas as pacientes dos estádios clínicos IA e IB apresentam-se sem evidência de doença (SED). As do EC IC 24 estao SED e uma apresentou metástases (MAD). As do EC IIA, cinco estao SED e uma MAD. As do EC IIB, seis estao SED, uma com progressao de doença local (PDL) e uma foi a óbito (OPD). As do EC IIIA, sete estao SED, uma MAD e uma apresentou progressao de doença. As do EC IIIB l está SED e duas apresentam progressao de doença. A paciente IIIC está SED, dois meses após o tratamento, e as IVA se apresentam SED, três e quatro meses após o término do tratamento. Oito pacientes apresentaram complicaçoes leves de tratamento Os resultados sao semelhantes aos dos tratamentos com braquiterapia de baixa taxa de dose, tanto em sobrevida como em complicaçao, com a vantagem de ser realizado em regime ambulatorial , sem os inconvenientes de uma internaçao hospitalar.