• Tuberculosis and Respiratory Diseases
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• v.73 no.6
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• pp.325-330
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• 2012

High-dose-rate endobronchial brachytherapy (HDREB) have been used as the treatment of early endobronchial cancer, as well as for palliation of advanced cancer. However, fatal hemoptysis can occur after HDREB at the rate of 7~32%. We report a case of massive hemoptysis due to radiation bronchitis developed after HDREB. A 67-year-old man was treated with HDREB for early endobronchial cancer on the left upper lobe bronchus. He complained of persistent cough from 4 weeks after completion of HDREB. Radiation bronchitis was observed on the bronchoscopy at 34 weeks, and it was progressed from mucosal swelling and exudate formation to necrosis and ulceration without local relapse. In addition, he died of massive hemoptysis after 15 months. The patient had no sign or radiologic evidences to predict the hemoptysis. This case implies that HDREB directly contributes to an occurrence of a fatal hemoptysis, and follow-up bronchoscopy is important to predict a progression of radiation bronchitis and fatal hemoptysis.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1487-1489
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• 2012

Objective: To compare the clinical efficacy of concurrent chemoradiotherapy, neoadjuvant chemotherapy, and intracavity brachytherapy in comprehensive treatment for young patients with stage Ib2 cervical cancer. Methods: One hundred and twelve young patients with stage Ib2 cervical cancer were enrolled retrospectively in our hospital from January 2003 to June 2005. They were categorized into three groups according to preoperative regimens, including the concurrent chemoradiotherapy group (Group 1, n=38), the neoadjuvant chemotherapy (Group 2, n=49), and the intracavity brachytherapy group (Group 3, n=25). Radical hysterectomy was performed following these regimens. Chemotherapy and radiotherapy were given according to pelvic lymph node metastasis, deep cervical stromal invasion, intravascular cancer emboli, histological grading, vaginal stump and positive surgical margin. Results: The cancer disappearance and superficial muscle invasion rates were statistically significantly better in the concurrent chemoradiotherapy group than in the other two groups (P<0.01). No statistically significant difference was noted in the deep muscle invasion rate, surgical time and intraoperative blood loss among three groups, but significantly more postoperative complications occurred in the concurrent chemoradiotherapy group. The 2-year pelvic recurrence was statistically significantly lower in the concurrent chemoradiotherapy group compared to other two groups, while the 5-year survival was higher. Conclusion: Concurrent chemoradiotherapy is efficacious for young patients with stage Ib2 cervical cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7805-7809
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• 2014

Objective: To explore the clinical efficacy and prognostic factors of chemoreduction combined with topical treatment of advanced intraocular retinoblastoma (RB). Materials and Methods: A total of 22 eyes from 17 children with RB were selected for the study and treated with chemoreduction combined with topical cryotherapy, transpupillary thermotherapy (TTT) or episcleral plaque brachytherapy. Clinical and follow-up data were retrospectively analyzed. Results: All children received 2~6 courses of chemoreduction treatment, ($4.5{\pm}0.8$ courses on average); 17 eyes from 13 children were treated by chemoreduction combined with cryotherapy or TTT and 5 eyes from 4 children with chemoreduction combined with $^{125}I$ episcleral plaque brachytherapy. The eye retention rate was 81.8% (18/22), among which 38.9% (7/18) featured restored or maintained good vision. Postoperative follow-up period was 7 to 34 months, ($18.6{\pm}5.2$ months on average). The recurrence rate was 41.2% (7/17), among which 57.1% (4/7) were controlled by supplementing or appending cryotherapy or TTT treatment during the follow-up period. The tumor basal diameter and thickness were significantly reduced (P<0.05 or P<0.01) after treatment. All children demonstrated different degrees of hair loss, 70.6% (12/17) with different degrees of gastrointestinal reactions, 5.88% (1/17) with neutropenia and 11.8% (2/17) being seriously infected during the chemotherapeutic treatment. Univariate and logistic regression analysis showed that tumor basal diameter before treatment had a significant effect on the prognosis (P<0.01). Conclusions: Chemoreduction combined with topical therapy can effectively control RB in the short term, and tumor basal diameter before treatment is an independent risk factor for prognosis.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6513-6518
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• 2013

Background: To evaluate the treatment outcome and major late complications of all patients with recurrent nasopharyngeal carcinoma (NPC) treated with intracavitary brachytherapy (ICBT) in Hospital Kuala Lumpur. Materials and Methods: This retrospective study was conducted at the Department of Radiotherapy and Oncology, Hospital Kuala Lumpur, Malaysia. All patients with histologically confirmed recurrent NPC in the absence of distant metastasis treated in the period 1997-2010 were included in this study. These patients were treated with ICBT alone or in combination with external beam radiotherapy (EBRT). Treatment outcomes measured were local recurrence free survival (LRFS), disease free survival (DFS) and overall survival (OS). Results: Thirty three patients were eligible for this study. The median age at recurrence was 56 years with a median time to initial local recurrence of 27 months. Majority of patients were staged as rT1-2 (94%) or rN0 (82%). The proportion of patients categorised as stage III-IV at first local recurrence was only 9%. Twenty one patients received a combination of ICBT and external beam radiotherapy while 12 patients were treated with ICBT alone. Median interval of recurrence post re-irradiation was 32 months (range: 4-110 months). The median LRFS, DFS and OS were 30 months, 29 months and 36 months respectively. The 5 year LRFS, DFS and OS were 44.7%, 38.8% and 28.1% respectively. The N stage at recurrence was found to be a significant prognostic factor for LRFS and DFS after multivariate analysis. Major late complications occurred in 34.9% of our patients. Conclusions: Our study shows ICBT was associated with a reasonable long term outcome in salvaging recurrent NPC although major complications remained a significant problem. The N stage at recurrence was a significant prognostic factor for both LRFS and DFS.

• Journal of the Korean Society of Radiology
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• v.10 no.1
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• pp.39-44
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• 2016

This study is fulfilled to evaluate the exposure dose nearby a patient during the brachytherapy of the prostate cancer treatment and to minimize the radiation exposure by evaluating the exposure dose of the person near the relevant implanted patient, technicians and gardians. The experiment method is used on the study is MCNPX that is stood on the basis monte-carlo method and implant the source to MIRD-type phantom in $^{192}Ir$, $^{125}I$, and $^{103}Pd$ in virtual space. For dose evaluations according to distance, the radiation dose on the patient near the corresponding implanted patient is evaluated by each distance of 30, 50, 100, 200 cm to anterior from the implanted patient. As a result, $^{192}Ir$ showed a higher dose than $^{125}I$ and $^{103}Pd$ in every distance.

• Journal of Biomedical Engineering Research
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• v.41 no.5
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• pp.195-202
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• 2020

Needle detection in ultrasound images is sometimes difficult due to obstruction of fat tissues. Accurate needle detection using continuous ultrasound (CUS) images is a vital stage of treatment planning for tissue biopsy and brachytherapy. The main goal of the study is classified into two categories. First, new detection model, i.e. D-Attention Unet, is developed by combining the context information of 3D medical data and CUS images. Second, the D-Attention Unet model was compared with other models to verify its usefulness for needle detection in continuous ultrasound images. The continuous needle images taken with ultrasonic waves were converted into still images for dataset to evaluate the performance of the D-Attention Unet. The dataset was used for training and testing. Based on the results, the proposed D-Attention Unet model showed the better performance than other 3 models (Unet, D-Unet and Attention Unet), with Dice Similarity Coefficient (DSC), Recall and Precision at 71.9%, 70.6% and 73.7%, respectively. In conclusion, the D-Attention Unet model provides accurate needle detection for US-guided biopsy or brachytherapy, facilitating the clinical workflow. Especially, this kind of research is enthusiastically being performed on how to add image processing techniques to learning techniques. Thus, the proposed method is applied in this manner, it will be more effective technique than before.

• The Journal of Korean Society for Radiation Therapy
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• v.16 no.1
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• pp.21-27
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• 2004

An isotope Ir-192, which is used in brachytherapy depends on import in whole quantities. There are a few ways for its activity. measurement using Welltype chamber or the way to rely on authentic decay table of manufacturer. In-air dosimetry using Farmer Chamber, etc. In this paper, let me introduce the way using Farmer chamber which is easier and simple. With the Farmer chamber and source calibration jig, take a measurement the activity of an isotope Ir-192 and compare the value with the value from decay table of manufacturer and check the activity of source. The result of measurement, compared the value from decay table, by ${\pm}2.1\%$. (which belongs to recommendable value for AAPM ${\pm}5\%$ as difference of error range) It is possible to use on clinical medicine. With the increase in use of brachytherapy, the increase of import is essential. And an accurate activity check of source is compulsory. For the activity check of source, it was possible to use Farmer chamber and source calibration jig without additional purchase of Well type chamber.

• Nuclear Engineering and Technology
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• v.50 no.6
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• pp.937-943
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• 2018

Background: This work presents the performance of a novel electronic brachytherapy (EBT) device and radiotherapy (RT) experiments on both skin cancer cells and animals using the device. Methods and materials: The performance of the EBT device was evaluated by measuring and analyzing the dosimetric characteristics of X-rays generated from the device. The apoptosis of skin cancer cells was analyzed using B16F10 melanoma cancer cells. Animal experiments were performed using C57BL/6 mice. Results: The X-ray characteristics of the EBT device satisfied the accepted tolerance level for RT. The results of the RT experiments on the skin cancer cells show that a significant apoptosis induction occurred after irradiation with 50 kVp X-rays generated from the EBT device. Furthermore, the results of the animal RT experiments demonstrate that the superficial X-rays significantly delay the tumor growth and that the tumor growth delay induced by irradiation with low-energy X-rays was almost the same as that induced by irradiation with a high-energy electron beam. Conclusions: The developed new EBT device has almost the same therapeutic effect on the skin cancer with a conventional linear accelerator. Consequently, the EBT device can be practically used for human skin cancer treatment in the near future.

• Radiation Oncology Journal
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• v.36 no.3
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• pp.227-234
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• 2018

Purpose: We compared how doses delivered via two-dimensional (2D) intracavitary brachytherapy (ICBT) and three-dimensional (3D) ICBT varied anatomically. Materials and Methods: A total of 50 patients who received 30 Gy of 3D ICBT after external radiotherapy (RT) were enrolled. We compared the doses of the actual 3D and 2D ICBT plans among patients grouped according to six anatomical variations: differences in a small-bowel V_2Gy, small bowel circumference, the direction of bladder distension, bladder volume, sigmoid V_3.5Gy, and sigmoid circumference. Seven dose parameters were measured in line with the EMBRACE recommendations. Results: In terms of bladder volume, the bladder and small-bowel D_2cc values were lower in the 150-250 mL bladder volume subgroup; and the rectum, sigmoid, and bladder D_2mL values were all lower in the >250 mL subgroup, for 3D vs. 2D ICBT. In the sigmoid V_3.5Gy >2 _mL subgroup, the sigmoid and bladder D_2mL values were significantly lower for 3D than 2D ICBT. The bladder D_2mL value was also significantly lower for 3D ICBT, as reflected by the sigmoid circumference. In patients with a small bowel V_2.0Gy >10 mL or small bowel circumference >15%, most dose parameters were significantly lower for 3D than 2D ICBT. The bladder distension direction did not significantly affect the doses. Conclusion: Compared to 2D ICBT, a greater bladder volume can reduce the internal 3D ICBT organ dose without affecting the target dose.

• Journal of radiological science and technology
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• v.43 no.6
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• pp.443-451
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• 2020

This study is to evaluate absorbed dose from right lung for brachytherapy and to estimate the effects of tissue heterogeneities on dose distribution for Iridium-192 source using Monte Carlo simulation. The study employed Geant4 code as Monte Carlo simulation to calculate the dosimetry parameters. The dose distribution of Iridium-192 source in solid water equivalent phantom including aluminium plate or steel plate inserted was calculated and compared with the measured dose by the ion chamber at various distances. And the simulation was used to evaluate the dose of gamma radiation absorbed in the lung organ and other organs around it. The dose distribution embedded in right lung was calculated due to the presence of heart, thymus, spine, stomach as well as left lung. The geometry of the human body was made up of adult male MIRD type of the computational human phantom. The dosimetric characteristics obtained for aluminium plate inserted were in good agreement with experimental results within 4%. The simulation results of steel plate inserted agreed well with a maximum difference 2.75%. Target organ considered to receive a dose of 100%, the surrounding organs were left the left lung of 3.93%, heart of 10.04%, thymus of 11.19%, spine of 12.64% and stomach of 0.95%. When the statistical error is performed for the computational human phantom, the statistical error of value is under 1%.