Aim: To analyze the inter-fraction, intra-fraction uncertainties and to verify the delivered total dose with planned dose in the combined intracavitary-interstitial brachytherapy of gynaecological cancer patients usin...Aim: To analyze the inter-fraction, intra-fraction uncertainties and to verify the delivered total dose with planned dose in the combined intracavitary-interstitial brachytherapy of gynaecological cancer patients using microMOSFET in-vivo dosimeter. Materials and Methods: Between May 2014 and March 2016, 22 patients who underwent brachytherapy treatments with an applicator combination of CT/MR compatible tandem, ring and Syed-Neblett template-guided rigid needles were included in this study. Specially designed microMOSFET, after calibration, was used to analyze the variations in dosimetry of combined intracavitary-interstitial application. Results: The standard deviation for Inter-fraction variation among 22 combined intracavitary interstitial applications ranged between 0.86% and 10.92%. When compared with the first fraction dose, the minimum and maximum dose variations were −9.5% and 26.36%, respectively. However, the mean doses varied between −5.95% and 14.49%. Intra-fraction variation, which is the difference of TPS calculated dose with first fraction microMOSFET-measured dose ranges from −6.77% to 8.68%. The variations in the delivered total mean dose in 66 sessions with planned doses were −3.09% to 10.83%. Conclusions: It is found that there was a gradual increase in microMOSFET measured doses as compared to the first fraction with that of subsequent fractions in 19 out of 22 applications. Tumor deformation and edema may be the influencing factors, but the applicator movements played a major role for the variations. We find that the microMOSFET is an easy and reliable system for independent verification of uncertainties during ICBT-ISBT treatments.展开更多
Background: Treatment of Cervical cancer includes a combination of external beam radiotherapy (EBRT) with intracavitary brachytherapy (ICBT). ICBT helps to boost radiation dose to primary disease. Organs like rectum, ...Background: Treatment of Cervical cancer includes a combination of external beam radiotherapy (EBRT) with intracavitary brachytherapy (ICBT). ICBT helps to boost radiation dose to primary disease. Organs like rectum, bladder, sigmoid and small bowel lie close to the cervix region and these organs receive dose from EBRT as well as ICBT and we want to know the dose to these organ at risk (OAR). Materials & Methods: Dosimetric details of 174 ICBT applications done in 58 patients were retrospectively analysed. All patients received EBRT dose of 50.4 Gy in 28 fractions. All patients had ICBT, three sessions with 7 Gy prescribed to point A. Dosimetric data including dose to right and left point A and dose to OARs were recorded from Oncentra Planning System. Results: Mean dose to point A on right side was 6.89 Gy and left side was 6.91 Gy. Mean D2cc dose to rectum, bladder, sigmoid and small bowel was 3.5 Gy, 5.25 Gy, 4.75 Gy and 4.2 Gy respectively. Mean EQD2 dose combining EBRT and ICBT in point A was 78.7 Gy on right side and 79 Gy on left side. Mean EQD2 doses to D2cc of rectum, bladder, sigmoid and small bowel was 62 Gy, 74.4 Gy, 70.5 Gy and 66.5 Gy respectively. Conclusion: From the results of this dosimetric study it is evident that OARs like rectum, sigmoid, bladder & bowel are receiving only acceptable doses of radiation using point A prescribed CT based ICBT planning. Hence with regards to OAR doses, CT based ICBT planning with dose prescribed to point A is a feasible option.展开更多
Purpose: Curative radiation therapy is an established treatment option for non-surgical patients with early-stage endometrial carcinoma. Dosimetric analyses were performed using a single tandem, double tandem, Heyman ...Purpose: Curative radiation therapy is an established treatment option for non-surgical patients with early-stage endometrial carcinoma. Dosimetric analyses were performed using a single tandem, double tandem, Heyman capsules, and an inflatable intrauterine balloon to assess the dose homogeneity and conformality in the definitive treatment of inoperable endometrial cancer. Methods and Materials: Patients’ informed-consent was obtained. Dosimetric analyses were performed using four different after-loading applicators to assess the dose homogeneity and conformality of isodose to the three-dimensional (3-D) shape of the target volume (uterus) based on CT data in four patients (n = 4). The single tandem and double tandems were standard Fletcher-type (Nucletron Corporation, Columbia, MD). Heyman capsules were the disposable after-loading type (Radiation Products Design, Inc., Albertville, MN). The inflatable balloon with a central bi-lumen catheter was the Mammo Site Radiation Therapy System (Proxima Therapeutics, Alpharetta, GA) that is currently used for local breast brachytherapy. Treatment planning and dosimetric analyses for all four techniques were done with HDR PLATO Brachytherapy (v14.2.3) Software (Nucletron Corporation). Results: The average dose gradient within the target (uterine wall) is highest with the tandem methods, followed by Heyman capsules. The intrauterine balloon method showed the least dose gradient across the uterine wall. The corresponding average homogeneity indices were 3.81, 3.83, 2.97, 2.50 for single tandem, double tandem, Heyman capsules, and intrauterine balloon respectively. Conclusions: The intra-uterine inflatable balloon appears to have the best overall dosimetric advantages for the treatment of the uterine wall. Furthermore, the potential ease of use, shorter time of applicator placement, and better patient comfort warrant further investigation and subsequent clinical implementation.展开更多
OBJECTIVE To evaluate the results and complications associated with nasopharyngeal carcinoma (NPC) treated with combined external-beam radiotherapy (EBR) and intracavitary brachytherapy (IB) using a new-type applicato...OBJECTIVE To evaluate the results and complications associated with nasopharyngeal carcinoma (NPC) treated with combined external-beam radiotherapy (EBR) and intracavitary brachytherapy (IB) using a new-type applicator. METHODS Eighty patients with untreated NPC were divided into two groups based on therapy methods. An experimental group was treated with EBR plus IB and a control group was treated only with EBR. IB was given to the patients of the experimental group when the external radiotherapy dose amounted to more than 60～65 Gy. The total dose of IB was 6～20 Gy and the total dose of EBR of the control group was 70～75 Gy. RESULTS Follow-up was conducted for 97.5% of the patients with results as follows: the overall response rates (ORR) for the experimental and the control groups were 92.5% and 75.3% respectively (P<0.05); the 3 and 5-year survival rates for the experimental group were 87.5% and 74.2% and for the control group, 65.0% and 55.6% (P<0.05); for the experimental group, the 3 and 5-year disease-free survival rates were 72.5% and 64.5% and for the control group, 60.0% and 52.8% (P>0.05).Some complications following radiotherapy showed a signi fi cant difference. CONCLUSION External irradiation plus intracavitary brachytherapy using a new-type applicator may improve the ORR and survival rates, reduce radiation complications and increase the quality of life.展开更多
Objective:To study the effect of iodine-125 interstitial brachytherapy on liver cancer. Methods: Animal model of human liver cancer was established by injecting SMMC-7721 cells cultivated in vitro subcutaneously into ...Objective:To study the effect of iodine-125 interstitial brachytherapy on liver cancer. Methods: Animal model of human liver cancer was established by injecting SMMC-7721 cells cultivated in vitro subcutaneously into the flank of BALB/c nude mice. Nude mice with tumor of 5 mm in diameter were randomly divided into 2 groups (n = 10). One iodine-125 seed of apparent activity 0. 8 mCi was implanted into the center of tumor in treatment group, whereas an inactive seed was implanted in control group. The other 20 nude mice with tumor reaching 10 mm in diameter were also treated as above. The size of tumor was determined weekly after implantation, and pathological examination and blood routine were taken on the 28th day. Results: Tumor growth was obviously inhibited in treatment group of tumor of 5 mm in diameter, and there was statistically significant difference in tumor volume between treatment and control groups (P<0. 01). Around iodine-125 seed, apparent necrosis of tumor was shown in treatment group, accompanied by karyopyknosis and reduced plasma in residual tumor cells microscopically. Tumor growth was not inhibited in either treatment or control group of tumor of 10 mm in diameter. There was no obvious adverse effect except for decreased white blood cells in treatment groups. Conclusion: There is certain effect of iodine-125 interstitial brachytherapy on liver cancer, which is associated with the size of tumor.展开更多
Brachytherapy forms an integral part of the radiation therapy in cancer cervix. The dose prescription for intracavitary brachytherapy(ICBT) in cancer cervix is based on Tod and Meredith's point A and has been in p...Brachytherapy forms an integral part of the radiation therapy in cancer cervix. The dose prescription for intracavitary brachytherapy(ICBT) in cancer cervix is based on Tod and Meredith's point A and has been in practice since 1938. This was proposed at a time when accessibility to imaging technology and dose computation facilities was limited. The concept has been in practice worldwide for more than half a century and has been the fulcrum of all ICBT treatments, strategies and outcome measures. The method is simple and can be adapted by all centres practicing ICBT in cancer cervix. However, with the widespread availability of imaging techniques, clinical use of different dose-rates, availability of a host of applicators fabricated with image compatible materials, radiobiological implications of dose equivalence and its impact on tumour and organs at risk; more and more weight is being laid down on individualised image based brachytherapy. Thus, computed tomography, magnetic-resonance imaging and even positron emission computerized tomographyalong with brachytherapy treatment planning system are being increasingly adopted with promising outcomes. The present article reviews the evolution of dose prescription concepts in ICBT in cancer cervix and brings forward the need for image based brachytherapy to evaluate clinical outcomes. As is evident, a gradual transition from "point" based brachytherapy to "profile" based image guided brachytherapy is gaining widespread acceptance for dose prescription, reporting and outcome evaluation in the clinical practice of ICBT in cancer cervix.展开更多
BACKGROUND Dedifferentiated liposarcoma in the mediastinum is an extremely rare malignant neoplasm.A few previous case reports indicate that surgical resection is the major treatment,but frequent recurrence occurs loc...BACKGROUND Dedifferentiated liposarcoma in the mediastinum is an extremely rare malignant neoplasm.A few previous case reports indicate that surgical resection is the major treatment,but frequent recurrence occurs locally.Due to its rarity,its clinical characteristics,optimal treatment and clinical outcomes remain unclear.Here,we report a case of multifocal recurrent dedifferentiated liposarcoma in the posterior mediastinum treated by combining surgery with 125I brachytherapy,and summarize its clinical features,treatment and prognosis.CASE SUMMARY A 75-year-old man was admitted to our hospital with a history of gradual dysphagia for one year and aggravated dysphagia for 3 mo.Contrast-enhanced computed tomography(CT)revealed several large cystic-solid masses with lipomatous density,and calcification in the posterior-inferior mediastinum.The patient received a wide excision by video-assisted thoracoscopic surgery.Pathological analysis confirmed the tumors were dedifferentiated liposarcomas.The tumor locally relapsed 24 mo later,and another operation was performed by video-assisted thoracoscopic surgery.Fifteen months after the second surgery,the tumor recurred again,and the patient received CT-guided radioactive seeds 125I implantation.After 8 mo,follow-up chest CT showed an enlarged tumor.Finally,his condition exacerbated with severe dysphagia and dyspnea,and he died of respiratory failure in July 2018.CONCLUSION We reviewed the literature,and suggest that surgical resection provides beneficial effects for dedifferentiated liposarcoma in the mediastinum,even in cases with local recurrence.125I brachytherapy may be beneficial for recurrent unresectable patients.展开更多
文摘Aim: To analyze the inter-fraction, intra-fraction uncertainties and to verify the delivered total dose with planned dose in the combined intracavitary-interstitial brachytherapy of gynaecological cancer patients using microMOSFET in-vivo dosimeter. Materials and Methods: Between May 2014 and March 2016, 22 patients who underwent brachytherapy treatments with an applicator combination of CT/MR compatible tandem, ring and Syed-Neblett template-guided rigid needles were included in this study. Specially designed microMOSFET, after calibration, was used to analyze the variations in dosimetry of combined intracavitary-interstitial application. Results: The standard deviation for Inter-fraction variation among 22 combined intracavitary interstitial applications ranged between 0.86% and 10.92%. When compared with the first fraction dose, the minimum and maximum dose variations were −9.5% and 26.36%, respectively. However, the mean doses varied between −5.95% and 14.49%. Intra-fraction variation, which is the difference of TPS calculated dose with first fraction microMOSFET-measured dose ranges from −6.77% to 8.68%. The variations in the delivered total mean dose in 66 sessions with planned doses were −3.09% to 10.83%. Conclusions: It is found that there was a gradual increase in microMOSFET measured doses as compared to the first fraction with that of subsequent fractions in 19 out of 22 applications. Tumor deformation and edema may be the influencing factors, but the applicator movements played a major role for the variations. We find that the microMOSFET is an easy and reliable system for independent verification of uncertainties during ICBT-ISBT treatments.
文摘Background: Treatment of Cervical cancer includes a combination of external beam radiotherapy (EBRT) with intracavitary brachytherapy (ICBT). ICBT helps to boost radiation dose to primary disease. Organs like rectum, bladder, sigmoid and small bowel lie close to the cervix region and these organs receive dose from EBRT as well as ICBT and we want to know the dose to these organ at risk (OAR). Materials & Methods: Dosimetric details of 174 ICBT applications done in 58 patients were retrospectively analysed. All patients received EBRT dose of 50.4 Gy in 28 fractions. All patients had ICBT, three sessions with 7 Gy prescribed to point A. Dosimetric data including dose to right and left point A and dose to OARs were recorded from Oncentra Planning System. Results: Mean dose to point A on right side was 6.89 Gy and left side was 6.91 Gy. Mean D2cc dose to rectum, bladder, sigmoid and small bowel was 3.5 Gy, 5.25 Gy, 4.75 Gy and 4.2 Gy respectively. Mean EQD2 dose combining EBRT and ICBT in point A was 78.7 Gy on right side and 79 Gy on left side. Mean EQD2 doses to D2cc of rectum, bladder, sigmoid and small bowel was 62 Gy, 74.4 Gy, 70.5 Gy and 66.5 Gy respectively. Conclusion: From the results of this dosimetric study it is evident that OARs like rectum, sigmoid, bladder & bowel are receiving only acceptable doses of radiation using point A prescribed CT based ICBT planning. Hence with regards to OAR doses, CT based ICBT planning with dose prescribed to point A is a feasible option.
文摘Purpose: Curative radiation therapy is an established treatment option for non-surgical patients with early-stage endometrial carcinoma. Dosimetric analyses were performed using a single tandem, double tandem, Heyman capsules, and an inflatable intrauterine balloon to assess the dose homogeneity and conformality in the definitive treatment of inoperable endometrial cancer. Methods and Materials: Patients’ informed-consent was obtained. Dosimetric analyses were performed using four different after-loading applicators to assess the dose homogeneity and conformality of isodose to the three-dimensional (3-D) shape of the target volume (uterus) based on CT data in four patients (n = 4). The single tandem and double tandems were standard Fletcher-type (Nucletron Corporation, Columbia, MD). Heyman capsules were the disposable after-loading type (Radiation Products Design, Inc., Albertville, MN). The inflatable balloon with a central bi-lumen catheter was the Mammo Site Radiation Therapy System (Proxima Therapeutics, Alpharetta, GA) that is currently used for local breast brachytherapy. Treatment planning and dosimetric analyses for all four techniques were done with HDR PLATO Brachytherapy (v14.2.3) Software (Nucletron Corporation). Results: The average dose gradient within the target (uterine wall) is highest with the tandem methods, followed by Heyman capsules. The intrauterine balloon method showed the least dose gradient across the uterine wall. The corresponding average homogeneity indices were 3.81, 3.83, 2.97, 2.50 for single tandem, double tandem, Heyman capsules, and intrauterine balloon respectively. Conclusions: The intra-uterine inflatable balloon appears to have the best overall dosimetric advantages for the treatment of the uterine wall. Furthermore, the potential ease of use, shorter time of applicator placement, and better patient comfort warrant further investigation and subsequent clinical implementation.
文摘OBJECTIVE To evaluate the results and complications associated with nasopharyngeal carcinoma (NPC) treated with combined external-beam radiotherapy (EBR) and intracavitary brachytherapy (IB) using a new-type applicator. METHODS Eighty patients with untreated NPC were divided into two groups based on therapy methods. An experimental group was treated with EBR plus IB and a control group was treated only with EBR. IB was given to the patients of the experimental group when the external radiotherapy dose amounted to more than 60～65 Gy. The total dose of IB was 6～20 Gy and the total dose of EBR of the control group was 70～75 Gy. RESULTS Follow-up was conducted for 97.5% of the patients with results as follows: the overall response rates (ORR) for the experimental and the control groups were 92.5% and 75.3% respectively (P<0.05); the 3 and 5-year survival rates for the experimental group were 87.5% and 74.2% and for the control group, 65.0% and 55.6% (P<0.05); for the experimental group, the 3 and 5-year disease-free survival rates were 72.5% and 64.5% and for the control group, 60.0% and 52.8% (P>0.05).Some complications following radiotherapy showed a signi fi cant difference. CONCLUSION External irradiation plus intracavitary brachytherapy using a new-type applicator may improve the ORR and survival rates, reduce radiation complications and increase the quality of life.
文摘Objective:To study the effect of iodine-125 interstitial brachytherapy on liver cancer. Methods: Animal model of human liver cancer was established by injecting SMMC-7721 cells cultivated in vitro subcutaneously into the flank of BALB/c nude mice. Nude mice with tumor of 5 mm in diameter were randomly divided into 2 groups (n = 10). One iodine-125 seed of apparent activity 0. 8 mCi was implanted into the center of tumor in treatment group, whereas an inactive seed was implanted in control group. The other 20 nude mice with tumor reaching 10 mm in diameter were also treated as above. The size of tumor was determined weekly after implantation, and pathological examination and blood routine were taken on the 28th day. Results: Tumor growth was obviously inhibited in treatment group of tumor of 5 mm in diameter, and there was statistically significant difference in tumor volume between treatment and control groups (P<0. 01). Around iodine-125 seed, apparent necrosis of tumor was shown in treatment group, accompanied by karyopyknosis and reduced plasma in residual tumor cells microscopically. Tumor growth was not inhibited in either treatment or control group of tumor of 10 mm in diameter. There was no obvious adverse effect except for decreased white blood cells in treatment groups. Conclusion: There is certain effect of iodine-125 interstitial brachytherapy on liver cancer, which is associated with the size of tumor.
文摘Brachytherapy forms an integral part of the radiation therapy in cancer cervix. The dose prescription for intracavitary brachytherapy(ICBT) in cancer cervix is based on Tod and Meredith's point A and has been in practice since 1938. This was proposed at a time when accessibility to imaging technology and dose computation facilities was limited. The concept has been in practice worldwide for more than half a century and has been the fulcrum of all ICBT treatments, strategies and outcome measures. The method is simple and can be adapted by all centres practicing ICBT in cancer cervix. However, with the widespread availability of imaging techniques, clinical use of different dose-rates, availability of a host of applicators fabricated with image compatible materials, radiobiological implications of dose equivalence and its impact on tumour and organs at risk; more and more weight is being laid down on individualised image based brachytherapy. Thus, computed tomography, magnetic-resonance imaging and even positron emission computerized tomographyalong with brachytherapy treatment planning system are being increasingly adopted with promising outcomes. The present article reviews the evolution of dose prescription concepts in ICBT in cancer cervix and brings forward the need for image based brachytherapy to evaluate clinical outcomes. As is evident, a gradual transition from "point" based brachytherapy to "profile" based image guided brachytherapy is gaining widespread acceptance for dose prescription, reporting and outcome evaluation in the clinical practice of ICBT in cancer cervix.
文摘BACKGROUND Dedifferentiated liposarcoma in the mediastinum is an extremely rare malignant neoplasm.A few previous case reports indicate that surgical resection is the major treatment,but frequent recurrence occurs locally.Due to its rarity,its clinical characteristics,optimal treatment and clinical outcomes remain unclear.Here,we report a case of multifocal recurrent dedifferentiated liposarcoma in the posterior mediastinum treated by combining surgery with 125I brachytherapy,and summarize its clinical features,treatment and prognosis.CASE SUMMARY A 75-year-old man was admitted to our hospital with a history of gradual dysphagia for one year and aggravated dysphagia for 3 mo.Contrast-enhanced computed tomography(CT)revealed several large cystic-solid masses with lipomatous density,and calcification in the posterior-inferior mediastinum.The patient received a wide excision by video-assisted thoracoscopic surgery.Pathological analysis confirmed the tumors were dedifferentiated liposarcomas.The tumor locally relapsed 24 mo later,and another operation was performed by video-assisted thoracoscopic surgery.Fifteen months after the second surgery,the tumor recurred again,and the patient received CT-guided radioactive seeds 125I implantation.After 8 mo,follow-up chest CT showed an enlarged tumor.Finally,his condition exacerbated with severe dysphagia and dyspnea,and he died of respiratory failure in July 2018.CONCLUSION We reviewed the literature,and suggest that surgical resection provides beneficial effects for dedifferentiated liposarcoma in the mediastinum,even in cases with local recurrence.125I brachytherapy may be beneficial for recurrent unresectable patients.
