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BACKGROUND: Crosslinked sodium hyaluronate gel has good mechanical property, biocompatibility, and biodegradability, and can be used as an isolated protective material in tumor radiation therapy to protect endangered organs from damage caused by excess radiation dose. OBJECTIVE : To investigate the safety and efficacy of crosslinked sodium hyaluronate gel in reducing the dose of radiation to dangerous organs during brachytherapy. METHODS: A total of 16 specific pathogen-free Kunming mice of the same age and similar body weight were selected as experimental subjects and divided into experimental group and control group by the random number table method, with 8 mice in each group. 125I seeds were implanted subcutaneously in the back of mice in the experimental group, and then crosslinked sodium hyaluronate gel was injected around the radioactive particles. Only 125I seeds were implanted subcutaneously in the back of mice in the control group. After injection, the distance between the radioactive particles and the epidermis was measured by spiral CT scan, and the surface radiation dose was measured by radiation dosimeter. Within 10 weeks after injection, the growth state, survival rate, skin radiation damage, and gel retention of mice were observed. RESULTS AND CONCLUSION: (1) Spiral CT scan showed that the implanted gel was relatively concentrated and created an effective distance between the radioactive seeds and the epidermis. The body surface radiation dose of the experimental group was significantly lower than that of the control group (P < 0.01). (2) During the experimental observation period, mice in both groups survived; mice in the control group showed obvious irritability and other unstable behavior in the late experimental period, and some mice in the experimental group showed similar behavior. The daily food intake of mice in the two groups had no significant change, and the body mass showed the same increasing trend. After implantation of radioactive seeds, the two groups of mice showed different degrees of radioactive skin injury. From day 23 after injection to the end of the experiment, the skin radiation injury score of the experimental group was lower than that of the control group (P < 0.01). At week 10 after implantation, 6 mice in the experimental group had no obvious gel residue under their skin, and 2 mice had a very small amount of scattered gel-like samples under their skin. (3) Therefore, the crosslinked sodium hyaluronate injection technique can increase the space between the radioactive target area of 125I seeds and the organ at risk outside the target through physical space occupying, which can effectively reduce the dose of the organ at risk, and play a role in the isolation and protection of the organ at risk. [ABSTRACT FROM AUTHOR]

Brachytherapy can kill cancer cells more effectively and make the normal tissues around the tumor free or less irradiated. It has become an effective means for the treatment of malignant tumors. 103Pd has a half-life of 16.96 days and a significant advantage in the field of brachytherapy due to its unique decay properties. In order to achieve the large-scale production of 103Pd, the preparation process based on Cyclone-30(C30) cyclotron was studied. The rhodium metal was electroplated on the copper target base by pulse electroplating method. The rhodium-plated target was transferred to C30 solid target station for irradiation with beam energy of 16-18 MeV, and the beam current was 200 μA. In order to obtain Curie-level 103Pd, the beam integral should be more than 10000 μA•h. After irradiation, the target was transferred to the separation and purification hot cell, the rhodium plating was separated from the target base first, then was ground into powder, and dissolved by high temperature melting of potassium bisulfate. The rhodium was converted into soluble rhodium sulfate, and the 103Pd nuclide was separated and purified by AG1-X8 resin. The impurities of Rh, Fe, Cu and Zn were rinsed with 6 mol/L hydrochloric acid and 0.03 mol/L hydrochloric acid, respectively. At last, 103Pd was desorbed with a mixed solution of ammonium chloride-ammonia mixed solution(volume ratio 1∶1). The radioactive activity, radionuclide purity and specific activity of 103Pd were measured respectively. The preparation of sealed seed core was studied by using the prepared 103Pd feed solution. The results show that the rhodium plating layer is smooth and dense, and firmly bonded with the copper plate, the rhodium layers mass thickness is greater than 150 mg/cm2. The production capacity of 103Pd is greater than 37 GBq, the radionuclide purity is greater than 99.9%, and the specific activity is greater than 875 GBq/mg, and activity concentrations greater than 6.2 GBq/mL. The preparation field of 103Pd brachytherapy sources is more than 90%, it can meet the requirements. The 103Pd preparation process is stable, and the quality is controllable. The large-scale production capacity has been reached, and it provides a stable source for the research of 103Pd brachytherapy sources.

Copyright of Journal of Isotopes is the property of Journal of Isotopes Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The preparation of rhodium target with high quality and thickness is the key to produce 103Pd by cyclotron. In order to improve the thickness and quality of plating, rhodium sulfate solution is pretreated, and a certain amount of electroplating additives A is added. The target plate for 103Pd is made of copper with a target size about 100 mm×10 mm. The optimal electroplating conditions are obtained according to the important conditions in the plating process (e.g., current density, plating temperature and H2SO4 concentration). In four consecutive batches of experiments, the mass thickness of the rhodium plating is higher than 150 mg/cm2. In the thermal shock and falling test, the plating layer does not show problems such as flaking, and is tight, smooth and firmly bonded to the substrate. After irradiation in C30 cyclotron for 5-51.5 hours, 103Pd nuclide with yield of 5.18-6.04 MBq/(μA·h) and nuclear purity greater than 99.9% can be obtained. The research solve the problem of poor stability of rhodium target preparation process by pulse electroplating, the quality of rhodiumtarget can meet the requirements of 103Pd production.

Copyright of Journal of China Medical University is the property of Journal of China Medical University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Journal of Oral & Maxillofacial Surgery is the property of Shanghai Jiao Tong University, College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective To explore the feasibility of repeated use of the same mold in the brachytherapy of cervical cancer by comparing the dosimetry of the 3D-printed vaginal applicator in the pre-plan and actual treatment plan in the brachytherapy of cervical cancer. Methods A total of 10 patients with cervical squamous cell carcinoma who received radical radiotherapy in our hospital from November 2019 to July 2020 were reruited in this study. All patients received concurrent radiotherapy and chemotherapy combined with 3D printed applicator assisted brachytherapy. Dosimetric parameters, including CT scan frequency, high risk clinical target area (HR-CTV) volume and D90 dose, conformity index (CI), Dose (D2cc, the absorbed dose received by 2 cm3 of OARs) variation in organs at risk (OARs), and short-term efficacy and 2-year survival outcome of local control rates (LCR), disease free survival (DFS) and overall survival (OS) were compared the parameters of 3D printed mold pre-planning and multiple actual treatment plans. Paired samples t test was used to compare the parameters of pre-planning and actual treatment plans. Kaplan-Meier survival analysis was applied to analyze the survival outcomes of the patients. Results Ten 3D printing applicators were designed, and a total of 84 CT scans and 47 practical treatments were completed. Only the target volume and CI of the first actual treatment plan were similar to those of the pre-plan, but the difference was not statistically significant (P>0.05). The more times of close treatment, the smaller HR-CTV volume was and the better CI of target area was. Both HR-CTV D90 dose and the OARs dose met clinical requirement. During the median follow-up of 23.5 months, the 2-year LCR, DFS and OS were 100%, 90% and 80%, respectively. Conclusion The 3D-printed vaginal applicator can be used repeatedly for brachytherapy of the same cervical cancer patient, but the needle depth needs to be adjusted by CT positioning.

Brachytherapy is an essential part of radical radiotherapy of cervical cancer. However, traditional brachytherapy applicators are difficult to be placed, cannot be adapted to individualized local lesions, and have unsatisfactory dose distribution for some patients with recurrent postoperative stumps or eccentric or large cervical cancer, which then affects the efficacy and prognosis. Personalized radiotherapy products can be designed for each patient by utilizing 3D printing technology. Combination of 3D printing technology and brachytherapy can effectively improve accuracy of radiotherapy. The application of 3D printing technology in cervical cancer brachytherapy mainly includes the construction of cervical cancer model to preoperative planning and display tumor shape as well as anatomic relationship between tumor and surrounding tissues. It also includes the production of personalized applicator to reduce the occurrence of air gaps to achieve precise dose distribution. In addition, the design of parallel/oblique needle channel applicator and the optimization of needle channel and target dose distribution are also included. Applications of 3D printing technology in brachytherapy of cervical cancer have been summarized in the afore-mentioned areas. At the same time, the challenges in the development of 3D printing materials, system establishment and image guidance have been discussed. [ABSTRACT FROM AUTHOR]

Brachytherapy is successfully used in the treatment of malignant neoplasms in males and females and rare cases in children, as an independent method (with localized prostate cancer) or adjuvant with remote focal radiation therapy (with cancer of the cervix, anal canal, head and neck, breast, etc.). The expansion of diagnostic capabilities (the advent of computer and magnetic resonance imaging) due to three-dimensional imaging has given brachytherapy an important technological advantage over other methods. Many options are available for combining brachytherapy with remote radiation or systemic antitumor therapy in the first line, as well as in a single mode for localized tumor recurrence in a previously irradiated area. Intrastates (hollow tubes) for intra-tissue high-dose brachytherapy are administered during surgery and encapsulated (closed) radioactive micro-sources for low-dose brachytherapy are directly administered (percutaneously). A distinctive feature of brachytherapy is a sharp drop in the dose outside the tumor focus, which minimizes the risk of irradiation of surrounding organs and tissues. The main advantage of brachytherapy in comparison with remote radiotherapy is a higher radiation dose gradient at the tumor border (from all sides). Moreover, clarifying the boundaries of uncertainty when irradiating the target is unnecessary. When the tumor changes during treatment, the sources fixed in the tumor synchronously change their position. In addition to the advantages in efficiency and safety, the total financial costs of brachytherapy are significantly lower than other radiotherapy options.

Copyright of Practical Oncology Journal is the property of Journal of Practical Oncology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cancer is one of the diseases that seriously harm human health. The cancer-related incidence and deaths are still increasing worldwide, which has brought heavy burden to the global public health system. During the long anticancer history, a variety of methods to treat tumors have been developed. More than 100 years ago, shortly after the discovery of Roentgen rays, people began to treat tumors with radiation, and thus pioneered radiation oncology. As a brachytherapy method, implantation of radioactive seeds acts well, has received public recognition, and becomes an important member of the oncology therapeutic spectrum. In vivo, some seeds can migrate from initial site of implantation to other locations. Permanent interstitial brachytherapy and the incidence, mechanism, influence and prevention of 125 I seed migration were reviewed here.

Cervical cancer is the most common malignant tumor of female reproductive tract in China, which seriously threatens women′s health. Brachytherapy is an essential component of the treatment of locally advanced cervical cancers. It enables the dose to the tumor to be boosted whilst allowing relative sparing of the normal tissues. In recent years, three - dimensional brachytherapy, interstitial implantation brachytherapy and radioactive seed implantation brachytherapy have developed rapidly． These technologies have improved the treatment effect of cervical cancer and reduced complications. The three factors are interrelated. For eccentric tumor, intracavitary brachytherapy has incomplete target coverage and poor dose distribution conformation, while interstitial implantation brachytherapy can make up for the deficiency of intracavitary brachytherapy. Radioactive seed implantation brachytherapy has the characteristics of low trauma and high safety, providing more possibilities for patients with recurrent cervical cancer. Therefore, individualized treatment plan should be formulated according to the characteristics of the patient′s condition in clinical practice. [ABSTRACT FROM AUTHOR]

The radioactive particle chain is a linear array of 125I particles and placed in a tubular conduit. The dose distribution of the particle chain is similar to the shape of a cylinder. It may be adapted to the tumors in the lumen and exerts the radiotherapy effect that may not be achieved by single particles. This article aims to review the history of 125I radioactive particle chains, dose distribution, placement methods and clinical application.

Objective To analyze the efficacy and safety of surgical excision combined with brachytherapy treatment on sarcoma surrounding important nerve and blood vessels. Methods We retrospectively analyzed 30 patients pathologically diagnosed as sarcoma which was adjacent to the important nerve and blood vessels from March 2015 to April 2017. Extensive resection was performed. All patients received brachytherapy 2-3 days after operation. The fractional dose was 4Gy. The total dose of radiotherapy was 40Gy, twice a day. Brachytherapy took 5 days. All patients were assessed with MSTS function before surgery and 6 months after treatment. Results The follow-up time was 18-43 months, with an average of 31.6 months. The median follow-up time was 32.0 months. The 2-year survival rate was 96.7%, 18 cases(60%) of surgical margin R0 and 12 cases(40%) of R1. The MSTS score was 23.36±1.51 before operation and 21.51±1.82 six months after operation(P > 0.05). The local control rate of tumors was 93.3%. One patient died and one patient had nonunion incision. The incidence of ≥ grade 2 radiotherapy complications was 16.7%. Conclusion Surgical excision combined with brachytherapy treatment on sarcoma surrounding important nerve and blood vessels could achieve high local control rate, preserve limbs and have little influence on limb function of patients, but it is necessary to actively prevent and control the complications associated with brachytherapy.

Objective To evaluate the safety, feasibility and efficacy of template-assisted 192Ir-based hypofractionated stereotactic ablative brachytherapy (SABT) combined with surgery for peripheral non-small cell lung cancer (NSCLC) patients. Methods We enrolled the patients who were pathologically confirmed as operable peripheral NSCLC. The patients underwent template-assisted SABT (30 Gy delivered in one fraction) and were scheduled for tumor resection 4-6 weeks after SABT. The perioperative adverse reactions of SABT were recorded to evaluate the safety and feasibility of SABT as a neoadjuvant therapy. Imaging with 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) and dynamic contrast-enhanced computed tomography (DCECT) were scheduled before SABT and surgery to evaluate the efficacy of SABT by comparing the gross tumor volume, maximum standardized uptake value, tumor blood volume and tumor blood flow. Results All patients did not experience any serious adverse event. After 4-6 weeks, the indicators for the efficacy of neoadjuvant therapy significantly decreased in all patients: gross tumor volume (P < 0.001), maximum standardized uptake value (P < 0.001), tumor blood volume (P < 0.001) and tumor blood flow (P=0.009). Conclusion The efficacy of template-assisted SABT as a neoadjuvant therapy is significant in operable peripheral NSCLC patients, without any serious adverse reaction.

Copyright of Practical Oncology Journal is the property of Journal of Practical Oncology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Medical Equipment Journal is the property of Chinese Medical Equipment Journal Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To investigate the dosimetric difference between manual and inverse optimization in 3-dimensional (3D) brachytherapy for gynecologic tumors., Methods: This retrospective study was conducted among a total of 110 patients with gynecologic tumors undergoing intracavitary combined with interstitial brachytherapy or interstitial brachytherapy. Based on the original images, the brachytherapy plans were optimized for each patient using Gro, IPSA1, IPSA2 (with increased volumetric dose limits on the basis of IPSA1) and HIPO algorithms. The dose-volume histogram (DVH) parameters of the clinical target volume (CTV) including V 200 , V 150 , V 100 , D 90 , D 98 and CI, and the dosimetric parameters D 2cc , D 1cc , and D 0.1cc for the bladder, rectum, and sigmoid colon were compared among the 4 plans., Results: Among the 4 plans, Gro optimization took the longest time, followed by HIPO, IPSA2 and IPSA1 optimization. The mean D 90 , D 98 , and V 100 of HIPO plans were significantly higher than those of Gro and IPSA plans, and D 90 and V 100 of IPSA1, IPSA2 and HIPO plans were higher than those of Gro plans ( P < 0.05), but the CI of the 4 plans were similar ( P > 0.05). For the organs at risk (OARs), the HIPO plan had the lowest D 2cc of the bladder and rectum; the bladder absorbed dose of Gro plans were significantly greater than those of IPSA1 and HIPO ( P < 0.05). The D 2cc and D 1cc of the rectum in IPSA1, IPSA2 and HIPO plans were better than Gro ( P < 0.05). The D 2cc and D 1cc of the sigmoid colon did not differ significantly among the 4 plans., Conclusion: Among the 4 algorithms, the HIPO algorithm can better improve dose coverage of the target and lower the radiation dose of the OARs, and is thus recommended for the initial plan optimization. Clinically, the combination of manual optimization can achieve more individualized dose distribution of the plan.

With the rapid development of precise radiotherapy technology, the use of intensity-modulated radiation therapy (IMRT) in gynecological malignant tumor has been gradually increased. IMRT could result in a good local control rate as well as superior clinical outcome in patients with cervical cancer after radical radiotherapy. The recurrence pattern of radiotherapy includes in-field recurrence, out-of-field and combined failure. The recurrence pattern of radical IMRT for cervical cancer is mainly out-of-field recurrence. Out-of-field recurrence may be related to inadequate imaging evaluation before treatment. In-field recurrence may be related to insufficient radiation dose in target area and differences of tumor sensitivity. [ABSTRACT FROM AUTHOR]

Objective To investigate the safety and feasibility of intraluminal brachytherapy using iodine-125 seed strand for locally advanced pancreatic ductal adenocarcinoma with obstructive jaundice. Methods Clinical data of 17 consecutive patients, from January 2010 to February 2015, diagnosed with pancreatic ductal adenocarcinoma (4 cases of T4N0M0 and 13 of T4N1M0) with obstructive jaundice and received intraluminal brachytherapy using iodine-125 seed strand were collected and analyzed retrospectively. Liver function was evaluated using paired-samples t test. The iodine-125 seed strand radiation doses were calculated using iodine-125 radiation field distribution calculation software (version 0.1, Institute of Radiation Medicine, Fudan University, Shanghai, China) based on the American Association of Physicists in Medicine TG43U1 brachytherapy formula. Obstruction free survival and overall survival were calculated using the Kaplan-Meier method. Complications were assessed according to the CTCAE 4.0 criteria. Results The estimated mean accumulating dose (r=5 mm, 240 days) was 167.2 Gy, from 164.19 Gy to 170.05 Gy. The mean and median obstruction free survival time were (9.62±1.47) months (95%CI: 6.73-12.50) and (7.26±1.71) months (95%CI: 3.90-10.62). The mean and median overall survival time were (9.89±1.59) months (95%CI: 6.78-13.00) and (7.26±1.71) months (95%CI: 3.90-10.62), retrospectively. Total bilirubin and conjugated bilirubin decreased significantly after the therapy. Two patients had adverse event of Grade 3, one of Grade 4. Stent dysfunction occurred in 1/17 (5.9%) patients. Conclusions Intraluminal brachytherapy using iodine-125 seed strand might be considered as a safe treatment option for the locally advanced pancreatic duct adenocarcinoma complicated by obstructive jaundice. [ABSTRACT FROM AUTHOR]

Copyright of China Journal of Oral & Maxillofacial Surgery is the property of Shanghai Jiao Tong University, College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background and objective The locations of mediastinal malignant tumor lesions are deep and occult, and are close to the pericardium, trachea, or major vessels. Therefore, the possibility of surgical resection is slim, and cryoablation and thermal ablation are restricted. In current study, image and life quality data were compared before and after 125I seeding therapy to investigate its safety and clinical effects. Methods From July 2010 to July 2011, a 43-patient follow-up of pathologically confirmed cancers, including 21 cases of primary mediastinal squamous lung cancer, 9 cases of primary esophagus cancer, and 13 cases of lymph node metastases were completed. Among these, 18 cases presented with tracheal stenosis >50%, 9 cases had esophageal obstruction, and 9 cases had superior vena cava reflux disorder. Each lesion was implanted with 10 to 60 pieces of 125I particles, with an average of 30.79±14.23. CT data at 2, 4, 6, and 12 months after therapy were obtained to evaluate the local lesion outcome. The quality of life of the patients as well as survival data was also recorded. Results The overall success rate of the operation was 100%. The longest time of follow-up was 12 months. At 6 months, 37 patients were alive, and the half-year survival rate was 85.0%. In terms of local lesions, 30 cases of PR and 7 cases of NC were found. The clinical effective rate was 81.08%, and the clinical beneficial rate was 100%. At 12 months after therapy, 31 patients were alive, and the one-year survival rate was 60.5%. In terms of local lesions, 16 cases of CR, 7 cases of PR, 2 cases of NC, and 6 cases of PD were found. The clinical effective rate was 74.19%, and the clinical beneficial rate was 80.65%. The KPS score increased after the treatment (P=0.000). Three cases of pneumothorax presented after treatment, and no severe complications, such as vessel, trachea, recurrent laryngeal nerve, or pericardiocentesis injuries, were found. Conclusion Radiation seed implantation in mediastinal malignant tumors is a relatively safe technique with high success rate, considerable efficacy, and clear clinical value in advanced cancer treatment.

Background and objective 125I seed implantation treatment of pulmonary metastases, often because of complicated structure of the chest, was considered as restricted areas. The aim of this study is to evaluate the effectiveness of CT guided radioactive 125I seed implantation in treating lung metastatic tumors. Methods Totally 115 metastatic masses were found in 30 patients with CT guiding. 125I seeds were implanted into lung metastatic masses. The approach of implantation was determined according to the location of the lesions (hilar masses, peripheral masses and masses covered by skeletal thorax). The therapeutic effects were evaluated by CT. Results Uniform distribution were achieved by single puncture in 84.3% of patients. The rest patients (15.7%) were received replanting. The follow-up period was 6-24 months (mean 14.6). Among 115 lesions in 30 cases, complete response (CR) was achieved in 80 nodes, partial response (PR) in 20 nodes, No change (NC) in 8 nodes and progressive disease (PD) in 7 nodes. The total response rate was 86.9%. The one-year local control rate were 93.9% (108/115). No severe perioperative complications occurred. Conclusion CT guided radioactive seed 125I implantation is a safe and effective procedure in treating multiple lung metastatic tumor with minimal invasion.

Background and objective It is very difficult for cryosurgery to ablate all tumors because of its large volume and irregular shape. It is a complementary method for chemo-radioactive concurrent therapy to treat tumor remains. The aim of this study is to evaluate the application, security and effectiveness of Argon-Helium cryosurgery combined with radioactive seeds/release-controlled drugs implantation for percutaneous treatment of pulmonary neoplasma by CT guidance. Methods Lung cryosurgery and radioactive seeds and release-controlled drugs implantation were sequentially performed in 20 cases with 16 primary lung cancer and 4 secondary lung cancer. Side effects were observed during cryosurgery and seeds implantation. Results (3.4±0.2) cryoprobes were inserted into a nodule which is average (5.8±0.5) cm in diameter in 20 cases with 21 tumors. 85.6%±2.4% of tumor size had been ablated for each procedure. Haemoptysis occurred in 80% patients after cryosurgery, and disappeared in a week. Pneumothroax happened in 15% patients and recovered in a short time without special treatment. Absorption fever occurred in 20% patients and returned to normal in a week. (23.4±1.4) radioactive seeds and (8.3±1.2) drug-released drugs were percutaneously inserted into the 21 remaining tumors in a week after cryosurgery and 4 tumors (

Objective To assess the efficacy and side effects of 125I seed implantation for locoregional recurrent and metastatic breast cancer, and to discuss its role in the comprehensive therapy of breast cancer. Methods Forty-three patients with locoregional recurrent or metastatic breast cancer were included in this study. They received 125I seed implantation and were followed up to evaluate the efficacy and adverse reactions of the treatment. Results Among 54 lesions in the 43 cases, there were complete response (CR) in 39, partial response (PR) in 13, stable disease (SD) in 2 patients, with a response rate of 96.3%. All 17 cases with local pain achieved pain relief. With a median follow up of 36 months (range 14 to 60 months), the 1-, 3-, and 5-year local control rate was 85.2%, 53.7% and 1.9%, and the 1-, 3-, and 5-year survival rate was 95.3%, 67.4% and 37.2%, respectively. No serious radiotherapy side effect was observed. Conclusion In patients with unresectable locoregional recurrent or metastatic breast cancer, 125I seed implantation shows proved efficacy and few complications, and can be an important treatment option. [ABSTRACT FROM AUTHOR]

In recent years, 125I radioactive seed implantation has been greatly developed for the treatment of unresectable pancreatic cancer,and clinical practice shows that it has good therapeutic effects in relieving pain,controlling local tumor progression,and prolonging patients’ survival time. This article introduces the physical and biological features of 125I radioactive seeds and the advantages and disadvantages of implantation,as well as the therapeutic method,surgical safety,and clinical effects of 125I radioactive seed implantation in the treatment of unresectable pancreatic cancer. This article points out that it is an effective therapeutic method and should be widely applied in well-equipped hospitals. [ABSTRACT FROM AUTHOR]

Objective To evaluate the efficacy of CT-guided percutaneous vertebroplasty (PVP) combined with 125I-seed implantation for treatment of vertebral metastasis. Methods 22 patients with 29 vertebral metastases underwent CT-guided PVP and 125I-seed implantation in the vertebral bodies using the anterolateral, lateral or posterolateral approach in the cervical (19) and posterolateral approach in the upper thoracic (10) spine with 18G needles. Patients were followed up by CT to determine the complications and therapeutic effect. Results The procedure was successful in all patients using 10.0±6.0 and 13.0±7.0 particles of 125I-seeds, 1.50±1.0 ml and 2.50±1.50 ml of bone cement for each cervical and thoracic vertebra, respectively. The rate of pain relief using the WHO standard was 90.9%. In 3-21 month CT follow-up of 15 vertebrae in 12 patients, the tumor control rate was 86.7% with cement leakage in 17.2% and no serious complications. Conclusion CT-guided PVP combined with 125I-seed implantation is effective and safe in patients with vertebral metastasis. [ABSTRACT FROM AUTHOR]

Despite the good prognosis of early stage endometrial cancer, a part of patients will experience localized disease relapse or distant metastasis following surgery. It is to be solved that how to choose the ideal adjuvant therapy according to the high risk factors. This article conducted a review for ! phase clinical trials on record during 1990-2013, to evaluate the efficacy and safety of different adjuvant therapies in patient with early stage endometrial cancer. Post-surgical observation is appropriate for low risk patients; brachytherapy may be a better choice for intermediate risk patients; while for high risk patients, external beam radiotherapy is not effective enough in local relapse control and survival rate improvement, and the efficacy of adjuvant chemotherapy is still in study. [ABSTRACT FROM AUTHOR]

Objective: According to the formula provided by the TG43 report [AAPM TG43 (2004)] proposed by the American Association of Physicists in Medicine (AAPM) in 2004, we calculated the dose distribution around the radioactive iodine-125 particles, and verified the calculation accuracy of the radioactive iodine-125 particles treatment planning system. Methods: AAPM TG43 (2004) report provides two calculation methods when calculating the dose around a single radioactive source. The calculation method that does not consider the geometric structure of the radioactive source is called point source calculation method, and the calculation method that considers the geometric structure of the radioactive source is called line source calculation method. Assuming a single Amersham 6711 radioactive iodine-125 particle with an activity of 100 U, the following point doses were calculated according to the two calculation methods provided by AAPM TG43 (2004) report, at 0°, 90° directions, distances 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 and 6 cm; In the direction of 45°, the doses at 0.71, 1.41, 2.12, 2.83, 3.54, 4.24, 4.95, 5.66, 6.36, 7.07, 7.78 and 8.49 cm. On the clinically used brachytherapy planning system variseeds 8.0, the above two calculation methods are used to calculate the corresponding activity and the dose around the corresponding type of radioactive iodine-125 particles, and the function of capturing points to templates built in the planning system is used to accurately find the above corresponding point position, using a single measurement of the above corresponding point dose; and comparation of the results were performed to see if there is a statistical difference. Results: The AAPM TG43 report uses point source calculation method to calculate the dose of single Amersham 6711 radioactive iodine-125 particles with activity of 100 U at 0° and 90° directions. The points with the same distance and the same dose are 8 082.18, 1 870.08, 756.58, 381.47, 217.11, 131.91, 86.55, 58.32, 39.97, 27.42, 19.74, 14.13 Gy, respectively, at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 and 6 cm away from them. In the 45° direction, the doses at the distances of 0.71, 1.41, 2.12, 2.83, 3.54, 4.24, 4.95, 5.66, 6.36, 7.07, 7.78 and 8.49 cm are 3 957.37, 865.83, 329.99, 155.69, 84.10, 48.50, 28.49, 17.80, 11.37, 7.38, 4.98 and 3.39 Gy, respectively; For line source calculation method, radioactive particles are at the same distance as above. The doses at each point in the direction of 0° are 3 128.71, 755.44, 330.30, 180.53, 107.74, 68.56, 46.40, 32.22, 22.70, 16.00, 11.51, 8.24 Gy, respectively. The doses at each point in the direction of 90° are 8 306.46, 1 981.01, 802.74, 405.38, 230.60, 140.03, 91.83, 61.84, 42.36, 29.05, 20.91, 14.97 Gy; In the 45° direction, the dose at the corresponding distance as above is 4 020.78, 877.43, 333.49, 156.93, 84.69, 48.81, 28.65, 17.89, 11.42, 7.41, 4.99 and 3.40 Gy, respectively. The maximum dose difference (0.3%) between the two methods is 7.78 cm in the 45° direction, the maximum difference (-0.3%) between the two methods is 8.49 cm in the 45° direction, and the value of other sampling points is less than 0.3%. The closer the Amersham 6711 iodine-125 particles are to the source in the directions of 0°, 45°, and 90°, the faster the dose will drop, and the dose will drop gradually as the distance increases. Conclusion: The brachytherapy planning system variseeds 8.0 and the AAPM TG43 report calculate a maximum dose difference of 0.3%, which can accurately calculate the dose distribution around radioactive iodine-125 seeds, and provide a reliable tool for the clinical implementation of radioactive iodine-125 particles implantation for tumor treatment.

Background and objective 125I seed implantation treatment of pulmonary metastases, often because of complicated structure of the chest, was considered as restricted areas. The aim of this study is to evaluate the effectiveness of CT guided radioactive 125I seed implantation in treating lung metastatic tumors. Methods Totally 115 metastatic masses were found in 30 patients with CT guiding. 125I seeds were implanted into lung metastatic masses. The approach of implantation was determined according to the location of the lesions (hilar masses, peripheral masses and masses covered by skeletal thorax). The therapeutic effects were evaluated by CT. Results Uniform distribution were achieved by single puncture in 84.3% of patients. The rest patients (15.7%) were received replanting. The follow-up period was 6-24 months (mean 14.6). Among 115 lesions in 30 cases, complete response (CR) was achieved in 80 nodes, partial response (PR) in 20 nodes, No change (NC) in 8 nodes and progressive disease (PD) in 7 nodes. The total response rate was 86.9%. The one-year local control rate were 93.9% (108/115). No severe perioperative complications occurred. Conclusion CT guided radioactive seed 125I implantation is a safe and effective procedure in treating multiple lung metastatic tumor with minimal invasion. [ABSTRACT FROM AUTHOR]

Objective To investigate the efficacy of argon - helium cryoablation combined with I125 particle implantation in the treatment of hilar cholangiocarcinoma. Methods Five patients with hilar cholangiocarcinoma who were admitted to our hospital from lanuary 2010 to lune 2013 were selected. Under CT localization, the tumor location and puncture angle were determined using a puncture needle, and then the tumor was pierced with a 17 mm argon - helium knife; a temperature - sensing needle was placed at the main bile duct and confluence of the left and right hepatic ducts closest to the ice ball and near the side of argon - helium knife ; the minimum distance between the argon -helium knife and bile duct wall was greater than 3 cm; for the tumor tissue surrounding the main bile duct, I125 particles were placed along the longitudinal axis about 0. 8 cm from the bile duct wall at a spacing of 0. 3 - 0. 5 cm, and then two cycles of cryoablation were performed. Results Of the five patients, two had complete relief of pain symptoms within one week after operation, and three had significant relief; two cases showed a significant decrease in total bilirubin within one week, and one showed a mild increase. No complications such as bleeding and pneumothorax were seen. Conclusion Argon - helium cryoablation combined with I125 particle implantation can effectively relieve symptoms and improve the quality of life in patients with hilar cholangiocarcinoma within a short period after operation, but the evaluation of its long - term efficacy stiil needs large - sample case studies and long - term follow - up. [ABSTRACT FROM AUTHOR]

Objective: To investigate the surgical therapeutic efficacy of uterine tumors patients underwent Cf-252 neutron intra-cavity and external radiotherapy, and evaluate the application value of Cf-252 neutron radiotherapy. Methods: Thirteen cases of uterine tumor with local suspicious lesions or poor prognostic factors after CF-252 neutron intracavity and external radiotherapy were treated with surgery. Among them, 12 cases underwent extrafascial hysterectomy, 1 case underwent extensive hysterectomy and lymphadenectomy. The postoperative pathology and follow-up results were used to evaluate the efficacy. Results: Nine cases showed severe response to radiotherapy in postoperative cervical pathological tissues without residual tumor, and survived for more than 3-14 years, the median survival time was 8 years. All of 4 cases with residual tumor died within 1 year. Delayed healing of vaginal wounds occurred in 3 of the 12 cases. Conclusions: Cf-252 is a good brachytherapy source. The cervical tissue shows severe response to radiotherapy and prolonged healing time of vaginal wound is observed in some cases after CF-252 radiotherapy. To those uterine tumor patients with local suspicious lesions or poor prognostic factors after CF-252 neutron intracavity and external radiotherapy, extrafascial hysterectomy is a safe and feasible treatment method.

Objective: To investigate the clinical application and efficacy of 125 Ⅰ radioactive seeds implantation in the treatment of recurrent salivary gland carcinoma after external radiotherapy., Methods: From July 2004 to July 2016, 43 cases of recurrent salivary gland carcinoma of the neck after external radiotherapy or surgery combined with external radiotherapy were treated. According to the conventional segmentation radiotherapy for head and neck cancer (once a day, 1.8-2.0 Gy each time, 5 days per week), the cumulative radiation dose of the patients in this group was calculated. In the study, 26 patients received 50-60 Gy, 7 patients received less than 50 Gy, 4 patients received 60-70 Gy, and 6 patients received more than 80 Gy (range: 80-120 Gy). The interval between the last external irradiation and local recurrence was 4-204 months, and the median interval was 48 months. Among them, 25 cases were treated with 125 Ⅰ radioactive seeds implantation only and 18 cases were treated with 125 Ⅰ radioactive seeds implantation after operation. The prescription dose was 100-140 Gy. The control rate, survival rate and disease-free survival rate were recorded to evaluate the side effects., Results: The median follow-up time was 27 months (ranging from 2.5 to 149.0 months). Among them, the median follow-up time of adenoid cystic carcinoma patients was 31 months (range: 2.5-112.0 months), and the median follow-up time of mucoepidermoid carcinoma patients was 18 months (range: 5-149 months). The local control rates for 1, 3 and 5 years were 66.5%, 48.8% and 42.7%, respectively. The 1-, 3- and 5- year survival rates were 88.0%, 56.7% and 45.8%, respectively. The disease-free survival rates of 1, 3 and 5 years were 58.3%, 45.4% and 38.1%, respectively. There was no statistically significant difference in local control rate, survival rate, and disease-free survival between the radioactive seeds implantation group and the radioactive seeds implantation group after surgical resection. There were 2 cases of acute radiation reaction Ⅰ/Ⅱ and 3 cases of reaction Ⅲ or above. In the late stage of radiotherapy, there were 8 cases with Ⅰ/Ⅱ grade reaction and 3 cases with Ⅲ grade or above reaction. The incidence of radiation reactions of Grade Ⅲ and above was 7%., Conclusion: 125 Ⅰ radioactive seeds implantation provides an alternative method for the treatment of recurrent salivary gland carcinoma after external radiotherapy. The local control rate and survival rate are improved on the premise of low incidence of side effects.

Objective: To investigate the clinical efficacy of percutaneous vertebroplasty (PVP) combined with iodine-125 ((125)I) seed brachytherapy in the treatment of spinal metastatic epidural spinal cord compression (MESCC) and toassess the changes inthe grade of epidural spinal cord compression (ESCC) by magnetic resonance imaging (MRI). Methods: A total of 37 MESCC patients treated with PVP combined with (125)I seed brachytherapy in the interventional and vascular surgery department of Zhongda Hospital affiliated to Southeast University from January 2014 to June 2019 were retrospectively analyzed, including 23 cases of bilateral lower limbs paralysis. Total diseased vertebrae are 39 segments. Visual analogue scale (VAS) and paralysis of lower extremities were evaluated regularly before and after treatment, and VAS values at different follow-up time points were compared. At the same time, MRI was used to evaluate the changes of ESCC grade in the spinal canal and calculate the local lesion efficiency after operation. The postoperative local lesion efficiency at different follow-up times was compared. Results: PVP combined with (125)I seed implantation in all diseased vertebral bodies was successful. The average injection volume of polymethylmethacrylate (PMMA) was (3.2±1.3) ml/segment, the average number of (125)I seed implanted was (25.0±8.6) seeds/segment and the average radiation dose was (15.0±5.1) mCi/segment. The VAS before operation was 8.5, and postoperative VAS were respectively 3.6±1.3, 3.8±1.5, 3.4±1.4, 5.5±1.0, 5.9±1.4 at 5 days, 1 month, 3 months, 6 months, and 1 year after operation. The differences between all follow-up time points and preoperative VAS values were statistically significant (all P <0.001). Compared with 5 days, 1 month and 3 months after operation, VAS increased significantly at 6 months and 1 year after operation, and the difference was statistically significant (all P <0.001); there was no significant difference between the VAS value at 6 months after operation and 1 year after operation ( P =0.405). At a follow-up of 3 months, 22 of 23 patients with paralysis of bilateral lower limbs regained the functions of autonomous walking and voiding; the effective rates of MESCC local lesions evaluated by MRI at 1 month, 3 months, 6 months, and>1 year were 89.7%, 91.9%, 90.6%, and 94.7%, respectively, and there was no statistically significant differences among those follow-up time points (all P >0.05). Conclusions: PVP combined with (125)I seed brachytherapy in the treatment of MESCC has significant improvement in immediate pain relief and spinal cord function. After combined treatment, MRI showed that the tumors around the spinal cord regressed dramatically, which could considerably reduce the MESCC grade and remain stable for a long time.

Objective: To investigate the safety and efficacy of external scleral plaque radiotherapy (PRT) in the treatment of uveal melanoma (UM). Methods: This was a retrospective case series study. The data of 819 patients who underwent ophthalmic PRT from July 2007 to November 2017 at Tongren Hospital Affiliated to Beijing Capital Medical University was collected, including preoperative visual acuity, intraocular pressure and slit lamp microscope, color fundus photography, indirect ophthalmoscopy, color Doppler ultrasound, fundus fluorescein angiography, indocyanine green angiography, orbital nuclear magnetic resonance imaging, PRT times and time, complications, follow-up time, the maximum basal diameter and height of the tumor UM half a year after the applicator was removed, tumor metastasis rate, mortality and visual acuity observed at the last follow-up. The tumor growth was considered when the tumor height increased by 2.0 mm or the extension of any boundary of the tumor was 2.5 mm; otherwise, the treatment was defined as effective. The paired t test and Kaplan-Meier survival curve were used for statistical analysis. Results: There were 408 males and 411 females. The age ranged from 13 to 85 years (mean, 47 years). Nine patients had ciliary body melanoma, 43 patients had choroidal melanoma involving the ciliary body, and 767 patients had choroidal melanoma. In all 819 eyes, the tumor was medium-sized in 697 eyes and large in 110 eyes. All patients were treated with PRT only one time. The average radiotherapy time was 15 days (range, 6 to 50 d). All operations were successfully completed, with no active bleeding, infection, adjacent tissue injury and other related complications. At 6 months after the treatment, the maximum basal diameter of the tumor was (12.41±3.20) mm, which was significantly different from that before treatment (12.82±3.21) mm ( t =2.40, P <0.01); the tumor height was (6.18±2.55) mm, which was significantly different from that before treatment (7.21±2.57) mm ( t =4.05, P <0.01). The average follow-up time was (34±24) months (range, 1 to 125 months). Twenty-five patients lost follow-up at 2 years after the PRT, and 71 patients underwent enucleation. The effective rate of the PRT treatment was 88.3% (723/819), and the eyeball retention rate was 91.1% (723/794). The visual acuity remained stable in 393 eyes, decreased in 344 eyes, and improved in 82 eyes. Sixty patients had systemic metastasis (liver, bone or breast metastasis). Twenty-two patients died of tumor metastasis. The 5-year metastasis rate was 12.8%; the 5-year mortality rate was 5.8%; the 10-year metastasis rate was 20.6%; the 10-year mortality rate was 5.8%. Conclusions: PRT is safe and effective in the treatment for UM and can preserve some useful visual acuity. PRT can be used as the main treatment for medium-sized UM. (Chin J Ophthalmol, 2020, 56: 670-675) .

Objective: To investigate the clinical efficacy radiofrequency ablation (RFA) combined with (125)I radioactive seed implantation in treatment of hepatocellular carcinoma HCC with the tumor diameter 3-5 cm. Methods: One hundred patients with HCC diagnosed clinically or pathologically with Barcelona staging of B or C in Lishui Central Hospital from February 2012 to September 2017 were retrospectively analyzed. Of the included 100 cases, 89 were males and 11 were females with the mean age of 18-80 (57±11) years old.According to the treatment modality, the subjects were divided into control group (RFA, n= 67) and combined group (RFA+(125)I, n= 33). Patients in control group were only received RFA and cases in combined group received RFA plus sequenced with (125)I implantation therapy. The prognosis of progression free survival (PFS) and overall survival (OS) between the two groups were compared through the Kaplan-Meier curve and Log-rank test. Results: The median follow-up time period was 6-55 months in the last follow-up time point of Dec 30, 2017. The median PFS were 4-55 (23.0±4.7) and 1-53 (12.0±1.6) months for combined and control groups respectively with significant statistical difference ( P= 0.015). The median OS were 6-55 (42.0±7.9) and 2-55 (38.0±2.8) months for combined and control groups with the trend of improvement in combined group, but without statistical difference ( P= 0.444). Subgroup analysis further indicated that the PFS was significant improved in patients with residual tumor lesions who received the combined treatment (PFS: 18 vs 9 months, P= 0.025). However, there was no statistical difference for PFS between the control and combined treatment groups for cases without residual tumor lesions after RAF treatment( P= 0.685). Conclusions: PFS was obviously increased in HCC patients(tumor diameter 3-5 cm) who received(125)I implantation after radiofrequency ablation, especially for cases with residual tumor lesions.

Objective: To evaluate the treatment of vasoproliferative tumors of the retina (VPTR). Methods: Retrospective case series study. The clinical data of 20 VPTR patients (20 eyes) were retrospectively analyzed, including 2 eyes only treated by cryotherapy, 1 eye only treated by photocoagulation and 1 eye only treated by ruthenium-106 brachytherapy. The remaining 16 eyes had combined treatment of ruthenium-106 brachytherapy, photodynamic therapy, anti-VEGF therapy, photocoagulation and cryotherapy. Nine eyes were also treated by vitrectomy because of complications such as retinal detachment and vitreous hemorrhage. Results: Single or multiple yellow white or orange red, highly vascular tumor lesions were found in ocular fundi of the 20 eyes. All eyes were accompanied by complications, including intraretinal and subretinal exudations (100%), macular edema ( n= 19, 95%), epiretinal membrane ( n= 4, 20%), retinal detachment ( n= 8, 40%), vitreous hemorrhage ( n= 6, 30%), abnormal blood vessels ( n= 16, 80%) and proliferative membrane ( n= 7, 35%). In the follow-up, the tumor in the eye treated by ruthenium-106 brachytherapy alone was atrophied and the vision improved. Regarding the 2 eyes treated by cryotherapy alone, macular edema and abnormal blood vessels decreased and visual acuity improved in 1 eye, and visual acuity did not change significantly in another eye. More leakages and increased visual acuity were found in the eye treated by photocoagulation alone. Among the 16 eyes treated with combined therapy, 9 eyes had decreased complications and improved visual acuity, 3 eyes did not change significantly, and 2 eyes had increased complications and decreased visual acuity. Conclusions: The conditions of VPTR are complex and difficult to treat. According to the specific conditions, clinicians should choose appropriate treatment methods; different treatment methods can be combined. Laser photocoagulation and cryotherapy may be chosen to treat small tumors complicated with abnormal blood vessels. Ruthenium-106 brachytherapy could treat big tumors complicated with exudative retinal detachment. Vitreous surgery can be used in hemorrhage and tractional retinal detachment. Anti-VEGF therapy is effective in the treatment of macular edema. (Chin J Ophthalmol, 2020, 56:272-278) .

Objective: To compare the dose difference of (125)I seeds implantation on superficial metastatic carcinoma between 3D print template guided operation and traditional implantation. To investigate the accuracy of seeds implantation according preplan guided by 3D print template. Methods: A total of 21 cases of patient with 27 lesions underwent (125)I seeds implantation from January 2015 to May 2018 in Hebei General Hospital were analyzed retrospectively. In which, ten lesions underwent seeds implantation guided by 3D print template (template group) and 17 lesions underwent free-hand traditional implantation (traditional group). All patients had been fixed as the position of operation and then performed CT scan. After preplan was designed, the 3D templates were printed in template group. Postplan was performed after the operation.The dose volume histogram, D90 was calculated. The D90 pre and post operation were collected and compared in each group. The difference of D90 and the percentage difference of D90 between pre and post operation were calculated by the formula D90d=D90post-D90pre, D90d%=(D90post-D90pre)/D90pre×100%, and compared the difference between two groups. Results: The mean D90 pre and post operation in template group were (92±26) and (93±27) Gy respectively, t= -0.749, P= 0.473. The mean D90 pre and post operation in traditional group were (104±29) and (104±26) Gy respectively, t= -0.139, P= 0.891. The difference of D90 in two groups were (3.1±2.4) and (10.0±8.7) Gy, Z= -2.5, P= 0.012. The percentage difference of D90 in two groups were 3.1%±1.9% and 9.5%±7.9%, Compared with the traditional group, the template group had smaller fluctuations, and the difference was statistically significant ( Z= -2.7, P= 0.006) (all P< 0.05). Conclusions: The dose parameters of 3D template guided seeds implantation between postplan and preplan are nearly consistent.3D template has good repeatability, which provides a theoretical basis for the popularization of 3D printing technology.

Objective: To retrospectively analyze the results of treatment outcome by surgery combined with 125 I brachytherapy and correlative factors of adenoid cystic carcinoma (ACC)., Methods: In the study, 75 patients with primary ACC of oral and maxillofacial region were treated by surgery combined with 125 I seeds brachytherapy. Radical resection or subtotal resection was applied for the tumor. The brachytherapy treatment planning system was used to create implant plans with the prescribed dose of 60 Gy to 120 Gy. The 125 I seeds were implanted intraoperatively or postoperatively. The regular follow-up was required. The Kaplan-Meier method was used to assess the tumor control rate and the patients' survival rates. Meanwhile, the Cox regression analysis was used to find out the prognostic factors., Results: Local control rates at the end of 3 and 5 years were as follows: T1-T2, 92.2% and 82.0%; T3-T4, 82.6% and 82.6%; and overall, 90.0% and 78.8%. The disease-free survival rates were 74.9% and 54.3%, respectively. The overall survival rates for all the patients were 86.0% and 79.6%, respectively at the end of 3 and 5 years and were 91.3% and 91.3% for T1-T2 patients vs. 73.9% and 59.7% for T3-T4 patients. Distant metastasis-free survival rates at the end of 3 and 5 years were 84.4% and 76.7%, respectively. The distant metastasis-free survival rates at the end of 3 and 5 years were 83.4% and 79.6% with T1-T2 lesion compared with 86.0% and 67.8% with T3-T4 lesion. According to the COX univariate analysis and multivariate analysis, the risk of local recurrence would be raised by the age. Tumor stage and tumor site were the prognostic factors of the overall survival rates., Conclusion: 125 I brachytherapy conducted as an adjuvant therapy postoperatively of ACC of oral and maxillofacial region can acquire satisfactory localregional control, distant metastasis-free survival, disease-free survival and overall survival. Tumors are prone to recur on the older patients. Patients having advanced tumor stage or tumor located in the nasal cavity or sinuses will suffer lower survival rates.

Objective: To investigate the long-term clinical value of prostate 125I brachytherapy (BT) combined with maximal androgen blockade (MAB) in the treatment of metastatic prostate cancer (mPCa)., Methods: We retrospectively analyzed the clinical data on 173 cases of mPCa treated by MAB (n = 126) or BT+MAB (n = 47) from December 2011 to December 2016 and followed up for 6－76 (44.17 ± 19.73) months. We compared the PSA level, prostate volume, IPSS, progression-free survival, and the rates of 3- and 5-year overall survival between the two groups., Results: After treatment, the minimum PSA level was significantly lower in the BT+MAB than in the MAB group ［3.77 ± 4.14］ vs ［5.96 ± 7.01］ ng/ml, P = 0.046) and the time to reach the minimum level was shorter in the former than in the latter (［5.19 ± 2.83］ vs ［6.52 ± 3.34］ mo, P = 0.016). The prostate volume was markedly reduced in both of the groups at 1, 3 and 5 years after treatment as compared with the baseline, even more significantly in the BT+MAB than in the MAB group (P < 0.01), though with no statistically significant difference between the two groups before treatment (P = 0.307). The IPSS was remarkably decreased in both of the groups at 1 and 3 years (P < 0.01) but showed no significant difference at 5 years after treatment as compared with the baseline (P > 0.05) or between the two groups before and after treatment (P > 0.05). The progression-free survival was obviously longer in the BT+MAB than in the MAB group (［37.29 ± 15.73］ vs ［29.41 ± 14.37］ mo, P = 0.011), and the rates of 3- and 5-year overall survival were higher in the former than in the latter (74.60% and 60.70% vs 62.60% and 51.50%, P = 0.227 and P = 0.356). Kaplan-Meier survival curves showed no statistically significant difference in the overall survival between the two groups (P = 0.105)., Conclusions: Both MAB and BT+MAB are effective therapies for mPCa, but the latter can achieve a longer progression-free survival.

Objective: To investigate the efficacy of CT-guidance interstitial Iodine-125 seed brachytherapy as a salvage therapy for recurrent head and neck carcinoma. Methods: A total of 122 patients who had been treated for recurrent head and neck carcinoma with CT-guided Iodine-125 seed permanent implantation were conducted a retrospective analysis at Peking University Third Hospital from February 2003 to December 2015. The study included 78 male and 44 female patients. Of the 122 patients, 76 had undergone radical surgery, 106 had received EBRT. Among the patients who underwent EBRT, the total dose delivered to PTV ranged from 30 to 140 Gy (median, 68.4 Gy). The actuarial median number of the implanted Iodine-125 seeds was 38 (range, 5-158). The specific activity of Iodine-125 seeds ranged from 14.8 to 28.9 MBq/seed (median, 22.2 MBq). The evaluation of post plan showed the actuarial D90 ranged from 46 to 282 Gy (median, 121 Gy). The overall local control and survival times were determined by using the Kaplan - Meier method from SPSS 13.0.Univariate analysis was performed on the local control rate and overall survival rate. Results: Tumor responses rate was 75.4%. The median local control time was 10.0 months (95% CI 9.8-24.2 months), and the 1-, 2-, 3-, and 5-year local control were 41.9%, 21.2%, 3.7%, and 3.7%, respectively. Univariate analysis showed that the local control in D90≥120 Gy group had an increasing tendency, but no statistical difference were found. The effect of local control in the squamous cell carcinoma group was slightly worse than that in the non-squamous cell carcinoma group ( P =0.032). Multi-factor analysis showed that the effect of local control in the squamous cell carcinoma group was slightly poor ( P =0.03). The median survival time was 14 months (95% CI 14.4-35.8 months), and the 1-, 2-, 3- and 5-year survival rate were 51.5%, 34.2%, 19.4%, and 19.4%, respectively. The three factors, such as the tumor responses, KPS status before the seed implantation, and the D90 after the seed implantation, had a tendency to improve the total survival, but there was still no statistical differences. Multivariate analysis showed no clear influence factors. Conclusions: Interstitial permanent Iodine-125 seed implantation is an effective salvage re-irradiation modality for recurrent head and neck carcinoma after previous surgery and/or EBRT. CT image-guided method could yield the reliable seeds configuration and accurate dose distribution.

Objective: To measure the activity of (125)I seed and compare the dose difference of ten patients treated with seed implantation in pre-plan with actual seed activity and calibrate activity. Method: The activity of 100 seeds from company A and B was measured with a well-type ionization chamber 1 day before operation and named group A and B. The activity of two groups was compared and the error between actual and calibrate activity (22.2 MBq, group C) was calculated. Ten patients implanted with (125)I seeds from November 1 st to 30 th, 2017, solstice 30 were selected in Hebei General Hospital. Firstly, pre-plans were designed with 22.2 MBq, prescribed dose were 100-140 Gy. The dose parameters of 90% volume absorbed dose (D(90)), 150% volume fraction (V(150)) and 100% volume fraction (V(100)) were calculated. Then changed 22.2 MBq to actual activity of group A and B, calculated the dose parameters above again. Then dose parameters of D(90), V(150), V(100) in group C were compared with those in group A and B respectively. Result: The actual activity 1 day before the operation was(22.6±0.7)and(23.9±0.9)MBq in group A and B respectively. Compared with 22.2 MBq, the difference was statistically significant( t =5.7, P <0.05 and t =19.2, P <0.05), and the activity error of group B was greater than 5%. The D(90) of group A, B and C were (124.3±9.7) , (131.2±10.2) and (121.9±9.5) Gy respectively.The V(150) were 58.4%±9.4%, 63.7%±8.9% and 56.5%±9.2% respectively. The V(100) were 88.9%±5.0%, 92.0%±4.1%, 88.1%±5.2% respectively.The difference of D(90) between calibrate activity(group C) and actual activity(group A and B) were statistically significant ( t =40.2, P <0.05 and t =40.3, P <0.05). The difference of V(150) between group C and group A and B were statistically significant ( t =7.5, P <0.05 and t =24.7, P <0.05). The difference of V(100) between group C and group A and B were statistically significant ( t =6.6, P <0.05 and t =7.3, P <0.05). Conclusion: There is difference between the actual activity and calibration activity. The difference affects the dose parameters in pre-plan.The seed activity should be measured before operation strictly and the pre-plan should be designed with the actual activity.

Objective: To investigate the dosimetric distribution characteristics of (125)I seed stents with different seed spacing, diameter and length, as well as different (125)I seed activity. The dosimetry table of (125)I seed esophageal stent was derived to provide dosimetry for its clinical application. Methods: The self-expanding coated esophagus stent was designed to carry radioactive (125)I seeds with different length, diameter and seed spacing. A cylindrical organic glass model (Thickness 0.8 cm, diameter 20 cm, height 20 cm) was fixed vertically to a cylindrical organic glass containing a solid paraffin (analytical pure) solution. After paraffin cooling and solidification, CT scan was used to transmit image information to TPS. With the center of the bracket as a dot, the cumulative dose at a distance of 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 5.0, 6.0 and 8.0 cm away from the dot was simulated respectively in 0° and 9° direction. Results: The radial cumulative dose with the seed spacing which was 1.0 and 1.5 cm were different by 4.8%, 5.8%, 7.2%, 8.0%, 8.6% and 13.3% respectively under the exposure of 18.5, 22.2, 25.9, 29.6, 33.3 and 37.0 MBq. When the seed spacing was the same as the length of the stent, the radial cumulative dose with the stent which diameter was 1.3, 2.0, 2.4 cm were different by 4.9% vs 3.4%, 4.7% vs 3.8%, 5.4% vs 6.6%, 4.5% vs 5.3%, 4.7% vs 4.8%, 4.8% vs 5.4% respectively under the exposure of 18.5, 22.2, 25.9, 29.6, 33.3 and 37.0 MBq. When the seed spacing was the same as the diameter of the stent, the radial cumulative dose with the stent which length was 8, 12, 16 cm were different by 1.9% vs 1.2%, 1.7% vs 0.8%, 1.6% vs 1.3%, 1.9% vs 1.5%, 1.7% vs 1.8%, 1.6% vs 1.3% respectively under the exposure of 18.5, 22.2, 25.9, 29.6, 33.3 and 37.0 MBq. Conclusions: The radial cumulative dose of the (125)I seed stent is positively correlated with the activity of the radioactive seeds, Which means the dose rate of a certain point of the (125)I seed stent increase with the increase of the activity of the radioactive seeds. The stent of the (125)I radioactive seeds is negatively correlated with the distance, the dose rate of the (125)I seed stents decrease rapidly with the increase of distance.

Objective: To evaluate the relationship of dosimetry parameters and efficacy of (125)I seeds implantation for pelvic recurrent cervical cancer (PRCC) after external beam radiotherapy(EBRT) under CT guidance. Methods: A retrospective analysis was made on 30 PRCC patients after EBRT in Peking University Third Hospital with (125)I seeds implantation under CT guidance. Postoperative plans were made to evaluate the dosimetric parameters. Kaplan - Meier method was used to calculate local progression free survival (LPFS) rate and overall survival (OS) rate, and Log - rank test and Cox regression were used for univariate and multivariate analysis. Results: The 1-year and 2-year LPFS rate was 39.4% and 22.5%, respectively. The 1-year and 2-year OS rate was 57.3% and 27.4%, respectively. On postoperative plan, D(90) was (132±47) Gy, D(100) was (51±24) Gy, V(100) was 88%±10%, V(150)was 69%±15%, V(200) was 51%±18%.LPFS time would be longer while D(90) ≥105 Gy or D(100) ≥ 55 Gy or V(100) ≥ 91% (all P <0.05). D(100) was significantly related to LPFS ( P <0.05). But these dosimetry parameters got no effect on OS. Conclusions: LPFS time of (125)I seeds implantation for PRCC after EBRT under CT guidance would be longer when D(90)≥105 Gy or D(100)≥ 55 Gy, or V(100)≥ 91%. D(100) is an independent factor related to LPFS.

Radiation treatment, including episcleral plaque radiotherapy, stereotactic radiosurgery, proton beam therapy and so on, is the primary eye-conserving choice for uveal melanoma. But the complications resulted from radiotherapy's nonselective kill to tumor cells can be visual-threatening and eventually result in the enucleation of eyeball. This review summarizes current radiation strategies for uveal melanoma and how these complications occur, develop and present, in the hope that it could provide insights for the radiation interventions and diagnosis of radiative complications. (Chin J Ophthalmol, 2018, 54: 707-711) .

Objective: To evaluate the effect of stereotactic iodine-125 brachytherapy in the management of adult thalamic high grade gliomas. Methods: Five cases of adult thalamic high grade gliomas (WHO Ⅲ-Ⅳ) were treated with stereotactic iodine-125 brachytherapy and temozolomide chemotherapy at the Second Affiliated Hospital of Zhejiang University School of Medicine between December 2016 and February 2018, assisted with stereotactic plan and radiation therapy planning system. Results: Pathology revealed anaplastic astrocytoma (WHO Ⅲ, 2 cases) and glioblastoma (WHO Ⅳ, 3 cases). The average amount of iodine-125 implanted was 10.6 seeds. After surgery, the Karnofsky Performance Scale (KPS) was the same as preoperative KPS, and there was no severe surgery related neurological deficits. The follow-up time was from 2 months to 16 months, with an average of 7.8 months. One patient (WHO Ⅲ) without chemotherapy presented with tumor progression 6.5 months later. The other four cases showed tumor stable on MRI. Conclusions: Stereotactic iodine-125 brachytherapy in the management of adult thalamic high grade gliomas showed satisfactory recent curative effect. Large case studies and long follow-up are needed for further evaluation.

Objective: To present a theoretical analysis of how the presence of bone in interstitial brachytherapy affects dose rate distributions with MCNP4C Monte Carlo code and to prepare for the next clinical study on the dose distribution of interstitial brachytherapy in head and neck neoplasm., Methods: Type 6711, 125 I brachytherapy source was simulated with MCNP4C Monte Carlo code whose cross section library was DLC-200. The dose distribution along the transverse axis in water and dose constant were compared with the American Association of Physicists in Medicine (AAPM) TG43UI update dosimetry formalism and current literature. The validated computer code was then applied to simple homogeneous bone tissue model to determine the affected different bone tissue had on dose distribution from 125 I interstitial implant., Results: 125 I brachytherapy source simulated with MCNP4C Monte Carlo code met the requirements of TG43UI report. Dose rate constant, 0.977 78 cGy/(h×U), was in agreement within 1.32% compared with the recommended value of TG43UI. There was a good agreement between TG43UI about the dosimetric parameters at distances of 1 to 10 cm along the transverse axis of the 125 I source established by MCNP4C and current published data. And the dose distribution of 125 I photon emitting source in different bone tissue was calculated. Dose-deposition capacity of photons was in decreasing order: cortical bone, spongy bone, cartilage, yellow bone marrow, red bone marrow in the same medium depth. Photons deposited significantly in traversal axis among the phantom material of cortical bone and sponge bone relevant to the dose to water. In the medium depth of 0.01 cm, 0.1 cm, and 1 cm, the dose in the cortical bone was 12.90 times, 9.72 times, and 0.30 times of water respectively., Conclusion: This study build a 125 I source model with MCNP4C Monte Carlo code, which is validated, and could be used in subsequent study. Dose distribution of photons in different bone medium is not the same as water, and its main energy deposits in bone medium surface, so we should consider the effect of bone medium when we design the target area adjacent to the bone tissue in 125 I sources implantation plan.