THUBrachy:fast Monte Carlo dose calculation tool accelerated by heterogeneous hardware for high-dose-rate brachytherapy

The Monte Carlo(MC)simulation is regarded as the gold standard for dose calculation in brachytherapy,but it consumes a large amount of computing resources.The development of heterogeneous computing makes it possible to substantially accelerate calculations with hardware accelerators.Accordingly,this study develops a fast MC tool,called THUBrachy,which can be accelerated by several types of hardware accelerators.THUBrachy can simulate photons with energy less than 3 MeV and considers all photon interactions in the energy range.It was benchmarked against the American Association of Physicists in Medicine Task Group No.43 Report using a water phantom and validated with Geant4 using a clinical case.A performance test was conducted using the clinical case,showing that a multicore central processing unit,Intel Xeon Phi,and graphics processing unit(GPU)can efficiently accelerate the simulation.GPU-accelerated THUBrachy is the fastest version,which is 200 times faster than the serial version and approximately 500 times faster than Geant4.The proposed tool shows great potential for fast and accurate dose calculations in clinical applications.

CT-guided high-dose-rate brachytherapy in the interdisciplinary treatment of patients with liver metastases of pancreatic cancer

BACKGROUND： CT-guided high-dose-rate brachytherapy（CT-HDRBT） is an interventional radiologic technique for local ablation of primary and secondary malignomas applying a radiation source through a brachycatheter percutaneously into the targeted lesion. The aim of this study was to assess local tumor control, safety and efficacy of CT-HDRBT in the treatment of liver metastases of pancreatic cancer. METHODS： Twenty consecutive patients with 49 unresectable liver metastases of pancreatic cancer were included in this retrospective trial and treated with CT-HDRBT, applied as a single fraction high-dose irradiation（15-20 Gy） using a 192 Irsource. Primary endpoint was local tumor control and secondary endpoints were complications, progression-free survival and overall survival.RESULTS： The mean tumor diameter was 29 mm（range 10-73）. The mean irradiation time was 20 minutes（range 7-42）. The mean coverage of the clinical target volume was 98%（range 88%-100%）. The mean D100 was 18.1 Gy and the median D100 was 19.78 Gy. Three major complications occurred with post-interventional abscesses, three of which were seen in 15 patients with biliodigestive anastomosis（20%）and overall 15%. The mean follow-up time was 13.7 months（range 1.4-55.0）. The median progression-free survival was 4.9 months（range 1.4-42.9, mean 9.4）. Local recurrence occurred in 5（10%） of 49 metastases treated. The median overall survival after CT-HDRBT was 8.6 months（range 1.5-55.3）. Eleven patients received chemotherapy after ablation with a median progression-free survival of 4.9 months（mean 12.9）. Nine patients did not receive chemotherapy after intervention with a median progression-free survival of 3.2 months（mean 5.0）. The rate of local tumor control was 91% in both groups after 12 months.CONCLUSION： CT-HDRBT was safe and effective for the treatment of liver metastases of pancreatic cancer.

High-dose-rate intraluminal brachytherapy during preoperative chemoradiation for locally advanced rectal cancers

AIM:To determine the feasibility and safety of high dose rate intraluminal brachytherapy(HDR-ILBT) boost during preoperative chemoradiation for rectal cancer.METHODS:Between 2008 and 2009,thirty-six patients with locally advanced rectal cancer(≥ T3 or N+),were treated initially with concurrent capecitabine(825 mg/m2 oral twice daily) and pelvic external beam radiotherapy(EBRT)(45 Gy in 25 fractions),then were randomized to group A;HDR-ILBT group(n = 17) to receive 5.5-7 Gy×2 to gross tumor volume(GTV) and group B;EBRT group(n = 19) to receive 5.4 Gy×3 fractions to GTV with EBRT.All patients underwent total mesorectal excision.RESULTS:Grade 3 acute toxicities were registered in 12 patients(70.6%) in group A and in 8(42.1%) in group B.Complete pathologic response of T stage(ypT0) in group A was registered in 10 patients(58.8%) and in group B,3 patients(15.8%) had ypT0(P < 0.0001).Sphincter preservation was reported in 6/9 patients(66.7%) in group A and in 5/10 patients(50%) in group B(P < 0.01).Overall radiological response was 68.15% and 66.04% in Group A and B,respectively.During a median follow up of 18 mo,late grade 1 and 2 sequelae were registered in 3 patients(17.6%) and 4 patients(21.1%) in the groups A and B,respectively.CONCLUSION:HDR-ILBT was found to be effective dose escalation technique in preoperative chemoradiation for rectal cancers,with higher response rates,downstaging and with manageable acute toxicities.

Dose-volume parameters and clinical outcome of CT-guided free-hand high-dose-rate interstitial brachytherapy for cervical cancer

Currently, image-based 3-dimentional (3D) planning brachytherapy allows for a better assessment of gross tumor volume (GTV) and the definition and delineation of target volume in cervix cancer. In this study, we investigated the feasibility of our novel computed tomography (CT)-guided free-hand high-dose- rate interstitial brachytherapy (HDRISBT) technique for cervical cancer by evaluating the dosimetry and preliminary clinical outcome of this approach. Dose-volume histogram (DVH) parameters were analyzed according to the Gynecological GEC-ESTRO Working Group recommendations for image-based 3D treatment in cervical cancer. Twenty cervical cancer patients who underwent CT-guided free-hand HDRISBT between March 2009 and June 2010 were studied. With a median of 5 (range, 4-7) implanted needles for each patient, the median dose of brachytherapy alone delivered to 90% of the target volume (D90 ) was 45 (range, 33-54) Gyα/β10 for high-risk clinical target volume (HR-CTV) and 30 (range, 20-36) Gyα/β10 for intermediate-risk clinical target volume (IR-CTV). The percentage of the CTV covered by the prescribed dose (V100 ) of HR-CTV with brachytherapy alone was 81.9%-99.2% (median, 96.7%). With an additional dose of external beam radiotherapy (EBRT), the median D90 was 94 (range, 83-104) Gyα/β10 for HR-CTV and 77 (range, 70 -87) Gyα/β10 for IR-CTV; the median dose delivered to 100% of the target volume (D100 ) was 75 (range, 66-84) Gyα/β10 for HR-CTV and 65 (range, 57-73) Gyα/β10 for IR-CTV. The minimum dose to the most irradiated 2 cc volume (D2cc ) was 73-96 (median, 83) Gyα/β3 for the bladder, 64-98 (median, 73) Gyα/β3 for the rectum, and 52-69 (median, 61) Gyα/β3 for the sigmoid colon. After a median follow-up of 15 months (range, 3 -24 months), two patients experienced local failure, and 1 showed internal iliac nodal metastasis. Despite the relatively small number of needles used, CT-guided HDRISBT for cervical cancer showed favorable DVH parameters and clinical outcome.

An Innovative Concept of High-Dose-Rate (HDR) Intracavitary Brachytherapy with an Intrauterine Inflatable Balloon for Endometrial Carcinoma

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.

A preliminary study on rectal dose reduction associated with hyaluronic acid implantation in brachytherapy for prostate cancer

Objectives: Hydrogel spacer (HS) was developed to reduce rectal toxicities caused by radiotherapy, but has been reported to cause major adverse events. Our institute has attempted to introduce a hyaluronic acid (HA) as an alternative spacer. This study aimed to compare rectal doses and geometric distributions between the HS and HA implantation in prostate cancer.Methods: HS and HA were inserted in 20 and 18 patients undergoing high-dose brachytherapy, respectively. The rectum spacer volumes injected were 10 mL and 22 mL, respectively. In the treatment planning system, 13.5 Gy was administered with common catheter positions. The rectal dose indices were assessed between the spacer groups for dosimetry evaluation. Distances between the prostate and rectum and configurations of the spacers were compared.Results: The mean doses irradiated to 0.1 and 2 mL of the rectum were 10.45 Gy and 6.71 Gy for HS, and 6.73 Gy and 4.90 Gy for HA (p<0.001). The mean minimum distances between the prostate and rectum were 1.23 cm and 1.79 cm for HS and HA, respectively (p<0.05). Geometrical configuration comparisons revealed that HA has a higher ability to expand the space than HS.Conclusion: The rectal dose reduction ability of HA is significantly greater than that of HS, suggesting its potential as a new spacer.

交联透明质酸钠凝胶对近距离放射治疗中危及器官的隔离防护作用

背景:交联透明质酸钠凝胶具备良好的力学性能、生物相容性与降解性,可作为肿瘤放射治疗中的隔离防护材料,用于保护危及器官免受多余辐照剂量的损伤。目的:探究交联透明质酸钠凝胶在近距离放射治疗中减少危及器官受照剂量等方面的安全性及有效性。方法:取周龄相同、体质量相近的无特定病原体级昆明小鼠作为实验对象,共16只,采用随机数字表法分为实验组与对照组,每组8只。在实验组小鼠背部皮下植入125Ⅰ放射性粒子,随后环绕放射性粒子周边注射交联透明质酸钠凝胶,在对照组小鼠背部皮下仅植入125Ⅰ放射性粒子。注射完成后,采用螺旋CT扫描测量放射性粒子与表皮的距离,采用辐射剂量仪检测体表辐射剂量;注射后10周内,观察小鼠生长状态及存活率、皮肤放射损伤情况及凝胶存留量。结果与结论:①螺旋CT扫描显示植入的凝胶相对集中,并且使放射性粒子与表皮之间产生有效的间隔距离。实验组小鼠体表辐射剂量明显低于对照组(P<0.01)。②在实验观察期内,两组小鼠均存活,对照组小鼠在实验观察后期出现明显烦躁等不稳定表现,部分实验组小鼠出现类似行为;两组小鼠日摄食量无明显变化,体质量呈现相同的增长趋势。植入放射性粒子后两组小鼠均出现不同程度的放射性皮肤损伤,自注射后第23天开始至实验结束,实验组小鼠皮肤放射损伤评分均低于对照组(P<0.01)。植入后第10周,实验组6只小鼠皮下无明显凝胶残留,2只小鼠皮下存在极少量散在的凝胶状样品。③结果表明,注射交联透明质酸钠凝胶可通过物理占位作用增加125Ⅰ放射性粒子放射靶区和靶外危及器官的间隔空间,有效降低危及器官的受照剂量,对危及器官起到隔离防护作用。

Image-based brachytherapy for cervical cancer

Cervical cancer is the third most common cancer in women worldwide; definitive radiation therapy and concurrent chemotherapy is the accepted standard of care for patients with node positive or locally advanced tumors > 4 cm. Brachytherapy is an important part of definitive radiotherapy shown to improve overall survival. While results for two-dimensional X-ray based brachytherapy have been good in terms of local control especially for early stage disease, unexplained toxicities and treatment failures remain. Improvements in brachytherapy planning have more recently paved the way for three-dimensional image-based brachytherapy with volumetric optimization which increases tumor control, reduces toxicity, and helps predict outcomes.Advantages of image-based brachytherapy include:improved tumor coverage(especially for large volume disease), decreased dose to critical organs(especially for small cervix), confirmation of applicator placement, and accounting for sigmoid colon dose. A number of modalities for image-based brachytherapy have emerged including: magnetic resonance imaging(MRI),computed tomography(CT), CT-MRI hybrid, and ultrasound with respective benefits and outcomes data. Forpractical application of image-based brachytherapy the Groupe Europeen de Curietherapie-European Society for Therapeutic Radiology and Oncology Working Group and American Brachytherapy Society working group guideline serve as invaluable tools, additionally here-in we outline our institutional clinical integration of these guidelines. While the body of literature supporting image-based brachytherapy continues to evolve a number of uncertainties and challenges remain including: applicator reconstruction, increasing resource/cost demands, mobile four-dimensional targets and organs-at-risk, and accurate contouring of "grey zones" to avoid marginal miss. Ongoing studies, including the prospective EMBRACE(an international study of MRI-guided brachytherapy in locally advanced cervical cancer) trial, along with continued improvements in imaging, contouring, quality assurance, physics, and brachytherapy delivery promise to perpetuate the advancement of image-based brachytherapy to optimize outcomes for cervical cancer patients.

Combined endovascular brachytherapy, sorafenib, and transarterial chemobolization therapy for hepatocellular carcinoma patients with portal vein tumor thrombus

AIM To evaluate the safety and efficacy of combined endovascular brachytherapy(EVBT),transarterial chemoembolization(TACE),and sorafenib to treat hepatocellular carcinoma(HCC) patients with main portal vein tumor thrombus(MPVTT).METHODS This single-center retrospective study involved 68 patients with unresectable HCC or those who were unfit for liver transplantation and percutaneous frequency ablation according to the BCLC classification. All patients had Child-Pugh classification grade A or B,Eastern Cooperative Oncology Group(ECOG)performance status of 0-2,and MPVTT. The patients received either EVBT with stent placement,TACE,and sorafenib(group A,n = 37),or TACE with sorafenib(group B,n = 31). The time to progression(TTP) and overall survival(OS) were evaluated by propensity score analysis.RESULTS In the entire cohort,the 6-,12-,and 24-mo survival rates were 88.9%,54.3%,and 14.1% in group A,and 45.8%,0%,and 0% in group B,respectively(P < 0.001). The median TTP and OS were significantly longer in group A than group B(TTP: 9.0 mo vs 3.4 mo,P < 0.001; OS: 12.3 mo vs 5.2 mo,P < 0.001). In the propensity score-matched cohort,the median OS was longer in group A than in group B(10.3 mo vs 6.0 mo,P < 0.001). Similarly,the median TTP was longer in group A than in group B(9.0 mo vs 3.4 mo,P < 0.001). Multivariate Cox analysis revealed that the EVBT combined with stent placement,TACE,and sorafenib strategy was an independent predictor of favorable OS(HR = 0.18,P < 0.001). CONCLUSION EVBT combined with stent placement,TACE,and sorafenib might be a safe and effective palliative treatment option for MPVTT.

A new endoscopic ultrasonography image processing method to evaluate the prognosis for pancreatic cancer treated with interstitial brachytherapy

AIM:To develop a fuzzy classification method to score the texture features of pancreatic cancer in endoscopic ultrasonography(EUS)images and evaluate its utility in making prognosis judgments for patients with unresectable pancreatic cancer treated by EUS-guided interstitial brachytherapy.METHODS:EUS images from our retrospective database were analyzed.The regions of interest were drawn,and texture features were extracted,selected,and scored with a fuzzy classification method using a C++program.Then,patients with unresectable pancreatic cancer were enrolled to receive EUS-guided iodine 125 radioactive seed implantation.Their fuzzy classification scores,tumor volumes,and carbohydrate antigen 199(CA199)levels before and after the brachytherapy were recorded.The association between the changes in these parameters and overall survival was analyzed statistically.RESULTS:EUS images of 153 patients with pancreatic cancer and 63 non-cancer patients were analyzed.A total of 25 consecutive patients were enrolled,and they tolerated the brachytherapy well without any complications.There was a correlation between the change in the fuzzy classification score and overall survival(Spearman test,r=0.616,P=0.001),whereas no correlation was found to be significant between the change in tumor volume(P=0.663),CA199 level(P=0.659),and overall survival.There were 15 patients with a decrease in their fuzzy classification score after brachytherapy,whereas the fuzzy classification score increased in another 10 patients.There was a significant difference in overall survival between the two groups(67 d vs 151 d,P=0.001),but not in the change of tumor volume and CA199 level.CONCLUSION:Using the fuzzy classification method to analyze EUS images of pancreatic cancer is feasible,and the method can be used to make prognosis judgments for patients with unresectable pancreatic cancer treated by interstitial brachytherapy.

Californium-252 neutron brachytherapy combined with external pelvic radiotherapy plus concurrent chemotherapy for cervical cancer: a retrospective clinical study

Background:Cervical cancer is the sixth most common cancer in Chinese women.A standard treatment modal?ity for cervical cancer is the combination of surgery,chemotherapy,external?beam radiotherapy and intracavitary brachytherapy.The aim of this study was to retrospectively assess the long?term treatment outcomes of patients with cervical cancer who were treated with californium?252 neutron brachytherapy combined with external?beam radio?therapy plus concurrent chemotherapy.Methods:We retrospectively analyzed the medical records of 150 patients with primary stages IB?IVB cervical cancer who received neutron brachytherapy combined with external?beam radiotherapy concurrently with cisplatin chemo?therapy.All patients were followed up.Using an actuarial analysis,patient outcomes and treatment?related adverse effects were evaluated and compared.Results:The median overall survival(OS)was 33.2 months.The 3?year progression?free survival rates for patients with stages I–II,III,and IV diseases were 81.0%(68/84),65.0%(39/60),and 0%(0/6),respectively;the 3?year OS rates were 90.5%(76/84),85.0%(51/60),and 16.7%(1/6),respectively.Vaginal bleeding was controlled within the median time of4.0 days.One month after treatment,97.3%of patients achieved short?term local control.The local recurrence rates for patients with stages I–II,III,and IV disease were 4.8%(4/84),11.7%(7/60),and 33.3%(2/6),respectively,and the occurrence rates of distant metastasis were 16.7%(14/84),25.0%(15/60),and 100.0%(6/6),respectively.Cancer stage,tumor size,and lymph node metastasis were identified as prognostic risk factors,but only lymph node metastasis was found to be an independent prognostic factor.The most common adverse effects during treatment were grades 1 and 2 irradiation?related proctitis and radiocystitis.Conclusion:For patients with cervical cancer,neutron brachytherapy combined with external?beam radiotherapy plus concurrent chemotherapy produces a rapid response and greatly improves local control and long?term survival rates with tolerable adverse effects.

New era of electronic brachytherapy

Traditional brachytherapy refers to the placement of radioactive sources on or inside the cancer tissues.Based on the type of sources,brachytherapy can be classified as radionuclide and electronic brachytherapy.Electronic brachytherapy uses miniaturized X-raysources instead of radionuclides to deliver high doses of radiation.The advantages of electronic brachytherapy include low dose to organs at risk,reduced dose to treating staff,no leakage radiation in off state,less shielding,and no radioactive waste.Most of these systems operate between 50 and 100 k Vp and are widely used in the treatment of skin cancer.Intrabeam,Xoft and Papillon systems are also used in the treatment of intra-operative radiotherapy to breast in addition to other treatment sites.The rapid fall-off in the dose due to its low energy is a highly desirable property in brachytherapy and results in a reduced dose to the surrounding normal tissues compared to the Ir-192 source.The Xoft Axxent brachytherapy system uses a 2.25 mm miniaturized X-ray tube and the source almost mimics the high dose rate Ir-192 source in terms of dose rate and it is the only electronic brachytherapy system specifically used in the treatment of cervical cancers.One of the limiting factors that impede the use of electronic brachytherapy for interstitial application is the source dimension.However,it is highly anticipated that the design of miniaturized X-ray tube closer to the dimension of an Ir-192 wire is not too far away,and the new era of electronic brachytherapy has just begun.

Long-term survival after intraluminal brachytherapy for inoperable hilar cholangiocarcinoma: A case report

Surgical resection with a tumor-free margin is the onlycurative treatment for hilar cholangiocarcinoma (Klatskin tumor). However, over half of the patients present late with unresectable tumors. Radiotherapy using external beamirradiation or intraluminal brachytherapy (ILBT) has been used to treat unresectable hilar cholangiocarcinoma with satisfactory outcome. We reported a patient with unresectable hilar cholangiocarcinoma surviving more than 6 years after combined external beam irradiation and ILBT.

Percutaneous biliary stent combined with brachytherapy using 125I seeds for treatment of unresectable malignant obstructive jaundice:A meta-analysis

BACKGROUND Malignant obstructive jaundice(MOJ)is a common pathologic manifestation of malignant biliary obstruction.Recently,several clinical trials have explored the clinical effectiveness of intraluminal^(125)I seed-based brachytherapy for MOJ patients,and various outcomes have been reported.AIM To assess the efficacy and safety of percutaneous biliary stents with^(125)I seeds compared to conventional metal stents in patients with unresectable MOJ.METHODS A systematic search of English-language databases(PubMed,Embase,Cochrane Library,and Web of Science)was performed to identify studies published prior to June 2020 that compared stents with or without^(125)I seeds in the treatment of unresectable MOJ.The outcomes analyzed included primary outcomes(stent patency and overall survival)and secondary outcomes(complications and liver function parameters).RESULTS Six randomized controlled trials and four retrospective studies involving 875 patients were eligible for the analysis.Of the 875 included patients,404 were treated with^(125)I seed stents,while 471 were treated with conventional stents.Unadjusted pooled analysis demonstrated that compared to conventional stents,^(125)I seed stents extended the stent patency time[hazard ratio(HR)=0.36,95%confidence interval(CI)=0.28-0.45,P<0.0001]and overall survival period(HR=0.52,95%CI=0.42–0.64,P<0.00001).Subgroup analyses based on the type of^(125)I seed stent and type of study design showed consistent results.However,there were no significant differences in the occurrence of total complications[odds ratio(OR)=1.12,95%CI=0.75-1.67,P=0.57],hemobilia(OR=1.02,95%CI=0.45-2.3,P=0.96),pancreatitis(OR=1.79,95%CI=0.42-7.53,P=0.43),cholangitis(OR=1.13,95%CI=0.60-2.13,P=0.71),or pain(OR=0.67,95%CI=0.22-2,P=0.47).In addition,there were no reductions in the levels of serum indices,including total bilirubin[mean difference(MD)=10.96,95%CI=-3.56-25.49,P=0.14],direct bilirubin(MD=7.37,95%CI=-9.76-24.5,P=0.4),alanine aminotransferase(MD=7.52,95%CI=-0.71-15.74,P=0.07),and aspartate aminotransferase(MD=-4.77,95%CI=-19.98-10.44,P=0.54),after treatment.Publication bias was detected regarding the outcome overall survival;however,the conclusions were not changed after the adjustment.CONCLUSION Placement of stents combined with brachytherapy using^(125)I seeds contributes to a longer stent patency and higher overall survival than placement of conventional stents without extra complications or severe liver damage.Thus,it can be considered an effective and safe treatment for unresectable MOJ.

Iodine-125 interstitial brachytherapy for experimental liver cancer

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 braehytherapy on liver cancer, which is associated with the size of tumor.

Image-Based Brachytherapy in Cervical Cancer: Review and Experiences in Faculty of Medicine, Chiang Mai University

Cervical cancer is the one of the most common cancer in female patients inThailand. Radiotherapy has the role for the treatment of cervical cancer by postoperative, radical and palliative treatments. For radical radiotherapy, the combination of external beam radiation therapy and brachytherapy will be used to increase the tumor dose to curative goal. With the new development of medical images (Computed tomography (CT), Magnetic Resonance Imaging (MRI) or Ultrasonography (US)), the treatment with brachytherapy will be developed from point-based to volume-based concepts. Many studies reported the benefit of image-based brachytherapy over conventional brachytherapy and clinical benefit of using image-based brachytherapy in the treatment of cervical cancer.

Rectal ulcer:Due to ketoprofen, argon plasma coagulation and prostatic brachytherapy

Prostatic brachytherapy with permanent seed implants is a recent and safe radiation therapy technique associated with radiation-induced digestive disease.Argon plasma coagulation procedure is a validated modality in the management of haemorrhagic radiation proctitis,which is known to occasionally induce chronic rectal ulcers.We report here an original case report of an acute painful rectal ulcer as a consequence of the combination of shortterm therapy with non-steroidal anti-inflammatory drugs therapy,prostatic brachytherapy with malposition of seed implants and argon plasma coagulation procedure in a patient with haemorrhagic radiation proctitis.The description of this clinical observation is essential to recommend the discontinuation of non-steroidal anti-inflammatory drugs therapy and the control of the position of seed implants in case of prostatic brachytherapy before argon plasma coagulation for radiation-induced proctitis.

Treatment Results of Adjuvant Brachytherapy as Monotherapy in Endometrial Cancer: A Retrospective Study from Faculty of Medicine, Chiang Mai University

Purpose: To report the retrospective study of using intravaginal brachytherapy as adjuvant monotherapy for endometrial cancer. Materials and Methods: From 2001-2009, 47 patients who received completely surgical staging for endometrial carcinoma and were designed by multidisciplinary team were enrolled. All patients received intravaginal brachytherapy (IVBT) with the dose of 5.5 - 7 Gy in 2 - 6 fractions. The treatment results and late toxicities were evaluated and recorded. Results: At the median follow-up time of 44 months, the local control, disease-free survival, metastasis-free survival and overall survival rates were 100%, 97.9%, 97.9% and, 97.9%, respectively. Only age showed the statistical significance with the p-value of 0.046. Two patients (4.3%) developed late genitourinary toxicity. Conclusion: The using of adjuvant IVBT as monotherapy for endometrial carcinoma is feasible.

Effectiveness and Safety of CT-Guided ¹²⁵I Brachytherapy for Lung Metastasis from Hepatocellular Carcinoma

To retrospectively evaluate effectiveness and safety of CT-guided 125I brachytherapy in patients with lung metastasis from hepatocellular carcinoma, sixty lung metastatic lesions in 29 patients were percutaneously treated in 34 125I brachytherapy sessions. Each metastatic lesion was treated with computed tomographic (CT) guidance. Follow-up contrast material-enhanced CT scans were reviewed and the efficacy of treatment was evaluated. Months are counted from the first time of 125I brachytherapy and the median duration of follow-up was 11 months (ranging from 6 - 17 months). The local control rates after 3, 6, 10 and 15 months were 86.2, 71.4, 60.9 and 50.0% respectively. At the time of writing, ten patients are alive without evidence of recurrence at 11 - 15 months. The 10 patients presented good control of local tumor and no systemic recurrence, and survived throughout the follow-up period. Other 11 patients died of multiple hematogenous metastases 5 - 15 months after brachytherapy. A small amount of local hematoma occurred in 5 patients that involved applicator insertion through the lung. Four patients presented pneumothorax with pulmonary compression of 30% - 40% after the procedure and recovered after drainage. Two patients had minor displacement of radioactive seeds. Severe complications such as massive bleeding and radiation pneumonitis did not occur. So CT-guided 125I brachytherapy is effective and may be safely applied to lung metastasis from hepatocellular carcinoma.

Perioperative Interstitial Brachytherapy as a Boost in Breast Cancer Conserving Therapy

Background: The aim of breast-conserving treatment (BCT) in breast cancer, consisting of wide local excision (WLE) and radiotherapy, is to obtain local control of disease as well as an optimal cosmetic result. The application of perioperative brachytherapy allows more precise deposition of the boost radiation dose to the lumpectomy cavity plus margins in a shorter period of time, as compared to external beam radiotherapy. The aim of the present study was to analyze the oncological outcome of interstitial brachytherapy in our patient population of patients with early-stage breast cancer. Patients and Methods: 107 breasts in 105 patients with T1-2 breast cancer were treated between 1996 and 2009 with BCT, including WLE combined with perioperative brachytherapy using Iridium-192 (15 Gy with low dose rate or 9 Gy with high dose rate) followed by whole breast irradiation (50 Gy). Outcomes analyzed included treatment toxicity (according to Common Terminology Criteria for Adverse Events), local recurrence rate, and disease-free and overall survival. Results: Median follow-up of patients still alive was 6.3 years (range 2.0 - 14.5). Mean age was 50.2 years (+/- S.D. 10.5). Mean tumor diameter was 15 mm (+/- S.D. 8 mm. Acute complications consisted of grade 1 and 3 complications, respectively n = 8 and n = 1. Late complications consisted of grade 1 or 2, respectively n = 25 and n = 2. Only three patients (2.8%) developed a local recurrence with a median time to recurrence of 9.3 years (range 3.3 - 9.3). Five- and ten-year local recurrence free survival was 99% and 91%, respectively. Five- and ten-year disease-specific and overall survival was 95% and 84% versus 92% and 78%, respectively. Conclusions: Treatment-related toxicity after brachytherapy for breast cancer was mild. The local recurrence rate is low. Therefore, brachytherapy is a good alternative to conventional radiation boost as a part of breast irradiation in breast conserving treatment in early stage breast cancer.