CT-guided Interstitial Brachytherapy Research Articles

Efficacy and Safety of Local Liver Radioablation in Hepatocellular Carcinoma Lesions within and beyond Limits of Thermal Ablation.

CT-guided interstitial brachytherapy (iBT) radiotherapy has been established in the treatment of liver tumors. With iBT, hepatocellular carcinoma (HCC) lesions can be treated beyond the limits of thermal ablation (i.e., size and location). However, a comprehensive analysis of the efficacy of iBT in patients within and beyond thermal ablation limits is lacking. A total of 146 patients with 216 HCC lesions have been analyzed retrospectively. Clinical and imaging follow-up data has been collected. Lesions were evaluated in terms of suitability for thermal ablation or not. The correlation between local tumor control (LTC), time to progression (TTP), overall survival (OS), and clinical and imaging parameters have been evaluated using univariable and multivariable Cox regression analyses. LTC rates at 12 months, 24 months, and 36 months were 87%, 75%, and 73%, respectively. 65% of lesions (n = 141) were not suitable for radiofrequency ablation (RFA). The median TTP was 13 months, and the median OS was not reached (3-year OS rate: 70%). No significant difference in LTC, TTP, or OS regarding RFA suitability existed. However, in the overall multivariable analysis, lesion diameter >5 cm was significantly associated with lower LTC (HR: 3.65, CI [1.60-8.31], p = 0.002) and shorter TTP (HR: 2.08, CI [1.17-3.70], p = 0.013). Advanced BCLC stage, Child-Pugh Stage, and Hepatitis B were associated with shorter OS. iBT offers excellent LTC rates and OS in local HCC treatment regardless of the limits of thermal ablation, suggesting further evidence of its alternative role to thermal ablation in patients with early-stage HCC.

Clinical outcomes of single application multi-fractionated CT-guided interstitial high-dose-rate brachytherapy for locally advanced cervical cancer: A multi-institution initial experience.

The aim of the study was to evaluate the safety and clinical outcomes of single application multi-fractionated computed tomography (CT)-guided interstitial high-dose-rate brachytherapy given in four fractions in locally advanced cervical cancer. Patients with locally advanced cervical cancer stage IIB-IVA treated definitively with external radiation ± weekly cisplatin, followed by single application multi-fractionated CT-guided interstitial high-dose-rate brachytherapy in four fractions were included. Dosimetry data, clinical response, and toxicity records were reviewed. Between January 2018 and December 2022, twenty-two patients were included. Clinical stage distribution was as follows: IIB - 13.6%, IIIB - 27.3%, IIIC - 22.7%, and IVA - 36.4%. Mean high-risk clinical target volume (HR-CTV) was 66.19 ±32.69 cm3, and HR-CTV D90 dose was 86.8 ±1.7 Gy. 2 cc doses to bladder, rectum, and sigmoid were 84.6 ±2.8 Gy, 71.5 ±2.4 Gy, and 65.6 ±4.0 Gy, respectively. Mean overall treatment time was 66 ±21 days. With a median follow-up of 11.5 months (range, 5-44 months), median survival and local control were not achieved. One-year local control rate, one-year progression-free survival, and one-year overall survival were 82%, 66%, and 78%, respectively. Univariate analysis showed overall treatment time to be the only variable associated with all oncologic outcomes. For acute toxicity, grade 3 toxicity in four patients and grade 4 toxicity of infection in one patient were observed. For late toxicity, grade 3 gastrointestinal toxicity was noted in two patients. Initial results suggest that single application multi-fractionated CT-guided interstitial brachytherapy given in four fractions in locally advanced cervical cancer seems to be feasible and safe, but additional evidence is needed to generate more validated conclusions.

The 3-Year Outcome of 3D High-Dose-Rate Brachytherapy in Combination With Regional Metastatic Lymph Nodes Intensity-Modulated Radiotherapy in Peripheral Locally Advanced Non-Small Cell Lung Cancer: A Phase I/II Clinical Trial

To determine the safety, late toxicities and locoregional control of three-dimensional(3D) high-dose-rate (HDR) brachytherapy in combination with regional metastatic lymph nodes intensity-modulated radiotherapy (IMRT) in patients with peripheral locally advanced non-small cell lung cancer (LA-NSCLC).Eligible patients with LA-NSCLC were recruited to this prospective, phase I/II clinical study. The primary lung tumors were treated with the CT-guided interstitial HDR brachytherapy, DT:30Gy/F. The IMRT was applied to the regional positive lymph nodes, DT: 60-70Gy/30-33F/ 6-7W. The concurrent chemotherapy regimens include used Etoposide and cisplatin, the sequential chemotherapy consisted of paclitaxel/pemetrexed + cisplatin/carboplatin. The safety analysis included operational complications and toxicity related to radiotherapy and chemotherapy. Clinical evaluation includes short-term efficacy, survival, and quality of life scores.A total of 83 patients were enrolled in this study. There were 56 males and 27 females, with a median age of 65 years (45-80 years). The median follow-up time was 55 months (32-114 months) up to November 2020. The operational complications included mild pneumothorax (16.8%) and minor hemorrhage around the needle (19.3%). The major toxicity was myelosuppression and gastrointestinal reaction during the concurrent chemoradiotherapy and sequential chemotherapy. The clinical symptoms alleviated after symptomatic supportive treatment. The radiotherapy was completed successfully without grade 4 or more serious acute toxicity. Grade 1 late radiation pneumonitis was found by in 5 patients (6.1%), and only showed imaging changes after radiotherapy. There were 61 patients achieved complete remission, 20 patients achieved partial remission, and 2 patients were in stable disease in the primary tumor, the total response rate was 97.6%. There were 55 patients achieved complete remission, 22 patients achieved partial remission, 5 patients were in stable disease and 1 patient with progressive disease in the positive lymph nodes, the total response rate was 92.8%. The 1-,2-,3-year overall survival rates were 90.6%, 70.6% and 62.4%. The 1-,2-,3-year local control rates were 90.0%,81.0% and 54.5%. The 1-,2-,3-year disease-free survival rates were 68.3%,42.2% and 23.9%. The 1-,2-,3-year metastasis-free survival rates were 73.3%, 50.9% and 39.5%. The patient who treated with 3D interstitial high dose rate brachytherapy has a higher life quality score than the baseline level.3D interstitial high dose rate brachytherapy combined with regional positive lymph node intensity-modulated radiotherapy is safe and feasible for the locally advanced peripheral non-small cell lung cancer, with low adverse reactions, increased the survival, and improved the life quality. But it still needs a phase III randomized controlled trial to investigate its clinical utility and promotion, compared to IMRT.

Radioablation of Upper Abdominal Malignancies by CT-Guided, Interstitial HDR Brachytherapy: A Multivariate Analysis of Catheter Placement Assisted by Ultrasound Imaging.

To evaluate the use of ultrasound (US) during catheter placement in interstitial brachytherapy (iBT) of abdominal malignancies as an alternative to computed tomography (CT) fluoroscopy. Catheter placement for CT-guided iBT was, if US visibility was sufficient, assisted by sonography in 52 consecutive patients with 82 lesions (liver N = 62; kidney N = 16; peritoneum N = 4) of various malignancies. We collected data on lesion visibility, location, depth, size, and dosimetry. Comparison of CT fluoroscopy versus US-assisted catheter placement was performed by Fisher's exact test for frequencies and U-test for lesion visibility and dosimetric data. Factors predicting the utility of sonography were determined in a lesion-based multivariate regression analysis. A p-value < 0.05 was regarded as statistically significant. 150 catheters (1 to 6 per lesion; mean diameter 3.6 ± 2.4 cm) were implanted. CT fluoroscopy was used for 44 catheters, and US was used for 106 catheters. Lesion visibility assessed by 5-point Likert scale was significantly better in US (median 2 vs. 3; p = 0.011) and effective dose was significantly reduced if US guidance was applicable (median 1.75 vs. 8.19 mSv; p = 0.014). In a multivariate regression analysis, we identified increased lesion size and caudal location within the target organ to independently predict the utility of ultrasound in catheter placement for iBT. Sonography is a helpful technique to assist CT-guided interstitial brachytherapy of upper abdominal malignancies. Especially for larger lesions localized in the lower liver segments or lower half of the kidney, superior visibility can be expected. As the effective dose of the patient is also reduced, radiation exposure of the medical staff may be indirectly lowered. · Ultrasound-assisted catheter placement in CT-guided brachytherapy of upper abdominal malignancies significantly improves lesion visibility.. · Predictors of successful ultrasound application are larger lesions within the lower portion of the liver and kidney.. · By reducing the need for CT fluoroscopy during intervention, radiation exposure to the medical staff may be indirectly lowered.. · Damm R, Damm R, Heinze C et al. Radioablation of Upper Abdominal Malignancies by CT-Guided, Interstitial HDR Brachytherapy: A Multivariate Analysis of Catheter Placement Assisted by Ultrasound Imaging. Fortschr Röntgenstr 2022; 194: 62 - 69.

OC-0113 Evaluation of early clinical response of CT-guided HDR interstitial brachytherapy in HCC

OC-0113 Evaluation of early clinical response of CT-guided HDR interstitial brachytherapy in HCC

PO-0255 CT-guided high-dose interstitial brachytherapy vs. SBRT in hepatocellular carcinoma

PO-0255 CT-guided high-dose interstitial brachytherapy vs. SBRT in hepatocellular carcinoma

Unresectable bulky chest wall recurrent breast cancer controlled with CT-guided interstitial high-dose-rate brachytherapy and external beam radiotherapy with adjuvant hormonal therapy – case report

PurposeBulky chest wall recurrence after mastectomy presents a therapeutic challenge because of high-dose of radiation required to control the disease, and its proximity to low-tolerance organs at risk. We report a case of successful computed tomography (CT)-guided high-dose-rate (HDR) salvage interstitial brachytherapy (ISBT) boost.Material and methodsA 70-year-old female initially presented with a tumor in right breast, and was treated with mastectomy and adjuvant chemotherapy, followed by hormonal therapy for 5 years without adjuvant radiotherapy. In 2018, 20 years after the initial treatment, she developed unresectable chest wall recurrence that measured 10.5 cm × 7.3 cm × 4.5 cm, with bone and parietal pleura invasion. Biopsy revealed invasive pleomorphic lobular carcinoma [estrogen receptor (ER)-positive, progesterone receptor (PR)-negative, HER2-negative]. There was no evidence of metastatic disease.ResultsThe patient underwent external beam radiotherapy (EBRT) plus ISBT. After EBRT of 50 Gy in 25 fractions was completed, CT-guided ISBT was performed as an outpatient treatment. HDR dose was 16 Gy delivered in 2 fractions with 2 implants. Dose was prescribed to gross tumor volume. ISBT plans were created using inverse planning simulated annealing (IPSA) algorithm. Gross tumor volume D90% plus EBRT dose was 82 Gy equivalent dose of 2 Gy (EQD2), assuming α/β of 4 for breast carcinoma. The patient continued on hormonal therapy. At the 30-month follow-up, the patient remains in remission. The tumor could not be detected by magnetic resonance imaging (MRI) or positron emission tomography (PET). There were no severe treatment-related complications.ConclusionsCT-guided HDR ISBT boost can be a useful modality in individualizing treatment strategies for breast cancer patients with unresectable bulky chest wall recurrence.

Efficacy and safety of percutaneous computed tomography-guided high-dose-rate interstitial brachytherapy in treatment of oligometastatic lymph node metastases of retroperitoneal space.

PurposeTo assess efficacy, safety, and outcome of computed tomography (CT)-guided high-dose-rate (HDR) interstitial brachytherapy in patients with oligometastatic lymph node metastases of the retroperitoneal space.Material and methods24 patients with a total of 47 retroperitoneal lymph node metastases from different primary tumors were treated with CT-guided interstitial brachytherapy using an 192Ir source (single fraction irradiation). Every three months after treatment, clinical and imaging follow-up were conducted to evaluate local control and safety.ResultsMedian follow-up was 9.6 months (range, 2.9-39.0 months). Local tumor control rate was 95.7%. The median diameter of the gross tumor volume was 2.2 cm (range, 1-8.6 cm), treated with a median D100 (minimal enclosing tumor dose) of 14.9 Gy (range, 4.5-20.6 Gy). One severe adverse event (grade three) was recorded.Cumulative median progression-free survival was 4.2 months (range, 1.4-23.7 months), and cumulative median overall survival after interstitial brachytherapy was 15.9 months (range, 3.8-39.0 months).ConclusionsCT-guided HDR interstitial brachytherapy is a safe and feasible method for local ablation of oligometastatic lymph node metastases of the retroperitoneal space, and might provide a well-tolerated additional therapeutic option in the multidisciplinary management of selected patients.

Dosimetry and short term effect comparison of CT-guided interstitial brachytherapy and intracavitary brachytherapy for locally advanced cervical cancer

Objective To discuss the dosimetric advantage of computed tomography-guided interstitial brachytherapy compared with the conventional intracavitary brachytherapy for locally advanced cervical cancer, offering a more advantageous clinical treatment approach. Methods Twenty-eight locally advanced cervical cancer patients with bulky tumors (tumor size>5 cm) after external beam radiotherapy received computed tomography-guided interstitial brachytherapy. Dosimetric outcomes of the current study, including the total dose (external beam radiotherapy+ brachytherapy) D90 for the HR-CTV and D2cc for the bladder, rectum, and sigmoid, were compared with a former patient group consisting of 30 patients who received the conventional intracavitary brachytherapy (uterine tandem+ ovoid pairs). Results The mean D90 value for HR-CTV in the intracavitary brachytherapy group and interstitial brachytherapy group were (76.9±5.7) and (88.1±3.3) Gy, respectively. The D2cc for the bladder, rectum, and sigmoid in the intracavitary brachytherapy group and interstitial brachytherapy group were (84.7±6.8) Gy, (69.2±4.2) Gy, (67.8±4.5) Gy and (81.8±6.5) Gy, (6.8±4.0) Gy, (64.8±4.1) Gy, respectively.1-year local tumor control rate in the intracavitary brachytherapy group and interstitial brachytherapy group were 59.3% and 85.2%, respectively. Conclusions CT-guided interstitial brachytherapy shows a significant dosimetric advantage compared with the conventional intracavitary brachytherapy, and is, thereby, clinically possible feasible. However, the long term curative effect and toxicity need to be further investigated. Key words: Cervical neoplasms/brachytherapy; Brachytherapy, interstitial; Brachytherapy, intracavitary; Dosimetry

Dosimetric analysis of CT-guided salvage interstitial brachytherapy for recurrent cervical cancer

Objective To analyze the dosimetric advantages of CT-guided interstitial brachytherapy for recurrent cervical cancer. Methods A total of 16 patients with recurrent cervical cancer after radical surgery and adjuvant external beam radiotherapy received interstitial brachytherapy with CT-guided implantation of metal needles. The high-risk clinical target volume (HR-CTV) was given 36 Gy in 6 fractions. D90 for HR-CTV in the brachytherapy and the cumulative D2 cm3 values for the bladder, rectum, and sigmoid colon in the previous external beam radiotherapy and the brachytherapy were analyzed. Results The mean D90 value for HR-CTV was 52.5±3.3 Gy. The cumulative D2 cm3 values for the bladder, rectum, and sigmoid colon were 85.6±5.8 Gy, 71.6±6.4 Gy, and 69.6±5.9 Gy, respectively. The mean number of metal needles was 6.1±1.5 in each brachytherapy. The actual 1-year overall survival and local control were 81% and 69%, respectively. Conclusions CT-guided interstitial brachytherapy for recurrent cervical cancer shows good dose-volume histogram parameters and few complications, so it may be clinically feasible. However, its long-term clinical efficacy needs further observation. Key words: Cervical neoplasms/interstitial brachytherapy; Dosimetry

CT-guided interstitial brachytherapy for locally advanced cervical cancer: introduction of the technique and report of dosimetry

Objective To examine the dosimetric advantages of three-dimensional (3D) computed tomography (CT)-guided interstitial brachytherapy (BT) for target volume and surrounding normal tissue in patients with locally advanced cervical cancer, and to provide a simple and effective clinical treatment approach. Methods A total of 52 patients who had poor tumor response to external beam radiotherapy (EBRT) with a residual tumor greater than 5 cm at the time of BT were included. The patients were treated by 3D CT-guided interstitial BT using a hybrid applicator comprised of uterine tandem and free metal needles. The high-risk clinical target volume (HR-CTV), intermediate-risk clinical target volume (IR-CTV), and organs at risk (OAR) were contoured. The total dose, including external beam radiotherapy and high dose-rate BT, was biologically normalized to conventional 2 Gy fractions (EQD2). D90 and D100 for both HR-CTV and IR-CTV, and D2 cc for the bladder, rectum, and sigmoid were analyzed. Results The mean D90 value for HR-CTV was 88.4±3.5 Gy. The D2 cc for the bladder, rectum, and sigmoid were 81.1±5.6, 65.7±5.1, and 63.1±5.4 Gy, respectively.D2 cc ≤90 Gy for the bladder and D2 cc ≤70 Gy for the sigmoid were observed in all the patients.D2 cc ≤70 Gy for the rectum was observed in 89% of patients. Conclusions 3DCT-guided interstitial BT has a significant dosimetric advantage for target volume accompanied by few minor complications, and thereby may be clinically feasible for treating locally advanced cervical cancer. However, its long-term efficacy and possible toxicities will require further clinical observation. Key words: Cervical neoplasms/interstitial brachytherapy; Tomogranphy, X-ray computed, guide; Dosimetry

Comparison of outcomes for MR-guided versus CT-guided high-dose-rate interstitial brachytherapy in women with locally advanced carcinoma of the cervix

ObjectiveThe purpose was to compare local control (LC), overall survival (OS) and dose to the organs at risk (OAR) in women with locally advanced cervical cancer treated with MR-guided versus CT-guided interstitial brachytherapy (BT). Methods56 patients (29 MR, 27 CT) were treated with high-dose-rate (HDR) interstitial BT between 2005–2015. The MR patients had been prospectively enrolled on a Phase II clinical trial. Data were analyzed using Kaplan-Meier (K-M) and Cox proportional hazards statistical modeling in JMP® & R®. ResultsMedian follow-up time was 19.7months (MR group) and 18.4months (CT group). There were no statistically significant differences in patient age at diagnosis, histology, percent with tumor size >4cm, grade, FIGO stage or lymph node involvement between the groups. Patients in the MR group had more lymphovascular involvement compared to patients in the CT group (p<0.01). When evaluating plans generated, there were no statistically significant differences in median cumulative dose to the high-risk clinical target volume or the OAR.2-year K-M LC rates for MR-based and CT-based treatments were 96% and 87%, respectively (log-rank p=0.65). At 2years, OS was significantly better in the MR-guided cohort (84% vs. 56%, p=0.036). On multivariate analysis, squamous histology was associated with longer OS (HR 0.23, 95% CI 0.07–0.72) in a model with MR BT (HR 0.35, 95% CI 0.08–1.18). There was no difference in toxicities between CT and MR BT. ConclusionIn this population of locally advanced cervical-cancer patients, MR-guided HDR BT resulted in estimated 96% 2-year local control and excellent survival and toxicity rates.

Image-guided interstitial high-dose-rate brachytherapy in the treatment of inoperable recurrent head and neck malignancies: An effective option of reirradiation.

In recurrent head and neck cancer, therapeutic options are limited and high-quality evidence is rare. The purpose of this report was to present our experience of CT-guided interstitial high-dose rate (HDR) brachytherapy in 4 challenging cases of inoperable recurrent head and neck cancer. A 53-year-old man with mucosal melanoma of the paranasal sinuses, a 61-year-old man with myofibroblastic sarcoma of the nasal cavity, a 51-year-old woman with nasopharyngeal cancer, and a 44-year-old woman with orbital leiomyosarcoma were treated with reirradiation by HDR brachytherapy after previous comprehensive therapy, including full course external radiotherapy (RT). All patients showed response to brachytherapy with 1 patient experiencing locoregional failure. The mean lesion-specific disease control was 15 months. Currently, 1 patient is alive and 3 patients died after mean 20 months after treatment. In patients with inoperable recurrent head and neck cancer, CT-guided interstitial HDR brachytherapy can play a role in providing palliation and tumor control. © 2017 Wiley Periodicals, Inc. Head Neck 39: E61-E68, 2017.

Interstitial Brachytherapy for the Treatment of Locally Recurrent Anorectal Cancer.

Local tumor control (LC), overall survival (OS), symptom palliation, and late toxicity for patients with locally recurrent anorectal cancer treated with a computed tomography (CT)-guided interstitial brachytherapy implant were examined. The medical records of 20 consecutive patients who had received interstitial brachytherapy for locally recurrent anorectal cancer from 2000 through 2012 were reviewed. Seventeen patients (85 %) had rectal cancer and three had anal cancer [median follow-up time for living patients, 23 months (range 13-132)]. Brachytherapy was used most commonly at the second pelvic recurrence (n = 13, 65 %). The implant dose was prescribed to 80 Gy to a 1-cm margin or 120 Gy to 100 % of the gross tumor volume. Endpoints were OS, LC, toxicity, and symptom palliation rate, all calculated from the time of implant. The actuarial 1-year rates of LC and OS were 80 and 95 %, respectively. At presentation, 17 patients (85 %) had symptoms related to the treated tumor which were palliated in 13 patients (76 %) at a median time of 3 months (range 1-6); palliation was permanent for seven patients (54 %), and the other six patients lost palliation after a median 8 months (range 5-17). One patient experienced a grade 3 late complication requiring a stent for hydronephrosis; five had grade 2 toxicity, and four had grade 1 toxicity. CT-guided interstitial brachytherapy for locally recurrent anorectal tumors produced durable tumor control and long-term survival, with effective palliation and minimal long-term morbidity.

CT-guided Interstitial Brachytherapy of Hepatocellular Carcinoma before Liver Transplantation: an Equivalent Alternative to Transarterial Chemoembolization?

Transarterial chemoembolization (TACE) is established as bridging therapy of HCC listed for transplantation (LT). CT-guided brachytherapy (CTB) has not been evaluated as a bridging concept. We compared CTB and TACE for bridging before LT in HCC patients. Twelve patients with HCC received LT after CTB (minimal tumour dose, 15-20Gy). Patients were matched (CTB:TACE, 1:2) by sex, age, number and size of lesions, and underlying liver disease with patients who received TACE before transplantation. Study endpoints were extent of necrosis at histopathology and recurrence rate after OLT. There were no significant differences between the CTB and TACE groups regarding Child-Pugh category (p = 0.732), AFP (0.765), time on waiting list (p = 0.659), number (p = 0.698) and size (p = 0.853) of HCC lesions, fulfilment of Milan-criteria (p = 0.638), or previous liver-specific treatments. CTB achieved higher tumour necrosis rates than TACE (p = 0.018). The 1- and 3-year recurrence rate in the CTB group was 10 and 10% vs. TACE, 14 and 30% (p = 0.292). Our data show comparable or even better response and post-LT recurrence rates of CTB compared to TACE for treating HCC in patients prior to LT. CTB should be further evaluated as an alternative bridging modality, especially for patients not suited for TACE. • CT-guided interstitial brachytherapy (CTB) is a promising alternative to transarterial chemoembolization (TACE). • CTB instead of TACE is possible for bridging to liver transplantation in HCC patients. • HCC recurrence was not associated with CTB despite potential tumour seeding.

CT-guided interstitial brachytherapy for metastatic carcinoma of lymph nodes in mediastinum

Objective To investigate the technique,safety and clinical value of CT-guided percutaneous interstitial brachytherapy for metastatic carcinoma of lymph nodes in mediastinum.Methods Eight patients with metastatic carcinoma of lymph nodes in mediastinum were treated by CT-guided interstitial implant of radioactive seeds in our department.Anterior approach were performed on all cases,125I radioactive seeds were implanted by setting CT Gantry at an oblique angle,three-dimensional reconstruction with SCT and separation the narrow gap between aortic arch and superior vena cava with fiatscalp core.Dose distributions were checked by TPS after operation.The improvement in clinical symptoms and lymph node sizes were documented in order to investigate the therapeutic effects.Results The particle coverage rate was 93.5％ ± 1.5％.According to the CT scans two months later,3 patients ( 37.5％ ) had complete ablation,4 (50％) partial ablation,and 1 ( 12.5％ ) stable disease.Overall response rate (CR + PR) for this group of patients was 87.5％.The symptoms of all patients including shortness of breath (5 patients),cough (4 patients),dysphagia (4 patients) showed varying degree of improvement.No edema of head-and-neck and upper extremity was observed.There was no major vascular,tracheal and esophageal injury.A small amount of pneumothorax was observed in one patient.Conclusions CT-guided percutaneous interstitial brachytherapy,a minimally invasive procedure associated with favorable therapeutic results,is a promising technique for treatment of metastatic carcinoma of lymph nodes with local pressure symptoms which may not respond to conventional therapy. Key words: Brachytherapy; Carcinoma; metastatic lymph node; Interstital irradiation; Implantation

Implant dosimetric Parameters Correlation To Local Control and Critical Organ Toxicity: Lessons From 240 CT based Interstitial Implants In Cervical Cancer!

Implant dosimetric Parameters Correlation To Local Control and Critical Organ Toxicity: Lessons From 240 CT based Interstitial Implants In Cervical Cancer!

CT-guided interstitial brachytherapy of inoperable non-small cell lung cancer

Purpose The aim of this study was to assess the technical feasibility, efficacy, and complications of CT-guided interstitial brachytherapy for treating inoperable non-small cell lung cancer (NSCLC). Materials and methods Twenty one patients were included in this prospective study. The median age was 72.6 years (57–85). Tumors were treated with brachytherapy that was positioned under CT-fluoroscopy. The treatment planning system (TPS) was used preoperatively to reconstruct three dimensional images of the tumor and to calculate the estimated seed number and distribution. The median matched peripheral dose (MPD) was 130 Gy (range, 100–160 Gy). All procedures were performed under local anesthesia. A follow-up CT was performed 6 weeks later and every 3 months post implantation. Results Follow-up period was 2–30 months. The mean diameter of the 21 lung tumors was 4.6 cm (range, 2.8–6.5 cm). The response rate of pain relief was 83.3% (10/12). The pain-free duration was 0–12 months (median: 6 months; 95% CI: 3–9 months). Overall responding rate (CR + PR) for this group of patients was 71.4%. Local tumor control rate was 85.7%. Six (28.6%) patients died as a result of primary tumor progression; thirteen (61.9%) patients died of multi-organ failure or other metastases. Two (9.5%) patients survived to follow-up. At the time of analysis, the median survival time for all patients was 10 months (95% CI: 6.6–13.4 months), with 1 year and 2 year survival rates were 42.4% and 6.5%, respectively. Median survival time for stage II, stage III, and stage IV was 20 months, 9 months, and 8 months, respectively. No major complications were observed. Minor complications (19%) included mild pneumothorax ( n = 1), hemosputum ( n = 1), pleural effusion ( n = 1), and localized skin erythema ( n = 1). None of these complications required further treatment, although hospital discharge was delayed. No 125I seeds migrated to other tissues or organs. Conclusion Minimally invasive CT-guided interstitial brachytherapy is safe, useful, less complicated and considered as a palliative treatment option for inoperable non-small cell lung cancer.

Quantitative in vivo assessment of radiation injury of the liver using Gd-EOB-DTPA enhanced MRI: tolerance dose of small liver volumes

BackroundHepatic radiation toxicity restricts irradiation of liver malignancies. Better knowledge of hepatic tolerance dose is favourable to gain higher safety and to optimize radiation regimes in radiotherapy of the liver. In this study we sought to determine the hepatic tolerance dose to small volume single fraction high dose rate irradiation.Materials and methods23 liver metastases were treated by CT-guided interstitial brachytherapy. MRI was performed 3 days, 6, 12 and 24 weeks after therapy. MR-sequences were conducted with T1-w GRE enhanced by hepatocyte-targeted Gd-EOB-DTPA. All MRI data sets were merged with 3D-dosimetry data. The reviewer indicated the border of hypointensity on T1-w images (loss of hepatocyte function) or hyperintensity on T2-w images (edema). Based on the volume data, a dose-volume-histogram was calculated. We estimated the threshold dose for edema or function loss as the D90, i.e. the dose achieved in at least 90% of the pseudolesion volume.ResultsAt six weeks post brachytherapy, the hepatocyte function loss reached its maximum extending to the former 9.4Gy isosurface in median (i.e., ≥9.4Gy dose exposure led to hepatocyte dysfunction). After 12 and 24 weeks, the dysfunctional volume had decreased significantly to a median of 11.4Gy and 14Gy isosurface, respectively, as a result of repair mechanisms. Development of edema was maximal at six weeks post brachytherapy (9.2Gy isosurface in median), and regeneration led to a decrease of the isosurface to a median of 11.3Gy between 6 and 12 weeks. The dose exposure leading to hepatocyte dysfunction was not significantly different from the dose provoking edema.ConclusionHepatic injury peaked 6 weeks after small volume irradiation. Ongoing repair was observed up to 6 months. Individual dose sensitivity may differ as demonstrated by a relatively high standard deviation of threshold values in our own as well as all other published data.

Treatment of hepatic metastases of breast cancer with CT-guided interstitial brachytherapy – A phase II-study

PurposeThe aim of the study was the evaluation of feasibility, safety and effectiveness of interstitial brachytherapy for the treatment of hepatic metastases of breast cancer. Materials and methodsForty-one consecutive patients with 115 unresectable hepatic metastases of breast cancer were included in this phase-II-trial. They were treated in 69 interventions of CT-guided-interstitial-brachytherapy of the liver. Brachytherapy was applied as a single fraction high-dose-irradiation (15–25Gy (Gray)) using a 192Ir-source of 10Ci. Nineteen patients presented systemically pretreated extrahepatic tumors. Primary endpoints were complications, local tumor control and progression-free survival. ResultsThe median tumor diameter was 4.6cm (1.5–11cm). The median irradiation time per intervention was 26.5min (range: 7–47min). The applied median minimal dose at the CTV (clinical target volume) margin was 18.5Gy (12–25Gy). In 69 interventions and during the postinterventional period, one major complication (symptomatic post-interventional bleeding) (1.5%) and six minor complications occurred (8.7%). The median follow-up time was 18months (range: 1–56). After 6, 12 and 18months, local tumor control was 97%, 93.5% and 93.5%, intra- and extrahepatic progression free survival was 53%, 40% and 27%, and overall survival was 97%, 79% and 60%, respectively. ConclusionCT-guided-brachytherapy is safe and effective for the treatment of liver metastases of breast cancer.