CT-guided Brachytherapy Research Articles

SU-E-T-459: Distance Matters - the Minimum CTV-To-Bladder Distance Tells All in HDR Cervical Cancer Treatment

Purpose: Bladder/rectum sparing is always the challenge in HDR 3D CT-guided brachytherapy treatment planning for cervical cancer due to the tight separation between them and High Risk Clinical Target Volume (HRCTV). In this study, we analyzed the minimum CTV-to-Bladder distance (MCBD), the minimum CTV-to-Rectum distance (MCRD), dose to 2cc of bladder (BD(2cc)) and rectum (RD(2cc)) respectively. The potential application of MCBD and MCRD as plan optimization indicators was investigated. Methods: Total 49 consecutive HDR plans for 11 patients with stage I–IIB cervical cancer were retrospectively reviewed. The prescribed dose (PD) was either 6 Gy/fraction × 5 or 7 Gy/fraction × 4 fractions. For each plan, MCBD and MCRD were measured on relevant transverse CT slices. BD(2cc), RD(2cc), the minimum dose cover 90% HRCTV (D90) were recorded. All plans were optimized with dose constrains BD(2cc)<80%PD, RD(2cc)<70%PD, D90>90%PD. Results: For 49 insertions, MCRD was 14±7mm. MCBD was 2±1mm. D90 was 100±15%PD. RD(2cc) and BD(2cc) were 57±12%, 74±10% of PD respectively. The correlation coefficient of MCBD and BD(2cc) was 0.31(p=0.03), indicating that bladder dose was significantly impacted by MCBD.Among 49 insertions, 19 cases had MCBD<=1mm with BD(2cc)>75% PD and D90 96±13%PD. 13 cases had 1mm<MCBD<=2mm with D90 103±15%PD. 4/13 cases had BD(2cc)>75% PD. 17 out of 49 insertions had MCBD>2mm with D90 105±15%PD. Only 2/17 cases had BD(2cc)>75% PD. For 46/49 insertions, MCRD was >=5mm, which caused RD(2cc) extremely low. Conclusion: Our study shows that bladder sparing is correlated with MCBD. 65% of 49 insertions had MCBD<=2mm. Among them, 72% cases had BD(2cc)>75%PD. We believe that MCBD and MCRD can be used as plan optimization indicators. When any of them is <2mm, the target coverage would be comprised in order to spare bladder or rectum. This allows physicians have a reasonable expectation before plan is completed and guide further insertions.

Comparing Dosimetric Values for Cervical Cancer Treated with CT-Guided and 3T MR-Guided Brachytherapy

Comparing Dosimetric Values for Cervical Cancer Treated with CT-Guided and 3T MR-Guided Brachytherapy

Computed tomography-guided permanent brachytherapy for locoregional recurrent gastric cancer

BackgroundLocoregional recurrence is the typical pattern of recurrence in gastric cancer, and cannot be removed by surgery in most of the patients. We aimed to evaluate the feasibility and efficacy of computed tomography (CT)-guided brachytherapy for patients with locoregional recurrent gastric cancer.Materials and methodsWe reviewed the case histories of 28 patients with locoregional recurrent gastric cancer that were selected for CT- guided brachytherapy by a multidisciplinary team. The clinical data of the patients including patient characteristics, treatment parameters, short-term effects, and survival data were collected and analyzed.Results15-75 125I seeds were implanted into each patient to produce a minimal peripheral dose (MPD) 100-160 Gy. Median day 0 dosimetry was significant for the following: V100 (the volume treated with the prescription dose) 95.8% (90.2-120.5%) and D90 (prescription dose received by at least 90% of the volume) 105.2% (98.0-124.6%) of prescription dose. No serious complications occurred during the study. Two months after brachytherapy, complete response, partial response and progressive disease were observed in 50.0%, 28.6% and 21.4% of patients, respectively. The median survival time was 22.0 ± 5.2 months, and the 1, 2,and 3-year survival rate was 89 ± 6%, 52 ± 10% and 11 ± 7%, respectively. A univariate analysis showed that the tumor size was a significant predictor of overall survival (P = 0.034). Patients with tumors <3 cm had relatively higher complete response rate (66.7%), compared to those with tumors >3 cm (30.8%). The PTV (planning target volume) smaller than 45 cm3 was significantly correlated with achieving complete tumor eradication in the treated region (P = 0.020).ConclusionsFor selected patients with limited locoregional recurrent gastric cancer, CT-guided brachytherapy using 125I seeds implantation can provide a high local control rate, with minimal trauma.

Update interstitielle Brachytherapie

Minimally invasive treatment procedures, such as image-guided local tumour ablation have gained increasing relevance in oncologic concepts. Limitations of thermal ablation procedures have led to the development of percutaneous, computed tomography (CT) guided brachytherapy. Thermal ablation procedures, such as radiofrequency ablation (RFA) and laser-induced thermotherapy (LITT) show limitations regarding maximum tumour size (<5cm), cooling effects of adjacent vessels and surrounding risk structures. The image-guided interstitial brachytherapy allows the single application of high-dose rate (HDR) irradiation with an extensive protracted cytotoxic effect. Adjacent risk structures play a minor role due to the steep dose gradient outside the clinical target volume. Studies using CT-guided brachytherapy resulted in a local tumour control rate of approximately 90% after 12months in the treatment of hepatocellular carcinoma (HCC) and 70-90% in the treatment of colorectal metastases or cholangiocellular carcinoma (CCC). Similar response rates were also seen in the treatment of metastases of renal cell carcinoma (RCC), non-small cell lung cancer (NSCLC) or neuroendocrine tumours. In colorectal liver metastases and HCC the method has proven to have a positive impact on prognosis. In contrast to thermal ablation the method can be used without restriction with respect to tumour location. Cooling effects do not play a role. It has already been applied in more than 5,000 cases and it is used in clinical routine. Image-guided brachytherapy is safe and effective and has found its way into the clinical routine.

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

Pain and symptom assessment during multiple fractions of gynecologic high-dose-rate brachytherapy

Purpose A prospective assessment of tolerability of gynecologic brachytherapy was completed to determine adequacy of analgesia and symptom control for patients undergoing CT-guided brachytherapy, with multiple fractions delivered during a single applicator insertion. Methods and Materials Seventeen patients receiving high-dose-rate brachytherapy for gynecologic cancer (other than vaginal vault) completed ratings of pain intensity, anxiety, and nausea at five key time points before, during, and after brachytherapy. Symptoms were assessed with patient-reported scores using an 11-point numeric rating scale. The patient population included cervical ( n = 12), endometrial ( n = 3), and vulvar-vaginal ( n = 2) malignancies. Patients underwent general anesthesia for applicator placement. Analgesia consisted of subcutaneous route opioid, and oral opioid and/or nonopioid as needed for the duration of the treatment planning and delivery. Results The mean scores for pain were highest after patients were transferred to the CT scanner, 3.3 ± 2.6, compared with baseline scores of 0.9 ± 1.7. Pain scores were 2.3 ± 2.3 during the remainder of the procedure, and 2.7 ± 2.1 after the removal of the applicator. The highest mean anxiety scores occurred before the brachytherapy procedure, 4.3 ± 3.4, with resolution of anxiety during the procedure to 1.3 ± 1.6. The mode of nausea scoring during the procedure was 0. Conclusion For most of the patients, the delivery of multiple fractions of image-guided high-dose-rate brachytherapy is well tolerated with maximum scores of mild-moderate pain and distress, and no significant nausea. This can be accomplished with applicator placement under general anesthesia and standard medical management.

Safety margin in irradiation of colorectal liver metastases: assessment of the control dose of micrometastases

BackroundMicrometastases of colorectal liver metastases are present in up to 50% of lesions. In this study we sought to determine the threshold dose for local control of occult micrometastases in patients undergoing CT (computed tomography)-guided brachytherapy of colorectal liver metastases.Materials and methodsNineteen patients demonstrated 34 local tumor recurrences originating from micrometastases after CT-guided brachytherapy of 27 colorectal liver metastases. We considered a local tumor recurrence as originating from a micrometastasis if tumor regrowth occurred adjacent to a formerly irradiated lesion and the distance of the 3D isocenter of the new lesion was ≤ 23.5 mm from the previous tumor margin. Follow-up MRI was fused with the planning-CT and dosimetry data. Two reviewers independently indicated the dose exposure at the isocenter of the micrometastases. Statistical analysis included an analysis of variance (ANOVA) using backward selection. 95% tolerance intervals with coverage of 87.5 and 75% of the data of the normal distribution were calculated.ResultsThe median distance of the micrometastases to the margin of the originating colorectal metastases was 8.75 mm (1-21 mm). Dose exposure at the isocenter was 12.25 Gy (7-19.8) in median. We stratified according to the distance from the isocenter to the initial tumor margin: ≤ 9 mm, > 9-15 mm and > 15 mm. The median dose in the according isocenters was 13.18, 11.6 and 11.85 Gy. The threshold dose failing to prevent micrometastasis growth was sigificantly higher in a subgroup of lesions with ≤ 9 mm distance as compared to > 15 mm (13.18 vs 11.85 Gy). Adjuvant chemotherapy correlated with greater distance of micrometastasis growth to the tumor but not with the threshold dose.ConclusionTo prevent loss of local tumor control by continuous growth of micrometastases a threshold dose of 15,4 Gy (single fraction) should be delivered at a distance of 21 mm to the gross tumor margin.

Local Response and Impact on Survival After Local Ablation of Liver Metastases From Colorectal Carcinoma by Computed Tomography–Guided High-Dose-Rate Brachytherapy

To determine local tumor control after CT-guided brachytherapy at various dose levels and the prognostic impact of extensive cytoreduction in colorectal liver metastases. Seventy-three patients were treated on a single-center prospective trial that was initially designed to be randomized to three dose levels of 15 Gy, 20 Gy, or 25 Gy per lesion, delivered in a single fraction. However, because there was a high rate of cross-over of subjects from higher to lower dose levels, this study is better understood as a prospective trial with three dose levels. No upper size limit for the metastases was applied. We assessed time to local progression, progression-free survival, and overall survival. According to safety constraints cross-over was performed. The final assignment was n = 98, n = 68, and n=33 in the 15-Gy, 20-Gy, and 25-Gy groups, respectively. Median diameter of the largest tumor lesion in each patient was 5 cm (range, 1-13.5 cm). Estimated mean local recurrence-free survival for all lesions was 34 months (median not reached). The group assigned to 15 Gy after cross-over displayed 34 local recurrences out of 98 lesions; 20 Gy, 15 out of 68 lesions; 25 Gy, 1 out of 33 lesions. The difference between the 25-Gy and the 20-Gy or 15-Gy group was significant (p < 0.05). Repeated local tumor ablations were the most prominent factor for increased survival and dominated additional systemic antitumor treatments. Local tumor control after CT-guided brachytherapy of colorectal liver metastases demonstrated a strong dose dependency. The role of extensive minimally invasive tumor ablation in metastatic colorectal cancer needs to be further established.

Clinical efficacy of CT-guided iodine-125 seed implantation therapy in patients with advanced pancreatic cancer

To examine the clinical efficacy of CT-guided radioactive iodine-125 (125I) seeds implantation treatment in patients with unresectable pancreatic cancer. Thirty-one patients with inoperable pancreatic cancer were enrolled in this study. The 125I seeds were implanted into pancreatic tumor under CT guidance. In addition, 10 patients received routine gemcitabine and 5-fluorouracil chemotherapy 1 week after brachytherapy. Median diameter of the tumor was 5.8 cm. Follow-up period was 2 to 25 months. Symptoms of refractory pain were significantly resolved post-interventionally (P < 0.05), and Karnofsky physical score increased dramatically (P < 0.05). Tumor response which was demonstrated on repeated CT film 2 months post-treatment revealed complete response (CR) in 3 cases, partial response (PR) in 16 cases, stable disease (SD) in 9 cases, and progressive disease (PD) in 3 cases. Overall responding rate (CR+PR) was 61.3%. Median survival time for all patients was 10.31 months. Two seeds of radioactive 125I migrated to the liver in 2 patients. There were no serious complications detected during the follow-up period. This study suggests that CT-guided brachytherapy using 125I seeds implantation appears to be safe, effective, uncomplicated, and could produce adequate pain relief for treating unresectable pancreatic cancer.

Value of Combined PET/CT for Radiation Planning in CT-Guided Percutaneous Interstitial High-Dose-Rate Single-Fraction Brachytherapy for Colorectal Liver Metastases

To determine the additional value of fluorodeoxyglucose-positron emission tomography (PET) for clinical target volume definition in the planning of computed tomography (CT)-guided interstitial brachytherapy for liver metastases. A total of 19 patients with liver metastases from colorectal cancer treated in 25 sessions were included in the present study. All patients had undergone fluorodeoxyglucose-PET for patient evaluation before interstitial CT-guided brachytherapy. A contrast-enhanced CT scan of the upper abdomen was obtained for radiation planning. The clinical target volume (CTV) was defined by a radiation oncologist and radiologist. After registration of the CT scan with the PET data set, the target volume was defined again using the fusion images. PET revealed one additional liver lesion that was not visible on CT. The median CT-CTV (defined using CT and magnetic resonance imaging) was 68 cm(3) (range 4-260). The PET/CT-CTV (median, 78 cm(3); range, 4-273) was significantly larger, with a median gain of 24.5% (interquartile range, 2.1-71.5%; p = .022). An increased CTV was observed in 15 cases and a decrease in 6; in 4 cases, the CT-CTV and PET/CT-CTV were equal. Incomplete dose coverage of PET/CT-CTVs was indicative of early local progression (p = .004); however, CT-based radiation plans did not show significant differences in the local control rates when stratified by dose coverage. Retrospective implementation of fluorodeoxyglucose-PET for CTV specification for CT-guided brachytherapy for colorectal liver metastases revealed a significant change in the CTVs. Additional PET-positive tumor regions with incomplete dose coverage could explain unexpected early local progression.

Directing Minimal Invasive Image Guided Therapy of Hepatic Colorectal Cancer Metastases – Imaging Strategies for Patient Evaluation, Therapy Planning, Therapy Monitoring, and Follow-Up

In contrast to surgical therapy and cytostatic therapy, locally ablative treatment of colorectal liver metastases is still lacking of large controlled trials to definitely prove its benefit on patient survival. Despite this, many different modalities have been developed for minimal invasive locoregional treatment, such as thermotherapy (radiofrequency ablation, laser induced thermotherapy) or brachytherapy (interstitial brachytherapy, transarterial radioembolization). As all of these modalities are performed under imaging guidance, success and risk strongly depends on the imaging strategy chosen for patient evaluation, treatment monitoring, and follow-up. There are not yet comprehensive guidelines on the use of locally ablative therapies, and, even more so, the use of diagnostic imaging largely depends on individual experiences and policies. Beyond oncological routines, the planning and monitoring of locally ablative treatment pose specific demands on the available imaging procedures. Many innovative applications of ultrasound, CT, MRI, PET and SPECT help to fulfill these requirements. Algorithms are needed for pretherapeutic decision making regarding the appropriate treatment strategy, as well as for posttherapeutic follow-up to confirm local control and to rule out new disease. This review summarizes current opinions to the use of diagnostic imaging in the scope of different image guided therapy modalities. Important, partly unpublished data for comprehensive pre- and posttherapeutic imaging algorithms is worked up. It also outlines challenges and possible solutions for improved guidance and monitoring of minimal invasive locoregional cancer treatment. Keywords: Image guided tumor ablation, PET, MRI, CT, colorectal cancer, liver metastases, radiofrequency ablation (RFA), laser induced thermotherapy (LITT), CT-guided brachytherapy, transarterial radioembolization (SIRT)

CT-Guided Brachytherapy (CTGB) versus Interstitial Laser Ablation (ILT) of Colorectal Liver Metastases

To compare local tumor control after percutaneous tumor ablation by interstitial laser therapy (ILT) or CT-guided brachytherapy (CTGB). In a matched pair analysis including 18 patients with 36 liver metastases of colorectal primary, both ILT and CTGB were performed in different lesions. The following matching factors were considered: (i) tumor size ≤ 5 cm, and (ii) execution of chemotherapy after tumor ablation. Primary endpoint was local tumor control. Treated lesions were identical in terms of tumor size and all matching criteria were fulfilled in all patients except for the performance of adjuvant chemotherapy. Median follow-up was 14 months (3–24 months) for both groups. Only five of 18 patients (28%) demonstrated local tumor progression after CTGB, whereas in ten of 18 patients (56%) tumor progression was found after ILT. Differences encountered were significant for all patients (p = 0.04), whereas in those who fulfilled all matching criteria (n = 14) the level of statistical significance was not reached (p = 0.23). CTGB demonstrated superior local tumor control compared to ILT in long-term follow-up.

CT-Guided Interstitial Single-Fraction Brachytherapy of Lung Tumors: Phase I Results of a Novel Technique

To assess the safety of CT-guided brachytherapy of lung malignancies and to evaluate the initial therapeutic response.Fifteen patients with 30 lung malignancies were included in this prospective phase I trial (metastases, 28; non-small cell lung cancers, 2). Pre-interventionally two patients had a vital capacity of < 80% (39% and 63%). These two patients, and one other, had FEV1 values of < 80% predicted (17%, 48%, and 64%). Tumors with a maximum diameter of 4 cm were treated with a single brachytherapy catheter that was positioned under CT-fluoroscopy. In two tumors with tumor diameters of 5.5 and 6.5 cm, two applicators were used. In one patient with an 11-cm irregularly shaped tumor, nine catheters were inserted. Treatment planning for 192Ir brachytherapy was performed using three-dimensional CT data that were acquired after percutaneous applicator positioning. All procedures were performed under local anesthesia. A follow-up CT was performed 6 weeks later and every 3 months pos-tintervention.The mean diameter of the 30 lung tumors was 2 cm (range, 0.6 to 11 cm; median diameter, 1.5 cm). The minimal dose within the tumor margin was 20 Gy in all 30 tumors treated. Except for nausea in one patient and focal hemorrhage detected on CT in two patients, no acute adverse events were recorded. One patient developed an abscess at the previous tumor location 9 months after treatment, which proved to be a local tumor recurrence. The median follow-up period was 5+ months with a local tumor control of 97%.The novel technique of CT-guided interstitial brachytherapy was safe for the treatment of lung tumors and yielded a very low complication rate. The initial data on therapeutic response are promising.

231 CT-Guided brachytherapy of hepatocellular carcinoma in liver cirrhosis — A novel therapeutic approach

231 CT-Guided brachytherapy of hepatocellular carcinoma in liver cirrhosis — A novel therapeutic approach

In vivo assessment of the tolerance dose of small liver volumes after single-fraction HDR irradiation

To prospectively assess a dose-response relationship for small volumes of liver parenchyma after single-fraction irradiation. Twenty-five liver metastases were treated by computed tomography (CT)-guided interstitial brachytherapy. Magnetic resonance imaging was performed 1 day before and 3 days and 6, 12, and 24 weeks after therapy. MR sequences included T1-w gradient echo (GRE) enhanced by hepatocyte-targeted gadobenate dimeglumine. All MRI data sets were merged with 3D dosimetry data and evaluated by two radiologists. The reviewers indicated the border of hyperintensity on T2-w images (edema) or hypointensity on T1-w images (loss of hepatocyte function). Based on the total 3D data, a dose-volume histogram was calculated. We estimated the threshold dose for either edema or function loss as the D(90), i.e., the dose achieved in at least 90% of the pseudolesion volume. Between 3 days and 6 weeks, the extension of the edema increased significantly from the 12.9 Gy isosurface to 9.9 Gy (standard deviation [SD], 3.3 and 2.6). No significant change was detected between 6 and 12 weeks. After 24 weeks, the edematous tissue had shrunk significantly to 14.7 Gy (SD, 4.2). Three days postbrachytherapy, the D(90) for hepatocyte function loss reached the 14.9 Gy isosurface (SD, 3.9). At 6 weeks, the respective zone had increased significantly to 9.9 Gy (SD, 2.3). After 12 and 24 weeks, the dysfunction volume had decreased significantly to the 11.9 Gy and 15.2 Gy isosurface, respectively (SD, 3 and 4.1). The 95% interval from 7.6 to 12.2 Gy found as the minimal hepatocyte tolerance after 6 weeks accounts for the radiobiologic variations found in CT-guided brachytherapy, including heterogeneous dose rates by variable catheter arrays.

Interventionelle Therapie von Lebermetastasen

Interventional radiology offers not only local but also loco-regional therapeutic concepts for the treatment of liver metastases. While the local concepts are employed as image-guided, interstitial techniques, a vascular access is ideal for the loco-regional distribution of anti-tumour drugs. In the present article interstitial employed ablation methods such as radiofrequency ablation, laser-induced thermotherapy and CT-guided brachytherapy are evaluated on the basis of the available literature. The field of loco-regional vascular techniques contributes analyses of intra-arterial chemotherapy via minimally invasively implanted port systems as well as transarterial chemoembolization.

Liver Malignancies: CT-Guided Interstitial Brachytherapy in Patients with Unfavorable Lesions for Thermal Ablation

To evaluate computed tomography (CT)-guided brachytherapy in patients with very large liver malignancies or with liver tumors located adjacent to the liver hilum. In this prospective nonrandomized phase II trial, we treated 20 patients (19 liver metastases and one cholangiocarcinoma) with CT-guided high-dose-rate (HDR) brachytherapy using a (192) Iridium source. All patients demonstrated no functional liver degradation prior to irradiation. Entry criteria were liver tumors > 5 cm (group A, n = 11, no upper limit) or liver tumors < or = 5 cm adjacent to the liver hilum (group B, n = 9). Dose planning for brachytherapy was performed with three dimensional (3D) CT data acquired after percutaneous applicator positioning. Magnetic resonance (MR) imaging follow-up was performed 6 weeks and every 3 months post intervention. Primary endpoints were complications, local tumor control (absence of tumor growth after treatment followed by shrinkage of the lesion starting at 6 months) and progression-free survival. The mean tumor diameter was 7.7 cm (range, 5.5-10.8 cm) in group A, 3.6 cm (range, 2.2-4.9 cm) in group B. On average, a minimal dose of 17 Gy in the target volume was applied (range, 12-25 Gy). Severe side effects were recorded in two patients (10%). One patient demonstrated an obstructive jaundice caused by tumor edema after irradiation of a metastasis adjacent to the bile duct bifurcation. One patient developed intra-abdominal hemorrhage that was treated by a single blood transfusion and has ceased. We frequently encountered moderate increases of liver enzymes (70% of patients) and bilirubin (50% of patients) without clinical symptoms and thus considered to be insignificant. The median follow-up was 13 months. In group A (tumors > 5 cm), primary local tumor control after 6 and 12 months was 74% and 40%, respectively; in group B, it was 100% and 71%, respectively. All but one local recurrence (in a patient with diffuse tumor progression) were successfully treated during another CT-guided brachytherapy leading to a primary assisted local control of 93% after 12 months. CT-guided brachytherapy based on individual dose plans and 3D CT data sets generated encouraging results in large liver malignancies as well as in tumors located adjacent to the liver hilum.

CT-guided interstitial brachytherapy of liver malignancies alone or in combination with thermal ablation: phase I?II results of a novel technique

Purpose To assess the safety and efficacy of CT-guided brachytherapy alone or in combination with laser-induced thermotherapy (LITT) in patients with liver malignancies. Methods and materials Thirty-seven patients presented with 36 liver metastases and two primary liver carcinomas. Twenty-one patients were treated with CT-guided high-dose-rate brachytherapy alone using a 192Ir source. Sixteen patients received brachytherapy directly after MRI-guided LITT. The indications for brachytherapy alone were a tumor size >5 cm, adjacent central bile duct or adjacent major vessels causing unfavorable cooling effects for thermal ablation, and technical failures of LITT. The dosimetry for brachytherapy was performed using three-dimensional CT data acquired after percutaneous applicator positioning. On average, a minimal dose of 17 Gy inside the tumor margin was applied (range, 10–20 Gy). Results The mean tumor size was 4.6 cm (range, 2.5–11 cm). The mean liver volume receiving ≥5 Gy was 16% (range, 2–40%) of the total liver. Severe complications were recorded in 2 patients (5%). One patient developed acute liver failure possibly related to accidental continuation of oral capecitabine treatment. Another patient demonstrated obstructive jaundice owing to tumor edema after irradiation of a metastasis adjacent to the bile duct bifurcation. A commonly encountered moderate increase of liver enzymes was greatest in patients with combined treatment. The local control rate after 6 months was 73% and 87% for combined treatment and brachytherapy alone, respectively. Conclusion CT-guided brachytherapy using three-dimensional CT data for dosimetry is safe and effective alone or in combination with LITT. Brachytherapy as a stand-alone treatment displayed genuine advantages over thermal tumor ablation.

CT-guided interstitial brachytherapy of liver malignancies alone or in combination with thermal ablation: phase I–II results of a novel technique

Purpose To assess the safety and efficacy of CT-guided brachytherapy alone or in combination with laser-induced thermotherapy (LITT) in patients with liver malignancies. Methods and materials Thirty-seven patients presented with 36 liver metastases and two primary liver carcinomas. Twenty-one patients were treated with CT-guided high-dose-rate brachytherapy alone using a 192Ir source. Sixteen patients received brachytherapy directly after MRI-guided LITT. The indications for brachytherapy alone were a tumor size >5 cm, adjacent central bile duct or adjacent major vessels causing unfavorable cooling effects for thermal ablation, and technical failures of LITT. The dosimetry for brachytherapy was performed using three-dimensional CT data acquired after percutaneous applicator positioning. On average, a minimal dose of 17 Gy inside the tumor margin was applied (range, 10–20 Gy). Results The mean tumor size was 4.6 cm (range, 2.5–11 cm). The mean liver volume receiving ≥5 Gy was 16% (range, 2–40%) of the total liver. Severe complications were recorded in 2 patients (5%). One patient developed acute liver failure possibly related to accidental continuation of oral capecitabine treatment. Another patient demonstrated obstructive jaundice owing to tumor edema after irradiation of a metastasis adjacent to the bile duct bifurcation. A commonly encountered moderate increase of liver enzymes was greatest in patients with combined treatment. The local control rate after 6 months was 73% and 87% for combined treatment and brachytherapy alone, respectively. Conclusion CT-guided brachytherapy using three-dimensional CT data for dosimetry is safe and effective alone or in combination with LITT. Brachytherapy as a stand-alone treatment displayed genuine advantages over thermal tumor ablation.

Synchronous CT-guided Brachytherapy in Patients at Risk for Incomplete Interstitial Laser Ablation of Liver Malignancies

Summary Objectives: Indications for additional brachytherapy after CT guided interstitial laser ablation in patients with liver malignancies. Materials and methods: Fourteen patients with eighteen liver metastasis received high-dose-rate (HDR) brachytherapy directly following MR-guided interstitial laser ablation. Indications for additional brachytherapy were as follows: tumor size >5 cm, adjacent central bile duct or adjacent major vessels causing unfavourable cooling effects for thermal ablation, and technical failures of laser ablation. Dosimetry for brachytherapy was performed using three-dimensional CT data acquired after percutaneous applicator positioning for laser treatment. In average, a minimal dose of 17 Gy inside the tumor margin was applied (range: 10–20 Gy). Results: The mean tumor size was 4.3 cm (2.1–7.2 cm). The mean liver volume receiving ≥5 Gy was 16% of the liver total (2–40%). Severe complications were recorded in 1 patient. One patient developed acute liver failure possibly related to accidental continuation of oral capecitabine treatment (5 FU). Commonly encountered moderate increase of liver enzymes was observed. Local control rates after 9 months were 93% and after 12 month 86% for combined treatment with brachytherapy, respectively. Conclusion: CT guided brachytherapy using 3D CT data for dosimetry is safe and effective in combination with interstitial laser ablation. Brachytherapy as an additional treatment displayed sincere advantages over thermal ablation alone in critical location of the tumor.