CT-guided High-dose-rate Brachytherapy Research Articles

CT-guided high dose rate brachytherapy can induce multiple systemic proteins of proliferation and angiogenesis predicting outcome in HCC

Background and purposeTo determine the potential prognostic value of proliferation and angiogenesis plasma proteins following CT-guided high dose rate brachytherapy (HDR-BT) of hepatocellular carcinoma (HCC). Materials and methodsFor this prospective study, HDR-BT (1 × 15 Gy) was administered to 24 HCC patients. Plasma was obtained and analyzed using an Olink proteomics Target-96 immuno-oncology-panel that included multiple markers of angiogenesis and proliferation. Fold-change (FC) ratios were calculated by comparing baseline and 48 h post HDR-BT paired samples. Patients were classified as responders (n = 12) if they had no local progression within 6 months or systemic progression within 2 years. Non-responders (n = 12) had recurrence within 6 months and/or tumor progression or extrahepatic disease within 2 years. ResultsProliferation marker EGF was significantly elevated in non-responders compared to responders (p = 0.0410) while FGF-2, HGF, and PlGF showed no significant differences. Angiogenesis markers Angiopoietin-1 and PDGF-B were likewise significantly elevated in non-responders compared to responders (p = 0.0171, p = 0.0462, respectively) while Angiopoietin-2, VEGF-A, and VEGFR-2 did not differ significantly. Kaplan-Meier analyses demonstrated significantly shorter time to systemic progression in patients with increased EGF and Angiopoietin-1 (p = 0.0185, both), but not in patients with one of the remaining proteins elevated (all p > 0.1). Pooled analysis for these 9 proteins showed significantly shorter time to systemic progression for FC ≥1.3 and ≥1.5 for at least 3 proteins elevated (p = 0.0415, p = 0.0193, respectively). ConclusionIncreased plasma levels of EGF and Angiopoietin-1 after HDR-BT for HCC are associated with poor response and may therefore function as predictive biomarkers of outcome.

CT-guided High-Dose-Rate Brachytherapy versus Transarterial Chemoembolization in Patients with Unresectable Hepatocellular Carcinoma.

Background CT-guided high-dose-rate (HDR) brachytherapy (hereafter, HDR brachytherapy) has been shown to be safe and effective for patients with unresectable hepatocellular carcinoma (HCC), but studies comparing this therapy with other local-regional therapies are scarce. Purpose To compare patient outcomes of HDR brachytherapy and transarterial chemoembolization (TACE) in patients with unresectable HCC. Materials and Methods This multi-institutional retrospective study included consecutive treatment-naive adult patients with unresectable HCC who underwent either HDR brachytherapy or TACE between January 2010 and December 2022. Overall survival (OS) and progression-free survival (PFS) were compared between patients matched for clinical and tumor characteristics by propensity score matching. Not all patients who underwent TACE had PFS available; thus, a different set of patients was used for PFS and OS analysis for this treatment. Hazard ratios (HRs) were calculated from Kaplan-Meier survival curves. Results After propensity matching, 150 patients who underwent HDR brachytherapy (median age, 71 years [IQR, 63-77 years]; 117 males) and 150 patients who underwent TACE (OS analysis median age, 70 years [IQR, 63-77 years]; 119 male; PFS analysis median age, 68 years [IQR: 63-76 years]; 119 male) were analyzed. Hazard of death was higher in the TACE versus HDR brachytherapy group (HR, 4.04; P < .001). Median estimated PFS was 32.8 months (95% CI: 12.5, 58.7) in the HDR brachytherapy group and 11.6 months (95% CI: 4.9, 22.7) in the TACE group. Hazard of disease progression was higher in the TACE versus HDR brachytherapy group (HR, 2.23; P < .001). Conclusion In selected treatment-naive patients with unresectable HCC, treatment with CT-guided HDR brachytherapy led to improved OS and PFS compared with TACE. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Chapiro in this issue.

Circulating miR-21 as a prognostic biomarker in HCC treated by CT-guided high-dose rate brachytherapy

Background and aimsPrognostic biomarkers identifying patients with early tumor progression after local ablative therapy remain an unmet clinical need. The aim of this study was to investigate circulating miR-21 and miR-210 levels as prognostic biomarkers of HCC treated by CT-guided high-dose rate brachytherapy (HDR-BT).Materials and Methods24 consecutive HCC patients (BCLC A and B) treated with CT-guided HDR-BT (1 × 15 Gy) were included in this prospective IRB-approved study. RT-PCR was performed to quantify miR-21 and miR-210 levels in blood samples acquired prior to and 2 d after HDR-BT. Follow-up imaging (contrast-enhanced liver MRI and whole-body CT) was performed in 3 months follow-up intervals. Therapy response was assessed with patients classified as either responders or non-responders (12 each). Responders were defined as having no local or diffuse systemic progression within 6 months and no diffuse systemic progression exceeding 3 nodules/nodule diameter > 3 cm from 6 months to 2 years. Non-responders had recurrence within 6 months and/or tumor progression with > 3 nodules or individual lesion diameter > 3 cm or extrahepatic disease within two years, respectively. Biostatistics included parametric and non-parametric testing (Mann–Whitney-U-test), as well as Kaplan–Meier curve construction.ResultsThe responder group demonstrated significantly decreasing miR-21 values 2 d post therapy compared to non-responders (median miR-21 2−ΔΔCт: responders 0.73 [IQR 0.34], non-responders 1.53 [IQR 1.48]; p = 0.0102). miR-210 did not show any significant difference between responders and non-responders (median miR-210 2−ΔΔCт: responders 0.74 [IQR 0.45], non-responders 0.99 [IQR 1.13]; p = 0.8399). Kaplan–Meier curves demonstrated significantly shorter time to systemic progression for increased miR-21 (p = 0.0095) but not miR-210 (p = 0.7412), with events accumulating > 1 year post therapy in non-responders (median time to systemic progression 397 days).ConclusionIncreasing circulating miR-21 levels are associated with poor response and shorter time to systemic progression in HDR-BT-treated HCC. This proof-of-concept study provides a basis for further investigation of miR-21 as a prognostic biomarker and potential stratifier in future clinical trials of interventional oncology therapies.Trial registration: In this monocentric clinical study, we analyzed prospectively acquired data of 24 patients from the “ESTIMATE” patient cohort (Studiennummer: DRKS00010587, Deutsches Register Klinischer Studien). Ethical approval was provided by the ethics committee “Ethikkommission bei der LMU München” (reference number “17-346”) on June 20, 2017 and August 26, 2020.

Clinical Outcomes and Toxicity of CT-guided High Dose-rate Brachytherapy in Women With Locally-advanced Cervical Cancer.

To evaluate the outcome and toxicities in patients with locally advanced cervical cancer (LACC) treated with radiochemotherapy and intracavitary brachytherapy. This study included 67 patients with LACC treated between 2010 and 2018. The most represented stage was FIGO IIB. The patients were treated with external beam radiotherapy (EBRT) to the pelvis and boost to the cervix and parametrials. Concomitant chemotherapy (CHT) with cisplatin (CDDP) 40 mg/mq was planned. Subsequently, the patients underwent CT-based endouterine brachytherapy (BT). The response was evaluated at 3 months with PET-CT and/or pelvic magnetic resonance imaging (MRI). Since then, the patients have been followed with clinical instrumental controls every 4 months for the first 2 years and every 6 months for the following 3 years. Local response was assessed with pelvic MRI and/or PET-CT scan at the end of intracavitary BT) according to RECIST 1.1 criteria. The median duration of treatment was 55 days (range=40-73 days). The prescription dose to the planning target volume (PTV) was delivered in 25 to 30 (median 28) daily fractions. The EBRT median dose to the pelvis and gross tumor volume were 50.4 Gy (range=45-56.25) and 61.6 Gy (range=45-70.4), respectively. The 1-year, 2-year, 3-year, and 5-year overall survival rates were 92.44%, 80.81%, 78.84%, and 76.45% respectively. The actuarial 1-year, 2-year, 3-year, and 5-year disease-free survival rates were 89.5%, 83.6%, 81%, and 78.2% respectively. This study analyzed acute and chronic toxicity, survival, and local control in cervical cancer patients treated with IMRT followed by CT-planned high dose rate-brachytherapy. Patients demonstrated satisfactory outcomes and incidence of acute and late toxicities.

Comparison of intrahepatic progression patterns of hepatocellular carcinoma and colorectal liver metastases following CT-guided high dose-rate brachytherapy

Introduction:Given the metachronous and multifocal occurrence of hepatocellular carcinoma (HCC) and colorectal cancer metastases in the liver (CRLM), this study aimed to compare intrahepatic progression patterns after computed tomography (CT)-guided high dose-rate brachytherapy.Patients and methods:This retrospective analysis included 164 patients (114 HCC, 50 CRLM) treated with brachytherapy between January 2016 and January 2018. Patients received multiparametric magnetic resonance imaging (MRI) before, and about 8 weeks after brachytherapy, then every 3 months for the first, and every 6 months for the following years, until progression or death. MRI scans were assessed for local or distant intrahepatic tumor progression according to RECIST 1.1 and electronic medical records were reviewed prior to therapy. The primary endpoint was progression-free survival (PFS). Specifically, local and distant intra-hepatic PFS were assessed to determine differences between the intrahepatic progression patterns of HCC and CRLM. Secondary endpoints included the identification of predictors of PFS, time to progression (TTP), and overall survival (OS). Statistics included Kaplan–Meier analysis and univariate and multivariate Cox regression modeling.Results:PFS was longer in HCC [11.30 (1.33–35.37) months] than in CRLM patients [8.03 (0.73–19.80) months, p = 0.048], respectively. Specifically, local recurrence occurred later in HCC [PFS: 36.83 (1.33–40.27) months] than CRLM patients [PFS: 12.43 (0.73–21.90) months, p = 0.001]. In contrast, distant intrahepatic progression occurred earlier in HCC [PFS: 13.50 (1.33–27.80) months] than in CRLM patients [PFS: 19.80 (1.43–19.80) months, p = 0.456] but without statistical significance. Multivariate Cox regression confirmed tumor type and patient age as independent predictors for PFS.Conclusion:Brachytherapy proved to achieve better local tumor control and overall PFS in patients with unresectable HCC as compared to those with CRLM. However, distant progression preceded local recurrence in HCC. As a result, these findings may help design disease-specific surveillance strategies and personalized treatment planning that highlights the strengths of brachytherapy. They may also help elucidate the potential benefits of combinations with other loco-regional or systemic therapies.

Feasibility and Safety of CT-Guided High-Dose-Rate Brachytherapy Combined with Transarterial Chemoembolization Using Irinotecan-Loaded Microspheres for the Treatment of Large, Unresectable Colorectal Liver Metastases

To evaluate feasibility and safety of combined irinotecan chemoembolization and CT-guided high-dose-rate brachytherapy (HDRBT) in patients with unresectable colorectal liver metastases > 3 cm in diameter. This prospective study included 23 patients (age, 70 y ± 11.3; 16 men) with 47 liver metastases (size, 62 mm ± 18.7). Catheter-related adverse events were reported per Society of Interventional Radiology classification, and treatment toxicities were reported per Common Terminology Criteria for Adverse Events. Liver-related blood values were analyzed by Wilcoxon test, with P < .05 as significant. Time to local tumor progression, progression-free survival (PFS), and overall survival (OS) were estimated by Kaplan-Meier method. No catheter-related major or minor complications were recorded. Significant differences vs baseline levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT; both P < .001), γ-glutamyltransferase (GGT; P = .013), and hemoglobin (P=.014) were recorded. After therapy, 11 of 23 patients (47.8%) presented with new grade I/II toxicities (bilirubin, n = 3 [13%]; AST, n = 16 [70%]; ALT, n = 18 [78%]; ALP, n = 12 [52%] and hemoglobin, n = 15 [65%]). Moreover, grade III/IV toxicities developed in 10 (43.5%; 1 grade IV): AST, n = 6 (26%), grade III, n = 5; grade IV, n = 1; ALT, n = 3 (13%); GGT, n = 7 (30%); and hemoglobin, n = 1 (4%). However, all new toxicities resolved within 3 months after therapy without additional treatment. Median local tumor control, PFS, and OS were 6, 4, and 8 months, respectively. Combined irinotecan chemoembolization and CT-guided HDRBT is safe and shows a low incidence of toxicities, which were self-resolving.

Primary and metastatic malignancies of the lung: Retrospective analysis of the CT-guided high-dose rate brachytherapy (CT-HDRBT) ablation in tumours

BackgroundMinimal invasive local therapies are alternative treatment options in patients with primary and metastatic lung malignancies being not eligible for resection. However, thermal ablations are often limited by large tumour volumes. PurposeTo evaluate the efficacy and safety of CT-HDRBT in pulmonary tumours ≥4 cm compared to smaller tumours. Material and methodsIn this retrospective study, 74 consecutive patients (mean age: 63 ± 12; m: 39, w: 35) with a total of 175 tumours treated in 132 interventions were enrolled between October 2003 and September 2016. Primary and assisted local tumour control (LTC), progression free survival (PFS) and overall survival (OS) after first CT-HDBRT were identified for two subgroups with tumours <4 cm (A) as well as ≥4 cm (B) using the Kaplan-Meier-Method. Radiation parameters and side effects were recorded. Log-Rank-Test and Mann-Whitney-U-Test were performed for statistical analyses with p-values <0.05 considered as significant. ResultsThere was no statistical difference in coverage with prescribed radiation dose (A:19.78 ± 8.62 mm (range 5–39 mm), 99.56 ± 0.99%; B:61.70 ± 21.09 mm (41–100 mm), 94.81 ± 7.19%, p = 0.263). LTC rates after 0.5-,1-,2-,3- and 5-years were higher in A compared to B (A:85%/74%/63%/60%/46%, B:71%/37%/32%/32%/32%) with longer primary (A:11months, B:5months, p = 0.003) and assisted LTC (A:9months B:20months, p = 0.339). Longer OS was observed in A (A:18.5months, B:14.5months, p = 0.011) with longer OS rates (A:96%/87%/60%/48%/19%, B:92%/73%/20%/20%/0%). Complication assessment revealed no bleedings, 16.6% pneumothoraxes and 48.5% of mild radiation fibrosis without clinical symptoms. ConclusionIn conclusion, higher LTC and OS were observed in patients with primary lung malignancies <4 cm. Nevertheless, CT-HDRBT is a safe and feasible alternative even in larger tumours ≥4 cm.

Cholangiocarcinoma: CT-guided High-Dose Rate Brachytherapy (CT-HDRBT) for Limited (4 cm) Tumors.

Thermal-ablative therapies are limited to tumors of 3-4 cm diameter. The purpose of this study was to evaluate the local tumor control (LTC) of CT-guided High-Dose-Rate-Brachytherapy (CT-HDRBT) for ablation of cholangiocarcinomas (CCA) ≥4 cm compared to smaller tumors. Sixty-one patients (tumors: 142, interventions: 91) were treated from March 2008 to January 2017. LTC, progression-free survival (PFS) and overall survival (OS) after first CT-HDRBT were identified for two subgroups (A:<4 cm, B:≥4 cm) and the influence of coverage and target-dose were evaluated. Log-Rank- and Mann-Whitney-U-Tests were performed for statistical analyses with p-values <0.05 considered as significant. Better coverage was achieved for smaller tumors (A: 99.22-0.25%, B: 95.10-1.40%, p<0.001). LTC was better in subgroup A (A: 8, B: 6 months, p=0.006). Larger tumors (4-7 cm) with incomplete coverage showed the poorest LTC (p=0.032). There were no statistical significances in PFS (A: 5, B: 3 months, p=0.597) and OS (A:15.5; B:10.0 months, p=0.107). CT-HDRBT is sufficient in CCA ≥4 cm, if full coverage with therapeutic doses can be achieved.

Local ablation or radioembolization of colorectal cancer metastases: comorbidities or older age do not affect overall survival

BackgroundLocal ablative techniques are emerging in patients with oligometastatic disease from colorectal carcinoma, commonly described as less invasive than surgical methods. This single arm cohort seeks to determine whether such methods are suitable in patients with comorbidities or higher age.MethodsTwo hundred sixty-six patients received radiofrequency ablation (RFA), CT-guided high-dose rate brachytherapy (HDR-BT) or Y90-radioembolization (Y90-RE) during treatment of metastatic colorectal cancer (mCRC). This cohort comprised of patients with heterogenous disease stages from single liver lesions to multiple organ systems involvement commonly following multiple chemotherapy lines. Data was reviewed retrospectively for patient demographics, previous therapies, initial or disease stages at first intervention, comorbidities and mortality. Comorbidity was measured using the Charlson Comorbidity Index (CCI) and age-adjusted Charlson Index (CACI) excluding mCRC as the index disease. Kaplan-Meier survival analysis and Cox regression were used for statistical analysis.ResultsOverall median survival of 266 patients was 14 months. Age ≥ 70 years did not influence survival after local therapies. Similarly, CCI or CACI did not affect the patients prognoses in multivariate analyses. Moderate or severe renal insufficiency (n = 12; p = 0.005) was the only single comorbidity identified to negatively affect the outcome after local therapy.ConclusionInterventional procedures for mCRC may be performed safely even in elderly and comorbid patients. In severe renal insufficiency, the use of invasive techniques should be limited to selected cases.

Activity-based cost analysis of hepatic tumor ablation using CT-guided high-dose rate brachytherapy or CT-guided radiofrequency ablation in hepatocellular carcinoma.

PurposeTo analyse and compare the costs of hepatic tumor ablation with computed tomography (CT)-guided high-dose rate brachytherapy (CT-HDRBT) and CT-guided radiofrequency ablation (CT-RFA) as two alternative minimally invasive treatment options of hepatocellular carcinoma (HCC).Materials and methodsAn activity based process model was created determining working steps and required staff of CT-RFA and CT-HDRBT. Prorated costs of equipment use (purchase, depreciation, and maintenance), costs of staff, and expenditure for disposables were identified in a sample of 20 patients (10 treated by CT-RFA and 10 by CT-HDRBT) and compared. A sensitivity and break even analysis was performed to analyse the dependence of costs on the number of patients treated annually with both methods.ResultsCosts of CT-RFA were nearly stable with mean overall costs of approximately 1909 €, 1847 €, 1816 € and 1801 € per patient when treating 25, 50, 100 or 200 patients annually, as the main factor influencing the costs of this procedure was the single-use RFA probe. Mean costs of CT-HDRBT decreased significantly per patient ablation with a rising number of patients treated annually, with prorated costs of 3442 €, 1962 €, 1222 € and 852 € when treating 25, 50, 100 or 200 patients, due to low costs of single-use disposables compared to high annual fix-costs which proportionally decreased per patient with a higher number of patients treated annually. A break-even between both methods was reached when treating at least 55 patients annually.ConclusionAlthough CT-HDRBT is a more complex procedure with more staff involved, it can be performed at lower costs per patient from the perspective of the medical provider when treating more than 55 patients compared to CT-RFA, mainly due to lower costs for disposables and a decreasing percentage of fixed costs with an increasing number of treatments.

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

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. 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 192Ir-source. Primary endpoint was local tumor control and secondary endpoints were complications, progression-free survival and overall survival. 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. CT-HDRBT was safe and effective for the treatment of liver metastases of pancreatic cancer.

CT-guided high-dose-rate brachytherapy of unresectable hepatocellular carcinoma.

The purpose of the present study was to evaluate the clinical outcome of CT-guided high-dose-rate brachytherapy (CT-HDRBT) in patients with unresectable hepatocellular carcinoma (HCC). Over a 6-year period, 98patients with 212unresectable HCC underwent CT-HDRBT applying a (192)Ir source at our institution. Magnetic resonance imaging (MRI) follow-up was performed 6weeks after the intervention and then every 3months. The primary endpoint was local tumor control (LTC); secondary endpoints included progression-free survival (PFS) and overall survival (OS). Patients were available for MRI evaluation for a mean follow-up of 23.1months (range 4-64months; median 20months). Mean tumor diameter was 5cm (range 1.8-12cm). Eighteen of 212 (8.5 %) tumors showed local progression after a mean LTC of 21.1months. In all, 67patients (68.4 %) experienced distant tumor progression. The mean PFS was 15.2months. Forty-six patients died during the follow-up period. Median OS was 29.2months. Actuarial 1-, 2-, and 3-year OS rates were 80, 62, and 46 %, respectively. CT-HDRBT is an effective therapy to attain local tumor control in patients with unresectable HCC. Prospective randomized studies comparing CT-HDRBT with the standard treatments like Radiofrequency ablation (RFA) and chemoembolization (TACE) are mandatory.

Unresectable Colorectal Liver Metastases: Percutaneous Ablation Using CT-Guided High-Dose-Rate Brachytherapy (CT-HDBRT)

To evaluate the clinical outcome of CT-guided high-dose-rate brachytherapy (CT-HDRBT) of unresectable colorectal liver metastases (CRLMs). Retrospective analysis of all consecutive patients with unresectable CRLMs treated with CT-HDRBT between January 2008 and November 2012. Treatment was performed by CT-guided catheter placement and high-dose-rate brachytherapy with an iridium-192 source. MRI follow-up was performed after 6 weeks and then every 3 months post-intervention. The primary endpoint was local tumor control (LTC); secondary endpoints included time to progression (TTP) and overall survival (OS). 80 heavily pretreated patients with 179 metastases were available for MRI evaluation for a mean follow-up time of 16.9 months. The mean tumor diameter was 28.5 mm (range: 8 - 107 mm). No major complications were observed. A total of 23 (12.9 %) local tumor progressions were observed. Lesions ≥ 4 cm in diameter showed significantly more local progression than smaller lesions (< 4 cm). 50 patients (62.5 %) experienced systemic tumor progression. The median TTP was 6 months. 28 (43 %) patients died during the follow-up period. The median OS after ablation was 18 months. CT-HDRBT is an effective technique for the treatment of unresectable CRLMs and warrants promising LTC rates compared to thermal ablative techniques. A combination with other local and systemic therapies should be evaluated in patients with lesions > 4 cm in diameter, in which higher progression rates are expected. • CT-HDRBT enables a highly cytotoxic irradiation of colorectal liver metastases with simultaneous conservation of important neighboring structures (eg liver parenchyma, bile ducts and bowel)• The local tumor control rates obtained by CT-HDRBT in patients with colorectal liver metastases are promising, also compared to the local tumor control rates after RFA• Metastases with a diameter of 4 cm or abow, display a higher local progression rate after CT-HDRBT, therefor a combination therapy with other locoregional or systemic treatments should be investigated in prospective studies.

CT-guided high dose rate brachytherapy ablation of liver metastases

Over the past two decades, several methods for minimally invasive tumor ablation have been developed and tested clinically. CT-guided high dose rate brachytherapy is an alternative radioablative technique that was introduced in clinical practice as a minimally treatment option almost 20 years ago with some crucial advantages over thermal ablation. This report reviews the current clinical status of percutaneous CT-guided high dose rate brachytherapy of liver metastases.

Percutaneous ablation of lymph node metastases using CT-guided high-dose-rate brachytherapy

To assess the technical feasibility, safety and clinical outcome of CT-guided high-dose-rate brachytherapy (CT-HDRBT) for achieving local tumour control (LTC) in isolated lymph node metastases. From January 2008 to December 2011, 10 patients (six males and four females) with isolated nodal metastases were treated with CT-HDRBT. Five lymph node metastases were para-aortic, three were at the liver hilum, one at the coeliac trunk and one was a left iliac nodal metastasis. The mean lesion diameter was 36.5 mm (range 12.0-67.0 mm). Patients were followed up by either contrast-enhanced CT or MRI 6 weeks and then every 3 months after the end of treatment. The primary end point was LTC. Secondary end points included primary technical effectiveness rate, adverse events and progression-free survival. The first follow-up examination after 6 weeks revealed complete coverage of all nodal metastases treated. There was no peri-interventional mortality or major complications. The mean follow-up period was 13.2 months (range 4-20 months). 2 out of 10 patients (20%) showed local tumour progression 9 and 10 months after ablation. 5 out of 10 patients (50%) showed systemic tumour progression. The mean progression-free interval was 9.2 months (range 2-20 months). CT-HDRBT is a safe and effective technique for minimally invasive ablation of nodal metastases. CT-HDRBT of lymph node metastases is feasible and safe. CT-HDRBT might be a viable therapeutic alternative to obtain LTC in selected patients with isolated lymph node metastases.

In vivo assessment of the gastric mucosal tolerance dose after single fraction, small volume irradiation of liver malignancies by computed tomography–guided, high-dose-rate brachytherapy

The aim of this study was to assess the tolerance dose of gastric mucosa for single-fraction computed tomography (CT)-guided, high-dose-rate (HDR) brachytherapy of liver malignancies. A total of 33 patients treated by CT-guided HDR brachytherapy of liver malignancies in segments II and/or III were included. Dose planning was performed upon a three-dimensional CT data set acquired after percutaneous applicator positioning. All patients received gastric protection post-treatment. For further analysis, the contours of the gastric wall were defined in every CT slice using Brachyvision Software. Dose-volume histograms were calculated for each treatment and correlated with clinical data derived from questionnaires assessing Common Toxicity Criteria (CTC). All patients presenting symptoms of upper GI toxicity were examined endoscopically. Summarizing all patients the minimum dose applied to 1 ml of the gastric wall (D(1 ml)) ranged from 6.3 to 34.2 Gy; median, 14.3 Gy. Toxicity was present in 18 patients (55%). We found nausea in 16 (69%), emesis in 9 (27%), cramping in 13 (39%), weight loss in 12 (36%), gastritis in 4 (12%), and ulceration in 5 patients (15%). We found a threshold dose D(1 ml) of 11 Gy for general gastric toxicity and 15.5 Gy for gastric ulceration verified by an univariate analysis (p = 0.01). For a single fraction, small volume irradiation we found in the upper abdomen a threshold dose D(1 ml) of 15.5 Gy for the clinical endpoint ulceration of the gastric mucosa. This in vivo assessment is in accordance with previously published tolerance data.

CT-guided interstitial brachytherapy in the local treatment of extrahepatic, extrapulmonary secondary malignancies

The purpose was to evaluate the safety and efficacy of high-dose-rate (HDR) CT-guided interstitial brachytherapy in the treatment of extrahepatic, extrapulmonary, secondary malignancies. Nineteen patients were included in this prospective study. The median age was 66 years (49-77). Underlying primaries comprised colorectal carcinomas in six, renal cell carcinoma in three, pancreatic carcinoma in three, cervical cancer in two, endometrial cancer in two and NSCLC, breast cancer and sarcoma in one patient each. All patients had undergone extensive pretreatments. CT-guided HDR brachytherapy employed a 192Iridium source. Dose planning for brachytherapy was performed using 3D CT data acquired after CT-guided percutaneous applicator positioning. MRI follow-up was performed 6 weeks and every 3 months post intervention. Primary endpoints were complications, local tumor control and progression-free survival. The median tumor diameter was 6 cm (2-15 cm). Tumor locations included the hepatoduodenal ligament, mesentery, adrenal gland, mesogastrium and local recurrences after rectal or pancreatic cancer. The minimal median dose in the target volume was 11 Gy (4-18 Gy). Minor complications comprised pain and fever (n=6, 32%). Major complications included one hospital death of unknown causes (n=1; 5%). Median follow-up was 7 months (1-16). Four patients (21%) died during the follow-up period. Local tumor control was 76.5% after 6 months and progression-free survival 47% after 6 months. Minimally invasive CT-guided HDR brachytherapy is safe and effective in the palliative treatment of extrahepatic, extrapulmonary secondary malignancies.