Ultrasound-assisted catheter placement in CT-guided HDR brachytherapy for the local ablation of abdominal malignancies: Initial experience

Abstract

Purpose To evaluate the safety and feasibility of sonographically-assisted catheter placement in interstitial high-dose-rate brachytherapy of abdominal malignancies. Materials and Methods In an initial cohort of 12 patients and 16 abdominal tumors (colorectal liver metastases n = 9; renal cell cancer n = 3; hepatocellular carcinoma n = 2; cholangiocellular carcinoma n = 2), initial puncture and catheter placement for CT-guided brachytherapy were performed under sonographic assistance when possible. The interventional procedure was prospectively recorded and in-patient data were collected. All data underwent descriptive statistics and comparative analysis by the Mann-Whitney test. Results In 12 out of 16 lesions (diameter 1.5 – 12.9 cm), initial puncture was successfully achieved under ultrasound guidance without utilization of CT fluoroscopy, yielding a significantly shorter mean total fluoroscopy time (14.5 vs. 105.5 s; p = 0.006). In 8 lesions visibility was rated better in ultrasound than in CT fluoroscopy (p = 0.2). No major or minor complications occurred within 30 days after treatment. Conclusion Ultrasound-assisted catheter placement during interstitial CT-guided brachytherapy of abdominal tumors could improve catheter positioning and reduce radiation exposure for medical staff. Key points Ultrasound-assisted catheter placement in CT-guided brachytherapy is safe and feasible. Ultrasound puncture may improve catheter positioning. Reduced CT fluoroscopy time can significantly help to minimize radiation exposure for medical staff. Citation Format

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

“…Besides our initial experience in 12 patients, no investigation on the utility of ultrasound imaging during puncture and catheter placement in CT-guided interstitial brachytherapy of hepatic or renal masses has been published to date [11]. As a CT data set is mandatory for 3 D treatment planning, our approach aims to prospectively append sonography to our routine procedure of CTF guidance for the insertion of irradiation catheters with subsequent CT scan all in the same room.…”

“…Ablative doses for the PTV were defined as 25 Gy for colorectal carcinoma, 20 Gy for cholangiocarcinoma, and 15 Gy for all other entities according to contemporary literature [13][14][15]. Dose constraints for organs at risk (OAR) have been published previously [11]. After the irradiation, removal of catheters and sheaths was performed with the insertion of a gelatin sponge into the catheter path to prevent post-interventional bleeding.…”

“…Still, precise catheter placement in interstitial brachytherapy (iBT) is just as crucial as applicator positioning in RFA or MWA to achieve successful ablation and depends on good lesion visibility during the intervention [10]. While most interventions today are performed under CT fluoroscopy and iBT furthermore requires a CT-based 3 D irradiation plan, the application of ultrasound imaging might bring additional value as initial studies suggest [11]. When choosing the imaging modality for a desired intervention by axial tomography studies, the utility of sonography is difficult to predict, and hybrid interventional suites are still unavailable in most institutions.…”

Interstitial Brachytherapy for Hepatocellular Carcinoma: Analysis of Prognostic Factors for Overall Survival and Progression-Free Survival and Application of a Risk Stratification Model

“…The procedure of percutaneous brachytherapy has been reported previously [ 7 , 18 , 19 ]. In short, after analgosedation of the patient, irradiation catheters were placed in the target lesions using CT-fluoroscopy or MR guidance by Seldinger's technique.…”