Indocyanine Green as a Navigational Adjunct for Laparoscopic Ablation of Liver Tumors.

BACKGROUND: Minimally invasive operative approaches for resection and thermal ablation (eg, microwave, radiofrequency) of hepatocellular carcinoma (HCC) have been successfully implemented over the last two decades, although identifying tumors can be challenging. Successfully performing laparoscopic ablation requires real-time visualization and ultrasonography skills for direct placement of the ablation probe. METHODS: In this study, we introduce a novel adjunct to ultrasound imaging for tumors located near or on the surface of the liver via intravenous delivery of indocyanine green (ICG) dye. Non-resectable lesion(s) not amenable to percutaneous ablation were considered for laparoscopic microwave ablation. Each patient initially received a dose of .3125 mg ICG via peripheral IV. RESULTS: A total of 17 patients were included. There was brisk uptake of ICG throughout the liver parenchyma in under 2 minutes in 15 of 17 patients; the remaining 2 required a second dose of ICG. In 14 cases, a hypo-fluorescent perfusion pattern in the tumor was clearly identified. DISCUSSION: Integrating ICG and fluorescent imaging provides a complementary adjunct to ultrasound in identifying HCC nodules. While previous applications of ICG typically require injections several days prior to surgery or segmental injections, this study demonstrates a novel real-time application of ICG to aid surgeons with various experiences in laparoscopic-assisted ablation procedures for HCC.

Navigation Improves Tumor Ablation Performance: Results From a Novel Liver Tumor Simulator Study.

BACKGROUND: The efficacy of microwave ablation in treating hepatic tumors requires advanced ultrasound skills. Failure of proper technique has the potential for either under- or over-treatment and possible harm to the patient. Emprint SX™ navigation provides surgeons with intra-operative, real-time navigation through augmented reality localization of the ablation antenna and the expected ablation zone. We hypothesize that incorporating this technology leads to improved targeting and optimizes ablation coverage. This study utilizes a simulated model to evaluate ablation outcomes using Emprint SX™ navigation vs standard ultrasound. METHODS: Surgical residents and faculty were recruited from a single institution. Using a novel tumor ablation simulator, participants performed ablations via 2 modes: standard ultrasound guidance (STD) and Emprint SX™ navigation (NAV). Primary outcome was the percentage of under-ablation. Secondary outcomes included percentage of over-ablation, time to complete trial, and number of attempts to position antenna. RESULTS: 281 trials were performed by fifteen participants, with 47% female and 60% novice ablationists. Under-ablation volume decreased by a mean of 16.3% (SEM ±12.9, P < .001) with NAV compared to STD. Over-ablation volume decreased by a mean of 14.0% (±8.2, P < .001). NAV time was faster by a mean of 32 seconds (±24.9, P < .001) and involved fewer antenna placement attempts by a mean of 1.3 (±1.0, P < .001). For novice ablationists, all outcomes were improved with NAV and novices saw larger improvements compared to experienced ablationists (P = .018). DISCUSSION: In a simulated model, NAV improves ablation efficacy and efficiency, with novices gaining the greatest benefit over standard ultrasound.

Comparison of butterfly volumetric modulated arc therapy to full arc with or without deep inspiration breath hold for the treatment of mediastinal lymphoma.

PURPOSE: Radiotherapy is an effective treatment for mediastinal lymphoma but induces late effects including cardiac toxicity and secondary breast and lung cancer. Therefore reducing the dose to these organs is vital. We compared full arc volumetric modulated arc therapy (F-VMAT) against limited angle 'Butterfly' VMAT (B-VMAT) on free breathing (FB) and deep inspiration breath-hold (DIBH) computed tomography scans. The aim was to assess the benefits of B-VMAT over F-VMAT and to establish if the addition of DIBH results is a cumulative benefit. MATERIALS AND METHODS: F-VMAT and B-VMAT plans were calculated for 20 consecutive patients (15 females) with mediastinal lymphoma on both FB and DIBH scans. The planning target volume V95% was kept comparable between all plans while reducing organ doses as much as possible. RESULTS: B-VMAT significantly reduced low lung doses (V5-10), while F-VMAT was better for higher lung doses (V20-30). DIBH further improved lung doses for both types of plans. DIBH B-VMAT produced the lowest mean lung dose. With FB, heart doses were slightly higher for B-VMAT but the maximum difference was small (0.8% for V20) and only statistically significant for V10-20. The mean heart dose increased by only 0.1 Gy. The addition of DIBH however significantly reduced heart doses. While DIBH F-VMAT had the lowest heart doses, the difference was small compared with DIBH B-VMAT. B-VMAT significantly reduced breast V4 while DIBH reduced the V10. CONCLUSION: B-VMAT and DIBH are both effective in reducing organ doses and the dosimetric benefit is additive for some parameters and complementary for others.