Outcomes of intravascular brachytherapy for recurrent drug-eluting in-stent restenosis.

OBJECTIVES: To examine the outcomes of vascular brachytherapy (VBT) for recurrent drug-eluting stents (DES) in-stent restenosis (ISR). BACKGROUND: Recurrent DES-ISR can be challenging to treat. VBT has been used with encouraging results. METHODS: We report the long-term outcomes of patients with recurrent DES-ISR treated with VBT between January 2014 and September 2018 at a tertiary care institution. The main outcome was target lesion failure (TLF), defined as the composite of clinically driven target lesion revascularization (TLR), target lesion myocardial infarction (MI), and target lesion-related cardiac death. Cox proportional hazards analysis was performed to identify variables associated with recurrent TLF. RESULTS: During the study period, 116 patients (143 lesions) underwent VBT. Median follow-up was 24.7 (14.5-35.4) months. The incidence of TLR, target-lesion MI, and TLF was 18.9%, 5.6%,and 20.1% at 1 year, and 29.4%, 10.5%, and 32.9% at 2 years.Initial presentation with acute coronary syndrome (ACS) was independently associated with TLF (hazard ratio = 1.975, 95% CI [1.120, 3.485], p = .019). Lesions treated with intravascular ultrasound (IVUS) guidance had a lower incidence of TLR (14.3% vs. 39.6%, log-rank p = .038), and a trend toward lower incidence of TLF (19% vs. 42.6%, log-rank p = .086). CONCLUSIONS: VBT can improve the treatment of recurrent DES-ISR, but TLF occurs in approximately one in three patients at 2 years. Initial presentation with ACS was associated with higher TLF and the use of IVUS with a trend for lower incidence of TLF.

Coronary Intravascular Brachytherapy for Recurrent Coronary Drug-Eluting Stent In-Stent Restenosis: A Systematic Review and Meta-Analysis.

OBJECTIVE: To examine the outcomes with intravascular brachytherapy (IVBT) in recurrent in-stent restenosis (ISR). BACKGROUND: Recurrent ISR can be challenging to treat and IVBT can be used for recurrent ISR but has received limited study. METHODS: We performed a systematic review and meta-analysis of five observational studies, including 917 patients (1014 lesions) with recurrent ISR, defined as having at least two prior ISR episodes with previous treatment with a stent, who underwent treatment with IVBT. Outcomes of interest included target vessel revascularization (TVR), myocardial infarction (MI), and all-cause mortality. RESULTS: During a mean follow-up of 24 ± 7 months, the incidence of TVR was 29.2% (95% CI 18.0-40.4%). The incidence of MI and all-cause mortality were 4.3% (95% CI 1.7%-6.9%) and 7.3% (95% CI 3.2-11.5%), respectively. At one- and two-years after PCI the incidence of TVR was 17.5% (95% CI 13.6%-21.4%) and 26.7% (95% CI 16.6%-36.9%), respectively and the incidence of MI was 3.1% (95% CI 2-4.2%) and 3.9% (95% CI 1-6.8%), respectively. CONCLUSION: Intravascular brachytherapy can be used to treat recurrent ISR, although TVR is needed in approximately one of four patients at two years.

Outcomes With Combined Laser Atherectomy and Intravascular Brachytherapy in Recurrent Drug-Eluting Stent In-Stent Restenosis.

BACKGROUND: Recurrent drug-eluting stents (DES) in-stent restenosis (ISR) can be challenging to treat. The combined use of excimer laser atherectomy (ELCA) and vascular brachytherapy (VBT) for this indication has received limited study. METHODS: We report the long-term outcomes of patients with recurrent DES ISR treated with combined VBT and ELCA from January 2014 to September 2018 at a single institution. Outcomes included target lesion failure (TLF), defined as the composite of clinically driven target lesion revascularization (TLR), target lesion myocardial infarction (MI), and target lesion-related cardiac death. RESULTS: During the study period, 116 patients (143 lesions) underwent VBT, of which 19 patients (19 lesions) underwent combined laser atherectomy and VBT. All procedures were successful without no-reflow or dissection. Two propensity-score matched cohorts (ELCA + VBT (n = 18) vs. VBT only (n = 18)) were compared. During a median follow-up of 25.5 (14.5-40) months, there was no difference in the incidence of TLF (38.9% vs. 38.9%, log-rank p = 0.688), target-lesion MI (5.6% vs. 5.6%, log-rank p = 0.915), or TLR (38.9% vs. 33.3%, log-rank p = 0.933) between both groups. There was no cardiac death related to the target lesion. CONCLUSIONS: When compared with VBT alone for the treatment of resistant DES ISR, combined use of ELCA and brachytherapy is associated with comparable long-term outcomes. ELCA should be considered in ISR lesions due to stent underexpansion.

The birth, decline, and contemporary re-emergence of endovascular brachytherapy for prevention of in-stent restenosis.

Despite the advent of drug-eluting stents and dual antiplatelet therapy in the interventional management of cardiovascular disease, restenosis rates remain high with significant sequelae. Endovascular brachytherapy-popular in the 1990s and early 2000s-has recently resurfaced as a cost-effective treatment option. In this work, we outline the history of endovascular brachytherapy starting with its earliest promise in the 1990s. We discuss the development of drug-eluting stents and dual antiplatelet strategies and their impact on the perceived benefit of endovascular brachytherapy. For the contemporary era, we propose novel roles for endovascular brachytherapy in complex coronary artery disease and in high-risk patients managed with drug-eluting stents. We discuss the impetus for reducing the requirement and duration of dual antiplatelet therapy using endovascular brachytherapy. We also review innovative opportunities for endovascular brachytherapy after bare-metal stent placement in both coronary and noncoronary territories and offer economic arguments in favor of endovascular brachytherapy. Trials of endovascular brachytherapy in these regimes are merited.

Impact of Intravascular Brachytherapy on Patient-Reported Outcomes in Patients with Coronary Artery Disease.

BACKGROUND: Intravascular brachytherapy (VBT) is an established treatment for the management of in-stent restenosis (ISR). However, whether VBT is associated with improved patient reported outcomes unknown. METHODS: We evaluated 51 consecutive patients undergoing VBT in one or more coronary arteries from January 2018 to September 2019. Data on baseline characteristics, procedural outcomes and adverse events were obtained. All patients completed the Seattle Angina Questionnaire - 7 (SAQ-7) form before and after VBT at 1 month and 6 months. RESULTS: The mean age was 69 ± 9 years and 29 (57%) of patients were males. Procedural success was 94.1%. The mean summary SAQ-7 score improved significantly (53.2 ± 21 vs. 83 ± 19, p < .001) at 30-days. The median Quality of Life (QoL) component of SAQ-7 score was 31.3 (Interquartile Range [IQR]: 18.8, 62.5) and improved to 82.5 (IQR: 62.5, 100), p < .001 at 30 days and 87.5 [IQR: 75, 100), p < .001 at last follow up. Likewise, the median angina frequency component of the SQL-7 score pre-VBT was 55 (IQR: 45, 80) and improved significantly to 90 (IQR: 60, 100) at 30-days, p < .001 and 100 [IQR: 68.8, 100], p = .02 at last follow up. Lastly, the median activity component of the SAQ-7 score improved from 83.3 (IQR: 60-100) to 100 (IQR: 83, 100), p = .01 at 30-days. Thus, results were evident as early as 1 month and sustained at median follow up of 17 months. CONCLUSION: VBT is associated with improvement in patient reported outcome measures at short term and long term follow up.

Effectiveness Evaluation of Skin Covers against Intravascular Brachytherapy Sources Using VARSKIN3 Code.

BACKGROUND AND OBJECTIVE: The most common intravascular brachytherapy sources include (32)P, (188)Re, (106)Rh and (90)Sr/(90)Y. In this research, skin absorbed dose for different covering materials in dealing with these sources were evaluated and the best covering material for skin protection and reduction of absorbed dose by radiation staff was recognized and recommended. METHOD: Four materials including polyethylene, cotton and two different kinds of plastic were proposed as skin covers and skin absorbed dose at different depths for each kind of the materials was calculated separately using the VARSKIN3 code. RESULTS: The results suggested that for all sources, skin absorbed dose was minimized when using polyethylene. Considering this material as skin cover, maximum and minimum doses at skin surface were related to (90)Sr/(90)Y and (106)Rh, respectively. CONCLUSION: polyethylene was found the most effective cover in reducing skin dose and protecting the skin. Furthermore, proper agreement between the results of VARSKIN3 and other experimental measurements indicated that VRASKIN3 is a powerful tool for skin dose calculations when working with beta emitter sources. Therefore, it can be utilized in dealing with the issue of radiation protection.

Verification and uniformity control of doses for Sr/Y intravascular brachytherapy sources using radiochromic film dosimetry.

Intravascular brachytherapy (IVBT) is a useful treatment modality for the recurrence of in-stent restenosis following drug-eluting stents (DES) or IVBT failure. The objective of this study was to measure the dose rate of (90)Sr/(90)Y IVBT sources for comparison with that given by the manufacturer and to control the dose uniformities of these sources along the source axis. The dose rates of (90)Sr/(90)Y beta sources were measured with a radiochromic film in a custom-made phantom. The films for calibration were irradiated using (60)Co photon beams. The results for the three sources were 4.5%, 2.3%, and 3.5% higher than the corresponding certificate values. Maximum and minimum of the dose rates varied within +/-10% of those at source center; and maximum dose discrepancy for the first (90)Sr/(90)Y source train was 8.2%; for the second source train, 7.1%; and for the third source train, 5.1%. Our study showed that the dose rates given by the manufacturer for the three (90)Sr/(90)Y IVBT sources were reliable and dose uniformities were within +/-10% along two thirds of the treatment length.

Conceptual Source Design and Dosimetric Feasibility Study for Intravascular Treatment: A Proposal for Intensity Modulated Brachytherapy / 대한방사선종양학회지

PURPOSE: To propose a conceptual design of a novel source for intensity modulated brachytherapy. MATERIALS AND METHODS: The source design incorporates both radioactive and shielding materials (stainless steel or tungsten), to provide an asymmetric dose intensity in the azimuthal direction. The intensity modulated intravascular brachytherapy was performed by combining a series of dwell positions and times, distributed along the azimuthal coordinates. Two simple designs for the beta-emitting sources, with similar physical dimensions to a 90Sr/Y Novoste Beat-Cath source, were considered in the dosimetric feasibility study. In the first design, the radioactive and materials each occupy half of the cylinder and in the second, the radioactive material occupies only a quater of the cylinder. The radial and azimuthal dose distributions around each source were calculated using the MCNP Monte Carlo code. RESULTS: The preliminary hypothetical simulation and optimization results demonstrated the 87% difference between the maximum and minimum doses to the lumen wall, due to off-centering of the radiation source, could be reduced to less than 7% by optimizing the azimuthal dwell positions and times of the partially shielded intravascular brachytherapy sources. CONCLUSION: The novel brachytherapy source design, and conceptual source delivery system, proposed in this study show promising dosimetric characteristics for the realization of intensity modulated brachytherapy in intravascular treatment. Further development of this concept will center on building a delivery system that can precisely control the angular motion of a radiation source in a small-diameter catheter.

Short-term results of cutting balloon and intravascular brachytherapy for the treatment of coronary in-stent restenosis / 中国临床药理学与治疗学

0.05); the levels of LL, LI, RRS in CBA group and CBA+IBT group were significantly lower than those in control group(P