Woodrum, David

Abstract Minimally invasive image-guided tumor ablation techniques have been established as safe, effective methods to treat a variety of unresectable soft tissue tumors. Standard thermal ablation methods include radiofrequency ablation, microwave ablation, and cryoablation. However, newer non-thermal and/or non-invasive ablation techniques are now available as alternative options to treat soft tissue tumors, particularly those that are near critical structures or otherwise susceptible to thermal energy sink effects. The 4 types of emerging ablation techniques discussed in this review are as follows: irreversible electroporation, pulsed electric field, high-intensity focused ultrasound, and histotripsy. While the clinical trials evaluating the safety and efficacy of these ablation techniques are in their early stages, initial results are promising in the treatment of various cancers at different stages. These include potential synergistic effects when combined with chemotherapy and immunotherapy.

Introduction: Ureteral stents are widely used in the specialty of urology to preserve renal function and provide ureteral patency in cases of urolithiasis, strictures, malignancy, and trauma. This paper presents a novel application of prophylactic ureteral stents deployed under MRI-guidance for ureteral protection in the setting of in-bore salvage cryoablation therapy for recurrent and metastatic prostate cancer. This is the first known case series of ureteral stent placement using near real-time MRI. Materials and Methods: A retrospective chart review was performed for all patients who underwent MRI-guided ureteral stent placement prior to in-bore cryoablation therapy from 2021 to 2022. Each case was managed by an interdisciplinary team of urologists and interventional radiologists. Preoperative and postoperative data were collected for descriptive analysis. Physics safety testing was conducted on the cystoscope and viewing apparatus prior to its implementation for stent deployment. Results: A total of seven males, mean age 73.4 years (range 65–81), underwent successful prophylactic, cystoscopic MRI-guided ureteral stent placement prior to cryoablation therapy of their prostate cancer. No intraoperative complications occurred. A Grade 2 postoperative complication of pyelonephritis and gross hematuria following stent removal occurred in one case. The majority of patients were discharged the same day as their procedure. Conclusions: This case series demonstrates the feasibility of in-bore cystoscopic aided MRI guidance for ureteral stent placement. Ureteral stents can be used to increase the safety margin of complex cryoablation treatments close to the ureter. Furthermore, by following the meticulous MRI safety protocols established by MRI facility safety design guidelines, MRI conditional tools can aid therapy in the burgeoning interventional MRI space.

Objective To define the natural history, patterns of recurrence and treatment modalities for local prostate cancer (PCa) recurrence following radical prostatectomy (RP) and radiation therapy (RT), and to investigate factors that could predict metastasis‐free survival (MFS) in this unique patient population. Methods We queried a prospectively maintained PCa registry to identify men developing in‐field recurrence (IFR) following RP and RT from 2008 to 2021 at a single institution. IFR was defined as biopsy‐proven recurrent PCa or the presence of persistent positron emission tomography‐avid lesions in the prior radiation field without evidence of metastasis. Cox regression was conducted to determine predictors of MFS. Kaplan–Meier methods were used to calculate MFS, cancer‐specific survival (CSS) and overall survival (OS) for patients in three primary therapy categories: cryoablation, androgen deprivation therapy (ADT) alone, and surveillance. Results Of 4575 patients from our registry, 108 (2.3%) with IFR were identified. The median (interquartile range [IQR]) time to IFR from salvage treatment was 78 (50–126) months. A total of 29 patients (26%) were managed with cryoablation, 23 (21%) with ADT, and 28 (25%) with surveillance. The median (IQR) follow‐up was 76 (48–100) months. There were no statistically significant differences in MFS ( P = 0.67) or OS ( P = 0.07) among the three primary treatment cohorts. Patients treated with ADT or cryoablation had longer CSS compared to patients managed with surveillance ( P = 0.047). Conclusions We found that IFR may present years after completion of primary treatment for PCa. While curative management strategies may be attempted, local and distant metastatic recurrence is common and often requires systemic therapy.

BACKGROUNDPlatelet (PLT) transfusion before interventional radiology procedures is commonly performed in patients with thrombocytopenia. However, it is unclear if PLT transfusion is associated with reduced bleeding complications.STUDY DESIGN AND METHODSThis is a retrospective cohort study of adults undergoing interventional radiology procedures between January 1, 2009, and December 31, 2013. Baseline characteristics, coagulation variables, transfusion requirements, and procedural details were evaluated. Propensity‐matched analyses were used to assess relationships between PLT transfusions and the outcomes of interest, including a primary outcome of periprocedural red blood cell (RBC) transfusion during the procedure or within the first 24 hours after procedure.RESULTSA total of 18,204 participants met inclusion criteria, and 2060 (11.3%) had a PLT count of not more than 100 × 109/L before their procedure. Of these, 203 patients (9.9) received preprocedural PLTs. There was no significant difference in RBC requirements between those receiving or not receiving preprocedural PLTs in propensity‐matched analysis (odds ratio [OR], 1.45; 95% confidence interval [CI], 0.95‐2.21; p = 0.085). PLT transfusion was associated with increased rates of intensive care unit admission (OR [95% CI], 1.57 [1.07‐2.32]; p = 0.022).CONCLUSIONIn patients with thrombocytopenia undergoing interventional radiology procedures, preprocedural PLT transfusion was not associated with reduced periprocedural RBC requirements. These findings suggest that prophylactic PLT transfusions are not warranted in nonbleeding patients with preprocedural PLT counts exceeding 50 × 109/L. Future clinical trials are needed to further define relationships between prophylactic PLT administration and bleeding complications, especially at more severe levels of thrombocytopenia or in the presence of PLT dysfunction.