Synergizing Thermal Ablation Modalities with Immunotherapy: Enough to Induce Systemic Antitumoral Immunity?

Thermal ablation modalities (cryoablation, radiofrequency ablation, and microwave ablation) have long been noted to occasionally induce a systemic antitumoral response. With the widespread use of checkpoint inhibitors, there is a significant interest in whether thermal ablation can promote immune system tumor recognition and increase checkpoint inhibitor response rates. In this review, we examine the current state of preclinical and clinical evidence examining the combination of checkpoint inhibitor therapies and thermal ablation modalities as well as discuss remaining the unanswered questions and directions for future research.

Virtual reading room for diagnostic radiology.

RATIONALE AND OBJECTIVE: To assess the perceptions of radiology staff regarding the role of virtual reality technology in diagnostic radiology after using a virtual reality (VR) headset METHODS: Participants completed a pre-study questionnaire assessing their familiarity with VR technology and its potential role in radiology. Using a VR headset, participants entered a simulated reading room (SieVRt, Luxsonic Technologies) with three large virtual monitors. They were able to view plain radiographs, ultrasound, CT, and MRI images and pull up and compare multiple images simultaneously. They then completed a post-study questionnaire to re-assess their perception about the role of VR technology for diagnostic radiology. RESULTS: Fifteen participants were enrolled, with 33.3 % attendings, 40 % fellows, and 26.7 % residents. Pre-study, 60 % reported they were "not familiar" with VR technology and 66.7 % had never used it. On a 1 to 5 scale, the median perceived likelihood of VR having a role in radiology significantly increased from 3 (IQR 2-3) pre-study to 4 (IQR 4-4) post-study; p = 0.014. Image contrast and resolution were adequate according to most participants, with 53.3 % strongly agreeing and 33.3 % agreeing. The headset was comfortable for 73.3 % and did not induce nausea in any participant. Confidence in VR technology improved after using the headset for 80 %. According to 80 %, future VR technology could replace a PACS workstation. DISCUSSION: Radiologists' perception regarding the role of virtual reality in diagnostic interpretation improves after a hands-on trial of the technology, and VR has the potential to replace a traditional workstation in certain situations.

Percutaneous Intratumoral Immunoadjuvant Gel Increases the Abscopal Effect of Cryoablation for Checkpoint Inhibitor Resistant Cancer.

Percutaneous cryoablation is a common clinical therapy for metastatic and primary cancer. There are rare clinical reports of cryoablation inducing regression of distant metastases, known as the "abscopal" effect. Intratumoral immunoadjuvants may be able to augment the abscopal rate of cryoablation, but existing intratumoral therapies suffer from the need for frequent injections and inability to confirm target delivery, leading to poor clinical trial outcomes. To address these shortcomings, an injectable thermoresponsive gel-based controlled release formulation is developed for the FDA-approved Toll-like-receptor 7 (TLR7) agonist imiquimod ("Imigel") that forms a tumor-resident depot upon injection and contains a contrast agent for visualization under computed tomography (CT). The poly-lactic-co-glycolic acid-polyethylene glycol-poly-lactic-co-glycolic acid (PLGA-PEG-PLGA)-based amphiphilic copolymer gel's underlying micellar nature enables high drug concentration and a logarithmic release profile that is additive with the neo-antigen release from cryoablation, requiring only a single injection. Rheological testing demonstrated the thermoresponsive increase in viscosity at body temperature and radio-opacity via microCT. Its ability to significantly augment the abscopal rate of cryoablation is demonstrated in otherwise immunotherapy resistant metastatic tumors in two aggressive colorectal and breast cancer dual tumor models with an all or nothing response, responders generally demonstrating complete regression of bilateral tumors in 90-day survival studies.