{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Sebek J"],"funding":["NIBIB NIH HHS"],"pagination":["584-594"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC9717487"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["39(1)"],"pubmed_abstract":["<h4>Purpose</h4>Bio-effects following thermal treatments are a function of the achieved temperature profile in tissue, which can be estimated across tumor volumes with real-time MRI thermometry (MRIT). Here, we report on expansion of a previously developed small-animal microwave hyperthermia system integrated with MRIT for delivering thermal ablation to subcutaneously implanted tumors in mice.<h4>Methods</h4>Computational models were employed to assess suitability of the 2.45 GHz microwave applicators for delivering ablation to subcutaneous tumor targets in mice. Phantoms and <i>ex-vivo</i> tissues were heated to temperatures in the range 47-67 °C with custom-made microwave applicators for validating MRIT with the proton resonance frequency shift method against fiberoptic thermometry. HAC15 tumors implanted in nude mice (<i>n</i> = 6) were ablated <i>in vivo</i> and monitored with MRIT in multiple planes. One day post ablation, animals were euthanized, and excised tumors were processed for viability assessment.<h4>Results</h4>Average absolute error between temperatures from fiberoptic sensors and MRIT was 0.6 °C across all <i>ex-vivo</i> ablations. During <i>in-vivo</i> experiments, tumors with volumes ranging between 5.4-35.9 mm<sup>3</sup> (mean 14.2 mm<sup>3</sup>) were ablated (duration: 103-150 s) to achieve 55 °C at the tumor boundary. Thermal doses ≥240 CEM43 were achieved across 90.7-98.0% of tumor volumes for four cases. Ablations were incomplete for remaining cases, attributed to motion-affected thermometry. Thermal dose-based ablative tumor coverage agreed with viability assessment of excised tumors.<h4>Conclusions</h4>We have developed a system for delivering microwave ablation to subcutaneous tumors in small animals under MRIT guidance and demonstrated its performance <i>in</i>-<i>vivo</i>."],"journal":["International journal of hyperthermia : the official journal of European Society for Hyperthermic Oncology, North American Hyperthermia Group"],"pubmed_title":["System for delivering microwave ablation to subcutaneous tumors in small-animals under high-field MRI thermometry guidance."],"pmcid":["PMC9717487"],"funding_grant_id":["R01 EB028848"],"pubmed_authors":["Basel MT","Faridi P","Zeinali N","Timmerman SA","Pyle M","Prakash P","Sebek J","O'Halloran M","Mali I","Bossmann SH","Payne M","Chamani F","Shrestha TB","Dennedy MC"],"additional_accession":[]},"is_claimable":false,"name":"System for delivering microwave ablation to subcutaneous tumors in small-animals under high-field MRI thermometry guidance.","description":"<h4>Purpose</h4>Bio-effects following thermal treatments are a function of the achieved temperature profile in tissue, which can be estimated across tumor volumes with real-time MRI thermometry (MRIT). Here, we report on expansion of a previously developed small-animal microwave hyperthermia system integrated with MRIT for delivering thermal ablation to subcutaneously implanted tumors in mice.<h4>Methods</h4>Computational models were employed to assess suitability of the 2.45 GHz microwave applicators for delivering ablation to subcutaneous tumor targets in mice. Phantoms and <i>ex-vivo</i> tissues were heated to temperatures in the range 47-67 °C with custom-made microwave applicators for validating MRIT with the proton resonance frequency shift method against fiberoptic thermometry. HAC15 tumors implanted in nude mice (<i>n</i> = 6) were ablated <i>in vivo</i> and monitored with MRIT in multiple planes. One day post ablation, animals were euthanized, and excised tumors were processed for viability assessment.<h4>Results</h4>Average absolute error between temperatures from fiberoptic sensors and MRIT was 0.6 °C across all <i>ex-vivo</i> ablations. During <i>in-vivo</i> experiments, tumors with volumes ranging between 5.4-35.9 mm<sup>3</sup> (mean 14.2 mm<sup>3</sup>) were ablated (duration: 103-150 s) to achieve 55 °C at the tumor boundary. Thermal doses ≥240 CEM43 were achieved across 90.7-98.0% of tumor volumes for four cases. Ablations were incomplete for remaining cases, attributed to motion-affected thermometry. Thermal dose-based ablative tumor coverage agreed with viability assessment of excised tumors.<h4>Conclusions</h4>We have developed a system for delivering microwave ablation to subcutaneous tumors in small animals under MRIT guidance and demonstrated its performance <i>in</i>-<i>vivo</i>.","dates":{"release":"2022-01-01T00:00:00Z","publication":"2022","modification":"2025-04-19T04:42:44.675Z","creation":"2025-04-19T04:42:44.675Z"},"accession":"S-EPMC9717487","cross_references":{"pubmed":["35435078"],"doi":["10.1080/02656736.2022.2061727"]}}