Laparoscopic high‐intensity focused ultrasound for renal tumours: a proof of concept study

Abstract

Study Type – Therapy (case series) Level of Evidence What’s known on the subject? and What does the study add? Renal cancer is increasingly diagnosed when tumours are small and asymptomatic, during routine abdominal imaging. Whilst surgery is an effective and potentially curative option, it carries a significant risk of complications. Recent work suggests that thermally ablative therapies (RFA, cryotherapy, HIFU) may be suitable minimally invasive treatment options in selected patients. The success of extracorporeal HIFU has been limited by the abdominal wall and rib‐cage limiting energy delivery. For this study, a purpose‐built laparoscopic HIFU probe was designed to allow direct application of the transducer to the tumour surface, thus facilitating tumour destruction. Successful and accurate tumour destruction was demonstrated, paving the way for further clinical trials, subject to device modifications. OBJECTIVE To test and establish clinical proof of concept for a laparoscopic high‐intensity focused ultrasound (HIFU) device that facilitates delivery of ultrasound by direct application of a probe to the tumour surface. PATIENTS AND METHODS Twelve patients with renal tumours were treated with laparoscopic HIFU using a newly designed probe inserted via an 18‐mm laparoscopic port. HIFU treatment was targeted at a pre‐defined proportion of the tumour and immediate laparoscopic partial or radical nephrectomy was then performed. RESULTS No tumour ablation was seen in the first five patients which made modifications in the treatment protocol necessary. After this, definite histological evidence of ablation was seen in the remaining seven patients. The ablated zones were within the targeted area in all patients and no intra‐lesional skipping was seen. Subcapsular skipping was seen at the probe–tumour interface in two patients with viable tumour cells seen at microscopy. One patient did not undergo surgical extirpation; subsequent biopsy revealed no viable tumour cells. There were no intraoperative or postoperative complications directly related to HIFU therapy and patients have reached a mean (range) follow‐up of 15 (8–24) months with no evidence of metastatic disease or late complications. CONCLUSIONS Tumour ablation with laparoscopic HIFU is feasible. Homogenous ablation can be achieved with no vital tissue within the targeted zone. The technique is associated with low morbidity and may have a role in the definitive management of small tumours.

Calibration of a Novel, Laparoscopic, 12-mm, Ultrasound, Image-guided, High-intensity Focused Ultrasound Probe for Ablation of Renal Neoplasms

“…Prior studies have described the use of an 18-mm laparoscopic HIFU probe in animal models as well as in phase 1 clinical trials. [18][19][20][21] In our study, we present initial data on a novel, 12-mm, laparoscopic, HIFU probe for renal ablation. The new probe design incorporates high-resolution imaging, 2 confocal transducers for generation of the HIFU beam, a disposable probe tip with an integrated acoustic coupling sheath, and an active cooling water circuit to make the entire procedure efficient.…”

“…Previously studied HIFU probes required an 18-mm trocar in animal and human studies. [18][19][20][21] Orvieto et al 19 used an 18-mm laparoscopic HIFU probe in the porcine model to create lesions in 15 kidneys. Animals were euthanized either 4 days (acute group) or 14 days (subacute group) after the procedure.…”

Surgical and Minimally Invasive Therapies for the Management of the Small Renal Mass

“…A recent study on the use of irreversible electroporation in 42 SRM indicated that at 3-year oncological outcomes may be unfavourable compared to other techniques [66]. Similarly, the treatment efficacy of both percutaneous and laparoscopic HIFU and the safety of the former in the treatment renal lesions have been questioned [67,68]. Overall, evidence is scarce and of low quality for newer energy sources.…”

Robot‐assisted laparoscopic high‐intensity focused ultrasound for focal therapy of prostate: Novel approach

“…HIFU delivers ultrasonic energy to a focal area of tissue with resultant local heat and complete coagulative necrosis. [1][2][3][4] Transrectal HIFU has been proven to be capable of providing long-term local control of prostate cancer.…”

“…HIFU delivers ultrasonic energy to a focal area of tissue with resultant local heat and complete coagulative necrosis. [1][2][3][4] Transrectal HIFU has been proven to be capable of providing long-term local control of prostate cancer. [5][6][7] A novel FDA (510k)-cleared laparoscopic HIFU probe for soft tissue ablation has been developed (Sonatherm laparoscopic probe; SonaCare Medical LLC, Indianapolis, IN, USA; Fig.…”