Is high-intensity focused ultrasound (HIFU) an option for neoadjuvant therapy for borderline resectable pancreatic cancer patients? - a systematic review.

Pancreatic cancer is with the poorest prognosis of all common cancers worldwide. Despite the advances in treatment the results are poor throughout the different methods. Pancreatic resection still yields the best outcome. However only a quarter of the patients present at operable stage. HIFU is a noninvasive technique that can be used to treat pancreatic cancer. The aim of this review is to perform a systematic review on the data about the resection rate after HIFU ablation in patients with borderline resectable pancreatic cancer (BRPC) and the impact of this technique over the oncological results. The PubMed and Wanfang databases were searched using keywords: pancreatic cancer, HIFU ablation and high-intensity focused ultrasound. All found articles were reviewed. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standard guidelines. This study was financially supported by 2019 'Kuan-Ren Elite' Program of 2nd Affiliated Hospital of Chongqing Medical University, China (Grant no. KY2019G019). The English database search showed 109 papers, of which 3 met the inclusion criteria. The Wanfang database resulted in 110 papers; however, none met the inclusion criteria of the review. From the included studies 97 patients underwent neoadjuvant HIFU ablation ± chemotherapy. Thirty-four patients reached resection (35.1%). In two patients, residual tumor (R) classification was not reported. R0 resection rate in all reported patients is 30.5% (29/95). R1 resection rate is 3.2% (3/95). HIFU is found to be safe and feasible in locally advanced and metastatic pancreatic cancer with proven downstaging and downsizing effects. Further research on role of HIFU ablation as a neoadjuvant treatment for borderline resectable pancreatic cancer is needed.