Clinical considerations of bleomycin based electrochemotherapy with variable electrode geometry electrodes for inoperable, deep-seated soft tissue sarcomas

Abstract

The aim of the current prospective pilot study exclusively for deep-seated soft tissue sarcomas (STS) was to evaluate efficacy and safety of bleomycin-based ECT using VEG (variable electrode geometry) electrodes. During a 2-year period, seven surgically inoperable STSs were treated at the University of Szeged, Department of Surgery in Hungary. Electrode placement was determined by software planning using preoperative imaging (CT/MRI) and intraoperative ultrasound. Intravenous bleomycin (15.000 IU/m2) was administered 8 min before first pulse generation which lasted up to 40 min. Tumour response was evaluated through CT/MRI 2 months after treatment as per RECIST v.1.1. Five male- and 2 female patients were treated with fibromyxoid sarcoma (n = 2), epitheloid sarcoma (n = 3), liposarcoma (n = 1) and myofibroblastic sarcoma (n = 1) with median age of 54 years (49–88). Median tumour diameter, tumour volume and tumour depth was 5.9 cm (3.7–22.5), 131.13 cm3 (35.6–2456.22) and 6.18 cm (3.74–18.18), respectively. Median operative time was 75 min (35–180), median hospital stay 2 days (2–20). Two month follow-up confirmed partial response in 5 patients, while stable disease in 1 patient, and progressive disease in 1 case as per RECIST v.1.1. Grade 2 ulceration was experienced in four cases, and a transient left musculus quadriceps femoris plegia occured in one patient. Local control of deep-seated STSs with BLM-based VEG ECT holds a promising perspective and our results may serve as a practical guide for further investigation and treatment planning.