Modified low-dose second window indocyanine green technique improves near-infrared fluorescence image-guided dermatofibrosarcoma protuberans resection: A randomized control trial.

Objective: Conventional second window indocyanine green (SWIG) technique has been widely attempted in near-infrared fluorescence (NIRF) imaging for intraoperative navigation of tumor radical resection. Nevertheless, the overuse of indocyanine green (ICG) led to an increased risk of drug lethal allergy and high medical cost. This prospective study was to explore clinical application of modified low-dose SWIG technique in guiding dermatofibrosarcoma protuberans (DFSPs) radical resection. Method: Patients with DFSPs were randomly assigned to control and experimental group. The ICG was injected intravenously 24 h before surgery, at a dose of 3.5 mg/kg in the control group and 25 mg/patient in the experiment group, respectively. Intraoperative NIRF imaging included serial views of gross tumor, tumor bed and cross-sectional specimen. Results: Although NIRF imaging of gross tumor and tumor bed in the experimental group demonstrated similar sensitivity and negative predictive value, the specificity and positive predictive value were obviously higher compared to control group. The tumor-to-background ratios of cross-sectional specimens in the experimental group was significantly higher than in the control group (P = 0.000). Data in both groups displayed that there was a positive correlation of tumor size in cross-sections between integrated histopathologic photomicrographs and NIRF imaging of specimen views (P = 0.000). NIRF imaging of cross-sectional specimens had a significant decrease in time cost, and an increase in the ability of examining more surgical margins (P = 0.000). Conclusion: This is the first study to demonstrate that a low-dose SWIG technique could improve the accuracy of near-infrared fluorescence image-guided dermatofibrosarcoma protuberans resection.Clinical Trial Registration: ChiCTR2100050174; date of registration: August 18, 2021 followed by "retrospectively registered".

A three-dimensional visualization of the full-field surgical region based on thin-slice MRI: A helpful approach for simultaneously guiding tumor resection and perforator flap elevation.

Background: The goal of the current study was to explore the application of preoperative three-dimensional reconstruction (3DR) based on thin-slice magnetic resonance imaging (MRI) in the simultaneous guidance of en bloc tumor resection and adjacent perforator flap elevation. Methods: The prospective cohort included 35 patients diagnosed with either soft tissue sarcoma or squamous cell skin cancer between 2019 and 2021. The preoperative 3DR based on thin-slice MRI illustrated the spatial anatomical relationship among the tumor, underlying muscle, adjacent perforator vessels, and bone around the surgical region. The accuracy of preoperative imaging data was verified by intraoperative vessel dissection and postoperative pathological measurements. Results: Tumor size from 3DR data showed relatively high concordance rates with pathological measurements within the 95% limits of agreement. An average of three perforators (range: 1-7) with a mean diameter of 0.32 cm (range: 0.18-0.74 cm) from the 3DR were present in our study. The average distance between tumor boundary and perforator piercing sites on the 3DR was 2.2 cm (range: 1.2-7.7 cm). The average length of artery perforator coursing along the subcutaneous tissue was 5.8 cm (range: 3.3-25.1 cm). The mean flap harvest time was 55 mins (range: 36-97 min). The average flap size was 92.2 cm2 (range: 32-126 cm2). One perforator flap occurred distal partial necrosis. Conclusion: A thorough understanding of anatomical structures in the surgical region according to full-field 3DR based on thin-slice MRI can improve the performance of radical resection of the tumor and adjacent perforator flap transfer, especially for junior surgeons with a poor experience.