Optically-tracked handheld fluorescence imaging platform for monitoring skin response in the management of soft tissue sarcoma

Abstract

Standard clinical management of extremity soft tissue sarcomas includes surgery with radiation therapy. Wound complications (WCs) arising from treatment may occur due to bacterial infection and tissue breakdown. The ability to detect changes in these parameters during treatment may lead to earlier interventions that mitigate WCs. We describe the use of a new system composed of an autofluorescence imaging device and an optical three-dimensional tracking system to detect and coregister the presence of bacteria with radiation doses. The imaging device visualized erythema using white light and detected bacterial autofluorescence using 405-nm excitation light. Its position was tracked relative to the patient using IR reflective spheres and registration to the computed tomography coordinates. Image coregistration software was developed to spatially overlay radiation treatment plans and dose distributions on the white light and autofluorescence images of the surgical site. We describe the technology, its use in the operating room, and standard operating procedures, as well as demonstrate technical feasibility and safety intraoperatively. This new clinical tool may help identify patients at greater risk of developing WCs and investigate correlations between radiation dose, skin response, and changes in bacterial load as biomarkers associated with WCs.

Autofluorescence imaging for recurrence detection in skin cancer postoperative scars

“…Recent study by Chamma et al illustrates the concept of autofluorescence imaging device to be fully integrated into clinical environment for monitoring skin response in both G and R spectral bands during and after the surgery—radiotherapy combined treatment . The study found red autofluorescence in the surgical site of soft tissue sarcoma originating from the presence of bacteria, further aiming to identify the risks of wound complications related to autofluorescence increase.…”

“…Dermoscopic criteria for skin cancer detection in situ, such as increased vascularity, the presence of pigmentation, ulceration, inflammation and keratinization are related to the appearance of unique autofluorescence features of biological tissue . The method of autofluorescence has already been shown to improve the identification of primary BCC and SCC lesions that may not be visible to the naked eye or dermoscopy .…”

Upcoming imaging concepts and their impact on treatment planning and treatment response in radiation oncology

“…Systems implementing autofluorescence have already been incorporated into devices spanning several clinical applications, including bronchoscopy, colonic polyp evaluation, quantification of colonic inflammation, and intraoperative tumor evaluation [ 14 , 15 ]. Bronchoscopes with autofluorescent capabilities are currently being evaluated in cancer and precancerous lesion detection.…”

“…When discriminating between adenomas from hyperplastic colonic polyps, autofluorescence has shown high sensitivity and specificity at 89 and 81%, respectively. It has been suggested that larger-scale studies need to be conducted to determine the efficacy of autofluorescence in diagnosing colon neoplasms and other inflammatory diseases [ 15 ].…”

“…Advantages of autofluorescence technology include real-time image acquisition, intra-surgical tumor assessment, lack of need for exogenous fluorophores, wide field-of-view, and ability to quantify fluorescence for objective diagnostic information. Limitations of this technology include its shallow depth-of-field, low specificity, high false positive rate, high cost, increased exam time, interference from bodily fluids within surgical field, and changes in tissue autofluorescence secondary to treatment [ 13 – 15 ].…”