Emerging intraoperative tumor margin assessment techniques require the development of more complex and reliable organ phantoms to assess the performance of the technique before its translation into the clinic. In this work, electrically conductive tissue-mimicking materials (TMMs) based on fat, water and agar/gelatin were produced with tunable optical properties. The composition of the phantoms allowed for the assessment of tumor margins using diffuse reflectance spectroscopy, as the fat/water ratio served as a discriminating factor between the healthy and malignant tissue. Moreover, the possibility of using polyvinyl alcohol (PVA) or transglutaminase in combination with fat, water and gelatin for developing TMMs was studied. The diffuse spectral response of the developed phantom materials had a good match with the spectral response of porcine muscle and adipose tissue, as well as in vitro human breast tissue. Using the developed recipe, anatomically relevant heterogeneous breast phantoms representing the optical properties of different layers of the human breast were fabricated using 3D-printed molds. These TMMs can be used for further development of phantoms applicable for simulating the realistic breast conserving surgery workflow in order to evaluate the intraoperative optical-based tumor margin assessment techniques during electrosurgery.

Distinguishing the diseased breast tissue from the healthy tissue is a sorely challenging task for the surgeons during breast conserving surgery (BCS) as both tissues own relatively similar visual and haptic characteristics. It has been shown that diffused reflectance spectroscopy (DRS) has the potential to be used as a real-time tumor margin detection technique during BCS. In this research, an electrosurgical knife is equipped with fiber-based DRS sensing to provide the surgeon with real-time oncological guidance during BCS. To prevent overheating of the fibers, they were placed inside quartz tubes which were mounted on the electrosurgical knife. The effect of using quartz tubes and debris formation during electrosurgery on the DRS measurements on porcine tissue was investigated. Furthermore to investigate the performance of the new device, a heterogeneous breast phantom representing optical properties and anatomical shape of the real breast was developed. The new device was then used to cut through the phantom’s layers to assess the performance of the new knife while cutting. Finally, a BCS was performed on the phantom using the new knife without receiving visual and haptic feedback from the tissue. The results show that both using the quartz tubes and the formed debris do not have a significant effect on the DRS output. Moreover, the DRS outputs obtained during cutting the layered phantom showed the transition between the layers clearly, demonstrating that the cutting effect on the phantom tissue does not significantly affect the measurements . The X-ray images from the phantom before and after BCS using the new device confirmed the complete resection of the tumors from the breast phantom. The results indicate that the electrosurgical knife equipped with DRS is a promising technique for simultaneously distinguishing and cutting the tissue, and assessing real-time tumor margins during BCS.