A new handheld Raman spectroscopy system, the UltraProbe, is transforming surgical practices by enabling real-time detection of retroperitoneal soft tissue sarcomas (STS) during surgeries. This novel technology, developed at Maisonneuve-Rosemont Hospital in Montreal, Canada, aims to redefine how surgeons approach these complex tumors, potentially improving patient outcomes significantly.
Soft tissue sarcomas represent a rare and diverse group of malignant tumors arising from mesenchymal tissues. Among the various types, retroperitoneal soft tissue sarcomas present unique treatment challenges due to their location and heterogeneous nature. They often require surgical resection as the cornerstone of treatment, but achieving negative margins—ensuring no cancerous cells are left behind—remains pivotal for enhancing survival rates.
The UltraProbe, described extensively in a recent study published on March 14, 2025, utilizes advanced Raman spectroscopy, significantly improving intraoperative tissue analysis. Through Raman scattering, the system analyzes the molecular composition of tissues quickly, aiding surgeons without interrupting the delicate workflow of surgery. Patients with diagnosed STS are evaluated using this device, which has demonstrated exceptionally high sensitivity and specificity—94% and 95%, respectively—for detecting well-differentiated liposarcomas using Raman spectra.
During the study, investigators recruited 30 patients between January 2022 and June 2023, who were undergoing surgery for STS. Of these participants, 24 presented with retroperitoneal soft tissue sarcomas, and six with extremity STS. The research team involved both surgical and pathology experts who employed machine learning to classify Raman spectra accurately. This provided the basis for predicting tissue types—healthy versus affected by STS—effectively.
Findings reveal remarkable classification capabilities of the UltraProbe, detecting well-differentiated liposarcomas with 94% sensitivity, 95% specificity, and 94% accuracy. The ability to differentiate between healthy adipose tissue and various types of liposarcomas is especially important during surgeries where visual assessment alone is challenging. According to the study authors, the integration of this technology enables nearly real-time analysis during operations, facilitating surgeons to make informed decisions on the fly.
Notably, the research accomplished its goals without compromising surgical outcomes. Data compiled show instances of well-differentiated liposarcomas with sensitivities of 90% and 93% for dedifferentiated liposarcomas. The UltraProbe maintained high accuracy levels across different tissue types, achieving 87% sensitivity when classifying non-liposarcoma STS against protein-rich non-adipose tissues.
Dr. Frédéric Leblond, one of the study's contributors, commented on the UltraProbe's design enhancements, stating, "The UltraProbe system has also shown... to acquire tissue spectra almost in real time during surgical resection of STS without disrupting surgical workflow." These advancements are made possible through the UltraProbe's innovative design, which includes 21 multi-mode detection fibers compared to its predecessor's seven, maximizing light collection and enhancing signal quality.
Despite promising results, the current study acknowledges the limitations inherent within small sample sizes. Only 30 patients were recruited, and the diversity of STS subtypes presents challenges for generalized conclusions. Comparisons with previous works where classification for well-differentiated liposarcomas were less favorable bolster the importance of the UltraProbe's advancements. A previous publication noted negative results for such classifications, highlighting the UltraProbe's significant improvement.
The complexity surrounding STS is compounded by their rarity, which necessitates focused studies. These insights indicate Raman spectroscopy could serve as a non-destructive tool, enhancing the accuracy of intraoperative assessments and reducing the number of positive resection margins—a key factor influencing patient survival.
The authors advocate for future studies, calling for the testing of larger cohorts to fortify the findings presented. Future evaluations could also assess the impact of therapies such as radiotherapy on the Raman signal, considering the preliminary findings from neoadjuvant radiotherapy patients were inconclusive.
This study's results represent meaningful progress toward integrating innovative technologies within surgical oncology, with the potential to revolutionize the management of soft tissue sarcomas and improve clinical outcomes.