A Randomized Pilot Trial of Virtual Reality Surgical Planning for Head and Neck Oncologic Resection

by Kathryn L. Nunes, BA, Victor Jegede, BS, Derek S. Mann, BS, Pablo Llerena, BS, Richard Wu, MD, Leonard Estephan, MD, Ayan Kumar, MD, Sana Siddiqui, MD, Raphael Banoub, MD, Scott W. Keith, PhD, Madalina Tuluc, MD, Arielle G. Thal, MD, Richard Goldman, MD, Leila J. Mady, MD, PhD, MPH, David M. Cognetti, MD, Adam J. Luginbuhl, MD, Michael C. Topf, MD, and Joseph M. Curry, MD •

Figure 2: VR Case Enhancement Protocol case. Screen captures of the patient’s scan and virtual resection (top). Images of the surgical specimen on the scanner and in EinScan (middle). 3D renderings of the surgical specimen in 3D slicer with and without markings (bottom).

The pre-operative case was uploaded and completed for 17/18 patients randomized to VRCEP. Three-dimensional specimens were loaded and marked by surgeons and pathologists for all 17 cases with completed pre-operative planning. Results are displayed in Figure 2.

Surgeon task-load burden

Surgeon task load burden was quantified using NASA-TLX. In the VRCEP and SOC cohorts, respectively, there was no significant difference in mean score (45.8 versus 53.0) or in any subcategory (p > 0.05). For both cohorts, the lowest scores were in the frustration subcategory and the highest were in mental demand. Following stratification by surgeon, there remained no significant differences in overall or subcategory scores.

Surgeon assessment survey—benefit of VRCEP

Surgeons assessed the impact of VR. Surgeons agreed that VRCEP was helpful and easily integrated in 16/16 cases. VR contributed to a change of plan before surgery in 31% of cases. Of those with pre-operative approach changes, only one included an intra-operative plan change. Overall, 3/17 cases in the VRCEP group had an intra-operative change in plan compared to 6/17 SOC cases (p = 0.44). In five cases, surgeons qualitatively commented on the somewhat/marginal helpfulness of VR. In all five comments, surgeons noted the benefit was limited by the technology’s level of detail, adequate segmentation, and differentiation of soft tissue. Surgeons noted the benefits of being able to view pre-operative imaging obliquely in addition to standard coronal, axial, and sagittal slicing.

Margin event rates and score

The impact of VR on margins was analyzed by comparing positive frozen margin, positive final margin, DDM, and composite metrics to SOC. The average MES per case was significantly lower in the VRCEP versus SOC cohorts (0.29 versus 0.94, p = 0.014). The VRCEP had a lower, though not statistically significant, positive frozen margin rate (18.8% versus 38.5%, p = 0.41) and positive final margin rate (5.9% versus 20.0%, p = 0.32) compared to SOC. The DDM rate was significantly lower in the VRCEP cohort compared to SOC (10.0% versus [58.8%], p = 0.032). There was a significant difference in MER in the VRCEP cohort (11.6% versus 40.0%, p = 0.0041). With the exclusion of the “expected” DDMs where specimen-driven margins were not feasible, the uDDM rate was still significantly lower in the VRCEP versus SOC cohort (10% versus 57.1%, p = 0.03). There, MER remained significantly reduced in the VRCEP cohort (11.6% versus 35.6%, p = 0.0047).

CONCLUSION

In this prospective trial, VRCEP was a feasible addition to a range of head and neck surgeries. It was associated with an improved margin event rate and score with no measured impact on surgeon TLB. Further investigation is warranted to evaluate the impact of similar technologies for oncologic surgical planning, the MER and MES as endpoints for surgical trials, and metrics of TLB.   

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