Toward Precise Osteotomies: A Coarse-to-Fine 3D Cut Plane Planning Method for Image-Guided Pelvis Tumor Resection Surgery

Automated elaborate resection planning for bone tumor surgery

PURPOSE

Planning for bone tumor resection surgery is a technically demanding and time-consuming task, reliant on manual positioning of planar cuts in a virtual space. More elaborate cutting approaches may be possible through the use of surgical robots or patient-specific instruments; however, methods for preparing such a resection plan must be developed.

METHODS

This work describes an automated approach for generating conformal bone tumor resection plans, where the resection geometry is defined by the convex hull of the tumor, and a focal point. The resection geometry is optimized using particle swarm, where the volume of healthy bone collaterally resected with the tumor is minimized. The approach was compared to manually prepared planar resection plans from an experienced surgeon for 20 tumor cases.

RESULTS

It was found that algorithm-generated hull-type resections greatly reduced the volume of collaterally resected healthy bone. The hull-type resections resulted in statistically significant improvements compared to the manual approach (paired t test, p < 0.001).

CONCLUSIONS

The described approach has potential to improve patient outcomes by reducing the volume of healthy bone collaterally resected with the tumor and preserving nearby critical anatomy.

Application of near-infrared fluorescence imaging in the accurate assessment of surgical margins during breast-conserving surgery

Objective

To evaluate the feasibility and accuracy of near-infrared fluorescence imaging technology for assessing margins during breast-conserving surgery for breast cancer.

Methods

Forty-three breast cancer patients who received surgical treatment at Yijishan Hospital of Wannan Medical College were selected. Before the operation, the patients were administered with an indocyanine green injection of 0.5 mg/kg intravenously 2 h before operation. During and after the operation, all patients underwent surgical margin monitoring with the near-infrared fluorescence imaging system for fluorescence imaging and acquisition of images and quantitative fluorescence intensity. During the operation, the patients’ tissue specimens were collected on the upper, lower, inner, outer, apical, and basal sides of the fluorescence boundary of the isolated lesions for pathological examination.

Results

Fluorescence was detected in the primary tumor in all patients. The average fluorescence intensities of tumor tissue, peritumoral tissue, and normal tissue were 219.41 ± 32.81, 143.35 ± 17.37, and 105.77 ± 17.79 arbitrary units, respectively (P < 0.05, t test). The signal-to-background ratio of tumor to peritumor tissue and normal tissue was 1.54 ± 0.20 and 2.14 ± 0.60, respectively (P < 0.05, t test). Abnormal indocyanine green fluorescence was detected in 11.6% patients (5/43), including 3 patients with residual infiltrating carcinoma and 2 patients with adenosis with ductal dilatation.

Conclusion

This study confirms the high sensitivity and specificity of near-infrared fluorescence imaging technology for breast-conserving surgery margin assessment. Near-infrared fluorescence imaging technology can be used as an intraoperative diagnosis and treatment tool to accurately determine the surgical margin and is of important guiding value in breast-conserving surgery for breast cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02827-4.

Biomechanics optimisation of the laminoplasty groove size and position: A numerical study

BACKGROUND

This study is focused on the opening technique of the cervical vertebrae during laminoplasty which serves to substantially reduce the most severe adverse effects of the simple resection of posterior vertebral elements. This computational study aims to clarify by an optimisation approach what shape and position upon the lamina the groove should have.

METHODS

The computational model was developed in the computational software COMSOL Multiphysics 5.6a based on a computer tomography data obtained from the C4 vertebra. For finding the optimal minimum or maximum of a function (surface), optimisation algorithms are developed following the Nelder-Mead algorithm.

RESULTS

The reaction-opening force increases with a decreasing groove radius and an increasing position from the vertebra body. The created area increases with a decreasing groove radius and a decreasing position. As the opening happens mostly only above the groove, the opening area increases only in this location. Moreover, the von Mises stress peak value is almost twice as large as in the case of maximization of the opening area, which might result in breaking of the lamina as the thickness of the lamina would be reduced to its minimum.

CONCLUSION

The groove radius and position can affect the opening force and the opening area in case of double door laminoplasty. The opening force is highly influenced by the groove position and radius. The best position for placing the groove is in the middle of the lamina and the radius of the groove should be as large as possible.

Automatic framework for patient-specific modelling of tumour resection-induced brain shift

Our motivation is to enable non-biomechanical engineering specialists to use sophisticated biomechanical models in the clinic to predict tumour resection-induced brain shift, and subsequently know the location of the residual tumour and its boundary. To achieve this goal, we developed a framework for automatically generating and solving patient-specific biomechanical models of the brain. This framework automatically determines patient-specific brain geometry from MRI data, generates patient-specific computational grid, assigns material properties, defines boundary conditions, applies external loads to the anatomical structures, and solves differential equations of nonlinear elasticity using Meshless Total Lagrangian Explicit Dynamics (MTLED) algorithm. We demonstrated the effectiveness and appropriateness of our framework on real clinical cases of tumour resection-induced brain shift.

Real-time surveillance of surgical margins via ICG-based near-infrared fluorescence imaging in patients with OSCC

Background

Local recurrence is the main cause of death among patients with oral squamous cell carcinoma (OSCC). This study assessed near-infrared fluorescence (NIF) imaging and spectroscopy to monitor surgical margins intraoperatively for OSCC.

Methods

Cytological and animal experiments were first performed to confirm the feasibility of monitoring surgical margins with NIF imaging and spectroscopy. Then, 20 patients with OSCC were included in the clinical trials. At 6–8 h after 0.75 mg/kg indocyanine green (ICG) injection, all patients underwent surgery with NIF imaging. During the surgery, both NIF images and quantified fluorescence intensity were acquired to monitor the surgical margins.

Results

In cytological and animal experiments, the results showed it was feasible to monitor surgical margins with NIF imaging and spectroscopy. Fluorescence was detected in primary tumors in all patients. The fluorescence intensities of the tumor, peritumoral, and normal tissues were 398.863 ± 151.47, 278.52 ± 84.89, and 274.5 ± 100.93 arbitrary units (AUs), respectively (P < 0.05). The SBR of tumor to peritumoral tissue and normal tissues was computed to be 1.45 ± 0.36 and 1.56 ± 0.41, respectively. After primary tumor excision, the wounds showed abnormal fluorescence in four patients (4/20), and residual cancer cells were confirmed by pathological examination in two patients (2/20).

Conclusion

These findings confirmed the complementary value of NIF imaging during radical tumor resection of OSCC. Before tumor resection, we could utilize the fluorescence margin produced by ICG NIF imaging to determine the surgical margin. Moreover, after tumor blocks were removed, the status of surgical margin could also be evaluated rapidly by ICG NIF imaging of tumor bed and in vitro specimens.