[Treatment and management of orbital tumors]

The role of surgical factors eliciting oculocardiac reflex of patients undergoing orbital tumor surgery: a retrospective study

PURPOSE

Orbital tumors are an interdisciplinary disease, and surgery is one of the main treatment methods. The oculocardiac reflex (OCR) is a condition of surgery for orbital tumors. The aim of this study was to investigate whether there is an association between many surgical factors and the incidence of OCR in orbital tumor surgery.

METHODS

Comparisons were made between patients with and without OCR using the Mann-Whitney test, Fisher's exact test, and Chi-square test. When comparing multiple groups (groups > 2), to explain which two groups had differences, post hoc testing was used for analysis, and the differences between groups were judged according to the adjusted standardized residuals.

RESULTS

The results showed that the incidence of intraoperative OCR was different based on the different exposed operative field locations (p = 0.021). The OCR incidence in those with lesions involving the orbital apex and lesions adhering to extraocular muscles was higher than that of others (p < 0.001 and p = 0.003). In addition, multivariate logistic regression analysis revealed that orbital apex involvement and extraocular muscle adhesion were highly associated with a higher incidence of OCR (p < 0.001 and p = 0.013), while the operative field located in the lateral-superior orbit was highly associated with a lower incidence of OCR (p = 0.029).

CONCLUSION

In orbital tumor surgery under general anesthesia, lesions involving the orbital apex and lesion adhesion to the extraocular muscles were independent risk factors for OCR, and an operative field located in the lateral-superior orbit was a protective factor for OCR.

Precision Surgery for Orbital Cavernous Hemangiomas: The Role of Three-Dimensional Printing in Individualized Resection-An Educational Experience

Orbital cavernous hemangiomas are the most common primary orbital tumors in adults, providing challenges for optimal surgical approach planning within an anatomically complex area with close proximity to vital neurovascular structures. The authors present an individualized lateral mini-orbitozygomatic approach for the resection of an orbital cavernous haemangioma based on a preoperative 3-dimensional-printed model. This individualized approach enabled the surgeons to achieve optimal exposure while maintaining safety during the resection of the lesion, but also to respect the patient's physiognomy and hairline. In addition, the model was used for patient informed consent, helping the patient understand the procedure. Although adding additional effort to preoperative planning, 3-dimensional model-based approaches can offer great benefits when it comes to customizing surgical approaches, especially for anatomically challenging resections.

Investigating variation of dose gradient index by different grid sizes in intensity-modulated radiation therapy of optic nerve sheath meningioma

In optic nerve sheath meningioma (ONSM) radiotherapy, vital organs with a low tolerance dose are very close to the target volume. Thus dose fall-off steepness around the target volume is the most critical parameter in intensity-modulated radiation therapy (IMRT) planning for this malignancy. We hypothesized that one of the parameters that can impact the dose fall-off steepness is dose calculation grid sizes. This study aimed to assess the impact of different dose calculation grid sizes on the newly introduced dose gradient indices (DGIs) for the steepness of dose fall-off around the target volume. Results showed that decreasing the dose calculation grid size in IMRT treatment planning of ONSM patients had a significant difference in the dosimetric parameters and DGIs of the target volume and at-risk organs. This study demonstrates that using a finer dose calculation grid size is preferred in treating ONSM patients.

Fetal Development of the Orbit

Human prenatal development is divided into an embryonic period and a fetal period. Intense organogenetic activity occurs in the embryonic period of prenatal life, while the fetal period is marked by less intense changes. Knowledge of the embryology of the orbit not only allows insights into how normal variations in the orbital structure arise but also provides an understanding of how congenital deformities occur when normal orbital development goes awry. In order to explore our understanding of the developmental anatomy of the orbit during the fetal period of prenatal life, the authors have summarized the major milestones in orbital morphogenesis, a temporally precise and morphogenetically intricate process. This process can be considered as an anatomic series of complex, well-orchestrated changes in morphology as well as a series of complex biochemical and molecular events that coordinate and control the anatomic development. Identifying and linking signaling pathways and regulatory genes linked with normal orbital morphogenesis is a crucial step to offer patients with chronic or incurable orbital diseases effective treatment options in the future.