Current Status of Transoral Surgery for Patients With Early-Stage Pharyngeal and Laryngeal Cancers in Japan

Safety and outcome of three-dimensional transoral videolaryngoscopic surgery

BACKGROUND

Transoral videolaryngoscopic surgery (TOVS) is widely used in Japan, and conventional two-dimensional (2D) endoscopic methods have been established. Three-dimensional (3D) endoscopic surgery offers superior distance perception because it provides stereoscopic views. Recently, we have developed 3D endoscopy for TOVS (3D TOVS).

METHODS

This study included 46 patients with pharyngeal cancer who underwent 3D TOVS. The perioperative complications and survival curves were retrospectively analyzed.

RESULTS

One patient with oropharyngeal cancer who underwent neck dissection and transoral resection simultaneously experienced postoperative hemorrhage of the neck. Another patient with oropharyngeal cancer underwent hemostasis for postoperative pharyngeal hemorrhage. There was one case of aspiration pneumonia. One patient developed cervical lymph node recurrence; however, there was no local recurrence or primary mortality. The 2-year overall survival, disease-specific survival, local control rates, locoregional control rate, and invasive disease-free survival were 90.9%, 100%, 100%, 97.4%, and 79.9%, respectively.

CONCLUSIONS

Three-dimensional endoscopy can be safely applied to TOVS.

Transoral robotic surgery (TORS) in Japan: procedures, advantages and current status

Transoral robotic surgery (TORS), introduced by Weinstein et al. in 2005, has been widely adopted as a minimally invasive procedure, particularly for the treatment of patients with early stage oropharyngeal cancer. TORS is typically performed using the da Vinci Surgical System, similar to robot-assisted surgeries for other malignancies. The main difference between TORS and these other robot-assisted surgeries is that it is performed through the natural orifice of the mouth, which limits the surgical working space, and that it progresses from the lumen of the pharynx to the deeper tissues. The advantages of TORS are mainly due to the benefits of using the da Vinci Surgical System, such as three-dimensional high-definition images, magnification, multiple forceps articulation, tremor-stabilization function and motion scale function. To date, many big data and meta-analyses have shown that TORS is superior to conventional surgeries, such as open surgery, in terms of oncological outcomes, post-operative functionality and quality of life. In Japan, TORS is expected to spread across the country, as it has been covered by health insurance since April 2022. This review highlights the procedures of TORS, its unique aspects, its unparalleled advantages as a minimally invasive surgery for treating laryngeal and pharyngeal cancers, and its current status in Japan.

Transoral Robotic-Assisted Neurosurgery for Skull Base and Upper Spine Lesions

OBJECTIVE

The application of the da Vinci Surgical System in neurosurgery is limited due to technical difficulties requiring precise maneuvers and small instruments. This study details the advantages and disadvantages of robotics in neurosurgery and the reachable range of the transoral approach to lesions of the skull base and upper cervical spine.

METHODS

In a cadaver study, the da Vinci Xi robot, lacking haptic feedback, was utilized for sagittal and coronal approaches on 5 heads, facilitating dura suturing in 3, with a 30°-angled drill for bone removal.

RESULTS

Perfect exposure of all the nasopharyngeal sites, clivus, sellar, and choana, including the bilateral eustachian tubes, was achieved without any external incisions using this palatal split approach of transoral robotic surgery. The time required to perform a single stitch, knot, and complete single suture in robotic suturing of deep-seated were significantly less compared to manual suturing via the endonasal approach.

CONCLUSION

This is the first report to show the feasibility of suturing the dural defect in deep-seated lesions transorally and revealed that the limit of reach in the coronal plane via a transoral approach with incision of the soft palate is the foramen ovale. This preclinical investigation also showed that the transoral robotic approach is feasible for lesions extending from the sellar to the C2 in the sagittal plane. Refinement of robotic instruments for specific anatomic sites and future neurosurgical studies are needed to further demonstrate the feasibility and effectiveness of this system in treating benign and malignant skull base lesions.

Posttreatment Head and Neck Cancer Imaging: Anatomic Considerations Based on Cancer Subsites

Posttreatment imaging surveillance of head and neck cancer is challenging owing to complex anatomic subsites and diverse treatment modalities. Early detection of residual disease or recurrence through surveillance imaging is crucial for devising optimal treatment strategies. Posttreatment imaging surveillance is performed using CT, fluorine 18-fluorodeoxyglucose PET/CT, and MRI. Radiologists should be familiar with postoperative imaging findings that can vary depending on surgical procedures and reconstruction methods that are used, which is dictated by the primary subsite and extent of the tumor. Morphologic changes in normal structures or denervation of muscles within the musculocutaneous flap may mimic recurrent tumors. Recurrence is more likely to occur at the resection margin, margin of the reconstructed flap, and deep sites that are difficult to access surgically. Radiation therapy also has a varying dose distribution depending on the primary site, resulting in various posttreatment changes. Normal tissues are affected by radiation, with edema and inflammation occurring in the early stages and fibrosis in the late stages. Distinguishing scar tissue from residual tumor becomes necessary, as radiation therapy may leave behind residual scar tissue. Local recurrence should be carefully evaluated within areas where these postradiation changes occur. Head and Neck Imaging Reporting and Data System (NI-RADS) is a standardized reporting and risk classification system with guidance for subsequent management. Familiarity with NI-RADS has implications for establishing surveillance protocols, interpreting posttreatment images, and management decisions. Knowledge of posttreatment imaging characteristics of each subsite of head and neck cancers and the areas prone to recurrence empowers radiologists to detect recurrences at early stages. ©RSNA, 2024 Test Your Knowledge questions in the supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Clinical Outcomes of Curative Intent Radiotherapy by Helical Tomotherapy for Laryngeal Squamous Cell Carcinoma: A Retrospective Analysis in a Tertiary Referral Center

Background

The management of laryngeal cancer involves balancing curative treatment with preserving essential functions. This study aimed to evaluate the clinical outcomes of helical tomotherapy, an advanced form of radiation therapy, as a primary treatment modality for laryngeal squamous cell carcinoma (LSCC).

Methods

A retrospective analysis of data obtained from a tertiary referral center was performed to assess treatment response rates, survival outcomes, disease control, and treatment-related adverse events.

Results

The study included 45 patients with LSCC treated with helical tomotherapy between May 2015 and September 2022. The 5-year overall survival (OS) rate and disease-free survival (DFS) rate were 89.2% and 71.1%, respectively. Local control and laryngeal preservation rates at 5 years were 79.7% and 84.7%, respectively. Subgroup analysis revealed higher DFS rates in early-stage patients (84.2%) compared to advanced-stage patients (58.9%).

Conclusions

The results indicate that helical tomotherapy offers effective tumor control and potential for laryngeal preservation in LSCC. Further prospective studies and longer follow-up are needed to validate these findings and optimize treatment strategies for LSCC patients.

Etiology, diagnosis, treatment, and prevention of human papilloma virus-associated oropharyngeal squamous cell carcinoma

Classical oropharyngeal squamous cell carcinoma (OPSCC) caused by alcohol consumption and smoking and HPV-associated OPSCC caused by human papillomavirus (HPV) infection have different etiologies, incidences, and prognoses. Therefore, the 8th American Joint committee on Cancer (AJCC) and Union for International Cancer Control (UICC) TNM classifications propose distinguishing HPV-associated OPSCC from classical OPSCC and classifying it as an independent disease. Therefore, this review provides an overview of HPV-associated OPSCC from the perspectives of epidemiology, carcinogenesis, development, diagnosis, treatment, and prevention. The incidence of HPV-associated OPSCC is increasing. Although HPV vaccination has been shown to be effective at reducing the incidence of cervical cancer, it is still unclear how it affects the incidence of HPV-associated OPSCC. Additionally, the prognosis of patients with HPV-associated OPSCC is extremely favorable compared to that of patients with classical OPSCC. Therefore, patients with HPV-associated OPSCC may undergo reduced-dose therapy, although attempts to reduce treatment intensity should be carefully planned to ensure they do not compromise oncological outcomes, and large-scale trials aimed at reducing treatment intensity are ongoing.