2007

A New Form of Robotic Surgery, A Less Invasive Alternative for Management of Tonsillar Cancer

Points to Remember

• Cancer of the tonsils or base of the tongue is now one of the most common oral cancers, developing in an estimated 1 in 30,000 persons each year.
• There is a rising incidence of this cancer in people younger than 50 years.
• The most common presenting symptom is generally a lump in the neck that proves on biopsy to be a metastasis from an advanced tonsillar cancer.
• A new, less invasive form of robotic surgery allows complete removal of the tumor and greatly reduces recovery time - 90% of patients are able to swallow in 2 weeks.
• At Mayo Clinic, the 5-year survival rate after transoral removal of tonsillar cancer is 81%.

Figure 1. Tonsillar cancer before surgery

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Figure 2. The surgical robotics system offers improved access to the oral cavity and better maneuverability.

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Figure 3. Intraoperative images of patient tonsil (A) and tongue (B). With the surgeon guiding the procedure from the command console, the robotics system provides binocular cameras that help project 3-dimensional images of tissue to be removed as the surgeon deploys a cutting tool.

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The Challenge

Cancer of the tonsil or base of the tongue is now one of the most common oral cancers; it develops in an estimated 1 in 30,000 persons each year, and the incidence of this cancer is rising. Its demographics are atypical for cancer in that it tends to affect otherwise healthy young people in their 20s through 50s. Although the cause of this rise in tonsillar cancers is not known, current research focuses on a link with oncogenic human papillomaviruses.

Typical presentation involves discovery of a lump in the neck. Biopsy often reveals advanced cancer. The standard treatments are chemotherapy and radiation. These may not be well tolerated and offer low to moderate success rates with poor outcomes because of adverse effects, including dysphagia, speech impairment, wide incisions, protracted use of a gastric feeding tube, and considerable morbidity from the treatment alone. Whether standard treatment has been effective may not be evident for 3 or 4 months. Mayo Clinic head and neck surgery specialists sought to develop a new surgical approach that offers an equal or better cure rate than the medical approach, while reducing adverse effects and thus improving patient quality of life.

A New Approach

During the past 2 years, the Mayo Clinic head and neck surgery team has worked to improve an existing surgical robotics system that could greatly improve access to the tumors by providing a precise, flexible wrist action in tight spaces. Designed originally for use in operations of the abdomen and pelvis, the system has been successfully fitted with smaller robotic instruments and adapted for use in the mouth. The robotic arms allow flexibility and freedom of movement in small spaces such as the mouth and throat. Two binocular cameras help project a 3-dimensional image from the lighted instrument that can be visualized by the surgeon at the robotic command console. The cutting technology of this robotic system offers cautery, ultrasonic vibration, and laser. Currently, Mayo Clinic is 1 of 3 US medical centers to have extensive experience in this service. Advantages of this approach include excellent survival rates of transoral surgery and reduced recovery time, pain, morbidity, and complications.

Advantages of Robotic Surgery for Tonsillar Cancer

• Total tumor removal
• Ability to check margins in real time with the pathologist
• Ability to remove neck lymph nodes
• No need to use tracheotomy tube
• No need to split the jaw and encounter extreme swelling and other complications
• Ability to avoid cutting muscles and nerves
• Reduced recovery time — of patients regain ability to swallow in 2 weeks, compared with the months required to do this after conventional surgery
• Reduced hospitalization — patients go home in 2 or 3 days versus spending a week in the hospital after conventional surgery
• Up to 80% of patients who undergo transoral tonsil cancer removal reach the 5-year survival mark, an outcome much better than that achieved with the standard approach