In recent decades, the advancements in medical treatment methods have revolutionised how wemanage, treat and cure a range of diseases. In the case of tonsil cancer, even something as routine as a surgery has been continually updated to overcome different challenges faced by surgeons and patients. In this article we will explore what tonsil cancer is, historical treatments and current and emerging use of robotics in surgery. 

Overview of tonsil cancer

Tonsil cancer occurs when an abnormal mass of cells begins to grow on one or both the tonsils. Our tonsils are found in the back of our mouth and form part of the oropharynx in our body. Tonsil cancer is regarded as one of the most common types of oropharyngeal cancers, accounting for approximately 23.1% of cases.¹ 

Tonsil cancer can be classified into 4 different stages depending on how far the disease has progressed: 

• Stages 1 and 2 represent early tonsil cancer, where the tumour is typically small and confined to the tonsils or nearby tissue
• Stage 3 represents advanced tonsil cancer in which the cancer cells have spread beyond the tonsils and towards other parts of the oropharynx such as the back of the tongue, the salivary glands or the larynx
• Stage 4 tonsil cancer is the most advanced and aggressive. The cancer may have spread to the lymph nodes or even more distant organs, or the tumour mass itself may have grown so large that it causes difficulty swallowing or eating

The overall aim for tonsil cancer treatment is to either eliminate the tumour entirely and prevent relapses. For advanced tonsil cancer, the main aim of treatment is to reduce the size of the cancer and alleviate symptoms. Surgical intervention remains a key component of treatment, and surgical techniques have evolved significantly over time to improve outcomes and increase survival rates for patients with tonsil cancer.

Types of surgeries used for tonsil cancer

Historical treatments for tonsil cancer

Radiotherapy 

Radiotherapy is a common treatment method used to manage the spread of cancer cells. It works by delivering high doses of radiation to target and destroy rapidly dividing cells, which includes cancerous cells. In the treatment of tonsil cancer, radiotherapy can help to eliminate small tumours and prevent recurrence of tonsil cancer or shrink larger tumours, making it effective across stages 1, 2, and 3 of the disease. 

Despite these advantages, radiotherapy is not specific to cancer cells and can damage other healthy cells surrounding the tonsils, resulting in side effects such as nausea, irritable skin and weakness. Some individuals may need to have feeding tubes to help with the recovery process. Because of the intensity of this treatment, radiotherapy is considered an aggressive form of medical treatment.

General surgery

Rradiotherapy may be done in combination with surgery. This may begin with a biopsy, also known as a diagnostic tonsillectomy, where a portion of the tonsil is removed and analysed to assess the spread of the cancer. Sometimes the whole afflicted tonsil may need to be removed (whole tonsillectomy) and the affected individual will be put under general anaesthesia. If the cancer has spread to the lymph nodes, removal of the nodes may be necessary. 

This combined approach is typically used for more advanced cancers to greatly maximise the chance of shrinking the tumour and improving the affected individual’s quality of life. A comprehensive research study concluded that combination therapy is associated with better long term survival outcomes for those with stage 1 or 2 tonsil cancer compared to radiotherapy alone.² 

However, this type of surgery can be greatly disruptive to muscle, bone and tissue surrounding the cancer. Following surgery, individuals may experience swelling, infection, swallowing and breathing difficulties. Whilst surgery for tonsil cancer is effective in eliminating the cancer, the recovery time could be improved upon. These challenges can be overcome by pivoting to minimally invasive surgical methods, which aim to reduce the amount of damage to healthy areas by specifically targetingthe cancer itself.

Advancements in surgical treatments for tonsil cancer

In the past, these treatments described above would have been used to treat tonsil cancer, and you may also recognise these treatments to treat other types of cancer. However, in recent decades, our knowledge and research of cancer has accelerated, allowing for development of new treatment methods. Here we will describe robot-assisted surgical methods for tonsil cancer. 

Transoral laser microsurgery (TLM)

TLM is a form of minimally invasive surgery that uses lasers to remove tumours from the body.When used to treat tonsil cancer, this method of surgery greatly reduces the risk of having speech and swallowing issues after surgery and limits the degree of damage to the healthy parts of tonsil and surrounding areas. Although the laser beam is very powerful and able to cut (or burn) the cancer cells from the body, it retains its specificity. TLM is mainly used to treat small tumours and can be used to help shrink the size of larger tumours.

TLM overcomes the issues surrounding radiotherapy, mainly by reducing the amount of damage to the body by only performing surgery on the afflicted area. Because of this, TLM is considered a minimally invasive surgery as the risk of damage to surrounding tissues and organs is minimal. This results in a shorter recovery time for patients and overall, TLM is considered to be a safe and effective form of treatment for cancers of the head and neck.³ 

Whilst TLM is beneficial in both the treatment and recovery of patients, performing TLM is difficult for surgeons, particularly if the cancer has spread beyond the tonsils. The procedure involves inserting a long, rigid endoscope equipped with a camera through the mouth to visualise the tumour and guide laser instruments to the target areas, such as the back of the throat. However, the use of this endoscope greatly limits the surgeon's view of the whole area compared to a general open surgery where the surgeon has full control. This restriction makes it difficult to distinguish between tumour tissue and critical structures like blood vessels, increasing the risk of unintentional damage. Moreover, the laser equipment is very sensitive, making it vulnerable to even a small tremor of the surgeon's hands. Therefore, great care and planning is needed prior to surgery. 

Transoral robotic surgery (TORS)

TORS uses robotic machinery to perform surgery, particularly for tonsil and other mouth cancers, including tongue, throat and salivary gland. This surgical method is able to overcome some of the challenges of TLM as it allows for ‘surgeons’ to fully rotate their ‘‘wrists’’ 360°, giving better access to deeper areas of the mouth and removes the risks of hand tremor. 

In spite of the additional help from the robotics, as with TLM, performing TORS is complex and surgeons are required to have specialist training to perform this procedure. It has been suggested for surgeons to observe at least a minimum of 20 cases before being able to be deemed suitably qualified (ref 4). In addition, obtaining the robotic machinery and hosting the training required is very expensive and overall, TORS is widely considered as not being cost-effective for hospitals. At present, in the UK, robotic surgery is being used by the NHS but no such robotic machinery is available for the treatment of tonsil cancer/oropharyngeal cancers specifically.

Transoral ultrasound surgery (TOUSS)

TOUSS uses an ultrasound scalpel as part of the surgeon's tool, utilising vibrations to make incisions through tissue. Different tissues are only able to be cut with a specific vibration therefore, TOUSS is very useful to target specific areas. This can be used to target cancer cells whilst minimising the damage done to healthy cells, hence TOUSS is considered a minimally invasive surgery. A major advantage of TOUSS over TLM is its ability to convert ultrasound-generated heat into a sealing mechanism, effectively closing surgical wounds during the procedure.⁴ This feature of the ultrasound scalpel greatly reduces the risk of bleeding from the operation, one of the major risks of this surgery.

Additionally, TOUSS is viewed as a promising and cheaper alternative to TORS. This surgical instrument is already widely used in general surgery procedures of the head and neck. Therefore, repurposing this tool in the treatment of tonsil cancer could hold great potential. 

Summary

Over the years, treatments for tonsil cancer have changed considerably, and the use of robotic machinery has opened up avenues for minimally invasive surgical procedures. This greatly reduces patients' recovery time and risks from performing surgery. In addition, the use of robotic tools can allow for more precise and accurate targeting of surgical removal of cancer cells from the body, facilitating recovery. Each new iteration of surgical methods have been built to solve challenges posed by older methods. In spite of the advantages, for surgeons, performing these types of operations still remain difficult. It will be exciting to see in the future how the UK and global healthcare systems will implement robotics in their routine treatments.