Introduction of an anti-cancer weapon

04 February 2020

According to the World Health Organization (WHO), cancer is the second leading cause of death worldwide causing an estimated 9.6 million deaths in 2018 – that makes one out of every six deaths occurring from cancer. In Malaysia, the number of people diagnosed with cancer is increasing day by day, with 13.6% of deaths in government hospitals in 2015.

Many associate cancer with death. In fact, cancer treatment has been improving and depending on the type of cancer, the severity of the disease and the patients’ physical condition, some patients can achieve good results with one type of treatment alone. However, some patients might have to combine multiple types of treatments. The types of treatments include surgery, chemotherapy, radiation therapy, targeted therapy and immunotherapy.

Thanks to the advances in computer technology and medical imaging, radiation therapy has become more advanced. Today, a machine integrated with computed tomography (CT) for a 360-degree stereotactic radiotherapy treatment has been brought into Malaysia. The new cancer treatment machine, the Radixact X9 Tomotherapy, can kill cancer cells more precisely and is another treatment option for head and neck cancer, prostate cancer, breast cancer and multiple systemic metastases.

“There is no single approach to treat all cancers and any additional treatment option is the same as giving further hope to cancer patients,” said Dr Aqilah Othman, Consultant Clinical Oncologist, Sunway Medical Centre.

Radiation therapy is one of the most effective means of treating malignant tumours today – eliminating cancer cells or shrinking tumours, reducing damage to healthy cells and reducing the side effects.

Tomotherapy, or Tomoknife for short, is an all-in-one radiation therapy machine that can be used for a wide range of cancer treatments. Tomotherapy combines the traditional CT imaging technology with Intensity Modulated Radiation Therapy (IMRT), which can treat a variety of complex tumours with precision and rapid irradiation while reducing the dose to the surrounding normal tissue.

“There are two situations where radiation therapy can be used. To treat cancer where it kills cancer cells and prevent cancer recurrence and secondly, in Palliative Radiotherapy, where it is used to control symptoms and reduce physical discomfort or pain in patients. Nevertheless, not all patients need to be treated through tomotherapy and treatments vary depending on the situation. Patients can discuss the treatment options with their doctors,” Dr Aqilah said.

She also stated that typical radiation therapy can target tumours about 40cm in size while tomotherapy can treat up to 135cm.

“For bone marrow transplant patients who require Total Marrow Irradiation (TMI), we can deliver the full dose of radiation evenly to the bone marrow of the entire spine. This reduces the damage to normal organs throughout the body, removes the bone marrow cancer cells precisely and increases the success rate of a bone marrow transplant,” said Dr Heng Siew Ping, a medical physicist at Sunway Medical Centre.

Apart from that, tomotherapy can be performed before or after a surgery. Take a breast cancer patient as an example: after a mastectomy surgery, the cancer cell may metastasize to the lymphatic system. With tomotherapy, we can target the lymph glands and reduce the chance of cancer metastasis and recurrence, Dr Aqilah said.

Although tomotherapy is not a one-size-fits-all treatment, its advent has brought new treatment option to many patients. Dr Aqilah suggests patients to learn more about their condition and treatment options and actively discuss the course of treatment with their primary care doctor as personalised treatment strategy will greatly enhance the effectiveness of the treatment and also improve the quality of life for the patient.

In the past, conventional radiotherapy is performed by matching the markings on the surface of the patient's skin. But the location of the tumour or organ may change due to respiratory movements or organ contents. The structure of the treatment site during the procedure may also be displaced and deviated due to factors such as tumour shrinkage, patient becoming thin or postoperative oedema. To avoid omissions, the scope of treatment is increased, impacting normal body cells.

The tomotherapy machine eliminates this large inaccuracy, no longer matching through skin markings, but using the built-in computed tomography (CT) to guide them.

“A medical physicist will 'design' the treatment based on a scan of the affected area on the patient before proceeding with the treatment. We'll divide the area into lots of little squares which are then adjusted for errors by the machine. Radiation therapy is then performed to the cancer cells while lowering the dose at other normal sites,” Dr Heng said.

A patient generally undergoes a treatment session for about 10 minutes, where they feel no pain or discomfort during the treatment. The fact that the treatment duration is so short and does not cause any discomfort surprises many patients, but Dr Heng assures that there is no need to worry too much about it. Some patients do not know much about radiotherapy and they think they enter into the device like a sci-fi movie with lasers and strong lights, she revealed.

With current medical technology, the side effects from radiotherapy is not immense. Dr Heng said that most people think that cancer treatment causes hair loss, vomiting and loss of appetite. Tomotherapy, on the other hand, can reduce the occurrence of side effects.

“It depends on the affected area that is being treated. If the tumour is within the skull, the radiotherapy site will be focused on the head which might cause hair loss problems. However, on other areas, most of the time there won’t be hair loss. At the most, the skin at the affected area may show signs of redness but it is nothing serious,” she said.

Patients who undergo radiation therapy are also concerned if they become radioactive to people around them, especially pregnant women, children or the elderly. Dr Aqilah emphasises that “tomotheraphy generally has some impact on the patient who is undergoing treatment but does not pose a health threat to others through physical contact. Therefore, there is nothing to worry about”.

Source: Oriental Daily News