Advanced Medical Technology for More Diverse Cancer Treatments
15 June 2020
Technology is constantly changing with new medical therapies emerging one after another and when it comes to cancer, an increasingly common disease, are you aware of the new advances in traditional therapies and the new technologies that provide more diverse treatment options?
People generally know chemotherapy and radiotherapy (radiation therapy), and the impression is that these two therapies often have many side effects that make cancer treatment difficult. In fact, with the advances in medical technology, the side effects of chemotherapy and radiotherapy have been greatly reduced.
With chemotherapy, oncologists can reduce the physical and psychological burden on patients by prescribing antiemetic drugs or adjusting the course of treatment. There are also many innovative medical devices that offer more precise, personalised and faster treatment with less side effects.
Sunway Medical Centre Senior Manager of Nuclear Medicine and Radiotherapy, Dr Heng Siew Ping said radiation therapy uses medical devices to deliver radiation into the patient’s body to kill tumours. In contrast to chemotherapy where drugs are circulated throughout the body, radiation therapy can be considered a localised treatment. After the tumour location is identified by an oncologist, a medical physicist will identify the target area for radiotherapy which will then be administered through a medical device.
Radiotherapy has three main functions in cancer treatment – curative, adjuvant and palliative radiotherapy. Generally, specialists will determine whether to perform radiotherapy before or after a tumour removal surgery, or vice versa, according to the type and stage of the cancer and the patient’s condition. Patients who require radiotherapy need to have their tumour location identified through a CT scan beforehand and based on the results, a medical physicist will draw up a radiotherapy treatment plan.
For patients with nasopharyngeal cancer, the tumour site is located adjacent to many vital organs such as the eyes and brain. Therefore, specialists and medical physicists need to accurately outline the tumour location and vital organs before entering the dose distribution data into the radiation therapy equipment, to ensure surrounding normal tissues and organs are not affected and reducing side effects.
“The radiation therapy devices which we use such as the tomotherapy is a breakthrough in the limitations of traditional accelerators. Tumours can be irradiated with a 360-degree focused tomography under CT guidance, allowing for efficient, accurate and safe treatment for patients with malignant tumours.
“The medical physicist will ensure that the device delivers the correct radiation dosage as prescribed by the oncologist at all times. The whole process of drawing and confirming the design usually takes three days to a week,” Dr Heng explained.
New generation radiation therapy device reduces cancer side effects
“Although radiotherapy is commonly known as ‘electrotherapy’, it does not use electricity but high-dose radiation; the same type of radiation used in chest x-rays. It’s just that radiation therapy rays are stronger so they can penetrate into the body to destroy the chromosomes of the cancer cells, this killing them,” Dr Heng said.
To meet the needs of different conditions, radiotherapy devices have evolved with the advancement of technology. Traditional radiotherapy equipment is not precise enough and has a large irradiation range, so it is easy to affect the normal tissues around the tumour.
Today, a new generation of external radiation has evolved to include a built-in 4D image guidance systems, motion tracking system and intensity modulated system, allowing precise targeting of highly concentrated radiation rays to the targeted tumour in a small area.
Also, if the patient moves due to breathing or changes posture, the irradiation immediately stops until the patient returns to the original position. This avoids irradiation to normal tissues and greatly reduces side effects.
“The side effects of radiotherapy vary depending on the organs and tissues that are irradiated. For example, in breast cancer patients, there are not many vital organs around the tumour so when radiotherapy is performed, the side effects are not significant as patients generally only feel warmness and redness on the skin at the irradiated site. However, in the case of nasopharyngeal cancer, the potential side effects are rather obvious such as dry mouth and problems with swallowing as there are vital organs, tissues and nerves in the area,” Dr Heng said.
High doses of radiation focused quickly and precisely on the lesion can not only reduce side effects, but significantly shorten the course of treatment and reduce the time and financial pressure for patients to travel to and from the hospital.
Currently, Sunway Medical Centre’s latest external radiation therapy equipment includes the TrueBeam STx, Gamma Knife and Tomotherapy. There are also internal radiotherapy equipment including the Brachytherapy and Intraoperative Radiation Therapy (IORT). The features and indications of each device varies, but the focus is to improve irradiation accuracy and reduce treatment errors and side effects.
Understanding to select the most appropriate treatment
Besides the IORT, most of these new radiotherapy treatments do not require general anaesthesia, so patients do not experience pain or discomfort. A single session can be completed in the same day and patients can simply come in as an outpatient, without the need for hospitalisation.
“Because of the short duration of treatment and lack of discomfort, many patients are surprised at the end of treatment and frequently come to us to confirm if the treatment has been done,” Dr Heng said.
She added that there is a limit to the amount of radiation that the body can tolerate at a time, hence the medial team will consider the patient’s condition before the appropriate dose is calculated using the gold standard of treatment. For example, a prostate cancer patient typically needs up to 40 radiotherapy treatments but now the medical team calculates the appropriate dose. This can reduce radiation therapy to just five sessions.
“The medical team usually let patients know upfront what are their treatment options so that they fully understand the different therapies available and the potential risks. However, patients should not take the liberty of deciding whether to continue or discontinue the course of treatment, but should complete the required course of treatment as planned,” Dr Heng said.
Reducing the duration of treatment and minimising side effects is the main focus of radiotherapy today, allowing patients to have a better quality of life. Although the new generation of radiotherapy equipment is capable of achieving this, it still requires the expertise of a medical team to plan and provide the best possible treatment.
“After all, the best equipment is still just a machine, so the efficiency of the treatment is not dependant on advanced equipment, but the result of a collaborative effort between the oncologist and the entire medical team,” Dr Heng said.
A complete cancer team includes not only the oncologist, but also the radiotherapy and chemotherapy team consisting of medical physicists, radiation therapists and oncology nurses as well as the nuclear medicine team comprising nuclear medicine physicians, nuclear medicine pharmacists and nuclear medicine physicists in order to provide a full range of cancer care from imaging and diagnostics to chemotherapy and radiotherapy.
With many advanced new technologies and cancer therapies available, how should patients make their choice? Dr Heng advises patients and their families to learn more about the disease, get to know the equipment available for them, and consider if the cancer team is complete and experienced to ensure that they make the most appropriate medical decisions.
Source: Sin Chew Daily Sabah
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