What is Radiation Therapy?
Radiotherapy is a treatment where radiation is used to kill cancer cells. It works by causing damage to the DNA of cancerous cells. This clinic offers state-of-the-art radiotherapy including TomoTherapy and Y-90 Radioembolisation effectively treat various kinds of cancer with low side effects based on the patient’s specific needs; opening new horizons for radiotherapy.
Is Radiotherapy compulsory for cancer patients?
Radiotherapy has different uses according to the stage of the cancer treatment and can be used as the main treatment, or together with another treatment or even as a method of pain relief. The majority of cancer patients are treated with radiotherapy following their surgery to kill off any remaining cancer cells and to reduce the risk of recurrence whilst improving their survival rate. In addition, some cancer patients may require radiotherapy before surgery so as to shrink the tumour and improve the success rate of the surgery plus lower the chance of post-operative infection. After radiotherapy, patients with inoperable cancers may be able to undergo surgical resection to remove their cancer.
Our Radiotherapy Treatment
Our center is equipped with high-speed spiral radiotherapy system (TomoTherapy), the latest model of Linear accelerator, ELEKTA Versa HD™, Y-90 liver cancer radiotherapy and other most advanced technologies and equipment, which can effectively handle different shapes and sizes of the tumor. In the view of opening up a new vision for radiotherapy, our treatments could enable patients to reduce the side effects from electrotherapy and also provide complementary treatment plans for the special needs of patients.
The center provides a one-stop cancer diagnosis and treatment service with a professional medical team. We are the only medical group in Hong Kong that provides “Seamless Radiotherapy Treatment Design” , which gathers HKAOC’s radiotherapy and medical physics department to provide personalized and precise treatment to achieve comprehensive disease control, so as to implement our commitment to commencing treatment within three days after diagnosis and enhance efficiency.
External beam radiotherapy
- Built-in CT scan function captures images of tumours immediately before treatment sessions for precise targeting of tumours
- Intensity-modulated radiation therapy (IMRT) technique to adjusts doses of radiation accurately
- 360-degree radiation to treat multiple tumours throughout the body
- Reduces radiation exposure to healthy tissues and organs, thus reducing side effects and improves survival
- Suitable for almost all tumours (especially head and neck cancer, nasopharyngeal cancer, lung cancer, etc.)
ELEKTA Versa HD™ Linear Accelerator
The latest model Linear accelerator offers high precision radiation therapy with integration of advanced beam-shaping, imaging and high dose rate technologies to aid in the visualization and treatment of a wide range of cancers. The distinct features are briefed below:
- 4D image guidance : Avoids shifts of tumours due to breathing and other factors
- 6D patient positioning platform : Provides six degrees of positional correction, ensuring maximum accuracy
- Agility™ 160-leaf MLC : High resolution beam shaping for more effective modulation and to protect important organs from radiation
- Volumetric modulated arc therapy (VMAT) : Radiation beams sweep in uninterrupted arcs around the patient, focusing the radiation dose on the tumour, reducing exposure to surrounding healthy tissues while speeding treatment delivery
Y-90 Radioembolisation is a breakthrough technology for liver cancer radiotherapy, especially for patients with advanced liver cancer who have limited treatment options. Compared with external beam radiation therapy, Yttrium 90 microspheres can enter the small blood vessels of the tumor and directly release a longer time and larger dose of radiation to the tumor tissue.
Y-90 Radioembolisation is like dropping explosive devices (Tiny glass or resin beads filled with the radioactive isotope yttrium Y-90) behind enemy lines so as to spare the innocent (normal tissues) from attack. Placed inside blood vessels that feed the tumour, Y-90 Radioembolisation can deliver a higher dose of radiation to the tumour for a longer period of time.
The advantages of Y-90 Radioembolisation:
Yttrium 90 can accurately treat liver cancer, and its coverage area is larger than traditional external radiotherapy. According to a study of ENRY, the survival rate of 325 patients with intermediate or advanced liver cancer who could not undergo surgery was extended by an average of more than one year after receiving internal radiotherapy. The British NICE guidelines also recommend Y-90 treatment as an alternative to standard treatments such as transarterial chemoembolization (TACE) or targeted drugs for primary liver cancer.
Since the radiation distance of β-rays to tissues is 1 cm, with an average of only 0.25 cm, it will only bring strong lethality to tumor cells at close range, and relatively low damage to normal cells adjacent to the tumor. Moreover, the blood flow of the hepatic artery is high, most of the radioactive substances are absorbed by the liver tumor, and normal cells do not receive much, and the side effects are less than traditional external radiotherapy.
The whole treatment generally takes only 1-2 hours. After the treatment, the patient is required to stay in a radiation isolation ward as instructed for a period of time, ranging from a few hours to a few days until the radiation dose in the body reaches a safe level. Patients should avoid visit by children and pregnant women within one week after treatment.
Note: Not all patients with liver cancer are suitable for Y-90 Radioembolisation. Please consult your physician for personalized medical advice.
Conventional Radiotherapy side effects:
Conventional radiotherapy tends to cover a larger radiation field with less precise delivery of the radiation dose to the targeted tumour area and therefore tends to cause damage to healthy cells and tissues in the vicinity, leading to side effects. In general, common side effects of conventional radiotherapy will include:
Short-term side effects of radiation therapy:
- Reduced saliva leading to dry mouth and taste changes
- Loss of appetite
- Inflammation of mouth, throat or oesophagus
- Difficulty swallowing
- Hoarseness with voice box involvement
- Skin problems such as red, dryness, peeling and ulcers
- Hair loss at the radiated area
- External and middle ear inflammation
Long-term side effects of radiation therapy:
- Long-term dry mouth with increased risk of of teeth and gum infections
- Damage to nasal mucosa that can cause nosebleeds
- Hardening of the soft tissues in the neck that leads to stiffness
- Skin dryness and colour changes
- Damage to the top of the lungs with no apparent symptoms
- Tinnitus, chronic middle ear inflammation or hearing loss
- Stiffness in the bones of the jaw
- Hoarseness with voice box involvement
- Reduced thyroid activity and the production of extraneous hormones