Intensity-modulated radiation therapy [IMRT] is a form of External Beam Radiation Therapy [EBRT] but with the ability to deliver different doses to different regions of the high risk volumes. It is a high precision type of radiotherapy treatment that uses computer-controlled linear accelerators to deliver high dose radiation to cancerous tumours by ‘sculpting’ the edges of a radiation beam.
For example, by using IMRT, one is able to deliver a higher dose to the tumor mass as well as deliver different doses to the surrounding lymph nodes, depending on the lymph node risk level of harbouring disease. This is known as dose painting. It is also used to increase the level of normal tissue sparing, so as to lower the risk of unwanted side effects. This form of treatment is used frequently in head and neck cancers, prostate cancers and pelvic tumors.
In the IMRT, radiation beans are precisely modulated, or controlled, to conform to the shape of the 3D mapped image of the tumour. The increased precision and accuracy significantly minimises damage to the surrounding healthy tissue, resulting in the potential for fewer side effects from treatment.
Volumetric modulated arc therapy [VMAT] involves the use of external radiation therapy beams being directed in a series of arcs or angles to allow for greater access to tumour. VMAT allows more difficult tumours, such as ones wrapped around other important structures, to be targeted precisely.
Image-guided radiation therapy [IGRT] is a radiation therapy which utilises advanced imaging equipment and computer software to accurately target tumours. This minimises the impact on surrounding healthy tissues, resulting in fewer potential side effects from treatment.
Brachytherapy is a special form of internal radiation therapy where a radioactive source is placed close to or inside the tumour.
Senior Consultant Radiation Oncologist, Medical Director, MBBS (Aust), FRANZCR (Radiation Oncology)
Dr Tang obtained his medical degree from the University of Newcastle, Australia in 1998 and completed his house officer training at the Hunter Area Health Service, Australia before returning to Singapore to start his specialty training in Radiation Oncology at the National University Hospital (NUH). After obtaining his fellowship from the Royal Australian College of Radiologist (FRANZCR) in 2006, Dr Tang underwent fellowships in breast brachytherapy at University of Wisconsin and Arizona Breast Cancer Specialist Centre as well as prostate brachytherapy, skin and paediatric fellowships at Peter Maccallum Cancer Institute, Australia.
Dr. Johann Tang is an experienced radiation oncologist who aims to deliver the highest level of care to his patients. With ethics and empathy held at the core of our practice, we strive to understand your individual needs and provide care that is compassionate and responsive.
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