New Delhi: Image-guided radiation therapy, an important advancement in the radiation technology, can help improve cancer treatment outcomes, said doctors on Sunday.
Image-guided radiation therapy (IGRT) refers to the use of imaging, usually CT scans and X-rays, to help precisely target the cancer with radiation therapy and avoid harm to healthy tissue. It’s used to treat all types of cancer and sometimes also used to control tumours that aren’t cancerous.
In IGRT, CT scans or X-rays, or both, are taken every day before each radiation treatment to ensure that the cancer or region to be treated lines up exactly as planned.
“IGRT is an advanced type of radiation therapy used to treat cancer and noncancerous tumours. By using this innovative technology now we can kill cancer cells by reducing the risk of damaging normal body tissues and structures. State-of-the-art technologies such as IGRT are vital to achieving continual improvement in patient outcomes and quality of life,” Dr Vineet Nakra, Radiation Oncologist at Max Super Speciality Hospital Vaishali, told IANS.
According to a recent study by Harvard Medical School in the US, IGRT is safer for patients with prostate cancer by helping clinicians accurately aim radiation beams at the prostate while avoiding nearby tissue in the bladder, urethra, and rectum.
It was associated with significantly fewer urinary and bowel side effects in the short term following radiation. Specifically, there was a 44 per cent reduction in urinary side effects and a 60 per cent reduction in bowel side effects, revealed the study publishedd in the journal Cancer.
“Modern treatment methodologies along with safe and effective treatment options like IGRT have helped improve the clinical outcomes in a big way. Many patients have recovered successfully just because they were able to complete the entire treatment owing to innovative modalities like IGRT which is now an important and effective treatment,” Dr Rahul Bhargava, Principal director of haematology and bone marrow transplant, at Fortis Memorial Research Institute, Gurugram, told IANS.
The patient is ‘set-up’ (usually lying down) on the treatment machine ‘couch’ in the same position every day. A quick X-ray or CT scan is taken using special equipment mounted on the treatment machine. Sometimes small markers made of metal (e.g. gold) or other materials seen well on X-rays, are placed inside a cancer or organ.
Adjustments can be made prior to each treatment to make certain the cancer is covered by the radiation beams, and to check that surrounding normal tissue or organs are not receiving too much dose.
For cancers located in the lung, the radiation therapists can take images during the delivery of the actual treatment so that they can compensate for the movement occurring during normal breathing. This has been called 4-dimensional radiation therapy (4D-RT) where the fourth dimension is ‘time’.