Cancer treatment: Attacking the bad, sparing the good and saving lives

Rapid advances in cancer treatment such as precision radiation therapy have helped target diseased cells while leaving healthy tissue untouched

The word ‘cancer’ may still invoke fear, but the disease is a long way from being the death sentence it once was.

These days, with rapid advancements in technology, treatment for cancer has become far more precise – this means, tumour cells alone are attacked and healthy tissue nearby as well as critical organs are spared.

Precision radiation therapy, in which a high-energy radiation beam is targeted at diseased cells, is one of the advanced cancer treatments, and doctors say it is enormously beneficial for patients.

“The goal of cancer treatment now is organ preservation. A curative dose of radiation is directed at the tumour, but technology is helping us prevent inflicting damage upon neighbouring tissue. Earlier, this precision was not there and a lot of healthy tissue was damaged in the process. Today, we are able to actively cure stage 1 and 2 of breast cancer, head and neck cancer and cervical cancer. We are also able to conserve these organ,” said S. Alex A. Prasad, secretary of the Association of Radiation Oncologists of India (AROI), Tamil Nadu and Puducherry.

Take a tumour in the lungs for instance.

“A high dose of radiation is used to ablate (destroy) the tumour, but the organs at risk here include the heart and trachea. With pancreatic cancer, the stomach, kidneys and liver are at risk. If radiation therapy cures the cancer but there is damage to the kidneys, it is not acceptable. But technological advances are helping us minimise damage to these organs,” he explained.

This is the idea behind precision radiation therapy, said L. Padmanabhan, consultant, clinical and radiation oncology, Billroth Hospitals.

“Earlier, cancer treatment was empirical and two-dimensional. The tumour was considered to be either rectangular or square and treatment was directed accordingly. But tumours generally have irregular shapes. With developments in imaging science, we can now study the tumour in detail. CT/MRI slice scans give us the tumour’s volume, and we can then plan the type of radiation to be given,” he said.

Radiation oncology has come a long way from superficial X-ray machines to linear accelerators, he said.

Some of the techniques today include Intensity Modulated Radiation Therapy, High Dose Rate Brachytherapy, Image Guided Radiotherapy, Stereotactic Radiosurgery and Stereotactic Radiotherapy.

“These techniques help in delivering precise or optimal doses of radiation to the tumour to kill the cell, and in turn cure or control the disease,” he said.

Dr. Prasad said radiosurgery was the most popular treatment now, and involved using radiation instead of a knife for precise treatment at the micro-millimetre level.

Ramesh S. Billimagga, president of AROI said proton therapy, in which a beam of protons is used to irradiate diseased tissue, was also coming up in several parts if the country. “We have a lot more to do to make treatment accessible and affordable. Knowledge about cancer is concentrated in urban areas and needs to spread in rural areas,” he said.