Radiation Therapy for Cancer: Separating Fear From Fact

We take a biopsy from the specimen, cut it into sections, make blocks, and apply immunohistochemistry staining, which lets us identify targets on the cells. We then do mutation testing to see what mutations are present in the genes, to identify further targets we can address. We also do PD-L1 testing, which tells us whether the patient can receive immunotherapy. It is a combination of these staining protocols along with NGS that tells us the best way forward for the patient.

We take the biopsy specimen and extract the DNA from the cancer cell, then sequence it to identify where something has gone wrong in the DNA or RNA, which tells us why that individual developed the cancer. Through this we identify specific mutations that may be the probable reason. Research is ongoing to counteract every change found on NGS, but currently we have a few drugs available for certain specific mutations — if we find one of those, we give that specific drug and the patient benefits.

If you don't have a PET-CT, the second-best modality is a CT scan of the probable areas — chest, abdomen, and maybe head and neck depending on the cancer — which will give some answers on staging. As for treatment: chemotherapy is calculated as per the height, weight and profile of the patient, not given as a simple fixed dose. There are specific mixing criteria — it cannot be mixed like an antibiotic — and India has specific mixing units where care is taken over contamination and dosing. Drugs also have to be given over an appropriate infusion time, since infusing over the wrong duration causes more side effects. We also have monitoring systems running during chemotherapy to catch problems early, and targeted therapies and immunotherapies have specific temperature and light-sensitivity handling requirements that are important to follow correctly.

Previously it used to take 30 days, and it still does in most institutes, but with the advanced machines we now have, our turnaround time is only about five to six working days — even including a Sunday, a comprehensive NGS report is usually ready by about the seventh day.

The cost is very different for every cancer and every stage — it can vary from a few thousand rupees to a million rupees. The good news is that targeted therapy and immunotherapy drugs, which used to be very costly, now have more reasonable generic alternatives. For example, a drug that used to cost about $5,000 for a single dose as immunotherapy now costs just around $1,000 for a single dose. We also try to provide assistance programmes through indications approved by the companies that manufacture these drugs, to help patients financially.

No. Radiation therapy uses ionising radiation similar in principle to an X-ray, not an open flame or direct heat source, so the common fear of being burnt by treatment is not an accurate picture of how it works.

It is delivered using computerised protocols that direct radiation specifically to the cancer site, minimising the dose reaching adjoining healthy tissue.

That the modern approach is carefully planned and computer-guided, designed specifically to protect healthy tissue while treating the tumour, rather than being an uncontrolled or indiscriminate treatment.