Cancer is treated in three basic ways: surgery, radiation or medicine. Today, those treatments can be less invasive thanks to a couple of key advancements.
For example, breast cancer patients 20 years ago were almost always prescribed chemotherapy. But, now doctors can determine the genetic profile of a cancer to prescribe more precise treatment, said Dr. Jaymin Jhaveri, a radiation oncologist at NGHS.
After a surgery is performed, doctors can take the tumor to biologists who are able to do tests to determine its genetic makeup to collect data to inform future treatments.
“Instead of blanketing every patient and saying every patient needs chemotherapy,” he said, “we can look at an individual tumor and look at its molecular and genetic composition. And we look at aggressive genetic signatures that predict for recurrence.”
Chemotherapy takes three to four months and is a very toxic treatment, he said.
Now, NGHS treats far fewer breast cancer patients with chemo because doctors are able to see which cases are most aggressive. The most recent studies on this method have been done in the last one to five years, Jhaveri said, and the first genetic study was done about 10 years ago for breast cancer.
“We’ve been tailoring therapy based on the individual tumor profile,” he said.
Scientists are genetically profiling other cancer types too, including melanoma, lung cancer and lymphoma, Jhaveri said.
Less invasive and less intense procedures can also be performed thanks to improved 3-D imaging of cancer sites inside the body. In the last two to five years, technology has improved so doctors are able to blend images of PET scans and MRIs and other planning systems to get a better picture of the target cancer as well as surrounding organs and other structures you want to avoid, said Dr. Jack Griffeth, a radiation oncologist at Northeast Georgia Health System.
With that better picture, doctors can target radiation.
In radiation, doctors and scientists use an important formula: the radiation dose is proportional to one over the square of the distance. In simple terms, if you are four feet away from a source of radiation, then you will receive one 16th of the amount of radiation as if you were one foot away. The dose of radiation decreases dramatically the further away you are from the source.
Doctors can use this scientific law to treat cancer very precisely in a treatment called brachytherapy.
In this treatment, doctors use a high-dose rate radioactive source, housed in a tiny long wire that is put into the body near the cancer site, Griffeth said. Most commonly, brachytherapy is used for prostate and gynecological cancers, Griffeth said.
Crude forms of brachytherapy have been around for decades in which doctors would use a piece of radioactive material like radium and put it on or near a cancer site, but the process has recently advanced with new software and methods of delivery.
“What has made this modality new, as well as many others, is the improvements in imaging and in the improvements of the appliances in which we can apply the radiation,” Griffeth said. “Those things have improved dramatically.”
Doctors can program the radioactive source to go into a catheter system and dwell there for a few seconds to deliver the correct dose to the cancer, Griffeth said. “If you have the appliances in correctly… you can apply radiation with precision that’s remarkable and unsurpassed,” he said. “You can within millimeters control the dose to where it needs to go.”
Because of that physics law, which states that the radiation emitted from a source decreases dramatically the further away from it you are, radiation can be delivered precisely when the appliance is put so close to a cancer site. It will have minimal impact on the rest of the body, Griffeth said, even places just a few millimeters away from the source of radiation.
For example, when treating prostate cancer, doctors can apply radiation to the prostate without a significant dose of radiation applied to the bladder or rectum nearby.
This high dose method can also decrease the number of times a patient has to come in for treatment, Griffeth said. For certain types of skin cancer, a patient used to have to come in 20 to 30 times for treatment, but now they may only need to come in five times, he said.
“Radiation will kill cancer; if you can get radiation into a cancer, you can kill it,” Griffeth said. “But the problem is doing so while sparing normal tissue, and this is a way… to elegantly apply the beam to the tumor, giving the full dose to the tumor while minimizing the dose to normal structures.”