We've all experienced a sore throat, either because of allergies or an illness. What happens when that pain won't go away?George Karl will undergo his final radiation therapy treatment for throat and neck cancer on Friday. On February 16, the Denver Nuggets coach revealed his second battle with cancer. Five years ago, Karl was treated for prostate cancer. Now he's just about to go through his last 15 minutes of radiation, part of a five day a week, six-week treatment schedule."About the time they had announced his cancer on the news, was about the time that I was doing the testing, so I'm about three weeks behind him probably," said throat and neck cancer patient Derek Miles.Just like Karl, Miles has already beat cancer once, non-Hotchkins lymphoma four years ago. Just like Karl, Miles has the same doctor, gets treatment at the same hospital and is going through the same one-two punch of chemotherapy and radiation therapy treatment."So far the radiation has been pretty easy," said Miles "You don't notice much the first couple of weeks, and then it builds and you eventually get a very sore throat, trouble swallowing, gets to be a bit painful, but I'm not there yet."Miles found out he was fighting cancer a second time after an annual appointment with his oncologist, checking up on his previous cancer."Basically he took one look in my throat and knew something was wrong," said Miles. "I had one swollen tonsil instead of two, which I guess is not a good sign."After having a sore throat for an extended period of time, Miles found out it was more than a simple illness."They assume at first that it's tonsillitis," said Miles.He was diagnosed with throat and neck cancer. HPV Link To Cancer Throat and neck cancer was typically a disease for those with certain lifestyles."No history of smoking or drinking, so ?" said Miles. "They tell me it's HPV-positive, so human papillomavirus. Possibly an infection maybe 20 years ago, nobody knows.""That typical patient is now changed to maybe a younger patient, and maybe patients with different risk factors, not just smoking and drinking," said Dr. Andy Nemechek, head and neck surgical specialist at Swedish Medical Center and the physician for Miles and Karl. "The point of time from exposure, inoculation to the development of tumor can be a long time, typically in the decades range, in the 20 years range."HPV can look as simple as a wart. It can also lead to cervical cancer in women. Only a few types of HPV have been identified to increase the risk of cancer."Don't recall ever having the infection, but it's a viral infection that you may not known you have," said Miles."We hope, ironically, that the ubiquitous exposure to HPV will keep this in the front of people's minds for a longer time," said Nemechek. Radiation Therapy Two months after the diagnosis, Miles was at Swedish Medical Center, to start radiation therapy and chemotherapy, just like Karl.The radiation therapy involves putting on a specially designed mask to help keep Miles' face still."I think I called it the Jason mask. Basically it looks like a flat piece of screen," said Miles. "Strap you to the table and stretch it over your face.""The mask that you saw is made from a material called Aquaplast. "It's stiff when it's at room temperature, but when you heat it up, it becomes soft," said Dr. Nancy Cersonsky, radiation oncologist at Swedish Medical Center. "For it to be safe, which we always deliver safe radiation, we need to make certain that the patient is what we call immobilized, which means staying still. We heat the mask up in a bath of water, we press it over the patient's face, so it's custom made for them -- it fits the shape of their face and head -- snaps to the table and keeps them from moving, but they can still talk, breathe, speak and see through the mask."At Swedish Medical Center, patients receive radiation from a linear accelerator machine."The actual method that the radiation therapy uses to kill the tumors is that it kills the DNA of the tumors," said Cersonsky. "It damages the DNA, so that when the cells try to divide, they're unable to."40 patients get treated using the linear accelerator each day. So far, about 120 patients have received treatment this way. Soon, Swedish Medical Center will have a RapidArc machine which can administer radiation in just two minutes.The machine currently in use takes about 15 minutes and regulates the amount of radiation to any specific part of the throat and neck, as well as where the radiation specifically hits. It's a method called dose painting."We can give higher dose to some areas and lower does to other areas," said Cersonsky. "It means more dose to the tumor and less does to the normal structures, so less side effects of treatment." Side Effects It's hard enough dealing with a sore throat, but what is it like to experience radiation directed at your throat?"The first few weeks apparently you don't really feel anything, then you start to get a sore throat," said Miles. "Pain, difficulty swallowing, mucus, all the pleasant things that go with that.""Typically patients will say it's the worst sore throat I ever had, so if you had a bad streptococcal infection, it's like that, and then drinking a hot liquid on top of that," said Nemechek.Because radiation is similar to the effects from the sun, patients can have the appearance of a sunburn on the outside. Side effects to the throat and mouth may also feel like a sunburn, on the inside."Taste buds generally do get altered usually about the third week of treatment," said Cersonsky. "Some people describe foods tasting metallic or cardboard."The radiation slows the production of saliva, drying out the patient's throat. There can also be a coating of mucus that irritates the throat. Many patients are unable to eat during the second half of radiation therapy, and require a feeding tube."About a month (after treatment), they'll come back and say, 'OK, it's not so bad.' And about another month out, 'OK, it's really not so bad,'" said Nemechek."I feel pretty good so far. They tell me that's going to change, but not much you can do about that," said Miles. "I think the scariest part is probably is going after it's done, when you go for your yearly scans or six-month scans. You know that hour or two or day or two when you're waiting for the results is probably the scariest thing." Symptoms Since most sore throats are simply sore throats, how do you know when to elevate your concern?"Sore throat, vocal change away from the viral season, for instance not in the middle of winter," said Nemechek. "Symptoms and signs greater than six weeks. Pain that you can't explain, that is pain that is in the absence of an exposure."Nemechek also said be aware of unexplained bleeding, weight loss and fatigue."That should prompt a visit and then vigilance by the person that you're visiting with," said Nemechek. "A slightly older man for instance, a smoking and drinking in the past, that should increase your level of suspicion for sure." George Karl blog 7NEWS spoke with Kimberly Van Deraa, Karl's life partner, who has put together a blog to update fans on Karl's condition. Karl was resting in the background, while Deraa facilitated our questions to Karl.Through Van Deraa, Karl said his pain level is very painful. He described it as pain on a daily basis and the hardest pain he's ever gone through. He wears a pain patch and takes pain medicine, but said what really gets him is the combination of pain and fatigue.Just before his final radiation treatment, Karl told 7NEWS, "I'm just glad it's over and I'm looking forward to the recovery of the treatment."Swedish Medical Center reports a 75 percent cure rate for throat and neck cancer.