The Pulse's Patient Files series explores your stories of illness, recovery, health and coping. In this week's edition, we take a look at the the permanent marks left behind after cancer treatment. 

About 60 percent of all cancer patients need radiation therapy, and nearly every one of them leaves that experience with three, tiny radiation tattoos. 

Barbara Wisotzkey, who was diagnosed with breast cancer in early 2013, says hers tattoos are no big deal.

"The way I look at it, whatever you have to do to get rid of this in my body--do it.," says Wisotzkey, a resident of Gettysburg, Pa. "I don't care."

The tattoos help therapists line-up patients properly before each treatment session.

"You want to be dead on the mark," says Allysa Green, a therapist at Fox Chase Cancer Center. "So it's kind of like a map to guide us. It's also a permanent record. So, God forbid if patients ever had to come back to be retreated."

"Accuracy is so important because body parts can only receive a certain amount of radiation through a person's lifetime," says Maureen Ferri, also a radiation therapist at Fox Chase.

Eric Horwitz, chairman of radiation oncology at Fox Chase, says patients often think the radiation tattoos will be more visible than they are. In the 1960s, physicians relied on large marks and crosshairs made with paint or Magic Marker.

"They were very obvious, you couldn't hide it, and [patients] were told: 'You can't wash it off.' Thankfully, we just don't do that anymore," Horwitz says.

Six surprising things about radiation therapy

Every cancer treatment center has professionals on hand to educate and prepare patients for therapy—but--it's easy to think you know what's what after watching an episode or two of "House" or "Grey's Anatomy."

We asked for tips from real-life pro Colleen Tegeler, clinical director of radiation oncology at the MD Anderson Cancer Center at Cooper.

1. Expect a daily dose. 

External beam radiation therapy is typically scheduled every day--Monday through Friday—for six to eight weeks. That rigorous—some say unrelenting schedule—is often a surprise.

Adjust your schedule accordingly.

"You don't want to have a week break in Florida for vacation," Tegeler said.

Cancer cells are more affected—more likely to die off—if they are bombarded daily by radiation, she said.

2. You'll keep your hair. 

"Everybody thinks that when they are having radiation, you are going to lose your hair on your head--that's not true," Tegeler. "If we are treating your breast you are not going to lose the hair on your head," Tegeler said.

Radiation treatment targets tumors and a small band of healthy tissue around them. That's different than chemotherapy, which is drug treatment delivered to the entire body.

"We are more accurate, we are curing more patients than we did 20 years ago and 30 years ago," said Tegeler, who's worked in the field for 32 years.

"If you are treating a pelvis area—a very large field," Tegeler said. "You could have someone with side effects of diarrhea everyday, dehydration, perforated bowels, the least amount of side effects the healthier a patient will be."

Today's "pinpoint" technology has reduced unintended side effects on nearby body parts.

3. Stillness is absolutely required. Absolute quiet is not. 

Patients need to lie perfectly still. To help, radiation techs often construct a custom body mold that vacuum locks patients into place.

"You may actually be held down to the table," Tegeler said.

The procedure often lasts just 10 or 15 minutes, but some people feel confined, others experience temporary claustrophobia.

"Anything that relaxes them, we tell them to bring," Tegeler said.

At some cancer centers, you can use your ear buds and iPod, or hand over a CD to play into the room.

"It's usually music they grew up with, Frank Sinatra for the older generation, some people like the ocean," Tegeler said.

4. Skin irritation is common. 

External beam radiation therapy can cause peeling, dryness, redness—or other skin changes.

"They can get a light tan to a burn," Tegeler said. "It may not go back to normal skin color but it will heal."

The treatment team will monitor the area and can recommend ways to soothe the skin.

"We ask them not to use their home remedies, we ask them only to use prescribed medications from the physician," Tegeler said.

5. You may get a golden guidance system. 

Lots of effort in radiation therapy goes toward sparing the tissue around a tumor—to avoid injury to healthy body parts.

When tumors are located in soft tissue that shifts, moves and jiggles with every breath, doctors sometimes use an implanted marker—called a fiducial—to zero in on the correct spot.

"It's really tiny--maybe three milliliters--it's real gold, very expensive," Tegeler said.

"The therapist locks onto the fiducial in the area that we want to treat."

Before each session, therapists use imaging equipment to find the implanted markers which fixes reference points to treat "moving parts" such as lungs, liver or the prostate.

The markers are "biocompatible"--and permanent.

Disclosure: Fox Chase supports WHYY programming.