It was the mid-1960s.
Robert Burkhart and 164 other young men were on their way to Vietnam in a C-130 cargo plane, strapped down with all their gear.
Halfway between Hawaii and Midway, the hatch in the middle of the airplane blew off, creating an instant vacuum and dropping temperatures to near freezing.
“Somebody had to get up there and close that off,” he said. “I was a young whippersnapper …”
Burkhart climbed atop a pile of equipment and pried the plywood lid off a toolbox. Using the lid, someone’s jacket and tie-wire he found in the toolbox, he fashioned a makeshift hatch that sealed the opening and allowed them to continue their seven-hour trip.
It wasn’t a comfortable flight – the C-130 isn’t a luxury liner on its best day – but “we didn’t freeze to death,” he laughs.
You could say Burkhart, now a burly, stately 75-year-old with big glasses and bushy black eyebrows, has a tolerance for discomfort.
He’s a survivor of prostate cancer. He has an artificial knee and hip. He’s a civil engineer who spent more than 27 years in the U.S. Navy Seabees and managed the office of the State Architect for the state of California for 21 years.
Lately, he has bounced around between Florida, California, Washington and Decatur, staying with his children and battling a succession of ailments.
“I’ve had some setbacks over the last 10 years,” he said.
Last Veterans Day, he was all set to go out to Wise County Veterans Memorial Park in Decatur and enjoy the ceremony. Instead, he found himself in the hospital, where a tumor the size of a grapefruit was removed from beneath his right arm.
“With God’s help and the doctors’ expertise, they got it,” he said. “I hope you don’t mind, but I’m not afraid to reference who my maker or my curator is.
“I’m a museum, and I have a great curator. He takes great care of me.”
The tumor was a melanoma – one of the most aggressive forms of cancer, and among the most likely to metastasize and pop up elsewhere in the body.
Recently, Burkhart’s melanoma showed up again, this time as a small tumor in his brain, close to the spot where the optic nerves come together.
It’s an extremely difficult place to operate.
But the doctors at Choice Cancer Care at Wise Regional have a new tool – the Varian Trilogy radiation therapy system – that gives them another option.
Using stereotactic radiosurgery, the neurosurgeon and radiation oncologist, working together with a physicist and radiation therapists, can pinpoint a location deep inside the brain for high doses of photon-beam radiation.
The goal is to kill the tumor while sparing the sensitive tissue and structures surrounding it.
INTO THE VAULT
The room where the radiosurgery takes place is called the “vault” because its walls, floor and ceiling are concrete, feet thick in most places. It took months to build the room, then about a month to assemble the machine and another month to calibrate it – making sure dosages of radiation are actually being delivered exactly as measured.
It has been in use since last November, but Burk-hart’s surgery – four treatments spread over 10 days in late February – represents the first time it has been used in Decatur for stereotactic radiosurgery.
Dr. Shelaine Mabanta, radiologic oncologist, said Burkhart’s case is a perfect fit for this technology.
“He’s got one metastatic lesion,” she said. “Sometimes patients present with multiple lesions, and you would treat the whole brain. The problem with that is, in treating the whole brain, you can’t give a lot of doses.
“This gentleman has come in with a small lesion. We feel like if we can give it one big pop in that area, we can spare the whole brain.”
The goal, she said, is to maximize his quality of life, treat the tumor and spare the other areas.
Because of the depth and location of the lesion, she brought in a neurosurgeon to consult.
“The neurosurgeon reviewed this with me, and he’s actually involved in our treatment planning,” she said. “He felt that because of the location, we’d be better served to do stereotactic. It’s very close to the middle part of the brain, close to the optic apparatus.”
She said this is all new to Mr. Burkhart – “but he’s a fantastic patient.”
Burkhart’s radiation was broken into four parts, each delivered a few days apart.
“Typically, stereotactic to the brain is one treatment – one big dose,” Dr. Mabanta said. “But sometimes when it’s close to critical structures you have to make sure you avoid the tolerance doses. By fractionating it and separating the dose, you’re allowing it to recover before you give another big dose.”
When radiation therapists Daniel Law Eh and Larissa Contreras come to get Burkhart, they joke and visit while leading him into the vault. They position him on the table, slide a cushion under his knees and bring out a mask to immobilize his head on the table.
It looks like something from a science-fiction movie as the lights go down and lasers line him up to make sure radiation goes exactly where it’s needed.
Physicist Chapple Musslewhite was on hand for the Feb. 20 treatment and explained the procedure.
“ALIGNMENT IS EVERYTHING”
After getting Burkhart on the table and screwing the mask into place, the radiation therapists leave the room, seal the big steel door, and do a rotation cone-beam CT scan.
“It’s like a CT scanner except that, instead of doing slice-by-slice, it does a volume of information all at once,” Musslewhite says. The ability to both image the patient and treat him with the same machine is one of the huge advances of the Varian Trilogy.
Through the whole process, the patient is always visible on multiple cameras, and can signal any discomfort with a wave of his hand. Mr. Burkhart doesn’t move a muscle.
“Now we’re waiting on it to do the reconstruction of that image,” Musslewhite says, while Eh and Contreras call out coordinates and an image pops up on computer screens in the control room.
“Through the computers, we can move it where we know we’re targeting where we want to be,” he says. “All this is predicated on not letting the patient move, so we have the mask frame around the patient. This is the final positioning.”
On this day, that “final positioning” takes about 30 minutes. The actual treatment takes less than 10 minutes.
They end up sending Contreras back into the vault a couple of times to adjust Burkhart’s position. It takes several scans and x-rays before Dr. Mabanta is fully satisfied with the patient’s alignment.
Musslewhite narrates as the process unfolds.
“So there’s still a misalignment, and it’s great enough – they want to be right, so they’re not going to allow the computer to make the decision on this,” he says. “Now, instead of doing the cone beam CT, they’re going to just take some plain films, like an x-ray, just to make sure we’re in the ballpark.
“Alignment is really everything, especially in this where we’re giving such a high dose over such a quick period,” he says. “Here, you have to be very precise.”
The four “fractions” Burkhart is receiving total 2,000 centigray – the unit of measure for this type of radiation. They’re delivered 500 centigray at a time – four treatments over about 12 days. Each treatment is about two-and-a-half times what other patients would get in a single session.
During treatment, beams come in at numerous angles, always entering from a different spot. No part of the brain gets more than one beam, but every beam passes through the tumor.
“The sum of all those beams coming in will be that tumor,” Musslewhite says. “One at a time, it’s not much, but once they all add up together, that’s where we’re looking for the full effect.”
Burkhart said the first treatment went relatively well.
“The table was hard,” he said. “It was cold. Other than that, it wasn’t too uncomfortable.”
When Eh comes to get him for the second treatment, he asks him how he’s doing. Getting up with his long walking stick and moving at a stately pace toward the vault, the patient replies.
“I’m a lot better than I was yesterday.”