The announcement by former President Jimmy Carter, 90, that he has been diagnosed with melanoma that has spread to the brain and that he will soon start high-dose radiation treatment for the four small cancerous lesions didn't surprise local oncologists on either count.
The metastasis of melanoma to the brain and liver is not uncommon, though it typically originates as a skin malignancy or in mucosal surfaces such as the mouth or women's gynecological tract, according to radiation oncologist Edwin Crandley, who uses the Cyberknife to deliver stereotactic (high-dose) radiation in treating such tumors at Sentara Norfolk General Hospital.
"We try for one treatment with brain metastasis, but as the Cyberknife doesn't require the stereotactic head frame (a device attached to a patient's head to ensure immobility), we can fractionate the treatment and have patients return from two to five times," he said. Crandley described the non-invasive treatment as a "frequent" procedure that has been used since the 1960s. "It's a good technique for small tumors or those that don't respond as well to conventional radiation," he said.
John Miller, a medical oncologist at Riverside Peninsula Cancer Institute in Williamsburg, agreed that metastasis to the brain is not unusual in melanoma. "It can occur anywhere, in the liver, the lymph nodes, the bone," he said. Nor is it unusual in someone of Carter's age, he said, noting that he had recently treated a 93-year-old.
Crandley said Carter's age would not be a consideration in a physician's decision to give radiosurgery treatment.
"Age shouldn't really matter," he said. "He's not goiong to tolerate radiosurgery less well than a 50-year-old. It would have minimal impact on the decision."
Allan Thornton, radiation oncologist at the Hampton University Proton Therapy Institute in Hampton, agreed.
"He's giving a news conference," he said of Carter's announcement, where the former president spoke for 40 minutes. "I think it's justifiable if the quality of life is good enough," he said. Thornton said many 90-year-olds are as energetic, or more so, than 60-year-olds, and statistically could have a better chance of another decade of life.
However, where Thornton diverged was in believing that Carter should be treated with proton therapy. "That's what he should be getting," he said, describing proton treatment as "the ultimate Gamma Knife."
Like the Cyberknife and Gamma Knife — both machines used to deliver stereotactic radiation — proton therapy also uses a targeted beam to reduce damage to surrounding tissue.
Thornton, who has treated patients with brain metastasis at several proton centers, including at Hampton and Indiana, suggested that Carter undoubtedly had cancer cells elsewhere in the brain too small to detect, which would make him a candidate for whole-brain X-ray treatment over several weeks prior to the discreet targeting of the four individual lesions by single-session proton therapy treatments.
"He's fortunate he's found it as small as possible, but it's symptomatic treatment. It will likely recur somewhere else and he'll need ongoing treatment," he said. "It's not cured. It's palliative therapy."
Miller was more optimistic.
"There's a lot of hope in immunotherapy. There have been a lot of breakthroughs in the past five years. There are five or six new drugs," he said.
Miller said Keytruda is one drug that became available in the past year that he believed Carter would be taking. "It can work extremely well," he said, noting that it has been shown to not only prolong life but provide a decent quality of life.
He also said the Gamma Knife and stereotactic radiation have minimal side effects compared to whole-brain radiation which people may "tolerate" but which can have major side effects.
Salasky can be reached by phone at 757-247-4784.