NEW YORK — When Mike Stevens learned his lungs were riddled with cancer, it took only a week to start chemotherapy — but six weeks to find out if it was doing any good.
“You’re going through all this suffering and stuff, and you want to know: Am I going to survive? Is this stuff working?” said Stevens, 48, of La Jolla, Calif. “Your whole life is in sort of a limbo.”
Doctors typically must wait weeks or months to see if a treatment is shrinking tumors or at least halting their growth. But researchers are exploring a new use for medical imaging that could shorten the stay in purgatory, possibly revealing within a few days whether chemo is working.
This experimental imaging relies on a familiar hospital workhorse: a PET scan, which can show a tumor’s internal activity, not just its size. When used to assess the effects of cancer treatment, it can reveal inside information about what the therapy is doing to a tumor even when there’s no outward sign.
To do a PET scan, doctors inject a patient with a radioactive substance that shows up on the scan in places where certain processes are happening — such as hungry cancer cells gobbling up a lot of blood sugar. The new research tests standard PET scans and a newer approach that involves injecting a different tracer substance.
The standard scan has gotten good results in tests with a variety of tumors, including breast, prostate, colorectal and esophageal cancers, said Dr. Steven Larson of the Memorial Sloan-Kettering Cancer Center in New York.
As a practical matter, researchers hope to persuade federal regulators to cover the procedure under Medicare and Medicaid.
Patient Mike Stevens’ disease has held generally stable by continuing chemo since 2005. He likes the idea of an earlier end to not knowing whether a treatment is working.
“It’s like having a rope tied around you and you’re leaning over a canyon at about a 45-degree angle, and you don’t know if someone is going to pull you back in or let go of it,” he said. “If you get that encouragement earlier on that you’re doing well … you’ve got something to fight for.”
