A doctor sees the curative potential in letting a patient with persistent leukemia leave the hospital to keep a promise he made to his daughter. (Vivienne Mildenberger/The New York Times)

At the age of 28, my patient was already a war-weary veteran of leukemia.

When his cancer was diagnosed, we treated him with a multidrug cocktail of chemotherapy over months, first with more intensive regimens that sidelined him from being able to work, and then with milder medicines.

His leukemia came raging back, though, so we treated him again, this time with one of the new, expensive immunotherapies that have been recently approved by the Food and Drug Administration. These are not curative, but in his case they eliminated enough of the leukemia to enable him to receive a bone-marrow transplant, which did have the potential of curing him.

But when he called my office six months after his transplant complaining of excruciating back pain, we feared the worst. The vertebrae are the major site of bone-marrow production in the body. Cells that grow too rapidly within the rigid confines of the bones can actually hurt, and it was the same symptom he had when we first met.

A bone-marrow biopsy confirmed that the leukemia had returned, and he was quickly admitted to the hospital, both to manage his pain and treat his cancer.

When I walked into his hospital room early the next morning, he was lying comfortably in bed. It had been a long enough time since the transplant that he now had a full head of hair and beard to boot. We had started him on steroids the previous day, which at high enough doses can actually treat his type of leukemia, and the resulting pain, temporarily.

We smiled and nodded, the way people do when they know each other well and are acknowledging the difficult task they are about to undertake together.

I sat at the edge of his bed and described the chemotherapy we would initiate, a regimen of drugs that would minimize major side effects that might compromise the efficacy of another transplant, his only shot at a cure.

“I guess we should get started,” he said, though hesitantly as he looked quickly over to his wife, who wore a sweatshirt printed with the message, “This is what I wear when I don’t feel like getting dressed up.” She was pragmatic like that. She also divined what was troubling him.

“Can he be treated as an outpatient?” she asked.

This time I hesitated, as I considered the toxicities of the drugs we would be using and the frequency with which we would have to monitor his blood counts.

“He could,” I said, softly. “There would be some risks, particularly of developing a fever and of bleeding as his white blood cells and platelets drop. But this isn’t exactly your first rodeo.” They both grimaced in acknowledging this truth.

“I know you’ll contact me if he gets sick,” I continued. “Is there a particular reason you’d like to be discharged?”

His wife answered for him: “He has a daddy-daughter dance tonight, with our 4-year-old. She’s been looking forward to it for weeks.”

She paused. “If he can’t leave the hospital, we understand,” she went on. “We have a backup plan. His friend could take her to the dance. But it would mean a lot.”

My patient gave her a broad smile, as if thanking her for saying what he couldn’t. His eyes were misty.

My own breath caught at the poignancy of the request. I remembered the first time I danced with my daughter, when she was only days old and I hugged her tight to my body, and the weddings we attended when she was the same age as my patient’s daughter. I would escort her to the dance floor as she carefully placed her pink sparkle shoes atop my staid black leather ones, while I raised and lowered them to the beat of the music. With the memory, I felt the gentle pressure of her weight on my toes.

The chances that the chemotherapy and transplant would work, with a leukemia that refused to be extinguished, were slight. The chances that he would get another opportunity to dance with his daughter were smaller still.

“I can’t imagine a better reason to be treated as an outpatient than a daddy-daughter dance,” I told them. “Whatever it takes, we’ll find a way to make it happen.”

As we get older and spend more years practicing medicine, doctors and nurses tend to get better at identifying the subtleties of illness, and our decisions and recommendations become more accurate. But more important than that, because we’ve lived more of our own lives, I hope we also recognize when what’s meaningful to our patients trumps anything medical that we can offer.