No doctor wants to look at a CT scan where a body is full of metastatic cancer, but it has to be particularly frightening when that’s a scan of your own body.

That’s what happened to 35 year-old Paul Kalanithi, a neurosurgeon and writer. His book "When Breath Becomes Air" is a memoir about his life and dealing with stage-four metastatic lung cancer. His book was posthumously published in January.

His wife, Lucy Kalanithi, is an internist and wrote the epilogue to the book. She joined Boston Public Radio to discuss her husband's life and his final project. Here are some selections from their interview.

On how they learned the news

He was in his 6th of 7 years of neurosurgery residency at Stanford. This was 2013...He was on his feet for 14 hours a day doing long spine and brain surgeries, and eating a Snickers bar for lunch and drinking a Diet Coke. And he started to lose weight. He had just returned to this really intense schedule and we thought, 'I guess you're adjusting to that schedule.' Then he started to develop really excruciating back pain and night sweats, and then a cough, and was sneaking away from the operating room to go see his doctor. Ultimately...he looked at his own CT scan and saw metastatic cancer. The two of us were standing in his hospital room together. Nobody delivered the news to us in words. We just stood there together looking at the scan.

On their reactions to his early symptoms

It's funny, we worried about it a little bit because he thought: 'Why am I having these symptoms?' I think there is a tendency— if you're having a funny symptom—your mind goes to cancer. It sort of happens to everybody, whether it's a mole or a headache or whatever. It happens to doctors too! But we just thought, it's vanishingly rare to be 36 and have metastatic cancer. Looking back we said, 'you've had these symptoms for five months or so.' By the time he started having back pain, that means it already would have been metastatic and in his spine. It had been there a little while.

On his decision to continue working as a neurosurgeon after his diagnosis

He was diagnosed with terminal cancer in the spring of 2013, and both of us obviously immediately took time off work to help him. He was quickly pretty debilitated. We both, being doctors, did not have illusions about the prognosis. We knew he would live months to a few years, and we immediately started thinking about: how are we going to spend that time? How are we going to cope? What are we going to do with that time? He decided he wanted to go back to being a neurosurgeon. Some people don't work at all and that would be totally justified, that might even be the most common. But he said: 'I chose this job for a reason,' and he wanted to continue doing it. It was part of who he was. By the time he became too ill to do it, he was writing.

On why he decided to write a book

It had been a lifelong dream of his to be a writer. He never thought he'd be a doctor. He was an English major—he studied history and philosophy of science after college, and English literature. Ultimately, he made his way into medicine because he was really interested in the big questions of what it means to be mortal and how do we find meaning despite the fact we'll all die, and what it means to be human. He was obsessed with literature as a way of answering those questions, and then he became obsessed with neuroscience. Ultimately, when he himself was diagnosed with terminal illness, he said: 'I need to draw on literature, I need to draw on my experience as a doctor,' and he began writing. Partly it's a journal, and partly it gave him a lot of purpose to be sharing the experience in words.

It's been exactly 14 months since he died, and everybody I meet wants to talk about Paul and says his name and asks me about him. I don't think that's a usual experience for someone who's grieving. For me, it's been wonderful.

On the painful but healing experience of shepherding her husband's book to publication

After Paul died, the manuscript was just a Word document on his computer. I worked really hard with his editor to make sure it was published. I told them: 'I will do anything for this book, let me know what it is: I'll do a  book tour, I'll do whatever.' What I've learned is talking about him is really helpful for me. It's funny—it's been exactly 14 months since he died, and everybody I meet wants to talk about Paul and says his name and asks me about him. I don't think that's a usual experience for someone who's grieving. For me, it's been wonderful.

On how being doctors helped them come to terms with his death

As a neurosurgeon, he had been involved with many families facing a terrible stroke, or a car crash, or an aneurysm, or something where it's this critical inflection point in your life and your family's life and you're oftentimes deciding: when do you continue pushing and when is it actually a step too far to be aggressive? He helped people grapple with: what are my deepest values? How does my medical care get to what I want for my life? It was very helpful for him to have gone through this. It helped us understand...We weren't necessarily angry, we didn't say 'Why me? How could this happen?' We had seen it happen to so many people before that I think in a way we felt somewhat prepared or at least not alone in that experience. We sort of said, 'Now it's our turn to face this.'

To hear more from Lucy Kalanithi, tune in to Boston Public Radio above.