For 10 years, Dr. Jon Bear flew F-18s for the U.S. Navy, including 19 combat missions in the opening days of the Iraq War.
“We needed to be precise, we needed to get everything done on target and on time,” the Coronado resident said. “That precision really carried over.”
Bear, who retired from the Navy in 2024 after 26 years of service, is now a radiation oncologist leading a new chapter at Palomar Health’s Cancer Institute: high-dose rate brachytherapy for prostate cancer.
The program, set to launch Sept. 16, will be the only one of its kind south of UCLA.
Brachytherapy, at its simplest, is the act of placing a radioactive source directly inside a tumor. The effect is twofold: it allows physicians to deliver extremely high doses of radiation precisely where they’re needed, while sparing surrounding tissue.
“The dose-limiting factor for radiation is not the cancer — you can kill any cancer if you give enough radiation — it’s the normal tissue,” Bear said.
Unlike external beam radiation, which passes through healthy structures on its way to the prostate, brachytherapy positions the source against the tumor itself, minimizing collateral damage.
The process
The process is both technically intricate and, for patients, straightforward.
After an initial consultation — often following a conversation with a urologist — patients undergo imaging and, in some cases, molecular testing to help guide treatment.
On the day of the procedure, they arrive early, are placed under anesthesia and in a lithotomy position, Bear described.
Guided by an ultrasound, he threads slender catheters through the perineum and into the prostate, usually 16 or 17 in total, depending on the size of the gland. A CT scan follows, allowing his team to map, with millimeter accuracy, how radiation will be delivered through each catheter.
From there, Bear said, the room is cleared. A shielded machine dispatches a tiny iridium-192 source through the wires, into the prostate, and then safely retracts it back again. The patient is never radioactive.
The entire process — from anesthesia to discharge — takes three to four hours.
“It’s outpatient,” Bear said. “Most men are up and walking the next day, sometimes playing golf.”
According to the American Cancer Society, most external radiation treatments for prostate cancer require daily sessions, five days a week, for several weeks at an outpatient center. In contrast, high-dose brachytherapy is typically completed in one to four short treatments over two days.
A randomized trial in 2023 found that men with intermediate- and high-risk prostate cancer who received a low-dose-rate brachytherapy boost were far less likely to experience disease progression than those treated with dose-escalated external beam radiation (85% vs. 67%).
A team effort for advanced care
Behind the procedure at Palomar Health lies a small army: urologists, anesthesiologists, nurses, physicists, radiation therapists, scrub techs and front desk staff, more than a dozen people in total.
For Bear, who once led a division of 48 mechanics aboard a carrier, the team structure is familiar.
“If I do my best and take care of the people who work for me, they’re going to meet me more than halfway every single time,” he said. “That’s the same in medicine.”
Palomar’s investment in brachytherapy is part of a larger expansion that includes two state-of-the-art linear accelerators, which enhance precision during external-beam radiation therapy. The technologies are complementary. External beam radiation covers broader areas, while brachytherapy delivers concentrated boosts.
Some patients, particularly older ones with heart or lung conditions, may be better suited to external beam therapy alone. Others, especially with aggressive prostate cancer, may receive a combination of both.
The program will begin with prostate cancer, but Bear said he envisions it expanding to gynecological malignancies such as cervical and endometrial cancers, and eventually to lung and gastrointestinal tumors.
Wherever the cancer is, the principle is the same: put the source as close to the tumor as possible, and shorten the course of treatment from weeks to days.
A veteran himself, Bear still works closely with the VA Medical Center-San Diego, and North County’s new program means men won’t need to travel to Orange County or beyond for advanced prostate cancer care.
“Taking care of veterans is near and dear to my heart,” he said. “This keeps them close to their families, their support networks.”
Congressman Scott Peters, who visited Palomar Health Aug. 19, has advocated for expanding access to such therapies, pressing for research funding and insurance reforms to make advanced cancer care more equitable.
Bear, who trained at the National Cancer Institute before coming to Palomar, said that progress depends on both: cutting-edge equipment and the political will to ensure patients can access it.
In conversation, Bear often returns to the idea of teamwork — the camaraderie of the cockpit, the operating room and the clinic.
“When I was a pilot, it was a team effort,” he said. “It’s the same here. Nurses, techs, executives — everyone has put in so much effort to launch this program.”
For Bear, the parallels between flying combat missions and fighting cancer are not merely rhetorical; both demand precision, adaptability and the ability to remain composed under pressure.
Yet the stakes of his current mission feel more intimate.
“I’m looking forward to the huge impact [this will have] on our community,” he said. “Patients won’t have to travel as far anymore to get this great treatment; it’s going to be in their own backyard.”
