Dr. Henry Hirschberg Retires After Four Decades of Medicine and Research 

After a distinguished career dedicated to advancing the frontiers of biomedical photonics and laser medicine, Dr. Henry Hirschberg of the UC Irvine Beckman Laser Institute & Medical Clinic is stepping back as a researcher, leaving behind a legacy that has shaped both the science and the scientists of tomorrow.

A Leader in Laser-based Medicine 

Dr. Hirschberg’s journey to becoming one of the leading figures in laser-based medicine began in Norway, where he earned his Bachelor of Electrical Engineering from City University of New York and both his M.D. and Ph.D. with a specialty in immunology from the University of Oslo. Before joining UC Irvine Beckman Laser Institute & Medical Clinic, he served as a consultant in neurosurgery and chief of image-guided and stereotactic surgery and neurosurgical oncology in the Department of Neurosurgery at University Hospital Rikshospitalet in Oslo, Norway. This role forged his deep expertise in the intersection of medicine, science, and engineering.

His unique combination of clinical neurosurgery experience and immunological expertise set the foundation for a research career that would span decades and continents. Dr. Hirschberg has two primary research areas: the clinical application of photodynamic therapy (PDT) and finding new ways to use photochemical internalization (PCI) as laser-based novel treatment modalities for malignant brain tumors. Over the course of his career, he has authored and co-authored more than 200 publications. His work stands as a testament to his tireless dedication to advancing cancer treatment.

 Pioneering Work in Brain Tumor Treatment

Dr. Hirschberg’s work has consistently targeted one of medicine’s most formidable challenges: malignant brain tumors. As he himself once noted, “These are the most malignant tumors in all of biology. Curing these patients hasn’t been possible because the cancer migrates and regenerates so readily, but we may be on our way toward better management of the disease.”

As early as 1999, while serving as a visiting researcher at the Institute, Dr. Hirschberg was already developing breakthrough approaches to brain cancer treatment. Working alongside collaborators including Drs. Steen Madsen, Chung-Ho Sun, and Bruce Tromberg [then Director of the Institute’s Laser Microbeam and Medical Program (LAMMP)] he developed a special balloon-tipped applicator for combined brachy-photodynamic therapy. The device, designed to be implanted in the cranial cavity following surgical resection, allowed physicians to continuously deliver both ionizing radiation and therapeutic laser light directly to tumor sites where undetected cancer cells were thought to remain.

“By keeping the applicator inflated in the brain cavity, we investigated if we could continue to treat the periphery of the tumor site where stray cancer cells might otherwise try to regenerate,” Dr. Hirschberg explained.

A Growing Research Portfolio and Recognition

 In 2003, Dr. Hirschberg was formally appointed as a Researcher at the Institute, supported by an award from the Norwegian Science Council for his continued research on photodynamic therapy of brain tumors. The appointment marked the beginning of an even more prolific chapter in his scientific career.

By 2006, he had been awarded three prestigious grants. Two were from the Nevada Cancer Institute Foundation and the Norwegian Radium Hospital Research Foundation for research into the selective opening of the blood-brain barrier (BBB) using photodynamic therapy and photochemical internalization. This proved to be a crucial avenue of inquiry, since the BBB poses a significant impediment to delivering therapeutic drugs into the brain, particularly for the treatment of malignant gliomas. A third grant from the Norwegian Radium Hospital Research Foundation supported research into the treatment of malignant brain tumors using viral and non-viral pax6 gene therapy combined with photochemical internalization, in collaboration with institutions in Norway, UC Irvine, and the University of Nevada, Las Vegas.

In 2009, Dr. Hirschberg, along with Drs. Steen Madsen and H. Michael Gach of the Nevada Cancer Institute, received a competitive grant from the Nevada Health Sciences System. The award was one of only five funded out of 40 submitted proposals. The grant supported a novel photothermal approach called “Macrophage-mediated delivery of nanoparticles for photothermal ablation of malignant gliomas,” which proposed harnessing the body’s own immune cells to carry therapeutic nanoparticles directly to tumor sites.

The following year, in 2010, a landmark review article co-authored by Drs. Hirschberg and Madsen titled, “Site-specific opening of the blood-brain barrier,” was selected as “Editor’s Choice” in the June 2010 issue of the Journal of Biophotonics. This served as a prestigious distinction that underscored the far-reaching significance of their research.

In 2014, Dr. Hirschberg was awarded a two-year National Institutes of Health (NIH) consortium grant between UC Irvine and UC Davis. The grant focused on “Photodynamic therapy mediated by Cerenkov light from radiopharmaceuticals,” further expanding the frontiers of light-based cancer treatment.

Most recently, in 2023, Dr. Hirschberg was named among the UC Irvine Anti-Cancer Challenge Pilot Project Awardees for his research title, “Enhancing the Efficacy of Radiation Therapy by Surgically Targeted Radiation-Sensitizer Loaded Hydrogels.” This project aimed to implant slow-release radiation sensitizers into the surgical cavity following tumor resection, enhancing the precision and effectiveness of image-guided radiation therapy while sparing healthy tissue. The project held promise not only for primary and metastatic brain tumors, but for other operable cancers such as breast and lung.

A Long-Standing Collaboration

 Central to much of Dr. Hirschberg’s research success has been his long-standing collaboration with Dr. Steen Madsen, a former Institute postdoctoral researcher who went on to become Professor and Chair of the Department of Integrated Health Sciences at the University of Nevada, Las Vegas (UNLV). The two researchers have collaborated across decades and across institutions, co-authoring influential work on PDT, BBB disruption, and macrophage-mediated drug delivery. In recognition of this enduring partnership, Dr. Hirschberg also served as an Adjunct Professor at UNLV.

A 2015 study exemplified the impact of their collaboration, demonstrating that gold-loaded macrophages, the body’s own immune cells, repurposed as therapeutic delivery vehicles, combined with photothermal laser therapy could kill tumor cells in models of glioblastoma multiforme (GBM), a brain cancer with a five-year survival rate of less than five percent. Their findings were published in the Annals of Biomedical Engineering and Lasers in Surgery and Medicine. While crossing the blood-brain barrier remained an ongoing challenge, both researchers remained confident that the approach held real promise for improving outcomes for GBM patients.

Esteemed Mentor & Colleague

 Beyond his scientific accomplishments, those who know Dr. Hirschberg recognize him for his unwavering commitment to mentorship. Over the course of his career, he guided numerous graduate students, postdoctoral researchers, and early-career scientists. Many of these researchers have continued to make their own significant contributions to the fields of biophotonics, oncology, and biomedical engineering. His expertise in immunology, combined with his passion for medicine, science, and engineering, created a broad investigatory environment.

“Henry showed us what a surgeon-scientist can do in a laser institute: ask clinically important questions and then pursue them relentlessly in the lab.,” said Bernard Choi, Ph.D., Director of the Beckman Laser Institute & Medical Clinic. “Henry is a gifted scientist who repeatedly demonstrated his dedication to training the next generation of cancer researchers. The Institute is better for his years here.”

A Lasting Impact

 Having retired on July 1, 2026, and transitioned to Research Emeritus, Dr. Hirschberg’s influence is far from over. The surgical devices he invented, the therapies he pioneered, the over 200 publications he contributed to the scientific record, and the researchers he mentored will continue to carry his work forward for years to come. From the operating theaters of Oslo to the laboratories of Irvine, his career has been defined by an unwavering commitment to giving patients hope in the face of the most aggressive cancers known to medicine.

As he transitions into this new chapter, the Institute extends its deepest gratitude and warmest wishes to Dr. Henry Hirschberg – a scientist, a surgeon, and a mentor.