Leading the Future of Radiation Oncology: An Interview with Dr. Hiromasa Kurosaki

-A leader in BNCT and Tomotherapy, based cancer treatment.

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Japan’s cancer treatment landscape has gained global attention in recent years, particularly for its advanced use of technologies like Tomotherapy-based IMRT (Intensity-Modulated Radiation Therapy) and BNCT (Boron Neutron Capture Therapy). At the forefront of these innovations is Dr. Hiromasa Kurosaki, a leading radiation oncologist known for his deep clinical expertise and pioneering contributions in the field.

In this special interview, we speak with Dr. Kurosaki to explore not only the cutting-edge treatments being developed and implemented in Japan, but also the philosophy, dedication, and vision behind his work. This article aims to share with the world the depth of Japan’s medical excellence—and the human stories behind it.

Dr. Hiromasa Kurosaki, MD – Radiation Oncologist

Head of Radiation Oncology, Edogawa Hospital (Tokyo, Japan)

Dr.Hiromasa Kurosaki

Q. Could you tell us about the current status of BNCT at Edogawa Hospital?

Dr.Kurosaki: I joined Edogawa Hospital in 2021. Since then, I’ve been overseeing tomotherapy treatments while also preparing to introduce BNCT. Thanks to the cooperation of many people, we were able to officially start BNCT in the summer of 2023, which was a significant milestone for our team.

Q. In July 2023, your team launched a pilot study using BNCT for recurrent breast cancer.

What have the results been so far?

Dr.Kurosaki: Yes, we began the pilot study on July 5, 2023, targeting patients with recurrent breast cancer after previous radiation therapy. So far, we've treated five patients. Four of them have shown tumor shrinkage and improvement in symptoms. One of the cases involved multiple recurrences on the skin, which are often difficult to treat even with X-ray or particle therapy. The patient herself noticed a clear improvement, which was very encouraging for all of us.

Q. Have the results of these treatments been shared in academic literature?

Dr.Kurosaki: Yes, we published our findings in the journal Cureus. In particular, we reported on the effects of BNCT on the lungs in recurrent breast cancer cases. Importantly, no cases of radiation pneumonitis were observed during the follow-up period, which is a very promising result.

Q. What was it like to perform the world’s first BNCT for breast cancer?

Dr.Kurosaki: It was both exciting and, to be honest, a bit nerve-wracking! (laughs) While BNCT has shown good results in brain tumors, applying it to breast cancer was a global first. We prepared carefully with the patient and our team, and when we successfully completed the treatment, it was truly moving. It felt like we were expanding the future of cancer therapy.

Q. How do you think this experience will impact the future of cancer treatment?

Dr.Kurosaki: Until now, BNCT has mainly been used for difficult-to-treat brain and head & neck tumors. Applying it to breast cancer—especially in cases where conventional treatment options are limited—shows great promise. I believe this is an important step forward in expanding the treatment options available for patients with various types of solid tumors.

Q. Could you tell us more about your next steps for expanding the use of BNCT?

Dr.Kurosaki: We’ve started a clinical research study focused on FDG-PET-positive tumors, with 10 patients. This will help us evaluate BNCT's effectiveness more scientifically and support future expansion of its indications. Our goal is to bring the potential of BNCT to more people in need.

Q. Is BNCT suitable for all cancer patients? What types of cases benefit the most?

Dr.Kurosaki: BNCT is especially effective for patients with local recurrence, inoperable tumors, or those who require re-irradiation. It’s particularly useful when conventional treatments are no longer effective. BNCT allows us to focus treatment on cancer cells while preserving surrounding healthy tissue. That said, it’s not for everyone—factors like tumor location and boron uptake need to be considered. While not a “magic bullet,” it has the potential to be used both early and late in a patient’s treatment journey.

Q. What makes the radiation oncology department at Edogawa Hospital unique?

Dr.Kurosaki: One of our key strengths is that the doctors handling BNCT also perform tomotherapy (IMRT). So even if a patient is not eligible for BNCT, we can offer other options like IMRT or endovascular therapies. Rather than relying on just one treatment, we take a flexible, personalized approach to find the best option for each patient.

Q. How is IMRT different from traditional radiation therapy, and why is it considered advanced?

Dr.Kurosaki: IMRT, or Intensity-Modulated Radiation Therapy, allows us to finely control the intensity of radiation across the tumor, like tailoring a suit specifically for the shape of the cancer. This enables us to deliver high doses to the tumor while reducing side effects. Edogawa Hospital was actually one of the first hospitals in Japan to introduce tomotherapy, and we are currently the only facility in the world operating three machines. We also have the highest number of tomotherapy cases in Japan, so our experience is extensive.

Q. Japan is known for its high standard in IMRT. What are some of the unique characteristics of how it’s practiced in Japan?

Dr.Kurosaki: In Japan, we spend a great deal of time on treatment planning to ensure precision. You could say it reflects our national attention to detail! (laughs) As a result, the quality of IMRT here is extremely high. Also, at Edogawa Hospital, our radiation oncology department includes inpatient facilities, which allows us to support patients who need more comprehensive care.

Q. Do you sometimes combine IMRT with other therapies?

Dr.Kurosaki: Yes, we often combine IMRT with hyperthermia or high-pressure oxygen therapy to increase the effectiveness of treatment. In some cases, we may use IMRT for one area and endovascular therapy (catheter-based treatment) for another. This kind of multidisciplinary approach allows us to respond flexibly to complex cancer cases.

Q. Finally, do you have a message for patients and healthcare professionals considering BNCT?

Dr.Kurosaki: BNCT is a promising treatment for patients who meet certain conditions. If you’re interested, I encourage you to reach out to us for more information. Our entire team is dedicated to finding the best possible treatment for each patient, and we’re here to support you every step of the way.

Doctor Profile

Dr. Hiromasa Kurosaki (born February 14, 1971) is a leading Japanese radiation oncologist with over two decades of clinical experience, particularly in the areas of hyperthermia-combined radiation therapy and advanced radiotherapy technologies such as tomotherapy and BNCT (Boron Neutron Capture Therapy).

After completing his initial training at the Department of Radiation Medicine at Gunma University, Dr. Kurosaki gained experience at several top institutions in Japan, including the Gunma Prefectural Cancer Center, Tokyo Metropolitan Komagome Hospital, and Toranomon Hospital. He developed deep expertise in hyperthermia-enhanced radiation treatment and patient-centered oncologic care.

In 2012, he joined Tokyo Kosei Nenkin Hospital (now JCHO Tokyo Shinjuku Medical Center), where he became Head of the Radiation Oncology Department in 2015.

In 2021, Dr. Kurosaki was invited to join Edogawa Hospital as the Head of Radiation Oncology. Edogawa Hospital was the first in mainland Japan to introduce tomotherapy and remains the only institution in the world operating three tomotherapy systems simultaneously. His leadership in integrating advanced technologies has significantly contributed to Japan’s high global standing in IMRT (Intensity-Modulated Radiation Therapy).

Under his direction, Edogawa Hospital ranked 6th nationwide in IMRT case volume in 2022.

In July 2023, Dr. Kurosaki led the world’s first BNCT treatment for recurrent breast cancer using an accelerator-based neutron source—a landmark moment in the evolution of cancer therapy. He is also active in academic and policy development, serving as:

Board Member, Japanese Society of Hyperthermia Oncology

Chair, Health Insurance Committee

President, 41st Annual Meeting of the Hyperthermia Society

Dr. Kurosaki continues to work on expanding the indications for BNCT and integrating multi-modal cancer therapies to provide the most effective and compassionate care for each patient.