Research stage — cell and mouse studies; effect in humans not confirmed For comparison: Japan’s insurance-covered brain tumor PDT (talaporfin) is a separate treatment
Among studies of photothermal therapy for glioblastoma, a Taiwanese study (Cancers, 2021) reported that IR-780 liposomes — the near-infrared dye IR-780 packed into liposomes (tiny spheres with a fatty membrane) — shrank brain tumors in mice. However, these results come from cell and mouse experiments only; the effect in humans has not yet been confirmed. In the sources we checked, there is no clinical trial of IR-780 liposomes in patients, and it is not an approved treatment.
What is IR-780 liposome photothermal therapy?
IR-780 is a dye that strongly absorbs invisible near-infrared light (wavelengths around 780–808 nm). Near-infrared light penetrates a little deeper into the body than visible light, so when the dye gathers in a tumor and a laser is applied, two things can happen: the light energy turns into heat that damages cancer cells (photothermal therapy, PTT), and reactive oxygen species that attack cells are produced (photodynamic therapy, PDT). Because the dye’s fluorescence can be seen on imaging, it is also studied as an agent that combines diagnosis and treatment.
The problem is that IR-780 barely dissolves in water and breaks down easily under light. In a treatment that needs repeated laser exposure, the dye degrades quickly and produces less heat. Researchers from the Department of Neurosurgery at Chang Gung Memorial Hospital and Chang Gung University in Taiwan tried to overcome this by inserting the dye into the fatty membrane of positively charged liposomes. The liposomes were about 137 nm in size, and about 82% of the dye was loaded into them (encapsulation efficiency).
Another feature is how the drug was delivered. The brain has a blood-brain barrier that keeps many substances in the blood from entering, so intravenous drugs reach brain tumors poorly. The researchers used convection-enhanced delivery (CED), in which a thin tube is placed directly in the tumor and the drug is pushed in slowly.
Which cancer was studied? Mice implanted with human glioblastoma cells
The target was glioblastoma, the most common and one of the hardest-to-treat malignant brain tumors. The experiments used a single human glioblastoma cell line (U87MG), which was implanted into the brains of immunodeficient mice to grow tumors before treatment. No patients took part, so there is not yet any answer to “which patients can receive this treatment.”
- Mouse groups: saline + laser, dye alone (IR-780) + laser, IR-780 liposomes + laser — 4 mice each
- Laser: 808 nm, 1 W/cm², 5 minutes, 3 times (days 7, 9 and 11 after implantation)
- Safety measure: brain temperature kept below 55°C
How large were the effects? The original numbers
First, in a test tube, the laser was switched on for 3 minutes and off for 15 minutes, three times. With the dye alone, the peak temperature fell from 37°C to 35°C to 29°C, while with the liposomes it stayed at 37°C, 38°C and 38°C. Under ordinary room light, the dye alone dropped to below 10% of its initial absorbance after 9 hours, while the liposomes showed no noticeable change over 24 hours. The liposomes also entered cancer cells faster (0.5 hours vs 1 hour).
| Measure (mouse study) | Saline + laser | IR-780 alone + laser | IR-780 liposomes + laser |
|---|---|---|---|
| MRI tumor volume, day 13 | 49.5 mm³ | 32.7 mm³ | 14.8 mm³ |
| MRI tumor volume, day 16 | 99 mm³ | 90.6 mm³ | 34.6 mm³ |
| Median survival | 16 days | 16 days | 22 days |
| Dye fluorescence retained in brain, day 12 | — | 13% | 52% |
Source: Lu YJ et al., Cancers 2021;13(15):3690. 4 mice per group; fluorescence retention is relative to day 6. These are mouse data and do not mean the same result can be expected in humans.
In the liposome group, tumors grew to about one third the size of those in the other groups, and median survival was 6 days longer. No notable abnormalities were reported in major organ tissue or blood tests. But there are clear limits to how these results can be read.
- The tumors did not disappear. Survival in the liposome group was also around 22 days; growth was slowed, not eliminated.
- The study was very small. Four mice per group and one cell line.
- Not every result favored the liposomes. In a solution test, the dye alone actually produced more reactive oxygen, and the rates of cell death (apoptosis) were almost the same at 12.0% and 11.7%.
- Light penetration remains a problem. A mouse brain is small, so the laser reaches the tumor easily; the human brain is much larger and the skull thicker, so the same approach cannot be assumed to work. Placing a tube into the tumor for CED is also a surgical procedure.
Approval status and light-based treatment available in Japan
- IR-780 liposomes: As of the date we checked, not approved in the US, Europe or Japan, and we found no human clinical trial on ClinicalTrials.gov or elsewhere. Research stage.
- Brain tumor photodynamic therapy in Japan (talaporfin sodium PDT): In Japan, photodynamic therapy using a drug (talaporfin sodium) and a semiconductor laser on the area where the tumor was removed during surgery became covered by health insurance for malignant brain tumors in September 2013. According to a 2016 review by Prof. Jiro Akimoto of Tokyo Medical University, 27 people took part in an investigator-initiated trial in 2009–2012; in 13 patients with newly diagnosed glioblastoma, median overall survival was 24.8 months and progression-free survival 12 months, and adverse events directly related to the treatment were reported as mild. However, it was a small trial without a comparison group.
- Photoimmunotherapy for head and neck cancer: The photoimmunotherapy conditionally approved in Japan in 2020 is for head and neck cancer and uses a different drug. How to tell similarly named treatments apart is explained in Same name “photoimmunotherapy”, not the same treatment.
In short, talaporfin PDT is an approved treatment given together with surgery, while IR-780 liposome photothermal therapy has only shown potential in mice. The two should not be treated as the same. Even if a Japanese clinic offers self-pay care (outside public approval and insurance) under names such as “near-infrared” or “photoimmunotherapy,” this paper does not confirm the effect of that treatment. Public information on photoimmunotherapy in Japan is available at Photoimmunotherapy information.
What patients should check — questions for your doctor
- What standard treatment (surgery, radiation, chemotherapy) is recommended for my glioblastoma now, and which clinical trials could I join?
- If I have surgery, would intraoperative light treatment such as Japan’s talaporfin PDT make sense in my case?
- If near-infrared or photothermal treatment is offered, what is the exact name of the agent, is it approved, and is there a paper with results in humans?
- How do you check that the light reaches the full depth of the tumor and that heat will not damage the normal brain around it?
- What are the cost and number of sessions, and which hospital will handle side effects?
Frequently asked questions
Can I receive glioblastoma treatment with IR-780 liposomes?
No. As of the date we checked, it is at the mouse-study stage, and we could not confirm any approval or ongoing clinical trial in patients.
What is the difference between photothermal and photodynamic therapy?
Photothermal therapy turns light into heat to damage cells; photodynamic therapy uses light to create reactive oxygen that damages cells. IR-780 is studied because it can do both.
Is there an insurance-covered light treatment for brain tumors in Japan?
Yes. Photodynamic therapy with talaporfin sodium has been covered by insurance since 2013 as an intraoperative treatment for malignant brain tumors. Which hospitals offer it and whether you are eligible should be confirmed with your neurosurgery team.
If survival improved in mice, won’t it work in people too?
That cannot be assumed. The experiment used four mice per group, and the human brain differs greatly in size and light penetration. The effect is unknown until confirmed in human trials.
Related: Same name “photoimmunotherapy”, not the same treatment · Proton therapy in Japan · Heparanase aptamer cancer research
Sources
- Lu YJ, Anilkumar TS, Chuang CC, Chen JP. Liposomal IR-780 as a Highly Stable Nanotheranostic Agent for Improved Photothermal/Photodynamic Therapy of Brain Tumors by Convection-Enhanced Delivery. Cancers 2021;13(15):3690
mdpi.com/2072-6694/13/15/3690
Checked: 2026-10-17 - Same paper, full text on PubMed Central (PMC8345063)
pmc.ncbi.nlm.nih.gov/articles/PMC8345063
Checked: 2026-10-17 - Akimoto J. Photodynamic Therapy for Malignant Brain Tumors. Neurologia medico-chirurgica 2016;56(4):151-157
jstage.jst.go.jp
Checked: 2026-10-17
Written by the FTH editorial team. Sources checked 2026-10-17 · Medical review: not applicable
This article is general information based on public sources and does not replace diagnosis or treatment. Please discuss treatment decisions with your medical team.
