Advanced Medical Care in Japan — delivered under the Japanese Society for Radiation Oncology's unified treatment policy US randomized phase IIB and Japanese multicenter results
Proton therapy for esophageal cancer is a form of radiotherapy designed to reduce the dose reaching the heart and lungs, which sit right next to the esophagus. In a randomized trial at MD Anderson Cancer Center, proton therapy kept survival on par with intensity-modulated radiotherapy (IMRT) while lowering the total toxicity burden 2.3-fold and the postoperative complication score 7.6-fold. In Japan it is available as Advanced Medical Care. This article summarizes who it suits, treatment results, side effects and how to receive it in Japan, based on international sources.
The esophagus lies between the heart and lungs
The esophagus runs from the throat to the stomach, passing through the middle of the chest directly behind the heart, with a lung on each side. In radiotherapy for esophageal cancer, how well the heart and lungs are spared while the tumor gets a full dose has a large effect on quality of life after treatment.
Conventional X-rays pass through the body and leave energy both in front of and behind the tumor. Protons release most of their energy at a set depth and then stop (the Bragg peak), so less radiation reaches the heart and lungs behind the tumor. A 2021 review in the journal Radiotherapy and Oncology concluded that this difference translates into fewer heart and lung side effects and less loss of immune cells (lymphocytes).
Which patients with esophageal cancer are candidates?
Proton therapy is mainly considered when the cancer is confined to the esophagus and nearby lymph nodes and has not spread to distant organs. Both squamous cell carcinoma and adenocarcinoma are eligible, and it is used most often in two settings:
- Before surgery — radiotherapy with chemotherapy first, followed by esophagectomy. It can help reduce complications such as pneumonia after surgery.
- Definitive chemoradiotherapy — for patients who cannot have surgery because of age or other conditions, or who prefer to keep their esophagus.
The same review reported larger benefits for patients with a history of heart disease and for tumors in the lower esophagus. Centers increasingly estimate each patient's expected side effects to identify those who gain the most.
Results: a US randomized trial and Japanese multicenter data
MD Anderson Cancer Center randomized 145 patients with locally advanced esophageal cancer to proton therapy or IMRT in a phase IIB trial published in the Journal of Clinical Oncology in 2020. Both arms received 50.4 Gy with chemotherapy, and 107 evaluable patients were followed for a median of 44.1 months.
| Measure | Proton therapy | IMRT |
|---|---|---|
| Evaluable patients | 46 | 61 |
| Total toxicity burden score | 17.4 | 39.9 |
| Postoperative complication score | 2.5 | 19.1 |
| 3-year progression-free survival | 44.5% | 44.5% |
| 3-year overall survival | 51.2% | 50.8% |
Source: Lin SH, et al. Journal of Clinical Oncology 2020 (reported by The ASCO Post). Lower scores mean fewer side effects. The probability that proton therapy lowered toxicity was calculated at 99.9%, so the trial reached its conclusion early at the interim analysis.
The investigators concluded that proton therapy reduced the risk and severity of adverse events while maintaining survival. The much lower complication score among patients who went on to surgery is meaningful for anyone facing radiotherapy before an operation.
Good results have also been reported in Japan. Two key studies are a multicenter analysis of 202 patients (about half with stage III or IV disease) treated at four Japanese proton centers from 2009 to 2013 (Cancers 2019), and a registry of 174 patients treated under one shared policy at 12 Japanese particle therapy centers (Journal of Radiation Research 2023).
| Study | Patients | 3-year survival | Grade 3+ heart/lung events |
|---|---|---|---|
| 4 Japanese centers (2009–2013) | 202 | 66.7% (5-year 56.3%) | 1.5% (no grade 4+) |
| 12-center Japanese registry (2016–2018) | 174 | 60.5% | 2.3% |
Sources: Cancers 2019;11(7):993; Journal of Radiation Research 2023 (rrad012). In the 2023 study, 3-year survival by stage was 84.8% for stage I, 60.3% for stage II and 42.9% for stage III; 94% of registered patients received proton therapy.
The Japanese investigators found that proton therapy was as effective as X-ray treatment with fewer heart and lung side effects, and concluded that it can serve as another treatment option for esophageal cancer.
Fewer side effects and how they are managed
In comparative studies collected in the 2021 review, proton therapy reduced the following side effects:
- Lymphocyte loss — severe (grade 4) lymphopenia, a sharp drop in immune lymphocytes, occurred in 15.5% with protons versus 33.1% with IMRT in one study, less than half.
- Heart effects — among patients with prior heart disease, cardiac events within two years occurred in 11% with protons versus 30% with IMRT.
- Lungs and recovery after surgery — in a 580-patient study, postoperative lung complications were 16.2% with protons and 24.3% with IMRT, and the average hospital stay was 9.3 versus 11.6 days.
During treatment, esophagitis that makes swallowing sore is common. It is managed with soft foods, pain relief and mucosal protectants, and usually settles within a few weeks after treatment ends. Fatigue and skin redness can occur, but most people continue treatment as outpatients. Fluid around the heart develops rarely, so regular check-ups continue after treatment.
Steps and duration of proton therapy for esophageal cancer
- Consultation and record review — endoscopic biopsy and CT/PET imaging confirm the stage and whether the cancer has spread.
- Planning CT — an immobilization device keeps the same position each day, and the beam angles and dose are designed to account for the esophagus moving with breathing.
- Daily treatment — five days a week as an outpatient. The US randomized trial delivered 50.4 Gy in 28 sessions of 1.8 Gy over about five and a half weeks, together with chemotherapy.
- Surgery or observation — after preoperative treatment, esophagectomy follows a few weeks of rest. After definitive treatment, response is checked by endoscopy and CT.
- Follow-up — regular endoscopy and imaging, along with checks of heart and lung health.
Positioning takes longer than the beam itself, so a typical visit lasts about an hour. See Proton therapy process and duration for each step in detail.
How to receive proton therapy for esophageal cancer in Japan, and the cost
As of June 2026, Japan's public insurance covers proton therapy for 10 indications, including pediatric cancer, prostate cancer, liver cancer, pancreatic cancer, early lung cancer and lung metastases from colorectal cancer; esophageal cancer is not among them. Instead, it is delivered as Advanced Medical Care under the Japanese Society for Radiation Oncology's unified treatment policy, so several centers treat patients to the same standard and pool their results.
Under Advanced Medical Care, the patient pays the proton therapy technical fee in full, while tests, medicines and hospital stays are covered for people enrolled in Japan's public insurance. For example, the technical fee at the University of Tsukuba Hospital Proton Medical Research Center is 3,266,000 yen (revised November 2025). Patients living abroad without Japanese public insurance pay for tests and hospital stays as well, so they should request a separate estimate from the hospital.
Evidence supporting insurance coverage is growing. A 2024 cost-effectiveness analysis by Japanese researchers (PLOS ONE) reported that covering proton therapy for esophageal cancer could be justified depending on the fee level. In the US, a 300-patient phase III trial comparing proton therapy with IMRT (NRG-GI006) completed enrollment in August 2026 and has moved on to analysis. For the differences between insurance, Advanced Medical Care and self-pay treatment, see Proton therapy in Japan; for how it works, see Proton therapy medical information.
Before contacting a hospital, prepare your endoscopic biopsy pathology report, CT/PET images (original discs), the names and dates of any chemotherapy, and records of heart or lung conditions. This speeds up the consultation.
Points to check and questions for your doctor
- Given my stage and tumor location, would proton therapy offer a larger benefit than IMRT?
- Should I have it before surgery, or as definitive chemoradiotherapy?
- Which chemotherapy will be given with it, and how many sessions are planned?
- I have heart or lung disease — can my expected side effects be estimated?
- When and where should I have endoscopy and imaging after treatment?
Frequently asked questions
Does proton therapy for esophageal cancer cause fewer side effects than standard radiotherapy?
In the US randomized trial, the total toxicity burden score was 17.4 with protons versus 39.9 with IMRT, 2.3 times lower, and the postoperative complication score was 7.6 times lower. Survival was at the same level with both treatments.
What are the survival rates after proton therapy for esophageal cancer?
In a study of 202 patients at four Japanese centers, 3-year survival was 66.7% and 5-year survival 56.3%; in a 174-patient study at 12 Japanese centers, 3-year survival was 60.5%. Results were better at earlier stages.
Is proton therapy for esophageal cancer covered by insurance in Japan?
As of June 2026 it is not covered by public insurance and is given as Advanced Medical Care. The proton technical fee is paid in full by the patient: 3,266,000 yen at the University of Tsukuba Hospital.
How many sessions of proton therapy are needed for esophageal cancer?
It depends on the center and treatment goal. In the US randomized trial, patients came five days a week for 28 sessions of 1.8 Gy over about five and a half weeks, with chemotherapy.
Related: Proton therapy process and duration · Proton therapy for prostate cancer · Proton therapy medical information
Sources
- Lin SH, et al. Randomized phase IIB trial of proton beam therapy versus intensity-modulated radiation therapy for locally advanced esophageal cancer. J Clin Oncol 2020 — The ASCO Post
doi.org/10.1200/JCO.19.02503
Checked: 2026-10-31 - Clinical results of proton beam therapy for esophageal cancer: multicenter retrospective study in Japan. Cancers 2019;11(7):993
doi.org/10.3390/cancers11070993
Checked: 2026-10-31 - Analysis of particle therapy registries based on a unified treatment policy for esophageal cancer. J Radiat Res 2023
doi.org/10.1093/jrr/rrad012
Checked: 2026-10-31 - Current status and applications of proton therapy for esophageal cancer. Radiother Oncol 2021;164:27–36
pmc.ncbi.nlm.nih.gov
Checked: 2026-10-31 - Sawada T, et al. Cost-utility analysis of proton beam therapy for locally advanced esophageal cancer in Japan. PLOS ONE 2024;19(9):e0308961
doi.org/10.1371/journal.pone.0308961
Checked: 2026-10-31 - NRG Oncology — NRG-GI006: phase III randomized trial of proton beam therapy versus IMRT for esophageal cancer
nrgoncology.org
Checked: 2026-10-31 - Kyoto Prefectural University of Medicine Hospital — expansion of public insurance coverage for proton therapy, June 2026 (Japanese)
h.kpu-m.ac.jp
Checked: 2026-10-31 - University of Tsukuba Hospital Proton Medical Research Center — treatment costs (Japanese)
pmrc.tsukuba.ac.jp
Checked: 2026-10-31
Written by the FTH editorial team. Sources checked 2026-10-31 · 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.
