Cost-utility analysis of proton beam therapy for locally advanced esophageal cancer in Japan.

PURPOSE: Proton beam therapy (PBT) has recently been included in Japan's health insurance benefit package for certain cancer types. This study aimed to determine the cost-effectiveness of PBT as a replacement for conventional three-dimensional conformal radiotherapy (3D-CRT) for locally advanced esophageal cancer (LAEC) that is not covered by social insurance. METHODS: We estimated the incremental cost-effectiveness ratio (ICER) of PBT as a replacement for 3D-CRT, using clinical evidence from the literature and expert opinions. We used an economic model, decision tree, and Markov model to illustrate the courses followed by patients with LAEC. Effectiveness was estimated as quality-adjusted life years (QALY) using utility weights for the health state. Social insurance fees were calculated as costs. We assumed two base cases depending on the two existing levels of fees for PBT in social insurance: 2,735,000 Japanese yen (US$20,652) or 1,600,000 yen (US$13,913). The stability of the ICER against these assumptions was appraised using sensitivity analysis. RESULTS: The effectiveness of PBT and 3D-CRT was 2.62 and 2.51 QALY, respectively. The estimated ICER was 14,025,268 yen (US$121,958) per QALY for the higher fee level and 7,026,402 yen (US$61,099) for the lower fee level. According to the Japanese threshold for cost-effectiveness of anticancer therapy of 7,500,000 yen (US$65,217) per QALY gain, the inclusion of PBT for LAEC in the benefit package of social insurance is cost-effective if a lower fee is applied. CONCLUSION: PBT is a cost-effective alternative to 3D-CRT for LAEC and making it available to patients under social insurance could be justifiable.

Analysis of the cost-effectiveness of proton beam therapy for unresectable pancreatic cancer in Japan.

BACKGROUND: Proton beam therapy (PBT) has recently been included in Japan's social health insurance benefits package. This study aimed to determine the cost-effectiveness of PBT for unresectable, locally advanced pancreatic cancer (LAPC) as a replacement for conventional photon radiotherapy (RT). METHODS: We estimated the incremental cost-effectiveness ratio (ICER) of PBT as a replacement for three-dimensional conformal RT (3DCRT), a conventional photon RT, using clinical evidence in the literature and expense complemented by expert opinions. We used a decision tree and an economic and Markov model to illustrate the disease courses followed by LAPC patients. Effectiveness was estimated as quality-adjusted life years (QALY) using utility weights for the health state. Social insurance fees were calculated as the costs. The stability of the ICER against the assumptions made was appraised using sensitivity analyses. RESULTS: The effectiveness of PBT and 3DCRT was 1.67610615 and 0.97181271 QALY, respectively. The ICER was estimated to be ¥5,376,915 (US$46,756) per QALY. According to the suggested threshold for anti-cancer therapy from the Japanese authority of ¥7,500,000 (US$65,217) per QALY gain, such a replacement would be considered cost-effective. The one-way and probabilistic sensitivity analyses demonstrated stability of the base-case ICER. CONCLUSION: PBT, as a replacement for conventional photon radiotherapy, is cost-effective and justifiable as an efficient use of finite healthcare resources. Making it a standard treatment option and available to every patient in Japan is socially acceptable from the perspective of health economics.

Stereotactic Body Radiotherapy for Stage I Lung Cancer With a New Real-time Tumor Tracking System.

BACKGROUND/AIM: Suppression of respiratory movement is crucial for safe and effective stereotactic body radiotherapy (SBRT). SyncTraX FX4 is a novel device for synchronous respiratory irradiation. The purpose of this study was to evaluate the efficacy and toxicity of SBRT using SyncTraX FX4 for patients with lung cancer. PATIENTS AND METHODS: Patients treated with SBRT using SyncTraX FX4 between November 2017 and August 2020 were included. In all cases, fiducial markers were inserted into the lung, and the total dose administered was 55 or 60 Gy, depending on the distance from the central region of the lung. Acute and late toxicities were reported, and local control, progression-free survival, cancer-specific survival, and overall survival were analyzed. RESULTS: We evaluated 16 patients and 17 sites. The median follow-up period was 14.4 months. In both the acute and late phases, one patient experienced grade 3 radiation pneumonitis; however, grade 4 or higher toxicities were not observed. There was no local recurrence during the observation period, and the overall survival, cancer-specific survival, and progression-free survival at 2 years were 54.6%, 85.1%, and 33.7%, respectively. CONCLUSION: SBRT with SyncTraX FX4 can provide safe and effective treatment for lung cancer patients in poor condition.

A Case Report of Radiotherapy for Skull Lesions of Langerhans Cell Histiocytosis With Dural Invasion.

Background: Langerhans cell histiocytosis (LCH) is a rare disease, especially in adults. It is often associated with non-fatal bone and skin lesions and has relatively good radiosensitivity. In contrast, brain and lymph node metastases from LCH lesions are considered to be less sensitive to radiotherapy. Case Report: At our institution, 30 Gy radiotherapy was used to treat bone lesions with dural invasion in a patient with adult-onset LCH. The patient was treated with chemotherapy and radiotherapy for 21 years since the initial diagnosis. After radiotherapy, the tumor shrank rapidly, and a complete response was achieved 1 year after treatment. The patient survived without local recurrence. Conclusion: Here, we report the details of this case, along with a review of the literature. We suggest that even with invasion of the tissues around the bone lesions in LCH, local recurrence can be prevented by middle radiation doses.

Long-term follow up of a patient with a recurrent desmoid tumor that was successfully treated with proton beam therapy: A case report and literature review.

Desmoid tumors are benign, but may have a locally invasive tendency that commonly results in local recurrence. Most occur on the body trunk or extremities, whereas a head and neck desmoid tumor is relatively rare. The efficacy of radiotherapy has been suggested and 50-60 Gy is used for unresectable or recurrent desmoid tumors, but there are few reports of use of particle beam therapy. However, since this tumor occurs more often in younger patients compared to malignant tumors and the prognosis is favorable, there may be an advantage of this therapy. We treated a male patient with a head and neck recurrent desmoid tumor with proton beam therapy (PBT) at a dose of 60 Gy (RBE). This patient underwent surgical resection as initial treatment, but the tumor recurred only six months after surgery, and resection was performed again. After PBT, the tumor gradually shrank and complete remission has been achieved for 10 years without any severe late toxicity. Here, we report the details of this case, with a review of the literature. We suggest that PBT may reduce the incidence of second malignant tumors by reducing the dose exposure around the planning target volume.

Immunogenic cell death due to a new photodynamic therapy (PDT) with glycoconjugated chlorin (G-chlorin).

Both the pre-apoptotic exposure to calreticulin (CRT) and the post-apoptotic release of high-mobility group box 1 protein (HMGB1) are required for immunogenic cell death. Photodynamic therapy (PDT) uses non-toxic photosensitizers and visible light at a specific wavelength in combination with oxygen to produce cytotoxic reactive oxygen species that kill malignant cells by apoptosis and/or necrosis, shut down the tumor microvasculature, and stimulate the host immune system. We have previously shown that glycoconjugated chlorin (G-chlorin) has superior cancer cell selectivity and effectively suppresses the growth of xenograft tumors. In the present study, we evaluated the immunogenicity of PDT with G-chlorin treatment in colon cancer cells. PDT with G-chlorin suppressed CT26 (mouse colon cancer cells) tumor growth considerably more efficiently in immunocompetent mice (wild-type mice, allograft model) than in immune-deficient mice (nude mice, xenograft model), although control treatments were not different between the two. This treatment also induced CRT translocation and HMGB1 release in cells, as shown by western blot and immunofluorescence staining. To evaluate the use of PDT-treated cells as a tumor vaccine, we employed a syngeneic mouse tumor model (allograft model). Mice inoculated with PDT-treated CT26 cells were significantly protected against a subsequent challenge with live CT26 cells, and this protection was inhibited by siRNA for CRT or HMGB1. In conclusion, PDT with G-chlorin treatment induced immunogenic cell death in a mouse model, where the immunogenicity of this treatment was directed by CRT expression and HMGB1 release.