Takeshi Arimura

Current status of the HIBMC and results of representative diseases

The proton radiotherapy (PRT) has been spreading, since 1990 when 250 MeV proton beams with rotation gantry was developed for medical use. On the other hand, carbon‐ion radiotherapy (CRT) that has both physical and biological features is available at 4 facilities in the world. HIBMC is the only facility to be able to use both particles. From Apr 2001 to Dec 2008, 2486 patients were treated with PRT in 2030 patients or with CRT in 456. Treatment to the Head and Neck (H&N: in 405 patients), the lung (245), the liver (371), and the prostatic carcinoma (1059) was a major subject. The 2‐year local control rates is 72% in H&N (n = 163, T1:9, T2:18, T3:36, T4:79, malignant melanoma 48, adenoid cystic carcinoma 35, squamous cell carcinoma (SCC) 32, adenocarcinoma 14, others 34), 88% in lung (n = 116, T1:59, T2:42, T3:4, T4:6, SCC 30, adenocarcinoma 59, others 27), and 89% in liver cancer (n = 153, Proton: 130, carbon: 23). Biochemical disease free 3‐year survival of 291 prostate cancer is 100% in 9 patients with ...

Comparison of proton beam radiotherapy and hyper-fractionated accelerated chemoradiotherapy for locally advanced pancreatic cancer

OBJECTIVES We compared the clinical outcomes of proton beam radiotherapy (PBRT) and those of conventional chemoradiotherapy via hyper-fractionated acceleration radiotherapy (HART) after induction chemotherapy in patients with locally advanced pancreatic cancer (LAPC). METHODS Twenty-five consecutive patients with LAPC received induction chemotherapy comprising gemcitabine and S-1 before radiotherapy. Of these, 15 and 10 were enrolled in the HART and PBRT groups, respectively. RESULTS Moderate hematological toxicities were observed only in the HART group, whereas two patients in the PBRT group developed duodenal ulcers. All patients underwent scheduled radiotherapy, with overall disease control rates of 93% and 80% in the HART and PBRT groups, respectively. Local progression was observed in 60% and 40% of patients in the HART and PBRT groups, respectively. However, there was no statistical significance between the two groups regarding the median time to progression (15.4 months in both) and the median overall survival (23.4 v.s. 22.3 months). CONCLUSIONS PBRT was feasible and tolerable, and scheduled protocols could be completed with careful attention to gastrointestinal ulcers. Despite the lower incidence of local recurrence, PBRT did not yield obvious progression control and survival benefits relative to conventional chemoradiotherapy.

A feasibility study of a hybrid breast-immobilization system for early breast cancer in proton beam therapy

Purpose We aimed to develop a new breast‐immobilizing system for proton beam therapy (PBT) of early breast cancer (EBC) that would provide the optimum breast shape during the treatment as well as increased fixation reliability by reducing the influence of respiratory movement. Methods The breast‐immobilizing system (HyBIS; hybrid breast‐immobilizing system) consists of a whole body immobilization system (WBIS), position‐converting device (to change patient position), photo‐scanning system, breast cup (made using a three‐dimensional printer), breast cup‐fitting apparatus, breast cup‐holding device (to ensure the breast remains lifted in the supine position), and dedicated stretcher fixed to the WBIS (to carry the patient). We conducted a phantom experiment to evaluate the effect of the HyBIS on breast immobilization during the respiratory cycle. Thirteen markers were embedded in the right breast of a female phantom that simulated respiratory thoracic movement at an amplitude of 15 mm, and their displacements on four‐dimensional computed tomography were compared between conditions with and without immobilization by HyBIS. Results When immobilization was applied with the HyBIS, breast protrusion was maintained in the phantom in the supine treatment position. The mean values of the anteroposterior, superoinferior, lateral, and three‐dimensional (3D) displacement of the markers were 2.7 ± 1.7, 0.3 ± 0.5, 0.9 ± 0.8, and 3.1 ± 1.6 mm with HyBIS, and 5.5 ± 2.9, 0.6 ± 0.8, 0.5 ± 0.4, and 5.6 ± 2.9 mm without HyBIS, respectively; thus, the anteroposterior (P = 0.014) and 3D (P = 0.007) displacements significantly improved with HyBIS. Conclusions We demonstrated that the HyBIS can help retain the protruded breast shape in the supine position during treatment and can reduce the influence of respiratory movement. Thus, the HyBIS can help to reliably and precisely perform PBT for EBC.

Pacemaker malfunction associated with proton beam therapy: a report of two cases and review of literature—does field-to-generator distance matter?

It is well known that radiotherapy causes malfunctions of cardiac implantable electronic devices such as pacemaker (PM) and implantable cardioverter-defibrillator because of incidental neutron production. Here, we report our experience with two cases of PM reset among seven patients with PM who underwent proton beam therapy (PBT) from January 2011 to April 2015 at our centre. Our experience shows PM reset can occur also with abdominal PBT. In both cases, PM reset was not detected by electrocardiogram (ECG) monitoring but was rather discovered by post-treatment programmer analysis. Our cases suggest that PM malfunction may not always be detected by ECG monitoring and emphasize the importance of daily programmer analysis.

The role of proton beam therapy for patients with intermediate- and high-risk prostate cancer.

97Background: Although there are many patterns of treatment in localized prostate caner, proton beam therapy has no definite role in them. We aimed to assess the outcomes of proton beam therapy (PBT) alone for patients with intermediate- and high-risk prostate cancer, and to clarify the role of PBT in the treatments. Methods: Between Jan. 2011 and Sep. 2014, 204 patients with intermediate- and high-risk prostate cancer who declined to receive hormonal treatments until biochemical or clinical recurrence were enrolled in the study. All patients were irradiated a 70-78 GyE in 28-39 fractions, and pre-treatment risk groups were classified in accordance with the D’Amico criteria. The 5-year (biochemical or clinical) recurrence-free survival (RFS), late gastrointestinal (GI) and genitourinary (GU) toxicity (NCI-CTCAE ver.4.0) were evaluated. We conducted a survey on sexual quality of life (QOL) every six months to evaluate any long-term damage to the sexual function using the Expanded Prostate Cancer Index Comp...

Proton Beam Therapy Alone for Intermediate- or High-Risk Prostate Cancer: An Institutional Prospective Cohort Study

The role of proton beam therapy (PBT) as monotherapy for localized prostate cancer (PCa) remains unclear. The purpose of this study was to evaluate the efficacy and adverse events of PBT alone for these patients. Between January 2011 and July 2014, 218 patients with intermediate- and high-risk PCa who declined androgen deprivation therapy (ADT) were enrolled to the study and were treated with PBT following one of the following protocols: 74 Gray (GyE) with 37 fractions (fr) (74 GyE/37 fr), 78 GyE/39 fr, and 70 GyE/28 fr. The 5-year progression-free survival rate in the intermediate- and high-risk groups was 97% and 83%, respectively (p = 0.002). The rate of grade 2 or higher late gastrointestinal toxicity was 3.9%, and a significant increased incidence was noted in those who received the 78 GyE/39 fr protocol (p < 0.05). Grade 2 or higher acute and late genitourinary toxicities were observed in 23.5% and 3.4% of patients, respectively. Our results indicated that PBT monotherapy can be a beneficial treatment for localized PCa. Furthermore, it can preserve the quality of life of these patients. We believe that this study provides crucial hypotheses for further study and for establishing new treatment strategies.

Effect of Film Dressing on Acute Radiation Dermatitis Secondary to Proton Beam Therapy.

PURPOSE Acute radiation dermatitis (ARD) is one of the most common adverse events of proton beam therapy (PBT), and there is currently no effective method to manage ARD. The purpose of this study was to examine the prophylactic effect of a film dressing using Airwall on PBT-induced ARD compared with standard skin managements. METHODS AND MATERIALS A total of 271 patients with prostate cancer who were scheduled for PBT at our center were divided into 2 groups based on their own requests: 145 patients (53%) chose Airwall (group A) and 126 patients (47%) received standard treatments (group B). We evaluated irradiated skin every other day during PBT and followed up once a week for a month after completion of PBT. RESULTS Grade 0, 1, 2, and 3 dermatitis were seen in 2, 122, 21, and 0 and 0, 65, 57, and 4 patients in groups A and B, respectively (P<.001). Numbers of days to grades 1 and 2 ARD development were 34.9 ± 14.3 and 54.7 ± 10.3 and 31.8 ± 11.3 and 54.4 ± 11.6 in groups A and B, respectively. There were no significant differences between the 2 groups. Eighteen patients (12%) in group A who experienced problems in the region covered with Airwall switched to standard skin care after peeling the film off. CONCLUSIONS Film dressing using Airwall reduced the severity of ARD without delaying the response time of the skin to proton beam irradiation compared with standard skin management. Hence, film dressing is considered a promising measure for preventing ARD secondary to PBT.