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Proton beam therapy can concentrate the dose on a tumour. In order to offer high-precision proton beam therapy to the patient, it is important to confirm the range every day. At the National Cancer Center Hospital East (NCC), the range measurement tool consists of a water phantom and an ionization chamber. These large and heavy tools take a long time to set up. Therefore, we developed a simple and easy-to-handle range measurement tool for proton beam therapy. This tool consists of a plastic scintillator block and a CCD camera. We recorded visible scintillation light generated by proton irradiation on the scintillator, and could measure the range from the shape of light distribution by using a computer with automatic analysis software installed. We carried out proton irradiation experiments with this tool to examine its performance as a tool of daily range measurements. The precision of the range measurement is within 0.3 mm (sd). The tool can measure possible short-term range variation with 1 s sampling time during the time interval of a typical treatment in a few minutes. We conclude that this tool can measure the range with sufficient resolution in a short time, and is useful for range control in a clinical setting.

BackgroundThis study aimed to determine the prognostic value of positron emission tomography (PET) metabolic parameters—namely metabolic tumor volume (MTV), total lesion glycolysis (TLG), and total lesion retention (TLR)—on fluorine-18 (18F) fluorodeoxyglucose (FDG) and L- [3-18F]-α-methyltyrosine (18F-FAMT) PET/CT in patients with non-small-cell lung cancer (NSCLC).MethodsThe study group comprised 112 NSCLC patients who underwent 18F-FDG and 18F-FAMT PET/CT prior to any therapy. The MTV, TLG, TLR, and maximum standardized uptake value (SUVmax) of the primary tumors were determined. Automatic MTV measurement was performed using PET volume computer assisted reading software. (GE Healthcare). Cox proportional hazards models were built to assess the prognostic value of MTV, TLG (for 18F-FDG), TLR (for 18F-FAMT), SUVmax, T stage, N stage, M stage, clinical stage, age, sex, tumor histological subtype, and treatment method (surgery or other therapy) on overall survival (OS).ResultsHigher TNM, higher clinical stage, inoperable status, and higher values for all PET parameters (both 18F-FAMT and 18F-FDG PET) were significantly associated (P < 0.05) with shorter OS. Multivariate analysis revealed that a higher MTV of 18F-FAMT (hazard ratio [HR]: 2.88, CI: 1.63–5.09, P < 0.01) and advanced clinical stage (HR: 5.36, CI: 1.88–15.34, P < 0.01) were significant predictors of shorter OS.ConclusionsMTV of 18F-FAMT is of prognostic value for OS in NSCLC cases and can help guide decision-making during patient management.

Optimisation of computed tomography (CT) parameters is important in avoiding excess radiation exposure. The aim of this study is to establish the diagnostic reference levels (DRL) of CT in Japan by using dose-length product (DLP). Datasheets were sent to all hospitals/clinics which had CT scanner(s) in Gunma prefecture. Data were obtained for all patients who underwent CT during a single month (June 2010), and the distributions of DLP were evaluated for eight anatomical regions and five patient age groups. The DRL was defined as the 25th and 75th percentiles of DLP. Datasheets were collected from 80 of 192 hospitals/clinics (26 090 patients). DLP for head CT of paediatric patients tended to be higher in Japan compared with DRLs of paediatric head CTs reported from the EU or Syria. Although this study was performed with limited samples, DLP for adult patients were at comparable levels for all anatomical regions.