Carbon Ion Radiotherapy in Hypofraction Regimen for Stage I Non-Small Cell Lung Cancer

From 1994 to 1999, we conducted a phase I/II clinical trial for stage I non-small cell lung cancer (NSCLC) by using carbon ion beams alone, demonstrating optimal doses of 90 GyE in 18 fractions over 6 weeks and 72 GyE in 9 fractions over 3 weeks for achieving more than 95% local control with minimal pulmonary damage. In the present study, the total dose was fixed at 72 GyE in 9 fractions over 3 weeks, and at 52.8 GyE for stage IA and 60 GyE for stage 1B in 4 fractions over 1 week. Following this schedule, we conducted a phase II clinical trial for stage I NSCLC from 1999 to 2003. Most targets were irradiated from four oblique directions. A respiratory-gated irradiation system was used for all sessions. Local control and survival were assessed by the Kaplan-Meier method. For statistical testing, the long-rank test was used.The local control rate for all patients was 91.5%, and those for T1 and T2 tumors were 96.3% and 84.7%, respectively. While there was significant difference (p=0.0156) in tumor control rate between T1 and T2, there was no significant difference (P=0.1516) between squamous and non-squamous. The five-year cause-specific survival rate was 67.0% (IA: 84.4, IB: 43.7), and overall survival was 45.3% (IA: 53.9, 1B: 34.2). No adverse effects greater than grade 3 occurred in the lung. Carbon beam radiotherapy, an excellent new modality in terms of high QOL and ADL, was proven to be a valid alternative to surgery for stage I cancer, especially for elderly and inoperable patients

Practical Approaches to Four-dimensional Heavy-Charged-Particle Lung Therapy

We have developed new design algorithms for compensating boli to facilitate the implementation of four-dimensional charged-particle lung therapy in clinical applications. Four-dimensional CT (4DCT) data for eight lung cancer patients were acquired with a 16-slice CT under free breathing. Six compensating boli were developed that may be categorized into three classes, i) boli-based on contoured gross tumor volumes (GTV) from a 4DCT data set during each respiratory phase, subsequently combined into one (GTV-4DCT bolus); ii) boli-based on contoured internal target volume (ITV) from image-processed 3DCT data only [temporal-maximum-intensity-projection (TMIP)/ temporal-average-intensity-projection (TAIP)] with calculated boli (ITV-TMIP and ITV-TAIP boli); and iii) boli-based on contoured ITV utilizing image-processed 3DCT data, applied to 4DCT for design of boli for each phase, which were then combined. The carbon beam dose distribution within each bolus was calculated as a function of time and compared to plans in which respiratory-ungated/gated strategies were used. The GTV-4DCT treatment plan required a prohibitively long time for contouring the GTV manually for each respiratory phase, but it delivered more than 95% of the prescribed dose to the target volume. The TMIP and TAIP treatments, although more time-efficient, resulted in an unacceptable excess dose to normal tissues and underdosing of the target volume. The dose distribution for the ITV-4DCT bolus was similar to that for the GTV-4DCT bolus and required significantly less practitioner time. The ITV-4DCT bolus treatment plan is time-efficient and provides a high-quality dose distribution, making it a practical alternative to the GTV-4DCT bolus treatment plan

Development of Peltier Current Lead for DC cable Hideo

AbstractThe widespread expectation is that superconducting technologies will be one of the effective technologies to decrease energy loss and improve efficiency in energy grids. Especially, in recent circumstances, applications connecting with renewable energy receive attention. Yamaguchi et al successfully developed 200 m-class superconducting direct current transmission and distribution system (CASER-2) in Chubu University and carried out the demonstration of this system. On this demonstration, “Peltier Current Lead (PCL)” was employed, wherein Peltier device was used for the purpose of pumping up the heat through the down-leads, It was observed that PCL reduced heat leak into cryostat as compared to usual Cu current leads on this demonstration, but some issues to be solved remained, such as heat-cycle performance etc.. In this paper, we designed a prototype PCL for the purpose of improvement of the mechanical strength and the durability for the heat cycle, and evaluated the performance

Intrafractional Respiratory Motion for Charged Particle Lung Therapy with Immobilization Assessed by Four-Dimensional Computed Tomography

The aim of this study was to quantify the magnitude of intrafractional lung tumor motion under free-breathing conditions with an immobilization device using four-dimensional computed tomography (4DCT). 4DCT data sets were acquired for 17 patients with lung tumors receiving carbon ion beam therapy. A single respiratory cycle was subdivided into 10 phases, and intrafractional tumor motion was calculated by identifying the gross tumor volume (GTV) center of mass (COM) in two scenarios; respiratory-ungated and -gated treatments, which were based on a whole respiratory cycle and a 30% duty cycle around peak exhalation, respectively. For the respiratory-ungated case, the mean (± standard deviation) GTV-COM dis-placements from the peak exhalation position over the 17 patients were 0.6 (± 0.8) / 0.9 (± 1.2) mm, 2.0 (± 1.4) / 0.4 (± 0.7) mm, and 0.2 (± 0.5) / 7.8 (± 6.9) mm in left/right, anterior/posterior and superior/infe-rior directions, respectively, while these were reduced for the respiratory-gated case to 0.3 (± 0.4) / 0.4 (±0.6) mm (left/right), 0.8 (± 0.7) / 0.3 (± 0.5) mm (anterior/posterior), and 0.1 (± 0.2) / 2.8 (± 2.9) mm (superior/inferior). Quantitative analysis of tumor motion with immobilization is valuable not only for par-ticle beam therapy but also for photon beam therapy

Uptake Decrease of Proliferative PET Tracer 18FLT in Bone Marrow after Carbon Ion Therapy in Lung Cancer

Purpose The aim of this study was to investigate the change of 3\u27-[18F]fluoro-3\u27-deoxy-l-thymidine (18FLT) uptake in normal bone marrow (BM) after inevitable radiation. Procedures Twenty-one non-small cell lung cancer patients who received carbon ion radiotherapy (CIRT) were studied with 18FLT-positron emission tomography/computed tomography (PET/CT) at pre- and post-CIRT. Radiation dose was calculated by radiation planning. Irradiated BM was divided into three groups (30%). Results 18FLT uptake clearly decreased at >10% irradiated areas and mildly decreased at 30% areas. Conclusion 18FLT revealed that BM function decreased by small dose such as 4.2-4.4 GyE/1 fraction