Respiratory gated irradiation system for heavy-ion radiotherapy

Minohara, Shinichi; Kanai, Tatsuaki; Endo, Masahiro; Noda, K.; Kanazawa, M.

doi:10.1016/s0360-3016(00)00524-1

Cited by 432 publications

(312 citation statements)

References 11 publications

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“…During treatment, patient‐machine alignment was achieved via the overlapping of the onboard image taken in a true lateral position with a kilovoltage X‐ray with the reconstructed 2‐dimensional image taken at planning CT; deviations in the skeletal anatomy, diaphragm, and inserted fiducial markers were minimized between the 2 images. Respiratory gating at the end of the expiratory phase was used for CT planning, positional verification on the treatment board, and irradiation 21. These treatment methods were the same for the 2 protocols.…”

Section: Methodsmentioning

confidence: 99%

Progressive hypofractionated carbon‐ion radiotherapy for hepatocellular carcinoma: Combined analyses of 2 prospective trials

Kasuya

Kato²,

Yasuda

et al. 2017

Cancer

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BACKGROUNDThe objective of this study was to evaluate the safety and efficacy of carbon‐ion radiotherapy (CIRT) in patients with hepatocellular carcinoma (HCC) with stepwise dose escalation and hypofractionation in 2 combined prospective trials.METHODSSequential phase 1/2 (protocol 9603) and phase 2 (protocol 0004) trials were conducted for patients with histologically proven HCC. The phase 1 component of protocol 9603 was a dose‐escalation study; CIRT was delivered in 12, 8, or 4 fractions. After determination of the recommended dose, 2 phase 2 trials were performed in an expanded cohort, and the data were pooled to analyze toxicity, local control, and overall survival.RESULTSIn the phase 1 component of protocol 9603, 69.6, 58.0, and 52.8 Gy (relative biological effectiveness [RBE]) in 12, 8, and 4 fractions, respectively, constituted the maximum tolerated doses, and 52.8 Gy (RBE) in 4 fractions was established as the recommended dose regimen for the 2 phase 2 studies. In 124 patients with a total of 133 lesions, few severe adverse effects occurred, and local‐control and overall survival rates at 1, 3, and 5 years were 94.7% and 90.3%, 91.4% and 50.0%, and 90.0% and 25.0%, respectively; this included 1‐, 3‐, and 5‐year local‐control rates of 97.8%, 95.5%, and 91.6%, respectively, in the phase 2 study. In a multivariate analysis, Child‐Pugh class B and the presence of a tumor thrombus were significant factors for mortality.CONCLUSIONSThe safety and efficacy of CIRT in 12, 8, and 4 fractions were confirmed, with 52.8 Gy (RBE) in 4 fractions established as the recommended treatment course for eligible HCC patients. Cancer 2017;123:3955‐65. © 2017 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

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Section: Methodsmentioning

confidence: 99%

Progressive hypofractionated carbon‐ion radiotherapy for hepatocellular carcinoma: Combined analyses of 2 prospective trials

Kasuya

Kato²,

Yasuda

et al. 2017

Cancer

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“…In the gating technique, the patient is treated at a particular phase of free breathing, generally by placing an external marker on the patient's chest and synchronizing beam delivery with the motion of the marker. ( 12 – 14 ) For this group of patients, the treatment plan should be based on a breathing‐adapted imaging technique. Four‐dimensional computed tomography (4D‐CT) is such a technique ( 15 – 19 ) and the focus of the present work.…”

Section: Introductionmentioning

confidence: 99%

Initial evaluation of a four‐dimensional computed tomography system, using a programmable motor

Simon

Giraud

Servois

et al. 2006

J Applied Clin Med Phys

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A dynamic lung tumor phantom was used to investigate the geometric reconstruction accuracy of a commercial four‐dimensional computed tomography (4D‐CT) system. A ball filled with resin, embedded in a cork cube, was placed on a moving platform. Various realistic antero‐posterior (AP) motions were programmed to reproduce the respiratory motion of a lung tumor. Several three‐dimensional (3D) CT and 4D‐CT images of this moving object were acquired and compared using different acquisition parameters. Apparent volume and diameter of the ball were measured and compared to the real values. The position of two points (the AP limits of the ball) during the motion in the coordinate system of the CT scanner were also compared with the expected values. Volume error was shown to increase with object speed. However, although the volume error was associated with intraslice artifacts, it did not reflect large interslice inconstancies in object position and should not be used as an indicator of image accuracy. The 3D‐CT gave a random position of the tumor along the phantom excursion; accuracy in the assessment of position by 4D‐CT ranged from 0.4 mm to 2.6 mm during extreme phases of breathing. We used average projection (AVE) and maximum intensity projection (MIP) algorithms available on the commercial software to create internal target volumes (ITVs) by merging gross tumor volume (GTV) images at various respiratory phases. The ITVs were compared to a theoretical value computed from the programmed ball excursion. The ITVs created from the MIP algorithm were closer to the theoretical value (within 12%) than were those created from the AVE algorithm (within 40%).PACS numbers: 87.53.Xd, 87.56.Mp, 87.57.Ce, 87.59.Fm

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“…Gating [10][11][12] and tracking techniques [13,14] using external surrogates have also been reported in particle therapy. However, internal organ motions and the external surrogate signals of abdominal motion are not necessarily correlated during treatment [15].…”

Section: Introductionmentioning

confidence: 99%

Optimization and evaluation of multiple gating beam delivery in a synchrotron-based proton beam scanning system using a real-time imaging technique

et al. 2016

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(Naoki Miyamoto) Purpose:To find the optimum parameter of a new beam control function installed in a synchrotron-based proton therapy system. Methods:A function enabling multiple gated irradiation in the flat top phase has been installed in a real-time-image gated proton beam therapy (RGPT) system. This function is realized by a waiting timer that monitors the elapsed time from the last gate-off signal in the flat top phase. The gated irradiation efficiency depends on the timer value, T w . To find the optimum T w value, gated irradiation efficiency was evaluated for each configurable T w value. 271 gate signal data sets from 58 patients were used for the simulation. Results:The highest mean efficiency 0.52 was obtained in T W = 0.2 s. The irradiation efficiency was approximately 21% higher than at T W = 0 s, which corresponds to ordinary synchrotron operation. The irradiation efficiency was improved in 154 (57%) of the 271 cases. The irradiation efficiency was reduced in 117 cases because the T W value was insufficient or the function introduced an unutilized wait time for the next gate-on signal in the flat top phase. In the actual treatment of a patient with a hepatic tumor at T w = 0.2 s, 4.48 GyE irradiation was completed within 250 s. In contrast, the treatment time of ordinary synchrotron operation was estimated to be 420 s. Conclusions:The results suggest that the multiple gated-irradiation function has potential to improve the gated irradiation efficiency and to reduce the treatment time.

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Respiratory gated irradiation system for heavy-ion radiotherapy

Cited by 432 publications

References 11 publications

Progressive hypofractionated carbon‐ion radiotherapy for hepatocellular carcinoma: Combined analyses of 2 prospective trials

Progressive hypofractionated carbon‐ion radiotherapy for hepatocellular carcinoma: Combined analyses of 2 prospective trials

Initial evaluation of a four‐dimensional computed tomography system, using a programmable motor

Optimization and evaluation of multiple gating beam delivery in a synchrotron-based proton beam scanning system using a real-time imaging technique

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