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Evaluation of Delivery Analysis to Detect Intrafractional Motion during Tomotherapy

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2019年第4期8卷 225-235页

作者： Kazuo Tarutani masao tanooka Keisuke Sano Okada Wataru Masayuki Fujiwara Koichiro Yamakado Department of Radiology Hyogo College of Medicine Nishinomiya Japan Japan Organization of Occupational Health and Safety Kansai Rousai Hospital Amagasaki Japan Department of Radiotherapy Takarazuka City Hospital Takarazuka Japan

The purpose of this study was to investigate the ability of a management system (Delivery Analysis: DA) to detect intrafractional motion during intensity-modulated radiation therapy (IMRT) in tomotherapy mode. Tomotherapy has made it possible to manage internal movements during treatment using software DA, which quantifies using the information of the passing dose obtained during the radiation treatment of patients. First, three treatment plans for the test were created (lumbar spine, prostate, and femur). Second, a pelvis phantom was moved in the X, Y, and Z directions, and a sinogram was acquired. The magnitudes of the movements were 3 mm, 5 mm, and 10 mm, respectively. Finally, the ability of DA to detect the motion was evaluated by comparing the sinogram obtained by moving the phantom with a reference sinogram obtained without movement. The sensitivity of DA could be detected with a shift amount of 3 mm (gamma analysis tolerance 0.3 mm/0.3%). The average gamma analysis of each direction at 0.3 mm/0.3% tolerance at each treatment site was 96.1% for the prostate, 93.5% for the lumbar spine, and 94.4% for the femur. Additionally, the average gamma pass rate results for the pelvic phantom in the X, Y, Z directions for a 10 mm shift were 96.2%, 96.3%, and 95.9%, respectively. DA is a powerful tool with high detection sensitivity and ability to detect body movement during treatment.

关键词： Delivery Analysis (DA) Tomotherapy Sinogram Intra-Fraction Motion Quality Assurance (QA)

Verification of Dosimetric and Positional Accuracy of Dynamic Tumor Tracking Intensity Modulated Radiation Therapy

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2019年第4期8卷 211-224页

作者： Masaki Sueoka Akira Sawada Hiroaki Tanabe Yuki Okada Sho Taniuchi Noboru Okuuchi masao tanooka Masaki Kokubo Koichiro Yamakado Department of Radiology Hyogo College of Medicine Nishinomiya Japan Department of Radiological Technology Kobe City Medical Center General Hospital Kobe Japan Department of Radiological Technology Faculty of Medical Science Kyoto College of Medical Science Nantan Japan Department of Radiation Oncology Kobe City Medical Center General Hospital Kobe Japan

Purpose: We performed both, dosimetric and positional accuracy verification of dynamic tumor tracking (DTT) intensity modulated radiation therapy (IMRT), with the Vero4DRT system using a moving phantom (QUASAR respiratory motion platform;QUASAR phantom) and system log files. Methods: The QUASAR phantom was placed on a treatment couch. Measurement of the point dose and dose distribution was performed for conventional IMRT, with the QUASAR phantom static and moving;for DTT IMRT, this was performed with the phantom moving for pyramid shaped, prostate, paranasal sinus, and pancreas targets. The QUASAR phantom was driven by a sinusoidal signal in the superior-inferior direction. Furthermore, predicted positional errors induced by the Vero4DRT system and mechanical positional errors of the gimbal head, were calculated using the system log files. Results and Conclusion: For DTT IMRT, the dose at the evaluation point was within 3% compared with the verification plan, and the dose distribution in the passing rates of γ was 97.9%, with the criteria of 3% dose and 3 mm distance to agreement. The position error calculated from the log files was within 2 mm, suggesting the feasibility of employing DTT IMRT with high accuracy using the Vero4DRT system.

关键词： Dynamic Tumor Tracking (DTT) Intensity Modulated Radiation Therapy (IMRT) Point Dose Verification Dose Distribution Verification Log File Analysis

Predicting Delivery Error Using a DICOM-RT Plan for Volumetric Modulated Arc Therapy

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2014年第2期3卷 82-87页

作者： Hideharu Miura masao tanooka Masayuki Fujiwara Yasuhiro Takada Hiroshi Doi Soichi Odawara Kengo Kosaka Norihiko Kamikonya Shozo Hirota Department of Radiological Technology Hyogo College of Medicine College Hospital Hyogo Mukogawa-cho Nishinomiya City Hyogo Japan Department of Radiology Hyogo College of Medicine 1-1 Mukogawa-cho Nishinomiya City Hyogo Japan

The purpose of this study was to investigate the prediction of mechanical error using DICOM-RT plan parameters for volumetric modulated arc therapy (VMAT). We created plans for gantry rotation arcs of 360° and 180° (full-arc and half-arc VMAT) for six maxillary sinus cancer cases using a Monaco treatment planning system, and delivered the doses with a linear accelerator. We calculated DICOM-RT plan parameters, including gantry, multileaf collimator (MLC) positions and Monitor Units (MU). We compared plans with regard to gantry angle per MU (degrees/MU) and MLC travel per MU (mm/MU) for each segment. Calculated gantry angle/MLC position speeds and errors were evaluated by comparison with the log file. On average, the half-arc VMAT plan resulted in 47% and 35% fewer degrees/MU and mm/MU than the full-arc VMAT plan, respectively. The root mean square (r.m.s.) gantry and MLC speeds showed a linear relationship with calculated degrees/MU and mm/MU, with coefficients of determination (R2) of 0.86 and 0.72, respectively. The r.m.s. gantry angle and MLC position errors showed a linear relationship with calculated degrees/MU and mm/MU with R2 of 0.63 and 0.76, respectively. Deviations from plan parameters were related to mechanical error for VMAT, and provided quantitative information without the need for VMAT delivery. These parameters can be used in the selection of treatment planning.

关键词： Volumetric-Modulated Arc Therapy DICOM-RT Plan Patient-Specific QA Radiotherapy Planning Computer-Assisted

Feasibility of Estimating Patient-Specific Dose Verification Results Directly from Linear Accelerator Log Files in Volumetric Modulated Arc Therapy

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2016年第4期5卷 317-328页

作者： Kengo Kosaka masao tanooka Hiroshi Doi Hiroyuki Inoue Kazuo Tarutani Hitomi Suzuki Yasuhiro Takada Masayuki Fujiwara Norihiko Kamikonya Shozo Hirota Department of Radiology Hyogo College of Medicine Nishinomiya Japan Department of Radiological Technology Hyogo College of Medicine College Hospital Nishinomiya Japan

The feasibility of estimating patient-specific dose verification results directly from linear accelerator (linac) log files has been investigated for prostate cancer patients who undergo volumetric modulated arc therapy (VMAT). Twenty-six patients who underwent VMAT in our facility were consecutively selected. VMAT plans were created using Monaco treatment planning system and were transferred to an Elekta linac. During the beam delivery, dynamic machine parameters such as positions of the multi-leaf collimator and the gantry were recorded in the log files;subsequently, root mean square (rms) values of control errors, speeds and accelerations of the above machine parameters were calculated for each delivery. Dose verification was performed for all the plans using a cylindrical phantom with diodes placed in a spiral array. The gamma index pass rates were evaluated under 3%/3 mm and 2%/2 mm criteria with a dose threshold of 10%. Subsequently, the correlation coefficients between the gamma index pass rates and each of the above rms values were calculated. Under the 2%/2 mm criteria, significant negative correlations were found between the gamma index pass rates and the rms gantry angle errors (r = 0.64, p < 0.001) as well as the pass rates and the rms gantry accelerations (r = 0.68, p < 0.001). On the other hand, the rms values of the other dynamic machine parameters did not significantly correlate with the gamma index pass rates. We suggest that the VMAT quality assurance (QA) results can be directly estimated from the log file thereby providing potential to simplify patient-specific prostate VMAT QA procedure.

关键词： Radiotherapy VMAT Log File Patient Specific QA Correlation Gamma Index

DICOM-RT Plan Complexity Verification for Volumetric Modulated Arc Therapy

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2014年第3期3卷 117-124页

作者： Hideharu Miura masao tanooka Hiroyuki Inoue Masayuki Fujiwara Kengo Kosaka Hiroshi Doi Yasuhiro Takada Soichi Odawara Norihiko Kamikonya Shozo Hirota Department of Radiological Technology Hyogo College of Medicine College Hospital Nishinomiya City Japan Department of Radiology Hyogo College of Medicine Nishinomiya City Japan

The purpose of this study was to investigate the relationship between plan parameters verified with DICOM-RT and dosimetric results for volumetric modulated arc therapy (VMAT). We investigated three treatment locations: prostate cancer (ten cases), maxillary sinus cancer (four cases), and malignant pleura mesothelioma (four cases) with treatment plans generated by a MonacoTM treatment planning system (TPS), and delivered with an Elekta SynergyTM linear accelerator. We calculated plan parameters, including gantry and multileaf collimator (MLC) positions, Monitor Units (MU), and millimeters of MLC motion per degree of gantry rotation (mm/degree), and performed quality assurance (QA) with a DICOM-RT plan verification system. We measured the VMAT dose with a two-dimensional diode array detector. The average gamma passing rate with percent dose acceptance criteria and distance to agreement criteria of 2 mm and 2% (2 mm/2%) were 97.4%, 97.8% and 92.0% for prostate cancer, maxillary sinus cancer, and malignant pleural mesothelioma, respectively. The mean 95th percentile value for DICOM-calculated mm/degree was 4.0, 5.2, and 11.1 for prostate cancer, maxillary sinus cancer, and malignant pleural mesothelioma, respectively. The gamma passing rate showed a correlation with calculated mm/degree, with a coefficient of determination (R2) of 0.60. Higher calculated mm/degree values led to increased dosimetric errors. We conclude that dose distribution calculated by a TPS is more reliable at smaller mm/degree.

关键词： Volumetric Modulated Arc Therapy Quality Assurance Radiation Treatment Planning Radiation Dosimetry

Usability of Deformable Image Registration for Adaptive Radiotherapy in Head and Neck Cancer and an Automatic Prediction of Replanning

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2017年第1期6卷 10-20页

作者： masao tanooka Hiroshi Doi Toshihisa Ishida Kazuhiro Kitajima Tsukasa Wakayama Toshiyuki Sakai Hiroyuki Inoue Noriko Kotoura Kengo Kosaka Kazuo Tarutani Masayuki Fujiwara Norihiko Kamikonya Department of Radiological Technology Hyogo College of Medicine College Hospital Nishinomiya Japan Department of Radiology Hyogo College of Medicine Hyogo Nishinomiya Japan

Deformable image registration (DIR) has been an important component in adaptive radiotherapy (ART). Our goal was to examine the accuracy of ART using the dice similarity coefficient (DSC) and to determine the optimal timing of replanning. A total of 22 patients who underwent volume modulated arc therapy (VMAT) for head and neck (H&N) cancers were prospectively analyzed. The planning target volume (PTV) was to receive a total of 70 Gy in 33 fractions. A second planning CT scan (rescan) was performed at the 15th fraction. The DSC was calculated for each structure on both CT scans. The continuous variables to predict the need for replanning were assessed. The optimal cut-off value was determined using receiver operating characteristic (ROC) curve analysis. In the correlation between body weight loss and DSC of each structure, weight loss correlated negatively with DSC of the whole face (rs = -0.45) and the face surface (rs = -0.51). Patients who required replanning tended to have experienced rapid weight loss. The threshold DSC was 0.98 and 0.60 in the whole face and the face surface, respectively. Patients who showed low DSC in the whole face and the face surface required replanning at a significantly high rate (P < 0.05 and P < 0.01). Weight loss correlated with DSC in both the whole face and the face surface (P < 0.05 and P < 0.05). The DSC values in the face predicted the need for replanning. In addition, weight loss tended to correlate with DSC. DIR during ART was found to be a useful tool for replanning.

关键词： Deformable Image Registration Adaptive Radiotherapy Head and Neck Can-cer Dice Similarity Coefficient Volume Modulated Arc Therapy