Impact of Intrafractional Bowel Gas Movement on Carbon Ion Beam Dose Distribution in Pancreatic Radiotherapy

Kumagai, Motoki; Hara, Ryusuke; Mori, Shinichiro; Yanagi, Takeshi; Asakura, Hiroshi; Kishimoto, Riwa; Kato, Hirotoshi; Yamada, Shigeru; Kandatsu, Susumu; Kamada, Tadashi

doi:10.1016/j.ijrobp.2008.10.055

Cited by 61 publications

(67 citation statements)

References 22 publications

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“…and Houweling et al. reported that the reproducibility of the volume or position of gas in the bowel surrounding the pancreas was very low 22, 23. Therefore, as shown in Fig.…”

Section: Discussionmentioning

confidence: 91%

Evaluation of the accuracy and clinical practicality of a calculation system for patient positional displacement in carbon ion radiotherapy at five sites

Kubota

Hayashi

Abe

et al. 2018

J Applied Clin Med Phys

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PurposeWe developed a system for calculating patient positional displacement between digital radiography images (DRs) and digitally reconstructed radiography images (DRRs) to reduce patient radiation exposure, minimize individual differences between radiological technologists in patient positioning, and decrease positioning time. The accuracy of this system at five sites was evaluated with clinical data from cancer patients. The dependence of calculation accuracy on the size of the region of interest (ROI) and initial position was evaluated for clinical use.MethodsFor a preliminary verification, treatment planning and positioning data from eight setup patterns using a head and neck phantom were evaluated. Following this, data from 50 patients with prostate, lung, head and neck, liver, or pancreatic cancer (n = 10 each) were evaluated. Root mean square errors (RMSEs) between the results calculated by our system and the reference positions were assessed. The reference positions were manually determined by two radiological technologists to best‐matching positions with orthogonal DRs and DRRs in six axial directions. The ROI size dependence was evaluated by comparing RMSEs for three different ROI sizes. Additionally, dependence on initial position parameters was evaluated by comparing RMSEs for four position patterns.ResultsFor the phantom study, the average (± standard deviation) translation error was 0.17 ± 0.05, rotation error was 0.17 ± 0.07, and ΔD was 0.14 ± 0.05. Using the optimal ROI size for each patient site, all cases of prostate, lung, and head and neck cancer with initial position parameters of 10 mm or under were acceptable in our tolerance. However, only four liver cancer cases and three pancreatic cancer cases were acceptable, because of low‐reproducibility regions in the ROIs.ConclusionOur system has clinical practicality for prostate, lung, and head and neck cancer cases. Additionally, our findings suggest ROI size dependence in some cases.

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“…and Houweling et al. reported that the reproducibility of the volume or position of gas in the bowel surrounding the pancreas was very low 22, 23. Therefore, as shown in Fig.…”

Section: Discussionmentioning

confidence: 91%

Evaluation of the accuracy and clinical practicality of a calculation system for patient positional displacement in carbon ion radiotherapy at five sites

Kubota

Hayashi

Abe

et al. 2018

J Applied Clin Med Phys

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“…Meanwhile, interfraction positional variations of

\geq 10 mm

were observed in 5 fractions (3.0%) in the SI direction, although visual feedback resulted in a lower positional uncertainty in the SI direction compared with pancreatic tumor motion under free breathing. Possible causes of interfraction positional variations in pancreatic tumors involve EE‐BH failure and daily variations in the surrounding organ fillings, including the stomach and bowel 17 , 18 , 19 , 20 , 21 . Although none of our patients consumed anything orally, with the exception of drugs or water, for

\geq 3 hr

before each BH‐CT scan, control of such physiological phenomena would be difficult.…”

Section: Discussionmentioning

confidence: 95%

“…However, the intra‐ and interfraction positional variations were based on three repeat CT scans at an interval of one to two weeks during the chemoradiation course. GI content, bowel gas, and other GI states generally vary with time, potentially affecting pancreatic tumor positions 17 , 18 , 19 , 20 , 21 . Therefore, it is important to verify the daily target position, especially in hypofractionated radiotherapy.…”

Section: Introductionmentioning

confidence: 99%

Interfraction positional variation in pancreatic tumors using daily breath‐hold cone‐beam computed tomography with visual feedback

Nakamura

Akimoto

Ono

et al. 2015

J Applied Clin Med Phys

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We assessed interfraction positional variation in pancreatic tumors using daily breath‐hold cone‐beam computed tomography at end‐exhalation (EE) with visual feedback (BH‐CBCT). Eleven consecutive patients with pancreatic cancer who underwent BH intensity‐modulated radiation therapy with visual feedback were enrolled. All participating patients stopped oral intake, with the exception of drugs and water, for >3 hr before treatment planning and daily treatment. Each patient was fixed in the supine position on an individualized vacuum pillow. An isotropic margin of 5 mm was added to the clinical target volume to create the planning target volume (PTV). The prescription dose was 42 to 51 Gy in 15 fractions. After correcting initial setup errors based on bony anatomy, the first BH‐CBCT scans were performed before beam delivery in every fraction. BH‐CBCT acquisition was obtained in three or four times breath holds by interrupting the acquisition two or three times, depending on the patient's BH ability. The image acquisition time for a 360° gantry rotation was approximately 90 s, including the interruption time due to BH. The initial setup errors were corrected based on bony structure, and the residual errors in the target position were then recorded. The magnitude of the interruptions variation in target position was assessed for 165 fractions. The systematic and random errors were 1.2 and 1.8 mm, 1.1 and 1.8 mm, and 1.7 and 2.9 mm in the left–right (LR), anterior–posterior (AP), and superior–inferior (SI) directions, respectively. Absolute interfraction variations of >5 mm were observed in 18 fractions (11.0%) from seven patients because of EE‐BH failure. In conclusion, target matching is required to correct interfraction variation even with visual feedback, especially to ensure safe delivery of escalated doses to patients with pancreatic cancer.PACS number: 87.57.Q‐, 87.57.‐s, 87.55.Qr

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“…Furthermore, the effect of air in the gastrointestinal system could lead to substantial difficulty for radiation modalities with tighter depth-dose profiles such as carbon ion beam therapy. 25 This current study serves as a proof of principle for the potential of adaptive re-planning with pancreas SBRT, though several technical aspects need attention before translating adaptive re-planning into a clinical setting. A primary technical component relates to the amount of time a patient spends on the treatment table during the adaptive re-planning process.…”

Section: Discussionmentioning

confidence: 99%

Dosimetric benefit of adaptive re-planning in pancreatic cancer stereotactic body radiotherapy

Hoisak

et al. 2015

Medical Dosimetry

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Impact of Intrafractional Bowel Gas Movement on Carbon Ion Beam Dose Distribution in Pancreatic Radiotherapy

Cited by 61 publications

References 22 publications

Evaluation of the accuracy and clinical practicality of a calculation system for patient positional displacement in carbon ion radiotherapy at five sites

Evaluation of the accuracy and clinical practicality of a calculation system for patient positional displacement in carbon ion radiotherapy at five sites

Interfraction positional variation in pancreatic tumors using daily breath‐hold cone‐beam computed tomography with visual feedback

Dosimetric benefit of adaptive re-planning in pancreatic cancer stereotactic body radiotherapy

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