Availability of applying diaphragm matching with the breath-holding technique in stereotactic body radiation therapy for liver tumors

Kawahara, Daisuke; Ozawa, Shogo; Kimura, Tomoki; Nakashima, Takeo; Aita, Masamichi; Tsuda, S.; Ochi, Yusuke; Okumura, Takuro; Masuda, Hirokazu; Ohno, Yoshimi; Murakami, Yuji; Nagata, Yasushi

doi:10.1016/j.ejmp.2016.02.007

Cited by 15 publications

(30 citation statements)

References 25 publications

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“…When using BH during radiotherapy, daily positioning based on cone-beam CT (CBCT) imaging while the patient is in BH should be used to account for interfractional position variations [15]. Also, to improve the accuracy of the daily positioning of the patient, the image registration between the daily CBCT and pretreatment CT should be based on the diaphragm instead of bony anatomy [16]. However, exhale BH durations are generally shorter compared with inhale, as performing exhale BHs can be more challenging for patients [9,11].…”

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confidence: 99%

Considerable pancreatic tumor motion during breath-holding

et al. 2016

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Background: Breath-holding (BH) is often used to reduce abdominal organ motion during radiotherapy. However, for inhale BH, abdominal tumor motion during BH has not yet been investigated. The aim of this study was to quantify tumor motion during inhale BH and tumor position variations between consecutive inhale BHs in pancreatic cancer patients. Material and methods: Twelve patients with intratumoral fiducials were included and asked to perform three consecutive 30-second inhale BHs on each of three measurement days. During BH, lateral fluoroscopic movies were obtained and a two-dimensional (2D) image correlation algorithm was used to track the fiducials and the diaphragm, yielding the tumor and diaphragm motion during each BH. The tumor position variation between consecutive BHs was obtained from the difference in initial tumor position between consecutive BHs on a single measurement day. Results: We observed tumor motion during BH with a mean absolute maximum displacement over all BHs of 4.2 mm (range 1.0-11.0 mm) in inferior-superior (IS) direction and 2.7 mm (range 0.5-8.0 mm) in anterior-posterior (AP) direction. We found only a moderate correlation between tumor and diaphragm motion in the IS direction (Pearson's correlation coefficient jrj>0.6 in 45 of 76 BHs). The mean tumor position variation between consecutive BHs was 0.2 [standard deviation (SD) 1.7] mm in the inferior direction and 0.5 (SD 0.8) mm in the anterior direction. Conclusion: We observed substantial pancreatic tumor motion during BH as well as considerable position variation between consecutive BHs on a single day. We recommend further quantifying these uncertainties before introducing breath-hold during radiation treatment of pancreatic cancer patients. Also, the diaphragm cannot be used as a surrogate for pancreatic tumor motion.

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confidence: 99%

Considerable pancreatic tumor motion during breath-holding

et al. 2016

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“…Additionally, Kawahara et al. reported that the average interfractional error in the diaphragm position was 3.4 mm in the superior–inferior direction 21. As shown above, because the positional reproducibility of the liver in the abdomen is low, the patient positioning calculation was misled by the diaphragm position although patient positioning should be performed based on the vertebra position.…”

Section: Discussionmentioning

confidence: 98%

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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“…The CTV margin was 0 mm around the GTV. The reproducibility of the tumor position at respiratory breath‐hold was suppressed within 5 mm using the breath‐hold technique with Abches 22 . Systematic error of the tumor position is corrected with the daily Cone‐beam CT. A PTV margin of 5 mm in left‐right (LR), anterior‐posterior (AP), and cranio‐caudal (CC) directions around the CTV including the respiratory motion reproducibility and the setup error was usually added.…”

Section: Methodsmentioning

confidence: 99%

Assessment of biological dosimetric margin for stereotactic body radiation therapy

Kawahara

Saito

Ozawa

et al. 2020

J Applied Clin Med Phys

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Purpose: To develop a novel biological dosimetric margin (BDM) and to create a biological conversion factor (BCF) that compensates for the difference between physical dosimetric margin (PDM) and BDM, which provides a novel scheme of a direct estimation of the BDM from the physical dose (PD) distribution.Methods: The offset to isocenter was applied in 1-mm steps along left-right (LR), anterior-posterior (AP), and cranio-caudal (CC) directions for 10 treatment plans of lung stereotactic body radiation therapy (SBRT) with a prescribed dose of 48 Gy.These plans were recalculated to biological equivalent dose (BED) by the linearquadratic model for the dose per fraction (DPF) of d = 3-20 Gy/fr and α=β ¼ 3 À 10. BDM and PDM were defined so that the region that satisfied that the dose covering 95% (or 98%) of the clinical target volume was greater than or equal to the 90% of the prescribed PD and BED, respectively. An empirical formula of the BCF was created as a function of the DPF.Results: There was no significant difference between LR and AP directions for neither the PDM nor BDM. On the other hand, BDM and PDM in the CC direction were significantly larger than in the other directions. BCFs of D 95% and D 98% were derived for the transverse (LR and AP) and longitudinal (CC) directions. Conclusions:A novel scheme to directly estimate the BDM using the BCF was developed. This technique is expected to enable the BED-based SBRT treatment planning using PD-based treatment planning systems. K E Y W O R D S biological equivalent dose, dosimetric margin, LQ model, SBRT 1 | INTRODUCTION In modern radiation therapy, dose-volume histogram (DVH) and isodose distribution are commonly used for treatment evaluation. Dosevolume constraints indicate organ volumes that should not receive doses exceeding certain limits derived from retrospective studies.Clinical and radiobiological studies have shown that two treatments delivering the same total dose through different fractionation schemes produce different biological results. 1,2 Fowler showed that the biological effective dose (BED) modeling is a valuable tool for understanding tumor and normal tissue response across different treatment modalities and fractionation schemes. 3 Based on the idea of BED, it has been shown that the relative biological effectiveness depends on the dose per fraction (DPF) and the number of fractions.---

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Availability of applying diaphragm matching with the breath-holding technique in stereotactic body radiation therapy for liver tumors

Cited by 15 publications

References 25 publications

Considerable pancreatic tumor motion during breath-holding

Considerable pancreatic tumor motion during breath-holding

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

Assessment of biological dosimetric margin for stereotactic body radiation therapy

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