担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of Applied Clinical Medical Physics  

Purpose: This study aimed to investigate the effect of inverse planning parameters on dose-volume indices in brachytherapy for uterine cervical cancer. Methods: Fourteen consecutive patients with cervical cancer who received intracavitary and interstitial brachytherapy (IC/ISBT) were selected. Tandem, ovoid, and interstitial needles were used in all cases. The evaluation plans were recalculated from the first fraction of clinical brachytherapy plans. The correlation between the 11 dose optimization parameters of inverse planning and the 13 dose-volume indices was evaluated. The parameters were adjusted in five levels, and dose optimization was performed in hybrid inverse planning optimization (HIPO). Spearman's rank correlation and multiple regression analyses were conducted to assess the association between the parameters and the indices. The indices included clinical target volume (CTV) dose, organ-at-risk (OAR) dose, homogeneity, and conformity. Additionally, the correlation between optimization parameters and calculation time was investigated, along with a technique for efficiently generating treatment plans. Results: “CTV Max Weight” and “OAR Max Weight” were the key parameters significantly affecting the indices. Increasing “CTV Max Weight” improved homogeneity but reduced the target coverage. The effect of “OAR Max Weight” on the dose reduction of CTV<inf>HR</inf> D<inf>90</inf> (β = −0.59) was more significant than that on the dose reduction of OAR D<inf>2cc</inf> (β = −0.21). In addition, adjusting “CTV Min Weight” and “CTV Volume” could reduce the hyper-dose sleeve without increasing the OAR dose. A large number of normal tissue sampling points could negatively affect the dose distributions and increase the calculation times. Conclusion: “CTV Max Weight” and “OAR Max Weight” were the most influential parameters in HIPO, significantly affecting dose-volume indices in IC/ISBT for uterine cervical cancer. Additionally, parameters that regulate the hyper-dose sleeve and needle-delivered dose were identified. The quality of treatment planning can be maintained and planning time reduced by appropriately optimizing these parameters.

DOI： 10.1002/acm2.70157

Open Access

Web of Science

Scopus

PubMed

記述言語：英語   掲載種別：研究論文（学術雑誌）  

This study focused on the dosimetric impact of variations in respiratory motion during lung stereotactic body radiotherapy (SBRT). Dosimetric comparisons between volumetric modulated arc therapy (VMAT) and three-dimensional conformal radiotherapy (3DCRT) were performed using four-dimensional computed tomography (4DCT)-based internal target volumes (ITV). We created retrospective plans for ten patients with lung cancer who underwent SBRT using 3DCRT and VMAT techniques. A Delta4 Phantom + (ScandiDos, Uppsala, Sweden) was used to evaluate the dosimetric robustness of 4DCT-based ITV against variations in respiratory motion during treatment. We analyzed respiratory motion during treatment. Dose-volume histogram parameters were evaluated for the 95% dose (D95%) to the planning target volume (PTV) contoured on CT images obtained under free breathing. The correlations between patient respiratory parameters and dosimetric errors were also evaluated. In the phantom study, the average PTV D95% dose differences for all fractions were - 2.9 ± 4.4% (- 16.0 - 1.2%) and - 2.0 ± 2.8% (- 11.2 - 0.7%) for 3DCRT and VMAT, respectively. The average dose difference was < 3% for both 3DCRT and VMAT; however, in 5 out of 42 fractions in 3DCRT, the difference in PTV D95% was > 10%. Dosimetric errors were correlated with respiratory amplitude and velocity, and differences in respiratory amplitude between 4DCT and treatment days were the main factors causing dosimetric errors. The overall average dose error of the PTV D95% was small; however, both 3DCRT and VMAT cases exceeding 10% error were observed. Larger errors occurred with amplitude variation or baseline drift, indicating limited robustness of 4DCT-based ITV.

DOI： 10.1007/s12194-023-00757-8

PubMed

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.ejmp.2022.06.020

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

DOI： 10.1002/acm2.13382

その他リンク： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/acm2.13382

記述言語：日本語   掲載種別：記事・総説・解説・論説等（商業誌、新聞、ウェブメディア）  

担当区分：筆頭著者   記述言語：英語   掲載種別：速報，短報，研究ノート等（学術雑誌）  

開催年月日： 2025年11月

会議種別：口頭発表（一般）  

開催年月日： 2025年11月

記述言語：英語   会議種別：口頭発表（一般）  

開催年月日： 2025年7月

記述言語：日本語   会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

開催年月日： 2025年4月

会議種別：ポスター発表  

開催年月日： 2025年4月

記述言語：日本語   会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

種別：大会・シンポジウム等 

種別：大会・シンポジウム等