CT Based 3-Dimensional Treatment Planning of Intracavitary Brachytherapy for Cancer of the Cervix : Comparison between Dose-Volume Histograms and ICRU Point Doses to the Rectum and Bladder

Hashim, Natasha; Jamalludin, Zulaikha; Ung, Ngie Min; Ho, Gwo Fuang; Malik, Rozita Abdul; Phua, Vincent Chee Ee

doi:10.7314/apjcp.2014.15.13.5259

Cited by 17 publications

(13 citation statements)

References 29 publications

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“…Given the defaults of 2D X-ray BT planning, three-dimensional (3D) imaging (e.g. computed tomography [CT] and magnetic resonance imaging [MRI])-guided intracavitary BT planning for cervical cancer has been developed [2, 5–7]. This involves the dose prescription according to a 3D target tumor volume instead of a fixed reference point, thereby providing better dosage optimization.…”

Section: Introductionmentioning

confidence: 99%

Dosimetric Comparison between Three-Dimensional Magnetic Resonance Imaging-Guided and Conventional Two-Dimensional Point A-Based Intracavitary Brachytherapy Planning for Cervical Cancer

et al. 2016

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ObjectiveThe purpose of this study was to comprehensively compare the 3-dimensional (3D) magnetic resonance imaging (MRI)-guided and conventional 2-dimensional (2D) point A-based intracavitary brachytherapy (BT) planning for cervical cancer with regard to target dose coverage and dosages to adjacent organs-at risk (OARs).MethodsA total of 79 patients with cervical cancer were enrolled to receive 2D point A-based BT planning and then immediately to receive 3D planning between October 2011 and April 2013 at the First Hospital Affiliated to Xi’an Jiao Tong University (Xi’an, China). The dose-volume histogram (DVH) parameters for gross tumor volume (GTV), high-risk clinical target volume (HR-CTV), intermediate-risk clinical target volume (IR-CTV) and OARs were compared between the 2D and 3D planning.ResultsIn small tumors, there was no significant difference in most of the DVHs between 2D and 3D planning (all p>0.05). While in big tumors, 3D BT planning significantly increased the DVHs for most of the GTV, HR-CTV and IR-CTV, and some OARs compared with 2D planning (all P<0.05). In 3D planning, DVHs for GTV, HR-CTV, IR-CTV and some OARs were significantly higher in big tumors than in small tumors (all p<0.05). In contrast, in 2D planning, DVHs for almost all of the HR-CTV and IR-CTV were significantly lower in big tumors (all p<0.05). In eccentric tumors, 3D planning significantly increased dose coverage but decreased dosages to OARs compared with 2D planning (p<0.05). In tumors invading adjacent tissues, the target dose coverage in 3D planning was generally significantly higher than in 2D planning (P<0.05); the dosages to the adjacent rectum and bladder were significantly higher but those to sigmoid colon were lower in 3D planning (all P<0.05).Conclusions3D MRI image-guided BT planning exhibits advantages over 2D planning in a complex way, generally showing advantages for the treatment of cervical cancer except small tumors.

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Section: Introductionmentioning

confidence: 99%

Dosimetric Comparison between Three-Dimensional Magnetic Resonance Imaging-Guided and Conventional Two-Dimensional Point A-Based Intracavitary Brachytherapy Planning for Cervical Cancer

et al. 2016

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“…An evaluation of ICR plans for 229 patients found a significant correlation between ICRU rectal point and D2cc, using the equation D2cc = 0.902 × ICRU point dose + 0.984, although ICRU may underestimate D2cc. 21 In contrast, an analysis of ICR plans for 20 patients found that the ICRU bladder point could be a reasonable surrogate for D2cc, whereas the ICRU rectal point could not. 22 Taken together, these studies yield conflicting results about whether the 2D-based ICRU rectal point is sufficiently reliable for OAR protection.…”

Section: Discussionmentioning

confidence: 95%

Who Really Benefits from 3D-Based Planning of Brachytherapy for Cervical Cancer?

Jeong

Kang

et al. 2018

J Korean Med Sci

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BackgroundAlthough intracavitary radiotherapy (ICR) is essential for the radiation therapy of cervical cancer, few institutions in Korea perform 3-dimensional (3D)-based ICR. To identify patients who would benefit from 3D-based ICR, dosimetric parameters for tumor targets and organs at risk (OARs) were compared between 2-dimensional (2D)- and 3D-based ICR.MethodsTwenty patients with locally advanced cervical cancer who underwent external beam radiation therapy (EBRT) following 3D-based ICR were retrospectively evaluated. New 2D-based plans based on the Manchester system were developed. Tumor size was measured by magnetic resonance imaging.ResultsThe mean high risk clinical target volume (HR-CTV) D90 value was about 10% lower for 2D- than for 3D-based plans (88.4% vs. 97.7%; P = 0.068). Tumor coverage did not differ between 2D- and 3D-based plans in patients with tumors ≤ 4 cm at the time of brachytherapy, but the mean HR-CTV D90 values in patients with tumors > 4 cm were significantly higher for 3D-based plans than for 2D-based plans (96.0% vs. 78.1%; P = 0.017). Similar results were found for patients with tumors > 5 cm initially. Other dosimetric parameters for OARs were similar between 2D- and 3D-based plans, except that mean sigmoid D2cc was higher for 2D- than for 3D-based plans (67.5% vs. 58.8%; P = 0.043).ConclusionThese findings indicate that 3D-based ICR plans improve tumor coverage while satisfying the dose constraints for OARs. 3D-based ICR should be considered in patients with tumors > 4 cm size at the time of brachytherapy or > 5 cm initially.

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“…For LACC, the radiotherapies for IMRT and ICBT were both based on CT to evaluate the dose distribution of the target and OARs. 15,16 The accuracy of CT in evaluating the targets is poor, which leads to a lack of recognition of the targets or too much recognition. 17 The primary concern of IMRT/ICBT in cervical cancer is how to accurately determine the targets of LACC radiotherapy.…”

Section: Discussionmentioning

confidence: 99%

Investigation of fusion dose distribution for locally advanced cervical cancer under different bladder statuses for intensity‐modulated radiotherapy combined with intracavitary brachytherapy

Yang

Liu

et al. 2017

Precision Radiation Oncology

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Objective Intensity‐modulated radiotherapy (IMRT) combined with intracavitary brachytherapy (ICBT) is a standard radiotherapy technology for locally advanced cervical cancer (LACC), and bladder status is a common factor that affects dose distribution of the target and organs at risk (OARs). Under different bladder statuses, fusion dose distribution of IMRT combined with ICBT is unclear. The aim of the present study was to analyze the fusion dose distribution of targets and OARs for IMRT combined with ICBT in LACC under different bladder statuses. Methods A total of 20 patients with LACC who were treated in our department from 1 January 2015 to 31 July 2015 underwent magnetic resonance imaging and simulation computed tomography (Sim‐CT) scans under filled and empty bladder status. The magnetic resonance imaging and Sim‐CT scans were transmitted by Sim‐CT to the Oncentra treatment planning system and fused. The gross tumor volume (GTV) was delineated in the magnetic resonance imaging, and the clinical target volume (CTV), planning target volume (PTV) and OARs (intestine, bladder, rectum, left, and right femoral head) were delineated in Sim‐CT. The IMRT plan was designed with seven fields and 3‐D ICBT in the treatment planning system, and the radiation sources were X‐ray (6 MV) and 192Ir. The doses of the targets (D95%, D90%, D85%, D80%) and OARs (D1 cc and 2cc for intestine, D5%, 10%, and 30% for bladder, D1cc, 2cc, and 5cc for rectum, D1% for femoral head) were planned separately with IMRT and ICBT, and the geometric sum was used as the geometric dose. The treatment planning system plan used the superposition function to superimpose the IMRT and ICBT plans as a fusion plan, and the doses of the targets and OARs were calculated as a fusion dose. The relationship between the geometric and fusion doses of the targets and OARs was analyzed under different bladder statuses, and the dose contribution rates to the targets and OARs were calculated from ICBT. Results For the empty bladder: D95% (uGTV = 3.92, tCTV = 11.28, tPTV = 10.79), D90% (uGTV, CTV = 3.92, uPTV = 3.25), and D85% (u = 3.92), D80% (u = 3.92). The geometric doses of the targets were lower than the fusion doses. For the full bladder: D95% (uGTV, PTV = 3.92, tCTV = 15.96), D90% (uGTV = 3.81, uCTV, PTV = 3.92), D85% (u = 3.92), and D80% (uGTV = 4.70, uCTV, PTV = 3.92). The geometric doses of the targets (D95%, D90%, D85%, D80%) were lower than the fusion doses at P < 0.001. The dose difference rate of GTV under the filled bladder condition was lower than that of the empty bladder (0.17–0.93% and 0.32–1.07%, respectively), whereas these values were similar in the empty bladder condition for CTV and PTV (1.10–2.75% and 1.22–3.40%, and 0.98–2.29% and 0.94–3.17%, respectively). For the empty bladder, the geometric doses of OARs (uintestine = 3.92; tintestine = 11.59; ubladder=3.92, 3.92, 3.36; urectum = 3.92; tfemoral head = 4.77 and 6.06) were higher than the fusion doses. For the full bladder, the geometric doses of OARs (tintestine = 10.27 and 8.84; ...

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CT Based 3-Dimensional Treatment Planning of Intracavitary Brachytherapy for Cancer of the Cervix : Comparison between Dose-Volume Histograms and ICRU Point Doses to the Rectum and Bladder

Cited by 17 publications

References 29 publications

Dosimetric Comparison between Three-Dimensional Magnetic Resonance Imaging-Guided and Conventional Two-Dimensional Point A-Based Intracavitary Brachytherapy Planning for Cervical Cancer

Dosimetric Comparison between Three-Dimensional Magnetic Resonance Imaging-Guided and Conventional Two-Dimensional Point A-Based Intracavitary Brachytherapy Planning for Cervical Cancer

Who Really Benefits from 3D-Based Planning of Brachytherapy for Cervical Cancer?

Investigation of fusion dose distribution for locally advanced cervical cancer under different bladder statuses for intensity‐modulated radiotherapy combined with intracavitary brachytherapy

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