Dosimetric evaluation of Point A and volume-based high-dose-rate plans: a single institution study on adaptive brachytherapy planning for cervical cancer

Paul, Arun George; Nalichowski, Adrian; Abrams, Judith; Paximadis, Peter; Zhuang, Lei; Miller, Steven

doi:10.5114/jcb.2018.76782

Cited by 7 publications

(3 citation statements)

References 51 publications

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“…Paul et al . reported a relative improvement in organs at risk (OAR) doses per HDR brachytherapy fraction by the volume-based HDR brachytherapy plan compared to the point A-based HDR brachytherapy plan, and described dosimetric advantages of using a volume-based HDR brachytherapy plan to create more conformal plans [16]. Moreover, Lee et al .…”

Section: Purposementioning

confidence: 99%

Assessment of the anatomical position of point B and the relationship between point B dose and the dose delivered to pelvic lymph nodes in CT-based high-dose-rate brachytherapy for uterine cervical cancer

Matsukawa

Sasaki

Hirayama

et al. 2019

jcb

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Purpose To examine the anatomical position of point B and the relationship between the dose at point B and the dose delivered to the pelvic lymph nodes in computed tomography (CT)-based brachytherapy for cervical cancer. Material and methods Forty-nine cervical cancer patients were treated at Kyushu University Hospital. For all cases, planning CT images obtained after the applicator insertion were imported to an Oncentra Brachy (Elekta AB, Stockholm, Sweden), and points A (dose prescription, 6 Gy) and points B were set according to the Manchester method. The pelvic lymph node regions (external iliac, internal iliac, and obturator) were contoured, and the anatomic positions of 98 points B in 49 patients were examined. Dose volume histogram (DVH) parameters (D 100 , D 90 , D 50 , D 2cc , D 1cc , and D 0.1cc ) were calculated for each lymph node region and compared with the point B dose. Results The mean bilateral dose to point B was 1.70 ±0.18 Gy, and 26 (27%) of 98 points B were not located in any pelvic lymph node regions. The DVH analysis indicated a low degree of correlation overall, and all values were significantly different from point B doses ( p < 0.05), except for D 0.1cc of the external iliac node ( p = 0.0594) and D 1cc of the internal iliac node ( p = 0.0711). Conclusions We investigated the anatomical location of point B in patients with cervical cancer who underwent brachytherapy, and the DVH analysis revealed that the point B dose was a poor surrogate for the dose delivered to the pelvic lymph nodes.

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Section: Purposementioning

confidence: 99%

Assessment of the anatomical position of point B and the relationship between point B dose and the dose delivered to pelvic lymph nodes in CT-based high-dose-rate brachytherapy for uterine cervical cancer

Matsukawa

Sasaki

Hirayama

et al. 2019

jcb

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“…demonstrated that the dosimetric advantages of volume-based intracavitary planning produced more conformal plans than point-A-based plans. Volume-based plans resulted in a 6-12% reduction in the total dose to 2 cc of the OARs as well as an 8-37% reduction per BT fraction compared to point-A-based plans [ 37 ]. Previous studies have pointed out the strong correlation between local tumor control and D 90 of HR-CTV, with the best results above 85 Gy EQD2 [ 24 ].…”

Section: Discussionmentioning

confidence: 99%

Comparative analysis of image-guided adaptive interstitial brachytherapy and intensity-modulated arc therapy versus conventional treatment techniques in cervical cancer using biological dose summation

Fröhlich¹,

Vízkeleti²,

Nguyen³

et al. 2019

jcb

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Purpose: To compare image-guided adaptive interstitial brachytherapy (BT) and intensity-modulated arc therapy (IMAT) with conventional treatment techniques in cervical cancer using an alternative biological dose summation method. Material and methods: Initially, 21 interstitial BT and IMAT plans of patients with cervical cancer were included and additional plans were created (inverse optimized interstitial, optimized intracavitary, non-optimized intracavitary BT plans, and conformal external beam radiotherapy [EBRT]). The most exposed volume of critical organs in BT were identified manually on EBRT CT images. Biological total doses (EQD2) were calculated and compared between each combination of BT and EBRT plans. This method was compared with uniform dose conception (UDC) in IMAT and conformal EBRT plans. Results: The D 90 of high-risk CTV and D 2 of bladder and sigmoid were different in BT techniques only: p = 0.0149, < 0.001, < 0.001, respectively. The most advantageous values were obtained in the interstitial treatment plans and inverse optimized interstitial plans did not differ dosimetrically from these, while optimized intracavitary plans resulted in worse dose-volume parameters, and the worst of all were intracavitary plans without optimization. The D 2 of rectum was significantly lower with IMAT than with conformal EBRT plans (p = 0.037) and showed the same trend in BT plans as the other parameters (p < 0.001). The UDC dose summation method overestimated D 2 of bladder, rectum, and sigmoid (p < 0.001 for all). Conclusions: Although optimization improves the quality of conventional BT plans, interstitial plans produce significantly higher dose coverage of high-risk clinical target volume (HR-CTV) and lower doses to organs at risk (OARs). IMAT plans decrease the dose to the rectum. UDC overestimates OARs doses.

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“…While IC applicators historically were used with a pre-defined source loading and dose prescription method to specify the dose to points A (Manchester system), in the possession of 3D anatomical information, tailoring the dose to the target volumes became possible with individualized dose optimization [ 20 , 21 ]. Otherwise, this transition cannot be smooth as dose to points A is not suitable for dose prescription when IS needles go through or directly next to the needles, increasing the dose to false value [ 22 ].…”

Section: Purposementioning

confidence: 99%

Are active dwell positions always necessary in the ring/ovoids channel of the cervical applicator in the intracavitary-interstitial brachytherapy of cervical cancer?

Fröhlich¹,

Vízkeleti²,

Nguyen³

et al. 2023

jcb

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Purpose: To compare dosimetric parameters of brachytherapy (BT) treatment plans made with or without active source positions of the ring/ovoid (R/O) applicator in locally advanced cervical cancer patients.Material and methods: Sixty patients with cervical cancer without vaginal involvement were selected for the study, who received intra-cavitary/interstitial BT. For each patient, two plans with and without active source dwell positions in R/O were created, using the same dose-volume constraints. EQD 2 total doses from external beam and BT of target volumes and organs at risk (OARs) between the competing plans were compared.Results: There was no significant difference in the dose of high-risk clinical target volume (HR-CTV) and gross tumor volume (GTV) between the plans with inactive vs. active R/O. The mean D 98 of intermediate-risk clinical target volume (IR-CTV) was significantly lower with inactive R/O; however, the GEC-ESTRO (EMBRACE II study) and ABS criteria were fulfilled in 96% in both plans. There was no difference in dose homogeneity, but conformity of the plans with inactive R/O was higher. Doses to all OARs were significantly lower in plans without R/O activation. While all the plans without R/O activation fulfilled the recommended dose criteria for OARs, it was less achievable with R/O activation.Conclusions: Inactivation of R/O applicator results in similar dose coverage of the target volumes with lower doses to all OARs, as activation of R/O in cervix cancer patients when HR-CTV does not extend to R/O applicator. The use of active source positions in R/O shows worse performance regarding the fulfilment of the recommended criteria for OARs.

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Dosimetric evaluation of Point A and volume-based high-dose-rate plans: a single institution study on adaptive brachytherapy planning for cervical cancer

Cited by 7 publications

References 51 publications

Assessment of the anatomical position of point B and the relationship between point B dose and the dose delivered to pelvic lymph nodes in CT-based high-dose-rate brachytherapy for uterine cervical cancer

Assessment of the anatomical position of point B and the relationship between point B dose and the dose delivered to pelvic lymph nodes in CT-based high-dose-rate brachytherapy for uterine cervical cancer

Comparative analysis of image-guided adaptive interstitial brachytherapy and intensity-modulated arc therapy versus conventional treatment techniques in cervical cancer using biological dose summation

Are active dwell positions always necessary in the ring/ovoids channel of the cervical applicator in the intracavitary-interstitial brachytherapy of cervical cancer?

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