Influence of contrast materials on dose calculation in radiotherapy planning using computed tomography for tumors at various anatomical regions: A prospective study

Shibamoto, Yuta; Naruse, Asaka; Fukuma, Hiroshi; Ayakawa, S.; Sugie, Chikao; Tomita, Natsuo

doi:10.1016/j.radonc.2007.05.015

Cited by 76 publications

(80 citation statements)

References 14 publications

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“…for example, the HU values of the heart and great vessels in the enhanced CT were replaced by average HU values obtained from the unenhanced CT, and in the Lung patients the CT to density conversion table used clinically was altered to reduce the effect of the increased density due to the contrast agent, in which tissues with a density between 1 g·cm -3 and 1.2 g·cm -3 were set equal to a density of 1 g·cm -3 . In comparison to the work conducted by Shibamoto and colleagues, (2) who used AP, RL, RA-LP oblique, and RA-LP oblique directional radiation, we used IMRT with an increased number of radiation directions and large weighed radiation ields at other angles. Hence, our dose disturbances in the spleen and kidney were less obvious than those reported previously (2) .…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, some institutes prefer to avoid enhanced CT during dose calculation (e.g., the Spain mode) (1) . However, other researchers suggest that this effect is not obvious because the differences can be ignored or are clinically acceptable (2)(3)(4)(5)(6) . Still other reports noted that large abdominal dose differences are in luenced by the spleen; (2) accordingly, enhanced CT has been widely accepted for head and neck (H&N) planning.…”

Section: Introductionmentioning

confidence: 99%

“…Previous reports (2)(3)(4)(5)(6) described the use of tumours in speci ic sites to illustrate the in luence of contrast agent. Shibamoto (2) conducted dose evaluations in the conventional anterior-posterior (AP) direction, but they were unable to re lect the multi-ield/multi-angle feature used in intensity-modulated radiotherapy (IMRT).…”

Section: Introductionmentioning

confidence: 99%

“…Shibamoto (2) conducted dose evaluations in the conventional anterior-posterior (AP) direction, but they were unable to re lect the multi-ield/multi-angle feature used in intensity-modulated radiotherapy (IMRT). The method used in those studies did not re lect the multi-beam and multi-angle set-up used in IMRT.…”

Section: Introductionmentioning

confidence: 99%

“…Choi et al, (3) Lee et al, (4) Liauw et al, (5) and Xiao et al (6) used IMRT to evaluate lung cancer, H&N cancers, and nasopharyngeal carcinoma (NPC). However, statistical comparisons of inter-plan dose variances in the above-mentioned studies (2)(3)(4)(5)(6) relied on dose volume histograms (DVHs) and statistical dose distribution parameters. For example, DVH statistical parameters such as the maximum dose (Dmax), average dose (Dmean), volume doses (D95, D50), and dose volumes (V20, V30) cannot be used to assess the geometric accuracy of a non-uniform dose distribution because spatial information is lost.…”

Section: Introductionmentioning

confidence: 99%

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The feasibility of direct treatment planning via contrast-enhanced computed tomography: an evaluation of dose differences based on the dimensional dose distribution comparison method

Sun

Wang

et al. 2017

IJRR

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Background: We used a MapCHECK so ware-based dimensional dose distribu on comparison method capable of evalua ng point-to-point geometrical dose differences in volume to determine whether doses obtained from an enhanced computed tomography (CT)-based treatment plan, which be%er defines the target regions and organs at risk, differs from doses obtained from plain CT and then evaluated the feasibility of treatment planning via enhanced CT. Materials and Methods: Forty-three randomly selected pa ents underwent plain and subsequent enhanced CT with the same se+ngs. Treatment plans developed for the two scans were iden cal in terms of planning parameters (e.g., isocentre, gantry angle, segments) and monitor units (MU) used for dose calcula on. Horizontal and ver cal dose distribu on planes across the same isocentre were selected from two types of plan; a two-dimensional dose distribu on analysis was used to determine the Distance-To-Agree (DTA) pass ra os of corresponding dose distribu on planes. Results: Obtained doses at the head and neck (H&N) and pelvic sites did not differ greatly between enhanced and plain CT. However, enhanced CT significantly influenced doses to the lower thoracic oesophagus. A corrected pass ra o that was achieved by non-pass points in lower isodose areas excluded from the sta s cal analysis had be%er clinical outcome. Conclusion: Radia on plans with mul -fields and mul -angles can reduce the influence of enhanced CT on torso cases and may even negate its influence on H&N cases. Enhanced CT can be directly used for planning unless the target region contains the lower oesophagus and its surrounding blood vessel whose high density requires correc on.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The feasibility of direct treatment planning via contrast-enhanced computed tomography: an evaluation of dose differences based on the dimensional dose distribution comparison method

Sun

Wang

et al. 2017

IJRR

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Improving radiation physics, tumor visualisation, and treatment quantification in radiotherapy with spectral or dual‐energy CT

Kruis

2021

J Applied Clin Med Phys

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Over the past decade, spectral or dual-energy CT has gained relevancy, especially in oncological radiology. Nonetheless, its use in the radiotherapy (RT) clinic remains limited. This review article aims to give an overview of the current state of spectral CT and to explore opportunities for applications in RT. In this article, three groups of benefits of spectral CT over conventional CT in RT are recognized. Firstly, spectral CT provides more information of physical properties of the body, which can improve dose calculation. Furthermore, it improves the visibility of tumors, for a wide variety of malignancies as well as organs-at-risk OARs, which could reduce treatment uncertainty. And finally, spectral CT provides quantitative physiological information, which can be used to personalize and quantify treatment.

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Helical tomotherapy for chemo‐refractory multiple liver metastases

et al. 2019

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Background Despite advances in chemotherapy, curing multiple liver metastases is quite rare. Even when response is obtained, regrowth of the tumors is almost inevitable. We aimed to evaluate the efficacy and adverse events of helical tomotherapy for chemo‐refractory multiple liver metastases. Methods Forty‐five patients with chemo‐refractory multiple (3‐10) liver metastases after standard systemic chemotherapy entered the single‐institutional prospective study. Liver metastases were the major disease; however, 31 also had uncontrolled primary lesions and/or other metastases. The prescribed dose was 55 Gy in 25 fractions. The median planning target volume (PTV) and normal liver volume (NLV) of first treatment were 128 cm3 and 1175 cm3, respectively. The median of V15Gy, V30Gy, and mean dose to NLV were 45%, 23%, and 19.4 Gy, respectively. Results Forty‐two patients (93%) completed the planned treatment. Median survival time (MST) for all patients was 8 months, and the 1‐year survival rate was 29%. The median local control (LC) period was 5 months and the 6‐month control rate of irradiated tumors was 33%. A ≥30% decrease in tumor markers was observed in 31%. The most common grade 3 toxicity was lymphocytopenia (40%), followed by fatigue (6%). Radiation‐induced liver disease (RILD) was not observed. Pancreatic cancer as the primary tumor, distant metastases outside the liver, low pretreatment neutrophil‐to‐lymphocyte ratio (NLR), and low pretreatment monocyte‐to‐lymphocyte ratio (MLR) were associated with poorer prognoses. Conclusions Helical tomotherapy for chemo‐refractory multiple liver metastases is a feasible and potentially effective treatment. Incorporating tomotherapy into the first‐line treatment in combination with systemic chemotherapy should be considered. Trial registration number CROG 12005.

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Influence of contrast materials on dose calculation in radiotherapy planning using computed tomography for tumors at various anatomical regions: A prospective study

Cited by 76 publications

References 14 publications

The feasibility of direct treatment planning via contrast-enhanced computed tomography: an evaluation of dose differences based on the dimensional dose distribution comparison method

The feasibility of direct treatment planning via contrast-enhanced computed tomography: an evaluation of dose differences based on the dimensional dose distribution comparison method

Improving radiation physics, tumor visualisation, and treatment quantification in radiotherapy with spectral or dual‐energy CT

Helical tomotherapy for chemo‐refractory multiple liver metastases

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