An intercomparison of the accuracy of computer planning systems for brachytherapy

Visser, A.G.

doi:10.1016/0167-8140(89)90093-5

Cited by 15 publications

(11 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In a comparison of computer planning systems performed in 1987, Visser [24] found deviations of up to 5 mm when reconstructing gynaecological applicators from orthogonal radiographs, leading to discrepancies of 10% in the dose rate. Kolkman-Deurloo et al [9] found an average reconstruction error of 0.04 mm for a dedicated brachytherapy localizer using a similar phantom and orthogonal reconstruction.…”

Section: Reconstruction Measurementsmentioning

confidence: 99%

See 1 more Smart Citation

Determination of the accuracy of implant reconstruction and dose delivery in brachytherapy in The Netherlands and Belgium

Elfrink¹,

Kolkman-Deurloo²,

Kleffens³

et al. 2001

Radiotherapy and Oncology

View full text Add to dashboard Cite

Purpose: To gain insight into the accuracy of brachytherapy treatments, the accuracy of implant reconstruction and dose delivery was investigated in 33 radiotherapy institutions in The Netherlands and Belgium.Materials and methods: The accuracy of the implant reconstruction method was determined using a cubic phantom containing 25 spheres at well-known positions. Reconstruction measurements were obtained on 41 brachytherapy localizers, 33 of which were simulators. The reconstructed distances between the spheres were compared with the true distances. The accuracy of the dose delivery was determined for high dose rate (HDR), pulsed dose rate (PDR) and low dose rate (LDR) afterloading systems using a polymethyl methacrylate cylindrical phantom containing a NE 2571 ionization chamber in its centre. The institutions were asked to deliver a prescribed dose at the centre of the phantom. The measured dose was compared with the prescribed dose.Results: The average reconstruction accuracy was 20.07 mm (^0.4 mm, 1 SD) for 41 localizers. The average deviation of the measured dose from the prescribed dose was 10.9% (^1.3%, 1 SD) for 21 HDR afterloading systems, 11.0% (^2.3%, 1 SD) for 12 PDR afterloaders, and 11.8% (^2.5%, 1 SD) for 15 LDR afterloaders.Conclusions: This comparison showed a good accuracy of brachytherapy implant reconstruction and dose delivery in The Netherlands and Belgium. q

show abstract

Section: Reconstruction Measurementsmentioning

confidence: 99%

“…The reconstruction accuracy has improved enormously since the 1987 investigation of Visser [24]. Based on the results of these measurements, the task group recommends an annual check of the reconstruction accuracy by reconstruction of a phantom with a well-known geometry.…”

Section: Reconstruction Measurementsmentioning

confidence: 99%

Determination of the accuracy of implant reconstruction and dose delivery in brachytherapy in The Netherlands and Belgium

Elfrink¹,

Kolkman-Deurloo²,

Kleffens³

et al. 2001

Radiotherapy and Oncology

View full text Add to dashboard Cite

show abstract

“…Failure to do so can produce a, difference between the prescribed dose distribution and the actual dose distribution large enough to produce a misadministration. Visser (1989) confirmed that operator accuracy and precision are crucial factors in dosimetry. Poor accuracy and precision result in localization errors and inaccurate source position values.…”

Section: Treatment Planningmentioning

confidence: 50%

“…Many articles discuss the software that is used in treatment planning (e.g., Plott, 1990;Roy et al, 1991;Ten Haken et al, 1988;Tolbert and Reed, 1981;Visser, 1989). Tolbert and Reed (1981) recommend that QA procedures be used for computerized treatment planning systems that are routinely used in dose calculations.…”

Section: Treatment Planningmentioning

confidence: 99%

Human factors evaluation of remote afterloading brachytherapy: Human error and critical tasks in remote afterloading brachytherapy and approaches for improved system performance. Volume 1

Callan¹,

Kelly²,

Quinn³

1995

View full text Add to dashboard Cite

“…The 95% isodose was at the level of the basal layer, while the 80% isodose was at the dermis±fat interface. Dosimetry was carried out in three different ways: (a) accurate calibration of the source activity, according to the NCS protocol [11,12]; (b) accurate computer planning for brachytherapy [13]; and (c) thermoluminescent dosimetry (TLD) measurements. Source calibration and computer planning allowed dose calculations to be made with errors of ,3%.…”

Section: Irradiationmentioning

confidence: 99%

Determination of colony numbers in pig epidermis as an estimate for radiosensitivity. A rapid assay based on in vitro BrdU-labelling.

Aardweg

Mooi²

1999

The British Journal of Radiology

View full text Add to dashboard Cite

Abstract. A rapid assay has been developed for the quantitation of colonies arising from surviving clonogenic cells in pig epidermis after irradiation. The number of surviving clonogenic cells per unit area was related to the epidermal in vivo response of moist desquamation. After irradiation with single doses, ranging from 20 to 36 Gy, skin biopsies were taken and incubated in dispase for enzymatic separation of the epidermis and dermis. Full thickness epidermal sheets were labelled with bromodeoxyuridine (BrdU) in vitro. Proliferating cells were visualized using standard immunohistochemical procedures. Cell groups containing ¢16 cells were counted as colonies. These colonies were ®rst seen on day 14/15 after irradiation. The number of colonies per cm 2 , as a function of skin surface dose, yielded a cell survival curve with a D 0 (¡SE) of 3.87¡0.57 Gy. The ED 50 for the epidermal in vivo reaction of moist desquamation corresponded with a colony density of 2.7 colonies per cm 2 . After higher doses, abundant smaller colonies of 4±8 BrdUpositive cells were seen and these were more radioresistant, as represented by higher D 0 values.Radiation-induced epidermal injury of the skin is often assessed with the use of macroscopic endpoints such as erythema and moist desquamation. In pig skin these endpoints can be evaluated at 4±6 weeks after irradiation. However, the severity and incidence of this damage may be in¯uenced by environmental factors, such as infections, partially obscuring the dose±effect relationship. To avoid these possible confounding factors a more direct approach was used, by studying colony formation from surviving epidermal clonogenic cells. There is likely to be an inverse relationship between the incidence of moist desquamation and the survival of clonogenic cells. Colony formation can be used as an estimate of radiosensitivity [1±3]. In the past, several groups have attempted to determine radiation damage (more directly) using the number of colonies arising from surviving clonogenic cells as a parameter for epidermal radiosensitivity [4±7]. Various types of assays were used, such as (i) a macroscopic in vivo colony assay for rodent skin [5±7], (ii) autoradiographs of whole epidermal sheets for the detection of proliferating cells in mouse skin [4], (iii) crosssections of pig skin viewed by light microscopy [8], or (iv) blocking cells in mitosis followed by staining with Schiff's reagents using whole epidermal sheets from biopsies of pig skin [9]. A drawback of the macroscopic colony assay is the fact that smaller colonies are easily missed, while the use of autoradiographs and cross-sections is laborious and time consuming. The assay introduced by Chen et al [9] involved three injections of vincristine, resulting in the induction of a metaphase arrest, which allowed recognition of proliferating cells by the presence of metaphases. In this assay, separation of the epidermis from the dermis was accomplished by hydrolysis with 5 N HC1 followed by teasing apart with forceps.The objective of this pap...

show abstract

An intercomparison of the accuracy of computer planning systems for brachytherapy

Cited by 15 publications

References 14 publications

Determination of the accuracy of implant reconstruction and dose delivery in brachytherapy in The Netherlands and Belgium

Determination of the accuracy of implant reconstruction and dose delivery in brachytherapy in The Netherlands and Belgium

Human factors evaluation of remote afterloading brachytherapy: Human error and critical tasks in remote afterloading brachytherapy and approaches for improved system performance. Volume 1

Determination of colony numbers in pig epidermis as an estimate for radiosensitivity. A rapid assay based on in vitro BrdU-labelling.

Contact Info

Product

Resources

About