Supralinearität von Radiothermolumineszenzdosimetern

Schedel, C; Seeger, W.

doi:10.1055/s-2008-1052900

Cited by 2 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thermolumuniscent dosimetry (TLD) with LiF crystals is advantageous for radiation techniques (Feist 1988, Horowitz 1984, 1987, Schedel and Seeger 1985. TLD LiF crystals are therefore frequently used for the verification of therapeutic doses (Folkard et al 1989, Heydarian et al 1996, Svensson et al 1990.…”

Section: Problems In Dose Measurementsmentioning

confidence: 99%

Dosimetry studies with TLDs for stereotactic radiation techniques for intraocular tumours

Ertl¹,

Zehetmayer²,

Schöggl³

et al. 1997

Phys. Med. Biol.

View full text Add to dashboard Cite

Between March 1993 and January 1997, stereotactic radiation techniques were used to irradiate 66 intraocular tumour patients with the Gamma Knife (Leksell Gamma Knife, model B unit) at the University of Vienna, Austria. This study investigates the dosimetry for stereotactic irradiation of ocular structures. For the dosimetry program KULA 4.4, Gamma Knife stereotactic irradiation of the eye represents an extreme frontal skull position. In addition, irradiation of the eye may be performed in the usual supine position in exceptional cases only. With the patient in the prone position, the dose planning program has to calculate with a significantly large number of single-beam extrapolations. In our first experiment we measured the isocentre dose for eight different gamma-angle positions, both in prone and supine positions, using TLD measurements in an Alderson head phantom. We found a maximum deviation of +/- 1.6% using these individually calibrated TLDs. In the second experiment we examined the dose cross profiles for the two most frequently used treatment positions (supine position, gamma = 65 degrees, and prone position, gamma = 140 degrees). For this purpose we implanted a specially designed TLD array into the orbit of a human cadaver head. We found excellent agreement of the dose values measured for the isocentre as well as the posterior part of the eye with orbit with deviations of less than -2.7%. However, for the anterior part of the eye, deviations between computer-generated calculations and the TLD measurements were found to range up to -30%. These differences were noticed both for supine and prone positions. For the Gamma Knife stereotactic irradiation of ocular tumours or pathologies, precautions should be taken to avoid significant underdosage in the anterior part of the radiation field.

show abstract

Section: Problems In Dose Measurementsmentioning

confidence: 99%

Dosimetry studies with TLDs for stereotactic radiation techniques for intraocular tumours

Ertl¹,

Zehetmayer²,

Schöggl³

et al. 1997

Phys. Med. Biol.

View full text Add to dashboard Cite

show abstract

“…As the TLD reader is based on the use of a photomultiplier, we used the unit of the collected charges (µC) which correspond directly to the total luminescence. The following annealing procedure included heating to 400 • C, 1 h heating at 400 • C, cooling down to 100 • C, 2 h heating at 100 • C and cooling to room temperature (Schedel and Seeger 1985, Horowitz 1987, 1984, Feist 1988, Folkard et al 1989, Svensson et al 1990. One day after the measurements described below, all TLDs were rechecked for a possible loss of sensitivity.…”

Section: Tld Calibrationmentioning

confidence: 99%

TLD array for precise dose measurements in stereotactic radiation techniques

et al. 1996

View full text Add to dashboard Cite

We developed a new TLD array for precise dose measurement and verification of the spatial dose distribution in small radiation targets. It consists of a hemicylindrical, tissue-equivalent rod made of polystyrene with 17 parallel moulds for an exact positioning of each TLD. The spatial resolution of the TLD array was evaluated using the Leskell spherical phantom. Dose planning was performed with KULA 4.4 under stereotactic conditions on axial CT images. In the Leksell gamma unit the TLD array was irradiated with a maximal dose of 10 Gy with an unplugged 14 mm collimator. The doses delivered to the TLDs were rechecked by diode detector and film dosimetry and compared to the computer-generated dose profile. We found excellent agreement of our measured values, even at the critical penumbra decline. For the 14 mm and 18 mm collimator and for the 11 mm collimator combination we compared the measured and calculated data at full width at half maximum. This TLD array may be useful for phantom or tissue model studies on the spatial dose distribution in confined radiation targets as used in stereotactic radiotherapy.

show abstract

Supralinearität von Radiothermolumineszenzdosimetern

Cited by 2 publications

References 0 publications

Dosimetry studies with TLDs for stereotactic radiation techniques for intraocular tumours

Dosimetry studies with TLDs for stereotactic radiation techniques for intraocular tumours

TLD array for precise dose measurements in stereotactic radiation techniques

Contact Info

Product

Resources

About