PLAY‐DOH ® AND WATER‐SOAKED GAUZE SPONGES AS ALTERNATIVE BOLUS MATERIAL FOR COBALT‐60 TELETHERAPY

The journal Veterinary Radiology & Ultrasound is a veterinary specialty journal devoted to the fields of veterinary diagnostic imaging and radiation oncology. The purpose of this retrospective, observational study is to evaluate progressive trends in radiation oncology articles published in Veterinary Radiology & Ultrasound during the 40-year period and describe a shift of trends through several viewpoints. This 40-year period was divided into four subperiods: Period These articles were divided into six categories based on the nature of the study: 1) studies related to teletherapy with endpoints being patient outcome, 2) radiation therapy dosimetry/planning, 3) patient setup, 4) reviews, 5) case reports, and 6) others. The number of radiation oncology articles in Veterinary Radiology & Ultrasound has increased over the 40-year period. The number of authors per article has increased between Periods 1 and 3. The number of articles related to linear accelerator has increased between Periods 3 and 4. The median number of treated patients per clinical article related to teletherapy ranged from 15 to 21, which has not changed significantly over the 40-year period. The most commonly used radiation therapy protocols during Periods 2 and 3 were finefractionated protocols (defined as 10 or more fractions), whereas coarse-fractionated protocols were more common during Periods 1 and 4. Findings from this study highlight the notable changes of trends in veterinary radiation oncology articles published in Veterinary Radiology & Ultrasound, which clearly reflect changes in the field of veterinary radiation oncology during the past 40 years.

Section: Resultsmentioning

confidence: 99%

A retrospective analysis of radiation oncology related scientific articles in the journal Veterinary Radiology and Ultrasound: Trends over 40 years (1976‐2015)

Nagata

2019

“…Sponges were water‐soaked and a bolus thickness of 0.5 cm ( d max for Cobalt 60) was used at a single field size. There was no significant difference between water‐soaked gauze and Superflab ® in terms of photon absorption, yet, variation between separate irradiations was significant 4 . There are no guidelines for wet gauze fabrication when used as a bolus material.…”

Section: Introductionmentioning

confidence: 97%

“…There was no significant difference between water-soaked gauze and Superflab s in terms of photon absorption, yet, variation between separate irradiations was significant. 4 There are no guidelines for wet gauze fabrication when used as a bolus material. Often, wetness is judged subjectively and the effect of various wetness levels on bolus efficacy is not known.…”

Section: Introductionmentioning

confidence: 99%

EFFECT OF WETNESS LEVEL ON THE SUITABILITY OF WET GAUZE AS A SUBSTITUTE FOR SUPERFLAB^® AS A BOLUS MATERIAL FOR USE WITH 6 MV PHOTONS

Benoît

Pruitt

Thrall

2009

Despite the availability of commercial tissue equivalent bolus material, wet gauze has an application in radiation therapy to provide superior conformance to irregular contours. Wet gauze bolus has the potential to reduce air gaps between the bolus and surface, which could decrease surface dose if sufficiently large to disrupt electronic equilibrium. Wet gauze bolus is often fabricated and wetness judged qualitatively. We assessed the effect of specific gauze wetness levels, quantified in terms of physical density, at various field sizes with respect to their effectiveness as bolus material compared with Superflab. For large fields, > 7 x 7 cm2 in this study, wet gauze sponges with a physical density of 1.02 g/cm3 performed essentially identical to Superflab; at a smaller field size the wet gauze was slightly less effective, likely due to the heterogeneity of the gauze-water matrix. Gauze that was wetter, with a physical density of 1.2 g/cm3, or less wet, with a physical density of 0.75 g/cm3 was not as effective either due to enhanced photon absorption in the wetter sponges, or less effective establishment of electronic equilibrium in the less wet sponges. The presence of an air gap under Superflab led to reduced surface dose, especially for small fields and large air gaps. Thus, if Superflab use leads to poor contact with the skin, wet gauze having a physical density of 1.02 g/cm3 can be used as a substitute. Judging the water content of wet gauze subjectively is not acceptable as over- or under wetness can lead to decreased effectiveness of the bolus material.

“…To our knowledge, the properties of SuperFlab, Play‐Doh and water soaked gauze have not been documented with regard to electron beam attenuation. With regard to cobalt photons, either Play‐Doh or water‐soaked gauze was comparable to SuperFlab (reference) but it is not certain that this similarity will apply to electron beams …”

Section: Introductionmentioning

confidence: 98%

THE ELECTRON BEAM ATTENUATING PROPERTIES OF SUPERFLAB, PLAY‐DOH, AND WET GAUZE, COMPARED TO PLASTIC WATER

Nagata¹,

Lattimer

March

2011

Bolus material is used commonly with electron treatments. The purpose of this study was to compare the electron beam attenuating properties of SuperFlab, Play-Doh, and wet gauze to that of plastic water, and evaluate their characteristics as bolus materials for electron beam therapy. Electron beams of 5, 6, 7, 8, 10, and 12 MeV were used. Dose reduction from a range of bolus thicknesses from 2 mm to a thickness well beyond the thickness required to reach peak ioization was measured for each of the bolus materials to establish independent isodose curves. Measurements performed at the known water Dmax for all bolus materials indicated similar results for SuperFlab and plastic water with less than 3% difference for most energies. Play-Doh resulted in more attenuation or less dose buildup compared with plastic water, especially at lower energies. The difference was as high as 24.7% for the beam energy of 5 MeV for Play-Doh. Evaluation of the dose build up curves for all materials indicated the peak dose build up for wet gauze and Play-Doh occurred at lesser thicknesses compared to plastic water and SuperFlab, particularly at lower energies. If Play-Doh and wet gauze are to be used for electron bolus materials, dose build up curves should be established for the machine being used and the appropriate thickness of bolus material be chosen based on those curves.