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A study on comparison of Gafchromic EBT2 film response under single and cumulative exposure conditions.

Ganapathy K, Kurup PG, Murali V, Muthukumaran M, Velmurugan J - J Med Phys (2013)

Bottom Line: Gafchromic films are used as dosimeter for in vivo and in phantom dose measurements.To check usability of Gafchromic EBT2 films in cumulative dose measurements, three EBT2 films were exposed to a daily fraction dose of 100 cGy, 150 cGy and 200 cGy, respectively, for 4 days.Gafchromic EBT2 films can be used to measure the cumulative dose delivered over multiple fractions, when the delivered dose is uniform across the film.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiotherapy, Apollo Specialty Hospital, Chennai, India.

ABSTRACT
Gafchromic films are used as dosimeter for in vivo and in phantom dose measurements. The dose response of Gafchromic EBT2 film under single and repeated exposure conditions is compared in this study to analyze the usability of Gafchromic EBT2 films in cumulative dose measurements. The post-irradiation change in response of the film is studied for up to 4 days after irradiation. The effect of repeated exposure to scanner light on the response of the film is also studied. To check usability of Gafchromic EBT2 films in cumulative dose measurements, three EBT2 films were exposed to a daily fraction dose of 100 cGy, 150 cGy and 200 cGy, respectively, for 4 days. The dose response of the films exposed to cumulative irradiation was compared with the dose measured from films exposed to the same dose but in a single exposure. It is observed that the post-irradiation darkening of the film does not saturate and continue to take place even 4 days after irradiation. The dose measured from the EBT2 films after 4 days from irradiation was around 2% higher than the dose measured from the same films at 24 hours post-irradiation. It was also observed that the repeated exposure to scanner light does not produce any significant change in the film response. The dose response of films exposed to cumulative irradiation agrees with the dose response of films exposed to the same dose in a single irradiation with less than 3% difference. Gafchromic EBT2 films can be used to measure the cumulative dose delivered over multiple fractions, when the delivered dose is uniform across the film.

No MeSH data available.


Related in: MedlinePlus

Effect of post-irradiation darkening of the film on the dose response of EBT2 films
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Figure 1: Effect of post-irradiation darkening of the film on the dose response of EBT2 films

Mentions: Three EBT2 films were used to study the post-irradiation darkening of the film. EBT2 films were exposed to doses of 200 cGy, 400 cGy and 800 cGy, respectively. All the three irradiated films were scanned repeatedly for up to 96 hours post-irradiation at different time interval. The change in scanner response of each EBT2 film up to 96 hours after irradiation was compared with the scanner response observed at 24 hours post-irradiation from the same film. The darkening of the EBT2 film initiated after irradiation was not saturated over the whole period of study. However, the rate of darkening was slower in the later part of the study compared to the earlier period. There was an increase of more than 2% in the dose-response of each film at 96 hours post-irradiation compared to the dose-response at 24 hours post-irradiation [Figure 1].


A study on comparison of Gafchromic EBT2 film response under single and cumulative exposure conditions.

Ganapathy K, Kurup PG, Murali V, Muthukumaran M, Velmurugan J - J Med Phys (2013)

Effect of post-irradiation darkening of the film on the dose response of EBT2 films
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3958996&req=5

Figure 1: Effect of post-irradiation darkening of the film on the dose response of EBT2 films
Mentions: Three EBT2 films were used to study the post-irradiation darkening of the film. EBT2 films were exposed to doses of 200 cGy, 400 cGy and 800 cGy, respectively. All the three irradiated films were scanned repeatedly for up to 96 hours post-irradiation at different time interval. The change in scanner response of each EBT2 film up to 96 hours after irradiation was compared with the scanner response observed at 24 hours post-irradiation from the same film. The darkening of the EBT2 film initiated after irradiation was not saturated over the whole period of study. However, the rate of darkening was slower in the later part of the study compared to the earlier period. There was an increase of more than 2% in the dose-response of each film at 96 hours post-irradiation compared to the dose-response at 24 hours post-irradiation [Figure 1].

Bottom Line: Gafchromic films are used as dosimeter for in vivo and in phantom dose measurements.To check usability of Gafchromic EBT2 films in cumulative dose measurements, three EBT2 films were exposed to a daily fraction dose of 100 cGy, 150 cGy and 200 cGy, respectively, for 4 days.Gafchromic EBT2 films can be used to measure the cumulative dose delivered over multiple fractions, when the delivered dose is uniform across the film.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiotherapy, Apollo Specialty Hospital, Chennai, India.

ABSTRACT
Gafchromic films are used as dosimeter for in vivo and in phantom dose measurements. The dose response of Gafchromic EBT2 film under single and repeated exposure conditions is compared in this study to analyze the usability of Gafchromic EBT2 films in cumulative dose measurements. The post-irradiation change in response of the film is studied for up to 4 days after irradiation. The effect of repeated exposure to scanner light on the response of the film is also studied. To check usability of Gafchromic EBT2 films in cumulative dose measurements, three EBT2 films were exposed to a daily fraction dose of 100 cGy, 150 cGy and 200 cGy, respectively, for 4 days. The dose response of the films exposed to cumulative irradiation was compared with the dose measured from films exposed to the same dose but in a single exposure. It is observed that the post-irradiation darkening of the film does not saturate and continue to take place even 4 days after irradiation. The dose measured from the EBT2 films after 4 days from irradiation was around 2% higher than the dose measured from the same films at 24 hours post-irradiation. It was also observed that the repeated exposure to scanner light does not produce any significant change in the film response. The dose response of films exposed to cumulative irradiation agrees with the dose response of films exposed to the same dose in a single irradiation with less than 3% difference. Gafchromic EBT2 films can be used to measure the cumulative dose delivered over multiple fractions, when the delivered dose is uniform across the film.

No MeSH data available.


Related in: MedlinePlus