High resolution radiochromic film dosimetry: Comparison of a microdensitometer and an optical microscope

Pellicioli, Paolo; Bartzsch, Stefan; Donzelli, Mattia; Krisch, M.; Bräuer-Krisch, Elke

doi:10.1016/j.ejmp.2019.08.012

Cited by 22 publications

(21 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Radiochromic films are well known detectors in radiation therapy, able to visualize the two-dimensional dose distribution of the irradiated area. The detailed description of the protocol developed for MRT film dosimetry at the micrometric scale and used in this work is documented in the literature (Pellicioli et al, 2019). Here, only the specific irradiation setup and geometry used in the study will be presented.…”

Section: Film Dosimetry For Quantification Of the Radiation Interactimentioning

confidence: 99%

“…A single film irradiation was performed for each field size at 5 mm, mm, 20 mm, 30 mm, 50 mm and 80 mm depth in the waterequivalent phantom. Films were scanned with an optical microscope 10 days after exposition, following the protocol presented by Pellicioli et al (2019). The dose profile of the five central valleys was considered for each microbeam array and dose values were integrated over the central 50 mm-wide region.…”

Section: Film Dosimetry For Quantification Of the Radiation Interactimentioning

confidence: 99%

See 1 more Smart Citation

Study of the X-ray radiation interaction with a multislit collimator for the creation of microbeams in radiation therapy

Pellicioli¹,

Donzelli²,

Davis³

et al. 2021

J Synchrotron Rad

Self Cite

View full text Add to dashboard Cite

Microbeam radiation therapy (MRT) is a developing radiotherapy, based on the use of beams only a few tens of micrometres wide, generated by synchrotron X-ray sources. The spatial fractionation of the homogeneous beam into an array of microbeams is possible using a multislit collimator (MSC), i.e. a machined metal block with regular apertures. Dosimetry in MRT is challenging and previous works still show differences between calculated and experimental dose profiles of 10–30%, which are not acceptable for a clinical implementation of treatment. The interaction of the X-rays with the MSC may contribute to the observed discrepancies; the present study therefore investigates the dose contribution due to radiation interaction with the MSC inner walls and radiation leakage of the MSC. Dose distributions inside a water-equivalent phantom were evaluated for different field sizes and three typical spectra used for MRT studies at the European Synchrotron Biomedical beamline ID17. Film dosimetry was utilized to determine the contribution of radiation interaction with the MSC inner walls; Monte Carlo simulations were implemented to calculate the radiation leakage contribution. Both factors turned out to be relevant for the dose deposition, especially for small fields. Photons interacting with the MSC walls may bring up to 16% more dose in the valley regions, between the microbeams. Depending on the chosen spectrum, the radiation leakage close to the phantom surface can contribute up to 50% of the valley dose for a 5 mm × 5 mm field. The current study underlines that a detailed characterization of the MSC must be performed systematically and accurate MRT dosimetry protocols must include the contribution of radiation leakage and radiation interaction with the MSC in order to avoid significant errors in the dose evaluation at the micrometric scale.

show abstract

Section: Film Dosimetry For Quantification Of the Radiation Interactimentioning

confidence: 99%

Section: Film Dosimetry For Quantification Of the Radiation Interactimentioning

confidence: 99%

Study of the X-ray radiation interaction with a multislit collimator for the creation of microbeams in radiation therapy

Pellicioli¹,

Donzelli²,

Davis³

et al. 2021

J Synchrotron Rad

Self Cite

View full text Add to dashboard Cite

show abstract

“…Film dosimetry for microbeam irradiation has been described extensively elsewhere (Ocadiz et al, 2019;Pellicioli et al, 2019). In brief, the microbeam array with planar view was recorded as the intensity pattern generated by the collimator by moving the films with constant velocity vertically through the stationary beam utilizing the vertical movement stage.…”

Section: Simulation and Dosimetrymentioning

confidence: 99%

Perspectives for microbeam irradiation at the SYRMEP beamline

et al. 2021

View full text Add to dashboard Cite

It has been shown previously both in vitro and in vivo that microbeam irradiation (MBI) can control malignant tumour cells more effectively than the clinically established concepts of broad beam irradiation. With the aim to extend the international capacity for microbeam research, the first MBI experiment at the biomedical beamline SYRMEP of the Italian synchrotron facility ELETTRA has been conducted. Using a multislit collimator produced by the company TECOMET, arrays of quasi-parallel microbeams were successfully generated with a beam width of 50 µm and a centre-to-centre distance of 400 µm. Murine melanoma cell cultures were irradiated with a target dose of approximately 65 Gy at a mean photon energy of ∼30 keV with a dose rate of 70 Gy s−1 and a peak-to-valley dose of ∼123. This work demonstrated a melanoma cell reduction of approximately 80% after MBI. It is suggested that, while a high energy is essential to achieve high dose rates in order to deposit high treatment doses in a short time in a deep-seated target, for in vitro studies and for the treatment of superficial tumours a spectrum in the lower energy range might be equally suitable or even advantageous.

show abstract

“…Microscopes equipped with motorized stages able to move with sub-micrometric precision combined with a charge-coupled device (CCD) camera, allow the acquisition of film areas up to 10 cm 2 in a few minutes with micrometric resolution and the evaluation of unusual field configurations such as pencil beams [26] or phantoms under motion conditions. Dedicated image processing protocols are being developed to correct the acquired digital images for noise and film inhomogeneities at the micrometric scale [117,118] . An example of a digitalized film image is reported in Figure 5.…”

Section: Radiochromic Film Dosimetrymentioning

confidence: 99%