Commissioning a hobby cutting device for radiochromic film preparation

Abstract

In addition to a high spatial resolution and well characterised dose response, one of the major advantages of radiochromic film as a dosimeter is that sheets of film can be cut into pieces suitable for use as calibration films, and for in vivo and phantom measurements. The cutting of film is typically done using scissors or a guillotine, and this process can be time-consuming, limited in precision, requires extensive handling and does not allow holes to be cut from the film without cutting from an existing edge. This study investigated the use of a Brother ScanNCut hobby cutting system for EBT3 film preparation. The optimal operating parameters (blade size, pressure, speed) that resulted in precise cuts with minimal delamination at cut edges were identified using test cutting patterns. These parameters were then used to cut a large film insert for a stereotactic head phantom for comparison against an insert cut with scissors. While the hobby cutting system caused a wider region of delamination at the film edge (1.8 mm) compared to scissors (1 mm), the hobby cutting system was found to be able to produce reproducible cuts more efficiently and more accurately than scissors. The use of the hobby cutting system is recommended for complex phantom inserts (containing sharp corners or holes for alignment rods) or in situations where large numbers of film pieces need to be prepared.

RSC: A 3D printed eyeball phantom for Sr-90 dosimetry measurements

“…This would be due to the curvature of the eyeball surface, which brings the treated tissue closer to the source than the applicator standoff distance, and is a more realistic approximate of what a patient would receive at this depth during a treatment. It would have been ideal to measure the dose at the surface of the eyeball phantom, but delamination is a common issue encountered in film dosimetry [12]. It is therefore advisable to use planar measurements (such as shown in Figure 2) for any routine quality assurance of the Sr-90 source, but as there is a difference between measurements performed on a flat set up and those done on an anthropomorphic phantom, the 3D printing of an eyeball phantom can help give a more realistic indication of the dose received by a patient undergoing this treatment.…”

Absorbed dose distributions from ophthalmic 106Ru/106Rh plaques measured in water with radiochromic film

“…The pieces of EBT3 film, of approximately 70 × 30 mm 2 , were cut following the curvature of the plaque, with the help of a paper template. Scissors were used, as it is reported to be a cutting method that minimizes film layer delamination, and care was taken to avoid brittle edges . All film pieces used in this work were irradiated at least 48 h after cutting, thus allowing relaxation of mechanical stress around the edges …”

Dosimetric evaluation of an intraoperative radiotherapy system: a measurement-based and Monte-Carlo modelling investigation

“…With access to a laser cutter, the film-cutting process can be automated, allowing film to be cut with greater precision and reproducibility than with scissors [ 7 ]. The slow water penetration rate of Gafchromic films in general make it feasible to perform measurements directly in water [ 8 ].…”