Prog Med Phys.  2024 Mar;35(1):10-15. 10.14316/pmp.2024.35.1.10.

Evaluations of a Commercial CLEANBOLUS-WHITE for Clinical Application

• Yu GB
• Kim Ji
• Son J

• KMID: 2554467
• DOI: http://doi.org/10.14316/pmp.2024.35.1.10

Abstract

Purpose
This study aimed to comprehensively investigate the diverse characteristics of a novel commercial bolus, CLEANBOLUS-WHITE (CBW), to ascertain its suitability for clinical application.
Methods
The evaluation of CBW encompassed both physical and biological assessments. Physical parameters such as mass density and shore hardness were measured alongside analyses of element composition. Biological evaluations included assessments for skin irritation and cytotoxicity. Dosimetric properties were examined by calculating surface dose and beam quality using a treatment planning system (TPS). Additionally, doses were measured at maximum and reference depths, and the results were compared with those obtained using a solid water phantom. The effect of air gap on dose measurement was also investigated by comparing measured doses on the RANDO phantom, under the bolus, with doses calculated from the TPS.
Results
Biological evaluation confirmed that CBW is non-cytotoxic, nonirritant, and nonsensitizing. The bolus exhibited a mass density of 1.02 g/cm 3 and 14 shore 00. Dosimetric evaluations revealed that using the 0.5 cm CBW resulted in less than a 1% difference compared to using the solid water phantom. Furthermore, beam quality calculations in the TPS indicated increased surface dose with the bolus. The air gap effect on dose measurement was deemed negligible, with a difference of approximately 1% between calculated and measured doses, aligning with measurement uncertainty.
Conclusions
CBW demonstrates outstanding properties for clinical utilization. The dosimetric evaluation underscores a strong agreement between calculated and measured doses, validating its reliability in both planning and clinical settings.

Keyword

Commercial bolus; Surface dose; Air gap

Figure

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  Fig. 1 Two measurement points where metal oxide silicon field effect transistor detectors were attached to the RANDO phantom: (a) chin, (b) breast, (c) inguinal area, and (d) nose.

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  Fig. 2 Beam’s eye view with an ideal bolus (blue sheet on the surface, 0.5 cm thickness, and HU=0) on the computed tomography-scanned RANDO phantom. Irradiations of the 6 MV photon beam, 100 cGy with a field size of 10×10 cm2, on (a) chin, (b) breast, (c) inguinal area, and (d) nose were conducted in the treatment planning system. Two measurement points per plan were considered for comparison between measured and planned doses.

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  Fig. 3 Percent depth dose (PDD) of the 6, 10, and 15 MV photon beam (field size of 10×10 cm2 and source-to-surface distance=100 cm) in a virtual water phantom in the treatment planning system. Dashed lines indicate normal PDDs, while solid lines represent PDDs with a 0.5 cm bolus on top of the surface. The inset provides a close-up view of the PDDs in the build-up area.

Reference

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