Validation of the Gel & Wax Boluses and Comparison of their Dosimetric Performance with Virtual Bolus
| Autor: | D Johny, Teerth Raj Verma, R Gupta, Madan Lal Brahma Bhatt, M Tyagi, N K Painuly |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
lcsh:Medical physics. Medical radiology. Nuclear medicine
Materials science tomography x-ray computed lcsh:R895-920 Bioengineering Computed tomography Imaging phantom 030218 nuclear medicine & medical imaging Imaging 03 medical and health sciences 0302 clinical medicine Bolus (medicine) Paraffin wax medicine Radiology Nuclear Medicine and imaging Tomography Wax Radiological and Ultrasound Technology medicine.diagnostic_test Radiotherapy treatment planning X-Ray Computed Paraffin 030220 oncology & carcinogenesis visual_art Waxes visual_art.visual_art_medium Photon beams Original Article Biomedical engineering |
| Zdroj: | Journal of Biomedical Physics & Engineering Journal of Biomedical Physics and Engineering, Vol 9, Iss 6, Pp 629-636 (2019) |
| ISSN: | 2251-7200 |
| Popis: | Background: In general, radiotherapy treatment planning is performed using the virtual bolus. It is necessary to investigate physical bolus in comparison to virtual one. Objectives: In the present study, first, radiological properties of superflab Gel bolus and Paraffin wax bolus was investigated in terms of their relative electron density. Then, dosimetric performance of both the bolus (i.e. Gel and Parafin wax) was compared with Virtual bolus.Material and Methods: In This experimental study, the radiological property of Wax and Gel boluses was investigated using two methods. In one, the relative electron density of both the Gel and Wax boluses was calculated by measuring their linear attenuation coefficient where in another method relative electron density was calculated by recording their CT No directly from their CT scan. Later CT scan of solid water slab phantom (dimension 30x30x15 cm3), with physical boluses (i.e. Gel and Wax bolus) of appropriate thicknesses required to deliver a dose of 200 cGy at Dmax using 4 MV, 6 MV and 15 MV photon beams, was taken. These CT data sets were retrieved to TPS. A plan was done to deliver a dose of 200 cGy at Dmax using Single 4 MV, 6 MV and 15 MV photon beams. Dose at depths Dmax, 1 cm, 2 cm, 3 cm, 4 cm and 5 cm was recorded. Using this similar method, doses at depths viz Dmax, 1 cm, 2 cm, 3 cm, 4 cm and 5 cm was recorded for the Gel and Wax boluses. The differences in dose of gel and wax bolus from virtual bolus were recorded for comparison of their dosimetric performance. Results: The measured (calculated) relative electron density of wax and Gel bolus was found to be 0.958 (0.926) and 0.923 (0.907), respectively. Variation in dosimetric performance of Gel and Wax with reference to Virtual bolus was studied. However, on average, Gel bolus was more consistent with virtual bolus. Conclusion: To avoid any dose difference between, delivered (using physical bolus) and planned (using virtual bolus), the physical boluses should be investigated for their dosimetric performance in comparison to virtual bolus. The results obtained and methodology used in this study can be applied in routine radiotherapy practices. |
| Databáze: | OpenAIRE |
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