Total scatter factor for small fields in radiotherapy: a dosimetric comparison. Issue 3 (27th November 2017)

• Record Type: Journal Article
• Authors: Shamsi, Qurat-ul-ain; Ahmad Buzdar, Saeed; Altaf, Saima; Atiq, Atia; Atiq, Maria; Iqbal, Khalid
• Is Part Of: Journal of radiotherapy in practice. Volume 17:Issue 3(2018)
• Page Start: 292
• Page End: 296
• Publication Date: 2017-11-27
• Subjects: chamber detectors CC01 and CC04, -- collimator jaws, -- linear accelerator, -- multi-leaf collimators, -- small field dosimetry; Radiotherapy -- Periodicals; 615.842005
• DOI: 10.1017/S1460396917000681
• Languages: English
• ISSNs: 1460-3969

Abstract

Abstract: Purpose: Small field dosimetry is complicated and accuracy in the measurement of total scatter factor (TSF) is crucial for dosimetric calculations, in making optimum intensity-modulated radiotherapy plans for treating small target volumes. In this study, we intended to determine the TSF measuring properties of CC01 and CC04 detectors for field sizes ranging from sub-centimetre to the centimetre fields. Material and methods: CC01 and CC04 chamber detectors were used to measure TSF for 6 and 18 MV photon beam delivered from the linear accelerator, through small fields in a water phantom. Small fields were created by collimator jaws and multi-leaf collimators separately, with field sizes ranging from 0·6 to 10 cm 2 and 0·5 to 20 cm 2, respectively. Results: CC01 measured TSF at all the given field sizes created by jaws and multi-leaf collimators for both 6 and 18 MV beams whereas CC04 could not measure TSF for field sizes <1 cm 2 due to volume averaging and perturbation effects. Conclusion: CC01 was shown to be effective for measurement of TSF in sub-centimetre field sizes. CC01 can be employed to measure other dosimetric quantities in small fields using different energy beams.