Table 5.

Trends of percentage reduction of surface dose under 1.0 cm gel bolus for different field sizes and air gaps

Field size (cm2) Air gap (cm)	5 × 5			10 × 10			15 × 15
	1	2	3	1	2	3	1	2	3
Shaw[22]a	*	*	*	1.0	5.0	9.0	*	*	*
Shaw[22]b	*	*	*	3.0	8.0	15.0	*	*	*
Shaw[22]c	15.0	31.0	47.0	5.0	11.0	20.0	5.0	9.0	12.0
Khan et al.[7]b	8.0	18.0	26.0	2.0	4.0	8.0	2.0	2.1	2.2
Chung et al.[13]a	*	*	*	4.2	*	*	*	*	*
Chung et al.[13]e	*	*	*	4.5	*	*	*	*	*
Present studyf	2.7	7.6	15.5	1.8	2.6	5.1	0.8	1.6	2.6

*Not quoted. ^aMarkus chamber, ^bRadiochromic film, ^cMonte Carlo simulation techniques, ^dParallel plate chamber (readings applied with correction factor), ^eMOSFET, ^fCylindrical (CC13) chamber