Table 4.

Local progression rates for 64 small lesions (< 2cm) according to the tumor size and SRS dose prescribed.

			Local progression
			Yes	No	Total
Size-dose	TS < 1 cm	Count	1	6	7
group	22–24 Gy/1 fx	% within group	11.1%	66.7%	100.0%
	TS < 1 cm	Count	4	13	17
	18–20 Gy/1 fx	% within group	23.5%	76.5%	100.0%
	TS < 1 cm	Count	3	2	5
	12–16 Gy/1 fx	% within group	60.0%	40.0%	100.0%
	TS 1.1–2 cm	Count	0	3	3
	22–24 Gy/1 fx	% within group	0.0%	100.0%	100.0%
	TS 1.1–2 cm	Count	3	12	15
	18–20 Gy/1 fx	% within group	18.8%	75.0%	100.0%
	TS 1.1–2 cm	Count	9	8	17
	12–16 Gy/1 fx	% within group	52.9%	47.1%	100.0%
Total		Count	20	44	64
		% within group	29.9%	65.7%	100.0%

Lesions for which the response was not known were excluded.

TS, tumor size (diameter). Chi-square test not valid because of small numbers in some cells.