Table 2.

Univariate FST analysis

	Median FST	2 year FST (95% CI)	HR 95% CI	Cox P
Risk group*
Favorable	25.5	54.5% (28.9–74.2)	1	.4053
Intermediate	13.2	47.4% (21.8–69.4)	1.44 (0.61–3.43)
No. of mets treated, initial†
1	25.5	53.0% (34.4–68.5)	1	.0500
2–4	4.8	28.6% (7.0–55.5)	2.26 (1.00–5.12)
No. of mets treated, total‡
1	20.2	47.3% (25.9–66.0)	1	.9829
≥2	9.1	45.7% (23.7–65.4)	1.01 (0.47–2.15)
Histologic subtype
Clear cell renal cell carcinoma	20.2	48.9% (32.0–63.8)	1	.5526
Non-clear cell renal cell carcinoma	5.8	33.3% (4.6–67.6)	1.38 (0.48–4.00)
pT
pT1	25.5	50.9% (23.6–72.9)	1	.8563
pT2	20.2	40.0% (5.2–75.3)	1.14 (0.35–3.76)
pT3	6.0	42.9% (21.8–62.6)	1.27 (0.55–2.95)
M§
M0	25.5	57.5% (39.0–72.3)	1	.0248
M1	5.6	11.7% (0.6–40.1)	2.67 (1.13–6.28)
Site of metastasis†
Bone	8.8	31.6% (12.9–52.2)	2.21 (1.04–4.68)	.0387
Nonbone	40.1	58.9% (36.8–75.6)	1

Abbreviations: CI = confidence interval; HR = hazard ratio; mets = metastases; SAbR = stereotactic ablative radiation therapy.

^*Heng’s criteria measured at the start of SAbR.

^†During initial SAbR course.

^‡During all SAbR courses before systemic therapy.

^§M stage at presentation.