Table 1.

Patient and tumor characteristics

Characteristics	Frequency (%)
Demographics
Mean age ± SD (range)	61.6 ± 10.1 (38–83)
Sex
Female	19 (40.4%)
Male	28 (59.6%)
Race
Nonwhite	4 (8.5%)
White	43 (91.5%)
Primary tumor
Mean tumor size, cm	7.5 ± 4.0
Histology
Non-clear cell renal cell carcinoma	6 (12.8%)
Clear cell renal cell carcinoma	41 (87.2%)
Grade
1	1 (2.1%)
2	8 (17.0%)
3	23 (48.9%)
4	11 (23.4%)
N/A	4 (8.5%)
pT
pT1	15 (31.9%)
pT2	5 (10.6%)
pT3	23 (48.9%)
N/A	4 (8.5%)
pN
pN0	10 (21.3%)
pN1	3 (6.4%)
pNX	29 (61.7%)
N/A	5 (10.6%)
M*
M0	34 (72.3%)
M1	11 (23.4%)
N/A	2 (4.3%)
Risk score†
0, Favorable	20 (42.6%)
1–2, Intermediate/unfavorable	16 (34.0%)
N/A	11 (23.4%)
Metastasis
Sum of largest diameters, cm (range)	4.5 ± 3.5 (0.8–14.8)
No. of metastases treated, initial‡
1	35 (74.5%)
2	7 (14.9%)
3	4 (8.5%)
4	1 (2.1%)
No. of metastases treated, total§
1	26 (55.3%)
2	12 (25.5%)
3	4 (8.5%)
≥4	5 (10.6%)
Treatment sites‡
Bone	28 (43.1%)
Lung	10 (15.4%)
Liver	6 (9.2%)
Soft tissue	6 (9.2%)
Lymph node	5 (7.7%)
Adrenal	4 (6.2%)
Others	6 (9.2%)
Radiation therapy‡
22.1 ± 4.0 Gy × 1 fraction	14 (21.5%)
12.8 ± 2.2 Gy × 3 fractions	21 (32.3%)
8.0 ± 1.4 Gy × 5 fractions	30 (46.2%)

^*M stage at presentation.

^†Heng’s criteria measured at the start of stereotactic ablative radiotherapy (SAbR).

^‡During initial SAbR course.

^§During all SAbR courses before systemic therapy.