Table 1.
Distribution of demographic and clinical characteristics among treatment groups.
| Characteristic | SBRT | LTA | P |
|---|---|---|---|
| No. of patients | 14,651 (93) | 1141 (7) | – |
| Follow-up, months | < .001 | ||
| Median | 26.1 | 28.0 | |
| Range | 3.0–148.7 | 3.0–144.4 | |
| Age, years Median |
75 | 75 | .488 |
| Range | 26–90 | 32–90 | |
| Sex Male |
6,758 (46) | 515 (45) | .518 |
| Female | 7,893 (54) | 626 (55) | |
| Race | < .001 | ||
| Caucasian | 12,905 (89) | 1045 (92) | |
| Other | 1,651 (11) | 85 (8) | |
| Charlson comorbitity score | < .001 | ||
| 0 | 8,256 (56) | 542 (48) | |
| 1 | 4,003 (27) | 381 (33) | |
| 2 | 1,671 (11) | 169 (15) | |
| 3+ | 721 (5) | 49 (4) | |
| Facility type | .019 | ||
| Academic | 6,400 (44) | 539 (47) | |
| Other | 8,248 (56) | 601 (53) | |
| Facility treatment volume | < .001 | ||
| Lowest 90% | 13,321 (91) | 595 (52) | |
| Highest 10% | 1330 (9) | 546 (48) | |
| Tumor size, cm | < .001 | ||
| Median | 2.1 | 1.8 | |
| Range | 0.1–5.0 | 0.1–5.0 | |
| Tumor size, cm | < .001 | ||
| ≤ 2.0 | 6,924 (47) | 695 (61) | |
| 2.1–3.0 | 4,781 (33) | 342 (30) | |
| 3.1–5.0 | 2,946 (20) | 104 (9) | |
| Histology | .127 | ||
| Squamous cell carcinoma | 6,324 (43) | 466 (41) | |
| Adenocarcinoma | 8,327 (57) | 675 (59) | |
| Grade | .360 | ||
| Well-differentiated | 1,279 (18) | 99 (18) | |
| Moderately-differentiated | 2,929 (42) | 254 (45) | |
| Poorly-differentiated | 2,722 (39) | 207 (37) | |
| Clinical T stage | < .001 | ||
| cT1 | 11,439 (78) | 1017 (89) | |
| cT2 | 3,212 (22) | 124 (11) | |
| SBRT dose | – | ||
| 34 Gy in 1 fx | 60 (< 1) | – | |
| 48 Gy in 3 fx | 165 (1) | – | |
| 45 Gy in 3 fx | 151 (1) | – | |
| 54 Gy in 3 fx | 2,887 (20) | – | |
| 50 Gy in 4 fx | 1,278 (9) | – | |
| 48 Gy in 4 fx | 3,797 (26) | – | |
| 55 Gy in 5 fx | 720 (5) | – | |
| 50 Gy in 5 fx | 5,593 (38) | – | |
| LTA type | – | ||
| Laser/Cryotherapy | – | 564 (49) | |
| Electrocautery/Fulguration | – | 97 (9) | |
| LTA NOS | – | 480 (42) | |
| Year of diagnosis | < .001 | ||
|
2004 |
12 (< 1) | 25 (2) | |
| 2005 | 32 (< 1) | 32 (3) | |
| 2006 | 114 (< 1) | 54 (5) | |
| 2007 | 196 (1) | 87 (8) | |
| 2008 | 439 (3) | 122 (11) | |
| 2009 | 757 (5) | 143 (13) | |
| 2010 | 1,435 (10) | 133 (12) | |
| 2011 | 1,906 (13) | 162 (14) | |
| 2012 | 2,578 (18) | 123 (11) | |
| 2013 | 3,299 (23) | 135 (12) | |
| 2014 | 3,883 (27) | 125 (11) |
Note: Data presented as No. (%) unless otherwise noted. P values given by Pearson’s chi-squared and two-sided t tests for categorical and continuous variables, respectively.
Abbreviations: SBRT, stereotactic body radiotherapy; LTA, local tumor ablation; No., number; cm, centimeter; Clinical T Stage, clinical tumor stage as per American Joint Committee on Cancer 6th or 7th Edition; Gy, gray; fx, fraction; NOS, not otherwise specified.