Table 1.
Clinical Characteristics of 59 Patients (59 tumors)
| Characteristic | Number of patients/tumors (%)* |
|---|---|
| Mean age | 69.4 years |
| Median age (range) | 70 years (45-86 years) |
| Sex | |
| Male | 32 (54) |
| Female | 27 (46) |
| Past or current smoker | 55 (93) |
| ECOG performance status | |
| 0 or 1 | 48 (81) |
| 2 | 11 (19) |
| Histology | |
| Adenocarcinoma | 36 (61) |
| Squamous cell carcinoma | 16 (27) |
| NSC NOS | 5 (8) |
| No pathologic findings† | 2 (3) |
| Prior stage | |
| I | 31 (53) |
| II | 15 (25) |
| III | 13 (22) |
| Interval between prior NSCLC diagnosis and recurrence | |
| Median (range) | 30 months (2-132 months) |
| < 4 years | 41 (69) |
| ≥ 4 years | 18 (31) |
| Treatment for prior NSCLC‡ | |
| Surgery, chemotherapy, radiation | 14 (24) |
| Surgery only | 13 (22) |
| Chemoradiation | 12 (20) |
| Surgery, chemotherapy | 11 (19) |
| Radiation only | 6 (10) |
| Other combinations | 3 (5) |
| Recurrent lesion location relative to prior tumor | |
| Contralateral lung | 33 (56) |
| Different lobe in ipsilateral lung | 17 (29) |
| Same lobe | 9 (15) |
| Maximum tumor diameter of recurrent lesion§ | |
| Mean | 1.5 cm |
| Median (range) | 1.4 cm (0.7-3.0 cm) |
| Tumor location | |
| Peripheral | 47 (80) |
| Central | 12 (20) |
| Median IGTV (range) | 3.84 cm3 (0.49-36.24 cm3) |
| Median PTV (range) | 38.47 cm3 (4.71-147.08 cm3) |
| SUVmax of recurrent tumor | |
| Mean | 4.5 |
| Median (range) | 4.1 (0-21.8) |
| SABR dose (BED) | |
| 50 Gy/4 fractions (112.5 Gy) | 57 (97) |
| 40 Gy/4 fractions (80 Gy)⊥ | 2 (3) |
Unless otherwise specified.
Two lesions with typical imaging feature were highly suspicious of malignancy. One lesion was involved lobe failure with SUVmax value of 9.2 and another lesions was in-field recurrence with SUVmax value of 5.0. They were not confirmed histologically due to the high risk of biopsy.
Forty patients were treated with lobectomy/limited resection and one patient was treated with pneumonectomy. Four patients had twice undergone thoracic surgery, and one patient had undergone thoracic surgery three times.
Tumor was measured on CT imaging within 2 months prior to SABR.
Two patients who had undergone thoracic irradiation previously received 40 Gy in 4 fractions in the same lung to meet normal-tissue dose constraints. Abbreviations: BED, biological equivalent dose; ECOG, Eastern Cooperative Oncology Group; IGTV, internal gross target volume; NOS, not otherwise specified; NSC, non-small-cell carcinomas; NSCLC, non-small-cell lung cancer; PTV, planning target volume; SABR, stereotactic ablative radiotherapy; SUVmax, maximum standardized uptake value.