Oligo-recurrence predicts favorable prognosis of brain-only oligometastases in patients with non-small cell lung cancer treated with stereotactic radiosurgery or stereotactic radiotherapy: a multi-institutional study of 61 subjects

Table 1 Patients’ characteristics

Characteristic	No.		Percent
Age, median (range), y		64 (22–86)
<65	30		49
≥65	31		51
Sex
Male	30		49
Female	31		51
No. of lesions
1–2	54		89
3–5	7		11
Oligostatus
Sync-oligometastases (primary active)	11		18
Oligo-recurrence (primary controlled)	50		82
Histological status
Sguamous cell carcinoma	6		10
Adenocarcinoma	48		79
Others	7		11
KPS score
70–80	5		8
90–100	56		92
Interval to initial brain recurrence, months
<12	29		48
≥12	32		52
No. of brain metastases
Single	42		69
2–4	19		31
RPA
Class I (aged <65 years; no active extracranial diseases)	26		43
class II (aged ≥65 years; active extracranial diseases)	35		57
GPA
Score 0–1.0 (scoring based on Age, KPS, ECM, No. of BM)	0		0
Score 1.5–2.0	5		8
Score 2.5–3.0	45		74
Score 3.5–4.0	11		18
Neurologic function^a
Grade 0	40		66
Grade 1	12		20
Grade 2	9		14
Grade 3	0		0
Grade 4	0		0
Maximum diameter of brain metastases, cm
Median (range)		1.2 (0.2–6.0)
Treatment method for brain tumor
SRS	45		74
SRT	16		26
Dose at the brain tumor margin, Gy
Median (range)		25 (10–36)
WBRT	9		15
Thoracic stage^b
I-II	27		44
III	34		56
Treatment method for thoracic lesions
Surgery	43		70
Radiation therapy	18		30
Chemotherapy	19		31

Abbreviations: KPS Karnofsky performance status, RPA recursive partition analysis, GPA graded prognostic assessment, SRS stereotactic radiosurgery, SRT stereotactic radiotherapy, WBRT whole brain radiation therapy
^aNeurologic function, grade 0 as no symptoms; grade 1 as minor symptoms, fully active without assistance; grade 2 as moderate symptoms, fully active but reguires assistance; grade 3 as moderate symptoms, less than fully active, reguires assistance; grade 4 as severe symptoms, totally inactive
^bThoracic stage classified according to the TNM classification of malignant tumors version 6 (UICC, Union for International Cancer Control version 6 edition) not evaluating M stage

ISSN: 1471-2407