Table 2.

Local tumor control of JROSG13-1 and JROSG99-1 according to the maximum tumor diameter

				Time point % (95 % CI)
	Maximum diameter	Treatment	N	6 months	12 months	24 months	p
JROSG13-1	All	RD-WBRT + SRS	72	96.9 (88.1–99.2)	86.7 (73.9–93.5)	86.7 (73.9–93.5)
(present study)	≥15 mm	RD-WBRT + SRS	28	91.5 (70.0–97.8)	75.3 % (50.1–89.0)	75.3 % (50.1–89.0)	0.009
	<15 mm	RD-WBRT + SRS	44	100 %	93.4 % (75.9–98.3)	93.4 % (75.9–98.3)
	≥20 mm	RD-WBRT + SRS	21	88.2 (60.6–96.9)	67.9 % (38.9–85.3)	67.9 % (38.9–85.3)	0.003
	<20 mm	RD-WBRT + SRS	51	100 %	94.2 % (78.5–98.5)	94.2 % (78.5–98.5)
JROSG99-1	All	All	205	87.4 % (80.5–92.0)	80.2 % (71.3–86.6)	71.0 % (58.4–80.4)
[2]	All	SD-WBRT + SRS	90	91.1 % (79.8–96.2)	88.6 % (76.0–94.8)	88.6 % (76.0–94.8)	0.004
		SRS-alone	115	84.8 % (74.9–91.0)	73.2 % (59.2–83.0)	51.2 % (29.8–69.1)
	≥15 mm	SD-WBRT + SRS	43	84.9 % (64.0–94.2)	79.2 % (56.0–91.1)	79.2 % (56.0–91.1)	0.042
		SRS-alone	50	83.0 % (62.2–92.9)	60.7 % (32.3–8.02)	16.2 % (9.5–49.1)
	<15 mm	SD-WBRT + SRS	47	96.4 % (77.2–99.5)	96.4 % (77.2–99.5)	96.4 % (77.2–99.5)	0.023
		SRS-alone	65	88.2 % (75.5–94.6)	81.1 % (64.3–90.6)	74.9 % (53.7–87.4)
	≥20 mm	SD-WBRT + SRS	30	90.5 % (66.7–97.6)	81.5 % (50.1–94.1)	81.5 % (50.1–94.1)	0.06
		SRS-alone	30	83.0 % (53.1–94.7)	59.8 % (23.3–83.4)	19.9 % (1.0–56.7)
	<20 mm	SD-WBRT + SRS	60	91.9 % (76.9–97.3)	91.9 % (76.9–97.3)	91.9 % (76.9–97.3)	0.013
		SRS-alone	85	85.4 % (74.3–92.0)	76.6 % (61.5–86.4)	62.8 % (38.7–79.7)

Abbreviations: RD-WBRT, reduced-dose whole brain radiation therapy; SD-WBRT, standard-dose whole brain radiation therapy; SRS, stereotactic radiosurgery