Table 3. . Radioisotope cerebrospinal fluid-flow study in leptomeningeal metastasis.

Site of obstruction	Solid tumor†				Lymphoma†		Leukemia†
	Cytology negative (n = 40); % (n)		Cytology positive (n = 125); % (n)		Flow cytometry positive (n = 50); % (n)		Flow cytometry positive (n = 25); % (n)
Brain
Total	10 (4)		9 (11)		4 (2)		8 (2)
Ventricular	2.5 (1)		2 (2)		0		0
Skull base	2.5 (1)		2 (2)		0		0
Convexity	5 (2)		5 (7)		4 (2)		8 (2)
Spine
Total	15 (6)		19 (24)		6 (3)		12 (3)
Cervical	2.5 (1)		4 (6)		0		4 (1)
Thoracic	2.5 (1)		5 (6)		2 (1)		0
Lumbar	10 (4)		10 (12)		4 (2)		8 (2)
Normal
Total	75 (30)		72 (90)		90 (45)		80 (20)

^†As shown on cerebrospinal fluid-flow study.