UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2019	Jul. 31, 2018
Income Statement [Abstract]
Oncology services revenue	$ 6,737	$ 6,225
Costs and operating expenses:
Cost of oncology services	3,752	3,083
Research and development	1,303	1,088
Sales and marketing	870	518
General and administrative	1,426	1,055
Total costs and operating expenses	7,351	5,744
(Loss) income from operations	(614)	481
Other expense (income):
Other expense (income)	12	(1)
Total other expense (income)	12	(1)
(Loss) income before provision for income taxes	(626)	482
Provision for income taxes	15	0
Net (loss) income	$ (641)	$ 482
Net (loss) income per common share outstanding
Net income (loss) per common share outstanding, basic (in dollars per share)	$ (0.06)	$ 0.04
Net income (loss) per common share outstanding, diluted (in dollars per share)	$ (0.06)	$ 0.04
Weighted average common shares outstanding
Weighted average common shares outstanding, basic (in shares)	11,619,538	11,012,281
Weighted average common shares outstanding, diluted (in shares)	11,619,538	12,618,021