UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2020	Jul. 31, 2019
Income Statement [Abstract]
Oncology services revenue	$ 9,547	$ 6,737
Costs and operating expenses:
Cost of oncology services	5,336	3,752
Research and development	1,597	1,303
Sales and marketing	1,208	870
General and administrative	1,382	1,426
Total costs and operating expenses	9,523	7,351
Income (loss) from operations	24	(614)
Other income (expense):
Other income (expense)	64	(12)
Income (loss) before provision for income taxes	88	(626)
Provision for income taxes	13	15
Net income (loss)	$ 75	$ (641)
Net income (loss) per common share outstanding
Net income (loss) per common share outstanding, basic (in dollars per share)	$ 0.01	$ (0.06)
Net income (loss) per common share outstanding, diluted (in dollars per share)	$ 0.01	$ (0.06)
Weighted average common shares outstanding
Weighted average common shares outstanding, basic (in shares)	12,727,275	11,619,538
Weighted average common shares outstanding, diluted (in shares)	14,231,641	11,619,538
Revenue, Product and Service [Extensible List]	us-gaap:ServiceMember
Cost, Product and Service [Extensible List]	us-gaap:ServiceMember