UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2022	Jul. 31, 2021
Income Statement [Abstract]
Oncology services revenue	$ 13,745	$ 11,253
Costs and operating expenses:
Cost of oncology services	7,052	5,396
Research and development	2,887	2,304
Sales and marketing	1,692	1,574
General and administrative	2,398	2,154
Total costs and operating expenses	14,029	11,428
Loss from operations	(284)	(175)
Other income (loss)	(18)	17
Loss before provision for income taxes	(302)	(158)
Provision for income taxes	17	14
Net loss	$ (319)	$ (172)
Net loss per common share outstanding
Net loss per common share outstanding, basic (in dollars per share)	$ (0.02)	$ (0.01)
Net loss per common share outstanding, diluted (in dollars per share)	$ (0.02)	$ (0.01)
Weighted average common shares outstanding
Weighted average common shares outstanding, basic (in shares)	13,522,433	13,401,929
Weighted average common shares outstanding, diluted (in shares)	13,522,433	13,401,929
Revenue, Product and Service [Extensible List]	Service [Member]	Service [Member]
Cost, Product and Service [Extensible List]	Service [Member]	Service [Member]