UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2023	Jul. 31, 2022
Income Statement [Abstract]
Revenue, Product and Service [Extensible List]	Service [Member]	Service [Member]
Oncology services revenue	$ 12,561	$ 13,745
Costs and operating expenses:
Cost, Product and Service [Extensible List]	Service [Member]	Service [Member]
Cost of oncology services	$ 7,684	$ 7,052
Research and development	2,793	2,887
Sales and marketing	1,696	1,692
General and administrative	2,940	2,398
Total costs and operating expenses	15,113	14,029
Loss from operations	(2,552)	(284)
Other income (loss)	14	(18)
Loss before provision for income taxes	(2,538)	(302)
Provision for income taxes	28	17
Net loss	$ (2,566)	$ (319)
Net loss per common share outstanding
Net loss per common share outstanding, basic (in dollars per share)	$ (0.19)	$ (0.02)
Net loss per common share outstanding, diluted (in dollars per share)	$ (0.19)	$ (0.02)
Weighted average common shares outstanding
Weighted average common shares outstanding, basic (in shares)	13,506,782	13,522,433
Weighted average common shares outstanding, diluted (in shares)	13,506,782	13,522,433