Note 3 - Revenue From Contracts With Customers (Tables)

9 Months Ended

Sep. 30, 2022

Notes Tables

Disaggregation of Revenue [Table Text Block]

	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021
Sales revenue:
Tc99m tilmanocept - Europe	$	7,516	$	—	$	14,035	$	—
License revenue:
Tc99m tilmanocept - Europe	$	—	$	9,116	$	—	$	44,665

Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]

	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022			2021
Total deferred revenue related to contracts with customers, beginning of period	$	700,000	$	700,000	$	700,000		$	700,000
Deferred revenue related to milestones achieved		—		—		100,000			—
Deferred revenue related to milestones achieved, written off due to contract renegotiations		—		—		(100,000	)		—
Total deferred revenue related to contracts with customers, end of period	$	700,000	$	700,000	$	700,000		$	700,000