Note 3 - Revenue From Contracts With Customers (Tables)

9 Months Ended

Sep. 30, 2020

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
Royalty revenue:
Tc99m tilmanocept - Europe	$	2,047	$	4,895	$	26,188	$	13,985

License revenue:
Tc99m tilmanocept - Europe	$	4,726	$	—	$	4,726	$	—
NAV4694		—		—		—		9,953
Total license revenue	$	4,726	$	—	$	4,726	$	9,953

Other revenue:
Additional stability studies	$	—	$	—	$	—	$	11,024

	Three Months Ended September 30,						Nine Months Ended September 30,
	20 20			201 9			20 20			201 9
Total deferred revenue, beginning of period	$	860,000		$	1,195,000		$	700,000		$	711,024
Revenue deferred related to sublicense		—			—			160,000			495,000
Refund of deferred revenue related to sublicense		(160,000	)		(495,000	)		(160,000	)		(495,000	)
Revenue recognized from satisfaction of performance obligations		—			—			—			(11,024	)
Total deferred revenue, end of period	$	700,000		$	700,000		$	700,000		$	700,000