Table 1.

Overview of recorded variables

Baseline information		Tumour or cyst specific questions		Treatment characteristics
Patient characteristics	Tumour/cyst characteristics*	Solid lesions	Cystic lesions	Intervention	Surgery	Interventional radiology
Age	Total number of lesions at baseline	Focal nodular hyperplasia	Simple hepatic cysts	Date of intervention	Type of approach (open, laparoscopic, robot)	Type of procedure (aspiration sclerotherapy, TAE, RFA/MWA)
Sex	Location of lesion (left hemiliver, right hemiliver, bilobar)	Haemangioma	Mucinous cystic neoplasms	Duration of hospital stay	Occurrence and reason for conversion	Sclerotherapy (volume of aspiration, length of sclerosing, type of sclerosing agent)
Mortality If yes, reason	Type of lesion	Hepatocellular adenoma	Intraductal papillary neoplasms	Operation or procedure time	Type of procedure (fenestration, wedge resection, segmental resection, hemihepatectomy, transplantation)	TAE (volume and type of embolisation agent(simple embolisation, chemo-embolisation or lipiodolisation))
Comorbidity (ASA score and Elixhauser comorbidity index)	Diameter, date and modality of diagnosis			30-day and 90-day mortality	Specification of resected segments
	Diameter, date and modality of follow-up				Amount of blood loss
	Occurrence of misdiagnosis If so, revised diagnosis and diagnostic modality				Additional procedures (eg, argon beam coagulation, omental transposition, concurring cholecystectomy)
	Histopathological diagnosis with immunohistochemistry if available				Complications (type, CD, CCI and SIR)

*According to RECIST V.1.1 criteria, lesions will only be measured on CT or MRI (longest diameter), measured on the transversal plane on post-contrast series. Maximum of two lesions. If the target lesion is not visible on follow-up imaging (index imaging is imaging shortest before inclusion), then the diameter of the next largest tumour will be measured.

ASA, American Society of Anesthesiologists; CCI, comprehensive complication index; CD, Clavien-Dindo; MWA, microwave ablation; RFA, radiofrequency ablation; SIR, society of interventional radiologists classification for adverse events; TAE, transarterial embolisation.