programma & abstracts - Nederlandse Vereniging voor Radiologie

6
programma abstracts & abstracts
O6.7
MAGNETIC RESONANCE IMAGING
FINDINGS CORRELATES WITH
PATHOLOGICAL SUBTYPE CLASSIFICATION
OF HEPATOCELLULAR ADENOMAS
S.M. van Aalten, M.G.J. Thomeer, T. Terkivatan,
R.S. Dwarkasing, J. Verheij, R.A. de Man, J.N.M. IJzermans
Erasmus Medisch Centrum, Rotterdam
Purpose: To investigate the correlation between magnetic
resonance imaging (MRI) findings and pathological subtype
classification of hepatocellular adenoma (HCA) and to propose
guidelines for follow-up and management.
Methods: This retrospective study was approved by the
institutional review board and the requirement for informed
consent was waived. Seventy-one resected tumours previously
diagnosed as HCA were classified based on pathological
findings and immunohistochemical analysis: liver-fatty
acid binding protein (L-FABP) negative HCA, inflammatory
HCA, β-catenin positive HCA and unclassified HCA. The
available MRI scans of 61 lesions (48 patients, median age
36 years) were independently reviewed by two radiologists,
thereafter consensus was obtained. Chi-square and Fishers’
exact tests were performed for statistical analysis.
Results: MRI signs of diffuse intratumoral fat deposition
were present in 7 of 9 L-FABP-negative HCA compared to
5 of 29 inflammatory HCA (P = 0.001). Steatosis within the
non-tumoral liver was present in 11 of 29 inflammatory
HCA compared to none L-FABP-negative HCA (P = 0.038). A
characteristic ‘atoll’ sign was only seen in the inflammatory
group (P = 0.027). Presence of a typical vaguely defined type
of scar was seen in 5 of 7 β-catenin positive HCA
(P = 0.003). No specific MRI features were identified for the
unclassified cases.
Conclusions: L-FABP-negative HCA, inflammatory HCA and
β-catenin positive HCA were related to MRI signs of diffuse
intratumoral fat deposition, an ‘atoll’ sign, and a typical
vagely defined scar, respectively. Since β-catenin positive
HCA are considered premalignant, closer follow-up with
MRI or resection may be preferred.
O6.8
MAGNETIC RESONACE IMAGING FOR
PREDICTING RESIDUAL DISEASE AFTER
RADIOTHERAPY IN LOCALLY ADVANCED
CERVICAL CANCER
J.E. Mongula 1 , D. Lambregts 1 , R. Kruitwagen 2 , T. van Gorp 2 ,
A .Kruse 2 , L. Lutgens 3 , R. Lalisang 2 , R. Vliegen 4 ,
B.F. Slangen 2 , R. Beets-Tan 1
1
Maastricht Universitair Medisch Centrum, Maastricht
2
GROW, School for Oncology and Developmental Biology,
Maastricht
3
Maastro clinic, Maastricht
4
Atrium Medisch Centrum, Heerlen
Objective: To assess whether MRI is valuable for evaluating
the presence of residual tumor after RT and which
imaging criteria are the best predictors of response.
Methods: 40 patients with histologically proven primary
cervical cancer FIGO ≥1b were retrospective included, to
date 20 out of 40 have been analyzed. Patients underwent
MRI (standard T2-weighted FSE in 3 planes at 1.5T) before
and 2-3 months after RT. An experienced gynaecologic radiologist
scored the likelihood of residual tumor on post-RT MRI
using a 5-point confidence level score based on assessment
of isointens residual mass, hypointens fibrotic mass, border
irregularity and nodular shape. The standard reference
consisted of gynecological examination with biopsy and/or
clinical follow-up. ROC curve analyses were performed to
determine the performance for assessing residual tumor. The
value of each imaging criterion was assessed.
Results: 3/20 patients had residual disease. AUC for identification
of residual tumor based on visual interpretation
was 0,94; sensitivity 100%, specificity 88%. The individual
imaging criteria resulted in AUCs of 0,94 (isointense mass),
0,50 (hypointense mass), 0,67 (irregular border) and 0,70
(nodular shape). The combination of an isointens nodular
mass resulted in a AUC of 0,98, sensitivity 100%, specificity
88%. Adding an irregular border in AUC of 1,00, sensitivity
100%, specificity 100%
Discussion: MRI can provide high accuracy for the assessment
of residual tumor after RT in patients with locally
advanced cervical carcinoma. The best imaging criteria to
predict residual disease are the presence of an isointense
residual mass with nodular shape and irregular borders.
Use of these criteria could benefit the MR assessment of
residual disease in daily clinical practice.
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