Gastro-Intestinal Stromal Tumors (GIST)are the most common tumors of non-epithelial gastrointestinal tract.Since the introduction of molecular targeted drug,
there has been increasing concern about the use of the traditional tumor response criteria.
Aim of this study is to compare diagnostic effectiveness of functional vs.
measured by MSCT after contrast medium (c.m.) administration,
in the follow-up of GIST metastatic patients receiving new generation Tirosine Kinase inhibitors (TKI).
Methods and Materials
In the period between April 2011 and March 2012 were evaluated CT scans of six women aged between 45 and 75 with GIST at an advanced stage with the presence of liver metastases.
Criteria for inclusion were evidence of disease that was unidimensionally measurable with CT; failure of previous treatment; adequate hepatic,
and cardiac function.
Exclusion criteria were renal insufficiency (serum creatinine greater than 2 mg/dL),
pregnancy and documented allergic reaction to iodinated contrast agent.
Patientswere observed by MSCT after c.m administration,
2 patients (33%) showed a partial response,
with a dimensional and densitometric lesions reduction.
3 patients (50%) showed stable disease with diameters unchanged although it was a reduction of the lesions density.
Only 1 patient (17%) did not respond to therapy,
showing after 6 months disease progression with an increase of lesions number.
after 3 and 6 months of treatment we have observed a reduction of the liver lesions total diameter average by 8% and 10% respectively,
and a reduction lesions density average by...
The standard imaging technique in advanced GIST patients should be contrast-enhanced CT.
CT is widely available,
allows high patient comfort,
is cost effective and has a high sensitivity in lesion detection,
particularly for liver metastases.
We observed that Gist liver lesion responding to targeted therapy showing myxoid degeneration that is reflected by distinctly hypodense,
almost cystic-appearing lesions on imaging.
CT lesion density should be considered in assessing response.
functional response criteria,
incorporating tumor density and using small changes in tumor size on CT,...
New response evaluation criteria in solid tumours: revised RECIST guideline (version 1.1).
Eur J Cancer 2009; 45: 228_47
de Castro FS et al.
CT evaluation of the response of gastrointestinal stromal tumors after imatinib mesylate treatment: a quantitativeanalysis correlated with FDG PET findings.
AJR Am J Roentgenol 2004; 183:1619–1628.