Dynamic 99mTc-Mebrofenin Hepatobiliary Scintigraphy (HBS) and SPECT/CT
at Sant’Orsola-Malpighi Hospital
Matteo Serenari MD*, Chiara Bonatti MD*, Cinzia Pettinato MD§
*Department of Medical and Surgical Sciences – DIMEC, S.Orsola – Malpighi Hospital, Alma
Mater Studiorum, University of Bologna
§Medical Physics Unit, Radiology Unit, S Orsola-Malpighi Hospital, Bologna, Italy
We recently started to use dynamic 99mTc-mebrofenin hepatobiliary scintigraphy (HBS) combined with Single Photon Emission Computed Tomography/ Computed Tomography (SPECT/CT) in the preoperative evaluation of patients candidate for major hepatic resection. The leading center in Europe in the application of hepatobiliary scintigraphy with SPECT is the Academic Medical Center (Amsterdam The Netherlands), where hepatobiliary scintigraphy data are routinely analyzed by an experienced nuclear medicine physician (R. J. Bennink) using a Hermes workstation (Hermes Medical Solutions, Stockholm, Sweden)1. According to AMC standardized protocol2, between November 2016 and November 2017, 99mTc-mebrofenin HBS combined with SPECT/CT were preoperatively performed in 27 patients who underwent a major hepatectomy at S.Orsola-Malpighi Hospital. HBS was performed with 99mTc-labeled (2,4,6 trimethyl-3-bromo) iminodiacetic acid (99mTc-mebrofenin, Bridatec, GE Healthcare) at the Nuclear Medicine Unit.
Patients were acquired in supine position with a large-field-of-view (FOV) SPECT/CT camera (Discovery NM/CT 670 ES, GE) covering the liver and the heart region. The SPECT/CT camera was equipped with low-energy high-resolution collimators. First, a dual-head dynamic acquisition (36 frames of 10 s/frame,128 matrix), was obtained immediately after the intravenous administration of approximately 200 MBq freshly prepared 99mTc-mebrofenin, which was used for the calculation of the hepatic mebrofenin uptake rate (TL-F). Subsequently, a fast SPECT acquisition was performed (60 projections of 5s/projection, 128 matrix), approximately centered on the peak of the hepatic time-activity curve, which was used to calculate the 3-dimensional distribution of function within the future liver remnant (FLR-C). Directly after SPECT, a low-dose, non-contrast-enhanced CT scan was acquired for attenuation correction and anatomic mapping.
Hepatic mebrofenin uptake rate was calculated using a standard software package. Three region of interest (ROI) were drawn manually on the dynamic images around the heart/large vessels, the total liver and the total field of view (FOV). These 3 ROI datasets were saved to make sure that identical ROIs were used for every frame of acquisition of the gmean dataset provided by our Workstation Xeleris GE. Three different time–activity curves were generated. Total liver function was expressed as percent per minute per square meter (%/min/m2). Afterwards, volumes of interest (VOI) were manually outlined to calculate total liver and future liver remnant (FLR-C) counts. The FLR was delineated on every transversal frame of the SPECT image. Future liver remnant function (FRL-F) was then calculated, as previously described3. We did not use any masking volume for the bile ducts. This procedure took approximately 20 minutes for each patient.
Hermes Gold3 Processing
Hermes Hybrid Viewer NM processing on TeleHERMES ™ (by Hermes Medical Solutions) was provided to us from Hermes company after our first cases of HBS, since we were looking for a software able to do all the measurements in a shorter time and also to make our results as much as possible comparable with those calculated by the Academic Medical Center. R.J. Bennink helped us to contact Hermes.
After a very clear demonstration via Skype (manual of instructions is also provided inside the TeleHERMES Green USB access tool), installation of the program encountered some difficulties due to the firewall settings but logining in as administrator was able to fix this initial problem. The upload of DICOM files was really intuitive and easy. Gmean dataset provided by own workstation or anterior and posterior datasets separately, could be both uploaded. Of note, there was a little difference between these two gmean datasets, with lower values if anterior and posterior projections were uploaded separately. After that the manual delineation of the liver and blood pool ROI was completed, TL-F was immediately calculated by the software. Thereafter, FRL was manually delineated on a single frame of the low-dose, non-contrast-enhanced CT scan linked to the SPECT images. Then, the outlined constraint was applied automatically to every frame of acquisition. This did not allow us to modify the transection plane as radiologists do when they perform hepatic volumetry. More importantly, the CT scans from other study in particular contrast enhanced scans, could not be uploaded to delineate more anatomically the remnant liver VOI. Future research will focus on showing whether a totally manual or semi-automatic method to delineate VOIs is comparable with this automatically but less time-consuming method. The masking volume for the bile ducts was applied only in 3 patients but in the other cases we were not able to solve this problem. However, difference with and without masking volume seemed not too big in terms of %FLR-C. In median, calculations of liver function parameters for each patient with TeleHERMES Green USB took 3 minutes.
In conclusion, standardization of the technique and use of a shared imaging software as Hermes Hybrid Viewer NM processing on TeleHERMES™ seems in our opinion of utmost importance to enable comparisons among different centers.
- Bennink RJ, Dinant S, Erdogan D, et al. Preoperative assessment of postoperative remnant liver function using hepatobiliary scintigraphy. J Nucl Med; 2004;45:965-71.
- De Graaf W, Van Lienden KP, Van Gulik TM, et al. 99m Tc-Mebrofenin Hepatobiliary Scintigraphy with SPECT for the Assessment of Hepatic Function and Liver Functional Volume Before Partial Hepatectomy. J Nucl Med; 2010;51:229–236.
- Dinant S, de Graaf W, Verwer BJ, et al. Risk Assessment of Posthepatectomy Liver Failure Using Hepatobiliary Scintigraphy and CT Volumetry. J Nucl Med; 2007;48:685–692.