Selective internal radiation therapy (SIRT), a catheter-based liver-directed modality for treating primary and metastatic liver cancer, requires appropriate planning to maximize its therapeutic response and minimize its side effects. 99m Tc-macroaggregated albumin (MAA) scanning should precede the therapy to detect any extrahepatic shunting to the lung or gastrointestinal tract. Our aim was to compare the ability of SPECT/CT with that of planar imaging and SPECT in the detection and localization of extrahepatic 99m Tc-MAA accumulation and to evaluate the impact of SPECT/CT on SIRT treatment planning and its added value to angiography in this setting. Methods: Ninety diagnostic hepatic angiograms with 99m Tc-MAA were obtained for 76 patients with different types of cancer. All images were reviewed retrospectively for extrahepatic MAA deposition in the following order: planar, non-attenuation-corrected SPECT, and SPECT/CT. Review of angiograms and follow-up of patients with abdominal shunting served as reference standards. Results: Extrahepatic accumulation was detected by planar imaging, SPECT, and SPECT/CT in 12%, 17%, and 42% of examinations, respectively. The sensitivity for detecting extrahepatic shunting with planar imaging, SPECT, and SPECT/CT was 32%, 41%, and 100%, respectively; specificity was 98%, 98%, and 93%, respectively. The respective positive predictive values were 92%, 93%, and 89%, and the respective negative predictive values were 71%, 73%, and 100%. The therapy plan was changed according to the results of planar imaging, SPECT, and SPECT/CT in 7.8%, 8.9%, and 29% of patients, respectively. Conclusion: In pre-SIRT planning, 99m Tc-MAA SPECT/CT is valuable for identifying extrahepatic visceral sites at risk for postradioembolization complications.

Purpose Unwanted deposition of 90Y microspheres in organs other than the liver during radioembolization of liver tumours may cause severe side effects such as duodenal ulcer. The aim of this study was to evaluate the significance of posttherapy bremsstrahlung (BS) SPECT/CT images of the liver in comparison to planar and SPECT images in the prediction of radioembolization-induced extrahepatic side effects.Methods A total of 188 radioembolization procedures were performed in 123 patients (50 women, 73 men) over a 2-year period. Planar, whole-body and BS SPECT/CT imaging were performed 24 h after treatment as a part of therapy work-up.Any focally increased extrahepatic accumulation was evaluated as suspicious. Clinical follow-up and gastroduodenoscopy served as reference standards. The studies were reviewed to evaluate whether BS SPECT/CT imaging was of benefit.Results In the light of anatomic data obtained from SPECT/CT, apparent extrahepatic BS in 43% of planar and in 52% of SPECT images proved to be in the liver and hence false positive.The results of planar scintigraphy could not be analysed further since 12 images were not assessable due to high scatter artefacts. On the basis of the gastrointestinal (GI)complications and the results of gastroduodenoscopy, true positive,true-negative, false-positive and false-negative results of BS SPECT and SPECT/CT imaging in the prediction of GI ulcers were determined. The sensitivity, specificity, positive and negative predictive values and the accuracy of SPECT and SPECT/CT in the prediction of GI ulcers were 13%, 88%, 8%,92% and 82%, and 87%, 100%, 100%, 99% and 99%,respectively.Conclusion Despite the low quality of BS images, BSSPECT/CT can be used as a reliable method to confirm the safe distribution of 90Y microspheres and in the prediction of GI side effects.

RE of the right liver lobe with resin microspheres caused a significant increase in the volume of the left liver lobe. This may allow liver resection in patients with metastases in the right liver lobe and a small left liver lobe.

99m Tc-macroaggregated albumin ( 99m Tc-MAA) scanning precedes radioembolization of the liver to detect extrahepatic shunting to the lung or gastrointestinal tract. Despite strict preventive measures in the production of 99m Tc-MAA and in scanning protocols, the images frequently show a gastric concentration of free 99m Tc-pertechnetate, hindering accurate evaluation of the gastroduodenal region. Our aim was to evaluate whether oral administration of sodium perchlorate (NaClO 4 ) before 99m Tc-MAA scanning will improve its accuracy by blocking free 99m Tc-pertechnetate gastric uptake. Methods: In 144 patients, 171 diagnostic hepatic angiograms combined with a 99m Tc-MAA scan were performed; 86 angiograms were performed after oral administration of NaClO 4 , and 85 were performed without this premedication. Clinical follow-up, esophagogastroduodenoscopy, and angiography served as reference standards. Results: 99m Tc-MAA studies showed tracer uptake in the gastric region of 25 patients who did not receive NaClO 4 . The uptake was interpreted as a free 99m Tc-pertechnetate concentration in 21 studies and as a 99m Tc-MAA accumulation in 4 studies. In 5 patients with a free 99m Tc-pertechnetate concentration, aberrant vessels were detected in angiographic reexamination, and 3 patients developed gastrointestinal ulcer. In 7 studies, gastric findings viewed pretherapeutically as free 99m Tc-pertechnetate were retrospectively classified as equivocal. Of the patients receiving NaClO 4 , 2 showed gastric accumulation of 99m Tc-MAA but no equivocal or free 99m Tc-pertechnetate. Oral administration of NaClO 4 increased the negative predictive value and accuracy of the test concerning the detection of gastric perfusion from 68% and 69%, respectively, to 93% and 94%, respectively. Conclusion: Oral administration of NaClO 4 before the test angiogram with 99m Tc-MAA resulted in effective avoidance of free 99m Tc-pertechnetate concentration and, consequently, of equivocal findings in the gastroduodenal region. This technique increased test accuracy and reporter confidence, saved time in reviewing the angiograms, and can improve treatment planning and reduce therapeutic side effects. Scanni ng with 99m Tc-macroaggregated albumin ( 99m Tc-MAA) generally precedes radioembolization of the liver to detect extrahepatic shunting to the lung or gastrointestinal tract (1). To avoid dissociated 99m Tc-pertechnetate, 99m Tc-MAA should be prepared under strict quality control assessments (2-4) and scintigraphy should be performed within 1 h of the radiopharmaceutical injection. Despite the preventive measures, a gastric concentration of free 99m Tc-pertechnetate is frequently seen in 99m Tc-MAA images and can hinder the accurate evaluation of the gastroduodenal region. Sodium perchlorate (NaClO 4 ) has a great affinity for the sodium-iodine symporter and is safely used for prophylaxis of iodine-induced hyperthyroidism due to iodinated contrast agents (5-7). Our aim was to evaluate whether oral administration of NaClO 4 before 99m Tc-MAA sca...

Side effects after radioembolization in patients with tracer accumulation in the anterior abdominal wall on (99m)Tc-MAA scans indicating a patent HFA are neither common nor severe. Thus, there is no absolute need for prophylactic embolization of the HFA or modification of the treatment plan if the HFA is not detectable on angiography.