747 The Utility of SPECT for 99mTc-MAA Hepatic Arterial Perfusion Scintigraphy Harvey A. 2 Richard L. Wahl1 Jack E. Juni1 John E. Gyves3 William D. Ensminger James H. Thrall4 John W. Keyes, Jr.4 Suzette C. Walkers Received February 4, 1985; accepted after re- vision May 10, 1985. I Department of Intemal Medicine, Division of Nuclear Medkne, lkiiversity of Michigan Medical Center, Ann Arbor, MI 48109. 2 Present address: Division of Nuclear Medicine, Georgetown lhiiversity Medical Center, 3800 Res- ervoir Rd., NW., Washington, DC 20007. Address reprint requests to H. A. Ziessman. 3 Department of Internal Medicine, Division of Hematology/Oncology, Wiversity of Michigan Med- ical Center, Ann Arbor, Ml 48109. 4 Department of Radiology. Henry Ford Hospital, Detroit, MI 48202. AJR 145:747-751, October 1985 0361-803X/ 85/1 454-0747 © American Roentgen Ray Society The utility of single-photon emission computed tomography (SPECT) for hepatic arterial perfusion scintigraphy was evaluated in 86 patients(91 studies). Previous reports have shown planar studies to be valuable for the clinical management of patients receiving intraarterial chemotherapy and more reliable than angiography in determining blood flow distribution. However, overlying areas of intra- and extrahepatic perfusion can sometimes make interpretation of these two-dimensional images difficult. Since SPECT has the potential to depict the three-dimensional distribution of perfusion, separate out overlying activity, and improve contrast resolution, SPECT Tc-MAA perfu- sion studies were compared to planar studies. Planar and SPECT studies both demon- strated the extent of hepatic and tumor perfusion, although occasionally SPECT added additional information SPECT was most useful in confirming or excluding extrahepatic perfusion that was suspected but not definite on planar studies. Extrahepatic abdominal perfusion was found to be present in 11 (12%) of 91 studies. All patients with confirmed extrahepatic perfusion who received intraarterial chemotherapy had symptoms of drug toxicity compared to only a 23% incidence in those without evidence of extrahepatic perfusion (p < 0.001). This report demonstrates that SPECT can improve the qualitative interpretation of hepatic arterial perfusion studies. Technetium-99m macroaggregated albumin (Tc-MAA) hepatic arterial perfusion scintigraphy has proven valuable in the clinical management of patients receiving intraarterial chemotherapy for primary and metastatic liver cancer [1 -3]. A good response to chemotherapy requires perfusion of the entire tumor-bearing liver. A component of extrahepatic abdominal perfusion can result in less drug delivered to the tumor as well as increased gastrointestinal and systemic exposure and resultant toxicity [1 J. Overlying areas of intra- and extrahepatic perfusion can sometimes make interpretation of these two-dimensional images difficult [4, 5]. Single-photon emission computed tomography (SPECT) has the potential to depict the three-dimensional distribution of perfusion, separate out overlying activity, and improve contrast resolution. We review our experience using SPECT for hepatic arterial perfusion scintigraphy. Materials and Materials Patient Population Ninety-one SPECT Tc-MAA hepatic arterial perfusion studies performed on 86 patients between 1 981 and 1984 were reviewed. All had biopsy-proven primary or metastatic liver cancer. Seventy-eight patients had totally implanted infusion systems. The rest had percuta- neously placed intraarterial catheters. The age range was 31 -74 years (mean, 58). The neoplasms were distributed as follows: adenocarcinoma of the colon (68), carcinoid (six), primary hepatocellular carcinoma (three), cholangiocarcinoma (three), pancreatic adenocarci- noma (two), and islet cell (two), ovarian (one), and breast (one) cancers. All patients had visceral angiography and planar #{176}‘Tc sulfur colloid (Tc-SC) liver-spleen scans. Twenty-six (30%) had SPECT Tc-SC studies.