Diagnosis of acute bacterial prostatitis by Ga-67 scintigraphy and SPECT-CT.

Gallium-67 (Ga-67) is effective in imaging neoplasms and infection; however, its potential role in diagnosis of acute prostatitis is not well reported. We report a 66-year-old male patient who presented with back pain, fever, chills, and elevated white blood count. Plain x-ray of the lumbosacral spine showed degenerative changes in the L4 to L5 intervertebral disc space. The patient subsequently underwent Ga-67 scintigraphy and SPECT-CT for evaluation of diskitis, which showed diffuse intense uptake of Ga-67 within the prostate, suggesting acute prostatitis. There was complete resolution of symptoms after a course of antibiotics. (Clin Nucl Med 2008;33: 813–815) REFERENCES 1. Nickel JC, Downey J, Young I, et al. Asymptomatic inflammation and/or infection in benign prostatic hyperplasia. BJU Int. 1999;84:976–981. 2. Talpur AN, Hasan AT, Sheikh MA. Intraprostatic tissue infection in catheterised patients in comparison to controls. J Pak Med Assoc. 2004; 54:20–24. 3. Krieger JN, Nyberg L Jr, Nickel JC. NIH consensus definition and classification of prostatitis. JAMA. 1999;282:236–237. 4. Mateos JJ, Lomena F, Velasco M, et al. Diagnosis and follow-up of acute bacterial prostatitis and orchiepididymitis detected by In-111-labeled leukocyte imaging. Clin Nucl Med. 2003;28:403–404. 5. Sullivan WT, Rosen PR, Weiland FL, et al. Prostatic uptake of Ga-67. Radiology. 1984;152:537. 6. Higashi TS, Hamana T, Takizawa K, et al. Using Ga-67 scintigraphy in prostatic abscess. Ann Nucl Med. 1995;9:89–92. 7. Lin CY, Sun SS, Chuang FJ, et al. Malignant lymphoma with prostate involvement detected by Ga-67 scintigraphy. Clin Nucl Med. 2004;29: 217. 8. Mansberg R, Roberts J, Roman M. Ga-67 scintigraphy in pericarditis associated with rheumatoid arthritis. Clin Nucl Med. 2001;26:340 – 341. Received for publication November 27, 2007; revision accepted July 4, 2008. From the Department of Nuclear Medicine, William Beaumont Hospital, Troy, Michigan. Reprints: Feng Qing MD, PhD, Department of Nuclear Medicine, William Beaumont Hospital, 44201 Dequindre, Troy, MI 48098. E-mail: fqing@beaumont.edu. Copyright © 2008 by Lippincott Williams & Wilkins ISSN: 0363-9762/08/3311-0813 Clinical Nuclear Medicine • Volume 33, Number 11, November 2008 813 FIGURE 1. A 66-year-old white man with a past medical history that was significant for insulin dependent diabetes mellitus, hypertension, and degenerative disc disease was admitted with low back pain, fever, chills, and worsening renal function. He had a Foley catheter placed on the day of admission, which had to be removed a day later because of complaints of discomfort by the patient. He subsequently developed frequency, urgency, and occasional incontinence. The prostate was normal in size with slight tenderness on examination. Relevant laboratory findings included leukocytosis (WBC 17,000), 30 WBC/HPF, and moderate leukocyte esterase on urine analysis, positive urine culture for 100,000 CFU’s of Escherichia coli and prostate specific antigen value of 1. Spinal x-ray showed degenerative disc disease in L4 to L5 and L5 to S1 with facet arthropathy. The patient was referred for gallium-67 (Ga-67) scintigraphy to rule out diskitis, considering the history of back pain, fever, and leukocytosis. After intravenous administration of 8.34 mCi of Ga-67 citrate, whole body planar images in the anterior and posterior positions were obtained at 48 hours, which showed physiologic activity of Ga-67 in the liver, spleen, colon, and bone marrow and increased tracer activity in the midline in the pelvic region (arrows). Bajaj et al Clinical Nuclear Medicine • Volume 33, Number 11, November 2008 © 2008 Lippincott Williams & Wilkins 814 FIGURE 2. SPECT-CT showed no abnormal uptake in the lumbar spine, but there was diffuse moderate uptake of Ga-67 within the prostate, which was suggestive of prostatitis. These findings, in conjunction with the laboratory findings, clinical presentation, and the fact that intraprostatic infection is more common in catheterized patients were thought to be consistent with acute prostatitis. After a course of antibiotics (Augmentin), the patient’s symptoms, including back pain, improved dramatically. His total white blood cell count normalized and urinalysis became negative for infection. These findings further supported the diagnosis of acute prostatitis. National Institutes of Health consensus classification recognizes acute prostatitis primarily as a clinical diagnosis rather than a histopathologic entity. Acute prostatitis is a common clinical problem. Approximately 50% of the male population will have prostatitis at some time in their lives. Only a few reports of Ga-67 uptake in prostatic inflammation/infection have been reported in the literature because the focal midline tracer uptake on planar images is usually considered to be physiologic activity in colon. Ga-67 citrate circulates in the plasma bound to transferrin. Localization to the site of infection is to a large extent secondary to binding to iron-binding compounds like lactoferrin released by degranulation of leukocytes and bacterial siderophores. Thus, Ga-67 uptake on SPECT-CT can be further used as an imaging modality in diagnosing acute prostatitis and in assessing the response to antibiotic therapy. The strength of the test is that it may be repeated as many times as radiation doses permit during the course of treatment. Clinical Nuclear Medicine • Volume 33, Number 11, November 2008 Diagnosis of Acute Bacterial Prostatitis © 2008 Lippincott Williams & Wilkins 815