Feasibility of Hyperfunctioning Parathyroid Gland Localization Using [18F]fluciclovine PET/CT.

PURPOSE: To evaluate the ability of anti-1-amino-3-anti-1-amino-3-[18F]fluorocyclobutane-1-carboxylic acid ([18F]fluciclovine) positron emission tomography/X-ray computed tomography (PET/CT) in comparison to Technetium-99m 2-methoxy isobutyl isonitrile ([99mTc]sestamibi) single-photon emission computed tomography/CT (SPECT/CT) for the localization of hyperfunctioning parathyroid glands in patients with hyperparathyroidism. PROCEDURES: Four patients with hyperparathyroidism underwent 60-minutes sequential neck and thorax PET/CT after [18F]fluciclovine (352 ± 28 MBq) injection. Lesion uptake and target-to-background ratios (TBR) were compared with [99mTc]sestamibi (798 ± 27 MBq) SPECT/CT in the same patient. RESULTS: Both techniques detected 4/5 hyperfunctioning parathyroid glands identified at surgery. The highest [18F]fluciclovine uptake and TBRs were at 5-9 min with rapid washout. [99mTc]sestamibi had significantly higher TBRs compared with [18F]fluciclovine (5-9 min) for blood pool (10.9 ± 4.7 vs 1.3 ± 0.6; p < 0.01) and reference muscle backgrounds (5.8 ± 3.0 vs 1.7 ± 0.6; p < 0.01), with non-significant trend for thyroid tissue background (1.3 ± 0.5 vs 1.1 ± 0.5; p = 0.73). CONCLUSION: Hyperfunctioning parathyroid glands can be detected on [18F]fluciclovine PET/CT at early imaging, but conspicuity (TBR) is better with [99mTc]sestamibi. [18F]fluciclovine PET/CT does not seem promising in the detection of hyperfunctioning parathyroid glands.

Another "great mimicker": FDG-PET/CT imaging findings of sarcoid-like reaction.

Sarcoid-like reaction (SLR) is a cause of non-caseating granulomas in some of the cancer patients with otherwise no signs or symptoms of sarcoidosis. SLR has been described in a variety of solid organ malignancies, including breast and lung cancer. SLR may result in hypermetabolic activity in 18-fludeoxyglucose positron emission tomography (PET)/CT scan, resulting in false positive reporting for malignancy. The purpose of this case series is to expose residents/practising physicians who interpret PET/CT to a series of cases illustrating findings of SLR.

Nissen fundoplication improves gastric motility in patients with delayed gastric emptying.

BACKGROUND: Fundoplication hastens gastric emptying in pediatric patients with gastroesophageal reflux disease (GERD). However, among adult GERD patients with impaired gastric emptying, the degree of improvement offered by fundoplication and the value of pyloroplasty are less well defined. Therefore, we compared outcomes in GERD patients with delayed gastric emptying after fundoplication alone or fundoplication with pyloroplasty. METHODS: Of 616 consecutive GERD patients who submitted to primary fundoplication (601 laparoscopic) between October 1991 and October 1997, 82 underwent preoperative solid-phase nuclear gastric emptying analysis. Of these, 25 had delayed gastric emptying (half-time >100 min). Of 12 patients with emptying half-times between 100 and 150 min, one underwent pyloroplasty at the time of Nissen fundoplication. Of 13 patients with emptying half-times >150 min, 11 had pyloroplasty at the time of Nissen fundoplication. Patients were asked to use a 0 ("none") to 4 ("incapacitating") scale to describe the severity of their symptoms of heartburn, regurgitation, dysphagia, bloating and diarrhea preoperatively and at 6 weeks and 1 year postoperatively. Eight patients consented to a postoperative analysis of gastric emptying. RESULTS: One year after fundoplication, patients with delayed gastric emptying and controls reported a similar improvement in heartburn, regurgitation, and dysphagia, with no increase in undesirable side effects such as bloating and diarrhea. Among the patients with delayed gastric emptying who consented to undergo a repeat gastric emptying study after their operation, fundoplication alone provided a 38% improvement (p < 0.05) in gastric emptying, whereas fundoplication with pyloroplasty resulted in a 70% improvement in gastric emptying (p < 0.05). CONCLUSION: Fundoplication improves gastric emptying. The addition of pyloroplasty results in even greater improvement and may have particular value for patients with severe gastric hypomotility.

Two-point, timesaving method for measurement of gastric emptying with diagnostic accuracy comparable to that of the conventional method.

Solid-phase gastric emptying is linear. Therefore, the authors calculated gastric-emptying half-time, the time for half of the ingested solids or liquids to leave the stomach, with the conventional multiple-point method and the proposed two-point method (at 0 and 120 minutes) in retrospective and prospective studies of 50 patients each. The results showed excellent correlation. Results with the two-point method were comparable to those with the multiple-point method, and the two-point method substantially reduced technologist and camera times.

Intraoperative probes.

OBJECTIVE: Design features of intraoperative probes are presented. A brief discussion of the sentinel node concept and relevant radiopharmaceuticals is given. The importance of the injection technique and the necessity of imaging in radiotracer techniques for sentinel node detection are explained. Probe calibration, procedural precautions, intraoperative techniques, and radiation dosimetry relevant to the successful use of intraoperative probes are discussed. Intraoperative use of gamma probes requires a team effort involving surgery and nuclear medicine personnel and requires that team members understand the fundamentals of probe use. After reading this paper, the nuclear medicine technologist will be able to: (a) describe present day and future potential use of intraoperative probes; (b) define the sentinel lymph node (SLN) concept; (c) state the radiopharmaceuticals and injection techniques used for SLN evaluation; (d) name several SLN detection procedures; and (e) discuss the design features and care of currently available probes.

Lymphoscintigraphic identification of sentinel lymph nodes: clinical evaluation of 0.22-micron filtration of Tc-99m sulfur colloid.

PURPOSE: To evaluate the use of 0.22-micron filtration of technetium-99m sulfur colloid particles in the optimization of lymphoscintigraphy. MATERIALS AND METHODS: Forty-one consecutive lymphoscintigraphic studies obtained with 0.22-micron filtration of Tc-99m sulfur colloid in 41 patients (26 men, 15 women; average age, 55.4 years) and 41 consecutive studies obtained with 5.0-micron filtration in 41 patients (20 men, 21 women; average age, 54.5 years) were retrospectively, randomly reviewed. Studies were evaluated for lymphatic channel depiction and sentinel lymph node depiction. Studies included immediate flow images (obtained at 10 seconds per frame) and multiview static images obtained up to 2 hours after intradermal Tc-99m sulfur colloid injection. RESULTS: The number of drainage beds visualized was 52 with 5.0-micron filtration and 51 with 0.22-micron filtration (P = .570). The number of lymphatic channels visualized was 45 with 5.0-micron filtration and 75 with 0.22-micron filtration (P = .006). The number of lymph nodes visualized was 102 with 5.0-micron filtration and 123 with 0.22-micron filtration (P = .123). The number of studies judged as optimal (i.e., depicted lymphatic channels leading to sentinel nodes) was 10 with 5.0-micron filtration and 19 with 0.22-micron filtration (P = .038). The number of studies with depicted lymph nodes but no depicted lymphatic channel was 15 with 5.0-micron filtration and six with 0.22-micron filtration (P = .023). CONCLUSION: The use of 0.22-micron filtration in the preparation of Tc-99m sulfur colloid substantially improves study quality and increases the diagnostic certainty in the identification of sentinel lymph nodes.

Background subtraction in technetium-99m-MAG3 renography.

UNLABELLED: Correction represents a potential source of error in estimating split renal function and camera-based clearances. The purpose of this study was to determine which of five background options and four time intervals was associated with the least error for 99mTc-mercaptoacetyltriglycine (MAG3). METHODS: Fifteen single-kidney patients were imaged supine after 111-370 MBq (3-10 mCi) 99mTc-MAG3 injection. A phantom kidney was drawn on the 2-3-min images, approximately equal in size to the solitary kidney and used for all time intervals. Counts in the phantom and native kidneys were calculated using manual inferior and lateral regions of interest (ROIs), automated elliptical and perirenal background ROIs and no background correction at various time intervals (1-2, 1-2.5, 1.5-2.5 and 2-3 min) postinjection. With optimal background correction, counts and the relative function in the phantom kidney should be zero. The error was measuring by estimating both the relative function and absolute function expressed as the percent injected dose in the phantom kidney. RESULTS: The percent injected dose in the phantom kidney as well as the error in measuring relative function were significantly greater than zero for the inferior background correction and the no background correction options at all time intervals, p < 0.05. The percent dose in the kidney and the error associated with the lateral, elliptical and perirenal ROIs were not significantly different from zero. CONCLUSION: Regardless of time interval, the greatest error was associated with no background correction. The inferior ROI consistently underestimated the background correction and probably should not be used for 99mTc-MAG3. There was no significant difference between errors generated using the lateral and automated ROIs, although automated ROIs are probably more reproducible for sequential studies.

In-111 labeled octreotide imaging of a primary carcinoid lesion undetected by conventional imaging studies in a patient with "chronic pancreatitis".

This is a case report of a patient with an initial diagnosis of chronic pancreatitis who actually had metastatic carcinoid tumor. His symptoms of abdominal pain, weight loss, and diarrhea were manifestations of the large tumor bulk within the liver as well as carcinoid syndrome. Although abdominal CT scans showed multiple liver lesions, the primary lesion was not identified by conventional imaging studies. However, the mid-gut primary lesion was visualized on in-111 labeled octreotide scintigraphy; where the liver lesions were better delineated and seen to be separate from the normal pancreas when the Tc-99m sulfur colloid images were compared to the octreotide images.