Download Octreotide (Somatostatin

Policy #:18.8.9.5
SUBJECT: Ocetreotide (Somatostinin‐Receptor) Imaging
APPROVED BY: Director of Radiology Written: 10/12 Reviewed:10/16
Page 1 of 3 Somatostatin-Receptor Imaging
Primary Indications: Detection and staging of neuroendocrine tumors containing somatostatin receptors,
especially carcinoid tumors, paragangliomas, gastrinomas, and other pancreatic islet cell tumors. Sensitivity for
detection of pheochro-mocytomas and neuroblastomas is comparable to that of scintigraphy with I-131 MIBG
and the sensitivity for detection of nearly all other neuroendocrine tumors is better than that with I-131 MIBG.
Rationale: In-111 pentetreotide is a [In-111 DTPA-D-Phe-] conjugate of octreotide, a somatostatin analog that
binds to somatostatin receptors on a variety of cells. This octapeptide concentrates in tumors containing a high
density of somatostatin receptors, e.g. neuroendocrine and some non-neuroen-docrine tumors. In addition to
these tumors, normal organs such as the pituitary, thyroid, spleen, liver, kidneys, and urinary bladder are also
visualized, and this agent is taken up in some granulomatous and autoimmune processes, due to the presence of
somatostatin receptor-positive activated mononuclear leukocytes.
Interfering Conditions: Tumor uptake of the radiopharmaceutical is reduced, but usually not completely
eliminated, in patients being treated with octreotide acetate (Sandostatin®). If possible, this treatment should be
discontinued 24 hours before injection of the radiopharmaceutical.
Precautions: Injection of In-111 pentetreotide may cause hypoglycemia or hyper-glycemia in patients with
insulinoma.
Radiopharmaceutical: In-111 pentetreotide (Octreoscan®)
Adult Dosage: 3 mCi for planar scintigraphy
6 mCi for SPECT or SPECT/CT
Pediatric Dosage: 40 µCi/kg for planar scintigraphy
80 µCi/kg for SPECT or SPECT/CT; maximum dosage – 6 mCi; minimum dosage – 0.5 mCi
Radiation Dosimetry: Adult. Effective dose: 1.2 rem/6 mCi dose; Critical organ (spleen): 12.7 rem/6 mCi
dose.
Infant (1 yr old; 9.72 kg 80 µCi/kg): Effective dose: 0.75 rem/0.77 mCi. Critical organ (spleen): 8.9 rem/0.77
mCi;
Route of Administration: Intravenous. (Do not administer into total parenteral nutrition i.v. lines.)
Note: in patients with suspected insulinoma, an intravenous line should be placed, and 5% dextrose
solution (D5W) should be infused before and during injection of the radiopharmaceutical, because of the
possibility of hypoglycemia.
Policy #:18.8.9.5
SUBJECT: Ocetreotide (Somatostinin‐Receptor) Imaging
APPROVED BY: Director of Radiology Written: 10/12 Reviewed:10/16
Page 2 of 3 Patient Scheduling: Requests for somatostatin-receptor scintigraphy should be directed to the attending nuclear
medicine physician or a nuclear medicine resident. This individual should obtain the relevant clinical history,
determine whether it is appropriate to perform this examination, determine the availability of In-111
pentetreotide for the time of study request, and schedule with radiopharmacy staff. All required scheduling
information should be entered on the “In-111 Pentetreotide (Octreoscan®) Imaging Record of Telephone
Scheduling” (attached).
Patients should be told that study requires approximately 5 hours on the first day. Additional images will
usually be required at 24 (and possibly 48 hours).
Patient Preparation: Discontinuation of octreotide acetate therapy (see above).
Patient should be well hydrated before and after administration of radio-pharmaceutical.
Use of a mild laxative (at discretion of nuclear medicine physician) may help to reduce bowel activity on 18-24
hour images. Consult with refer-ring endocrinologist before prescribing laxative to a patient with suspected
insulinoma.
Equipment Setup: Gamma Camera: LFOV dual-head with whole-body imaging capability, and SPECT or
SPECT/CT (preferred).
Collimator: medium-energy parallel-hole collimator
Energy Window: 172 and 247 keV with 20% windows
If scatter estimation is used during SPECT reconstruction additional windows are utilized: a 10% window
below and adjacent to the window for the 247 keV peak and 15% window below and adjacent to the window for
the 172 keV peak and an 8% window above and adjacent to the 172 keV peak window.
Patient Positioning: Verify that the patient has no metallic objects in the area to be scanned. Patients should be
given a hospital gown to ensure that there is no urinary contamination and all metallic objects including jewelry
are removed from the area of interest. Supine for planar and whole-body imaging and for SPECT or
SPECT/CT; 1-2 pillows may be placed under knees to minimize low back discomfort. If SPECT/CT or SPECT
are performed with the arms above the head; the arms should be comfortably positioned and NOT be physically
restrained above the head.
Procedure: The routine examination consists of 4-hour delayed and 18- to 24-hour delayed planar whole-body
images (head to mid thighs), preferably with a dual-head whole-body camera. At the discretion of the nuclear
medicine physician, the examination may be limited to a smaller area of the body. In most cases, SPECT/CT or
SPECT imaging will also be performed, usually of the abdomen and usually at 18-24 hours.
View
Spot images
Digital Acquisition
256 x 256 matrix, word mode; 10 minutes per view
Film Display (If Applicable)
Spot image format
Policy #:18.8.9.5
SUBJECT: Ocetreotide (Somatostinin‐Receptor) Imaging
APPROVED BY: Director of Radiology Whole-body images 256 x 1024 matrix, word mode; Zoom 1.0
Head out, Supine
30-min acquisition (4 cm/min scan speed)
Written: 10/12 Reviewed:10/16
Page 3 of 3 DEC/Alpha Bone Display
Whole-body Dual-intensity
SPECT
See “SPECT Acquisition and Filtering Guidelines”
To be filmed by physician
SPECT/CT
See “SPECT/CT Acquisition and Filtering Guidelines” To be filmed by physician
Items Required For Complete Study:
1. Transfer whole-body images to the DEC/Alphas and save screen capture to PACS.
2. Limited examination: planar images of area of interest in projections directed by physician
3. Processed SPECT or SPECT/CT images are sent to the Nuclear Medicine Archive, and PACS.
4. The nuclear medicine physician will create screen captures at the workstation which will be transferred to
PACS