gallium Ga 68 dotatoc (Rx)

1-10%

Nausea (<2%)

<1%

Pruritus

Flushing

Postmarketing Reports

Immune system disorders: Hypersensitivity reactions, predominantly rash, pruritus, less frequently angioedema or features of anaphylaxis

Contraindications

None

Cautions

Hypersensitivity reactions consisting of cutaneous reactions such as rash and pruritus reported; reactions reversed either spontaneously or with routine symptomatic management; less frequently hypersensitivity reactions included angioedema or cases with features of anaphylaxis

Radiation risk

• Contributes to a patient’s overall long-term cumulative radiation exposure; long-term cumulative radiation exposure associated with increased cancer risk
• Ensure safe handling and preparation procedures to protect patients and healthcare workers from unintentional radiation exposure

Risk for image misinterpretation

• Uptake of Ga 68 dotatoc reflects somatostatin receptor density level in NETs
• Uptake can also be seen in other tumors that express somatostatin receptors
• Increased uptake might also be seen in other pathologic conditions (eg, thyroid disease, subacute inflammation) or might occur as a normal physiologic variant (eg, uncinate process of the pancreas)
• Negative scan after administration in patients without history of NET disease does not rule out disease

Drug interaction overview

• Nonradioactive somatostatin analogs (eg, lanreotide, octreotide, pasireotide) competitively bind to the same somatostatin receptors as Ga 68 dotatoc

Pregnancy

No data available on use in pregnant women to identify a risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes

Animal data

• Animal reproduction studies have not been conducted
• All radiopharmaceuticals may cause fetal harm depending on fetal stage of development and radiation dose magnitude
• If considering administration to a pregnant woman, inform of potential for adverse pregnancy outcomes based on the radiation dose from Ga 68 dotatoc and the gestational timing of exposure

Lactation

There is no information on the presence of Ga 68 dotatoc in human milk, the effect on the breastfed infant, or the effect on milk production

Consider developmental and health benefits of breastfeeding along with the mother’s clinical need and any potential adverse effects on the breastfed child from injection or from the underlying maternal condition

Clinical considerations

• Advise a lactating woman to interrupt breastfeeding and pump and discard breast milk for 8 hr after administration

Pregnancy Categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.

Mechanism of Action

Ga 68 dotatoc binds to somatostatin receptors, with highest affinity for subtype 2 receptors (sstr2)

Drug binds to cells that express somatostatin receptors including malignant neuroendocrine cells, which overexpress sstr2 receptors

Gallium 68 is a beta-emitting radionuclide with associated 511 keV annihilation photons that allow PET imaging

Distribution

Distributed to all sstr2-expressing organs such as pituitary, thyroid, spleen, adrenals, kidney, pancreas, prostate, liver, and salivary glands

Uptake in the lung and lymph nodes is lower compared with other sstr-2 expressing organs

Elimination

Excretion: Exclusively via urine (~16%)

IV Preparation

Drug handling

• Handle injection with appropriate safety measures to minimize radiation exposure

• Use waterproof gloves, effective radiation shielding, and appropriate safety measures when preparing and handling injection

• Use radiopharmaceuticals under the control of physicians who are qualified by specific training and experience in the safe use and handling of radionuclides, and whose experience and training have been approved by the appropriate governmental agency authorized to license the use of radionuclides

Patient hydration

• Instruct patients to drink water to ensure adequate hydration before administration and to continue to drink and void frequently during first hours following administration to reduce radiation exposure

IV Administration

Use injection within 3 hr of calibration time

Visually inspect injection for particulate matter and discoloration before administration; do not use if solution contains particulate matter or is discolored

Calculate the necessary volume to administer based on measured activity, volume, calibration time, and date

Measure dose immediately before administration in a dose calibrator; refer to prescribing information for dose and estimated radiation absorbed

Inject IV bolus at ~ 10 sec/mL

After administration, flush IV with 0.9% NaCl to ensure dose is fully delivered

Dispose of any unused drug in a safe manner in compliance with applicable regulations

Image Acquisition

For Ga 68 dotatoc PET imaging, acquisition must include a whole body acquisition from skull to mid-thigh

Image can be acquired at 60 min (range 55-90 min) after IV bolus

Adapt injection uptake time and scan duration according to the equipment used, the patient, and tumor characteristics, to obtain optimal image quality

Image Interpretation

Drug binds to somatostatin receptors

Based upon the intensity of the signals, PET images obtained indicate presence and density of somatostatin receptors in tissues

Storage

Store upright in a lead shielded container at 25ºC (77ºF); excursions permitted to 15-30ºC (59-86ºF)

Store and dispose of injection in accordance with the regulations and a general license, or its equivalent, of an agreement state or a licensing state