4. Paediatric population The decision to administer pentetrotide (111In) to a child must be taken by a nuclear medicine specialist familiar with somatostatin receptor scintigraphy, after considering using alternative radiopharmaceuticals with a lower radiation burden (PET in particular).
Pentetreotide (111In) should only be administered to a child when alternative radiopharmaceuticals are not available or they do not yield a satisfactory performance in the clinical setting of the child. Method of administration The medicinal product is for single use.
Administration by intravenous injection. Careful administration is necessary to avoid paravasal deposition of activity. This medicinal product should be reconstituted before administration to the patient. For instructions on reconstitution of the medicinal product before administration, see section 12.
4. Image acquisition Images can be acquired at 4 and 24 hours, or 24 and 48 hours post-injection. 4 hours images may be useful for comparison and evaluation of abdominal activity imaged at 24 hours. When activity in the abdomen is observed at 24 hours which cannot be interpreted with certainty as uptake in tumour or activity in bowel contents, scintigraphy should be repeated at 48 hours.
It is important to acquire two sets of images with at least one SPECT (or SPECT/CT) acquisition. i. to allow clearance of interfering bowel radioactivity. Physiologic uptake occurs in spleen, liver, kidneys and bladder. Thyroid, pituitary and intestines are visible in most patients.
1. 4 Special warnings and precautions for use Potential for hypersensitivity or anaphylactic reactions If hypersensitivity or anaphylactic reactions occur, the administration of the medicinal product must be discontinued immediately and intravenous treatment initiated, if necessary.
To enable immediate action in emergencies, the necessary medicinal products and equipment such as endotracheal tube and ventilator must immediately available. Individual benefit/risk justification For each patient, the radiation exposure must be justifiable by the likely benefit.
The activity administered should in any case be as low as reasonably achievable to obtain the required diagnostic information. Renal impairment Careful consideration of the activity to be administered is required since an increased radiation exposure is possible in these patients.
In patients with significant renal failure administration of 111In-pentetreotide is not advisable because the reduced or absent function of the principal route of excretion will lead to delivery of an increased radiation dose. Administration should be considered only when the possible damage from radiation is outweighed by the potential diagnostic information.
Interpretable scintigrams may be obtained after haemodialysis during which the high background activity can at least partially be removed. Prior to dialysis images are non-diagnostic because of activity in the circulation. After dialysis a higher than usual uptake in liver, spleen and intestinal tract, and a higher than usual activity in circulation, were observed.
Peadiatric population Because of the potential hazard of the ionizing radiation 111In-pentetreotide should not be used in children under 18 years of age, unless the value of the expected clinical information is considered to outweigh the possible damage from radiation.
2. Patient preparation The patient should be well hydrated before the start of the examination and urged to void as often as possible during the first hours after the examination in order to reduce radiation. Administration of a laxative is necessary in patients not suffering from diarrhoea, to differentiate stationary activity accumulations in lesions in, or adjacent to, the intestinal tract from moving accumulations in the bowel contents.
Indium(111In)-pentetreotide not bound to receptors, and non-peptide bound indium(111In), are rapidly eliminated through the kidneys. To enhance the process of excretion, in order to reduce background noise and to reduce the radiation dose to kidneys and bladder, a liberal fluid intake (at least 2 litres) is required for 2 or 3 days following administration.
Regarding patients on octreotide therapy it is recommended to withdraw this therapy temporarily to avoid a possible blockade of somatostatin receptors. This recommendation is given on empirical grounds, the absolute need for such measure has not been demonstrated.
In some patients the withdrawal of therapy might be not tolerated and may cause rebound effects. This is notably the case in insulinoma patients, where the danger of sudden hypoglycaemia must be considered, and in patients suffering from the carcinoid syndrome.
If the clinician responsible for the patients therapeutic management considers withdrawal of octreotide therapy tolerable a three days withdrawal period is recommended. Interpretation of images Positive scintigraphy with indium(111In)-pentetreotide reflects the presence of an increased density of tissue somatostatin receptors rather than a malignant disease.
Furthermore positive uptake is not specific for GEP- and carcinoid-tumours. Positive scintigraphic results require evaluation of the possibility that another disease, characterised by high local somatostatin receptor concentrations, may be present.
An increase in somatostatin receptor density can also occur in the following pathological conditions: tumours arising from tissue embryologically derived from the neural crest, (paragangliomas, medullary thyroid carcinomas, neuroblastomas, pheochromocytomas), tumours of the pituitary gland, endocrine neoplasms of the lungs (small-cell carcinoma), meningiomas, mammary carcinomas, […]