Re: Product Description Pamphlet for In-111

["Kelly Crebs" <Kelly.Crebs@m.cc.utah.edu>]

In message <9505042043.AA01017@gemini.oscs.montana.edu>  writes:
> Radsafers:
> 
> Does anyone have access to a product description pamphlet for In-111 labeled
> octreotide?  I'm told it is used as a metastatin analogue for pituitary
> imaging.  I've got a concerned employee who says she was adminstered a 6 mCi
> dose, and she wants more information.  I'd like to get some info on dose
> factors, biological half-life, etc.
> 
> Any assistance will be appreciated.
> 
> -Erick
> +-------------------------------+
> | Erick Lindstrom               |
> | Radiation Safety Officer      |
> | 309 Montana Hall              |
> | Montana State University      |
> | Bozeman, MT  59717-0244       |
> | Phone: (406) 994-2108         |	
> | Fax:	 (406) 994-4792         |
> | avrel@gemini.oscs.montana.edu |
> +-------------------------------+
> 

Here is some info re: Octreoscan (In-111 octreotide)

The critical organ doses for Octreoscan are:
Spleen: 14.77 rads/6mCi
Kidneys: 10.83 rads/6mCi

The biological half-life of In-111 octreotide is 6 hours
The physical half-life of In-111 is 2.83 days
Therefore the effective half-life of In-111 octreotide is approximately 5.5 
hours.


OctreoScan Imaging Guidelines 

Introduction

Somatostatin is an endogenous neuropeptide that acts as a regulator of growth 
hormone secretion. Neuroendocrine tumors contain a high density of somatostatin 
receptors. OctreoScan(, a radiolabeled form of the somatostatin analog 
octreotide, shares the same binding site as naturally occurring somatostatin, 
which makes it a sensitive indicator for somatostatin receptorbearing 
neuroendocrine tumors. Since the concentration of receptors on tumors may vary, 
the sensitivity of OctreoScan( may vary among tumor types.

Neuroendocrine tumors generally are small and slowgrowing in nature, which can 
make localization difficult. Functional imaging with OctreoScan' frequently is 
sensitive enough to localize small primary tumors or metastases. OctreoScan ' 
wholebody imaging enables rapid localization of metastatic sites once the 
primary tumor is established. Planar imaging may be used to direct a more 
focused SPECT analysis of any region of interest. OctreoScan'' provides 
excellent image quality with a high targettobackground ratio. In a multicenter
study, OctreoScan results were consistent with the final diagnosis in 86.4% of 
patients (276/309). OctreoScan'<' imaging results produced a change in patient 
management in 31 1 'Y, of cases (64/206). OctreoScan' provides tumor 
localization and characterization information that can help determine the extent
of a patient's disease accurately, and may obviate the need for multiple 
invasive procedures such as biopsy or angiography. OctreoScan imaging also may 
enable modification of a patient's diagnostic workup so that appropriate 
measures (such as resection or drug therapy) can be initiated at an early stage 
of the disease process.

OctreoScan imaging may be used for patient followup to monitor the effects of 
surgery, radiotherapy, or chemotherapy. Because OctreoScan' imaging provides a 
functional assessment of the tumor cell, it may also allow for the selection of 
optimal therapy based on tumor biochemistry.

Adverse effects observed in clinical trials (at a frequency of < 1 %) included 
dizziness, fever, flush, headache, hypotension, changes in liver enzymes, joint 
pain, nausea, sweating and weakness.