Re: Beta Emitters and Dose Calibrators

[maay100@bgumail.bgu.ac.il (Quastel)]

>Carol- You wrote:
>
>"Your assumption that more precision is needed for therapy than
>diagnosis is dead wrong.  Many diagnostic tests require more precision
>because of the technique and data processing involved.  Any old amount of
>I-131 can treat hyperthyroidism, and if it isn't enough the first time, you
>give a second or third dose.  The same patient can go to 2 doctors, and one
>could prescribe 2 mCi and the other 30 mCi
>and each doctor would manage to cure the disease.
>
>Ciao, Carol"

Depends on the source of the hyperthyroidism.

If due to an autonomous hot nodule, 2 mCi won't be of any use. 25-30 mCi is
an accepted dose for this.

If from Grave's disease, 30 mCi would 'cure' it, but you'd be very certain
to induce hypothyroidism, though admittedly, hypothroidism is can also
occur following regular therapuetic doses of 7-10 mCi.

In our experience, there is a lot of variation in radiation responsiveness
among patients, and it is difficult to predict the therapeutic response of
patients to therapeutic doses of I-131 for the treatment of Grave's
disease.

                                        Mike Quastel
                                        Soroka Medical Center
                                        Faculty of Health Sciences
                                        Ben Gurion University of the Negev
                                        POB 151, Beer Sheva, Israel 84101



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