Ls. Zuckier et al., REMOTELY POLLABLE GEIGER-MULLER DETECTOR FOR CONTINUOUS MONITORING OFI-131 THERAPY PATIENTS, The Journal of nuclear medicine, 39(9), 1998, pp. 1558-1562
In many countries, patients treated with therapeutic amounts of I-131
are hospitalized because of radiation safety considerations. To determ
ine when they can return home, radiation levels are intermittently mon
itored at bedside using a handheld Geiger-Muller (GM) counter, althoug
h this procedure can be cumbersome and inexact. Methods: We have devel
oped and tested a remotely pollable system for continuous radiation mo
nitoring of I-131 therapy inpatients, using readily available hardware
and standard telephone lines. The remote detector system, consisting
of a palmtop IBM-compatible personal computer, specialized software, P
CMCIA modem and miniature serial port-based GM detector, is placed opp
osite the patient's bed at a fixed distance, and continuous 1-min acqu
isitions are started. Initially and at least twice daily, the remote p
almtop is contacted by modem, and all interval data are uploaded onto
the operator's base computer over the telephone line, including measur
ements taken with the patient in a predetermined standardized position
. Continuous minute-to-minute data may be viewed in native form or can
be imported into graphing and spreadsheet programs. Points acquired w
ith the patient in standardized position are specially marked to highl
ight the constant geometry used. The ratio of initial counting rate to
administered dose is used to estimate residual I-131 body burden by p
roportionality. Display of data as a semilogarithmic plot facilitates
extrapolation of the activity curves and prediction of the patient's e
arliest time of discharge. Results: We have characterized the remote G
M detector system to confirm accuracy, counting rate linearity and rel
iability of data transfer. We describe examples that illustrate the ap
plicability and usefulness of this method for remote monitoring of inp
atient I-131 therapy levels. Conclusion: Monitoring patients with the
described remotely poltable GM detector is an accurate and easy-to-imp
lement technique that could conceivably lead to shortened hospital sta
ys for I-131 therapy inpatients. Continuous quantitative data obtained
are useful for kinetic and dosimetric analyses, which may be applied
to study other gamma-emitting radiopharmaceuticals as well. The flexib
ility of the technique may permit its use in the monitoring of therapy
on an outpatient basis, where allowed.