Avraham Eisbruch, MD

The review by Kahn andJohnstone published in this issueof ONCOLOGY is comprehensiveand interesting. A fewpoints deserve emphasis, the first ofwhich is the issue of how we shouldmeasure and report xerostomia. Accurateand reliable measurements ofxerostomia are necessary in order toproperly assess its severity, timecourse, dose-response relationships,and the efficacy of measures to protectthe glands or to stimulate salivaryproduction following irradiation. Xerostomiaencompasses the objectivereduction in salivary output andchanges in its composition, as well asthe subjective symptoms reported bythe patient. Currently available measurementsof xerostomia include(1) functional imaging of gland activity,(2) measurements of the salivaryoutput, (3) observer-assessed toxicitygrading, and (4) instruments assessingpatient-reported evaluation of thevarious xerostomia-related symptoms.

Gemcitabine is a potent radiosensitizer in both laboratory studies and in the clinic. Initial laboratory studies showed that gemcitabine radiosensitizes a wide variety of rodent and human tumor cells in culture. Maximum