Dose Calibrator with Decay Correction for Hot Cell Therapy Preparation

The Dose Calibrator with Decay Correction is specifically designed for therapeutic radiopharmaceuticals, where doses are often prepared hours or days before administration. For long-lived therapy isotopes such as Lu-177 (half-life 6.6 days), Y-90 (2.7 days), and I-131 (8.0 days), decay between preparation and administration is significant and must be calculated correctly to ensure the patient receives the prescribed activity. This instrument automates the decay correction calculation, eliminating a common source of dosing errors. The user enters the desired activity at administration time and the administration time; the calibrator calculates the activity that must be measured at preparation time and guides the user in adjusting the dose volume.

The Decay Correction Dose Calibrator is designed for nuclear medicine departments performing radiopharmaceutical therapy for cancer, hyperthyroidism, and other conditions. Primary applications include Lu-177 DOTATATE or PSMA preparation for PRRT (peptide receptor radionuclide therapy), Y-90 microsphere preparation for liver cancer treatment, I-131 solution or capsule preparation for thyroid cancer and hyperthyroidism, and Ac-225 PSMA preparation for targeted alpha therapy. The instrument is equally valuable for research applications involving long-lived radiotracers and for quality control of therapy doses where decay correction is required.

The Decay Correction Dose Calibrator automates the calculation that is the most common source of therapy dosing errors. The process works as follows: The user selects the isotope (Lu-177, Y-90, I-131, Ac-225, etc.) and enters the desired activity at administration time (e.g., 150 mCi for Lu-177 PRRT) and the planned administration time (e.g., 10:00 tomorrow). The calibrator calculates the activity that must be present in the dose when it is prepared (today at 14:00). The calculation uses the precise half-life of the isotope (Lu-177: 6.647 days, Y-90: 2.668 days, I-131: 8.021 days) and accounts for the time difference to the minute. The instrument displays both the target preparation activity and, for liquid doses, the required volume based on the stock solution concentration. The user then measures the prepared dose. The calibrator compares the measured activity to the target, calculates the percent difference, and indicates whether the dose is within acceptable tolerance (typically ±10% for therapy doses). If the dose is outside tolerance, the calibrator suggests an adjustment — add or remove volume from the vial. For multi-dose vials (e.g., a single Lu-177 vial containing enough activity for multiple patients), the calibrator can track the residual activity after each dose withdrawal, automatically updating decay correction for subsequent patients. This feature is invaluable for therapy centers that batch-prepare doses for multiple patients from the same stock vial. The instrument's accuracy for therapy isotopes is ±5% for gamma-emitting isotopes (Lu-177, I-131) and ±10% for pure beta emitters (Y-90, using bremsstrahlung measurement). The measurement range covers from 1 mCi to 10 Ci, accommodating both low-activity test doses and high-activity therapy vials. The remote display unit shows the measured activity, target activity, and percent difference on a single screen, with color coding (green for within tolerance, yellow for approaching limit, red for out of tolerance). An audible alert sounds when the dose is within tolerance. The data logging system stores all dose preparation records, including the target activity, measured activity, preparation time, administration time, and calculated decay. The printer output produces a record that can be attached to the patient chart. For nuclear medicine departments, the primary benefit of automated decay correction is elimination of calculation errors. In a busy therapy center, manual decay correction calculations are time-consuming and error-prone — a misplaced decimal point or incorrect half-life can result in a patient receiving half the prescribed dose or twice the prescribed dose. The automated system eliminates this risk. The decay correction feature also saves time, reducing dose preparation time by 5–10 minutes per patient. For therapy centers that treat multiple patients per week, this time saving is significant. The Dose Calibrator with Decay Correction transforms therapy dose preparation from a complex calculation-intensive process into a simple, guided procedure.