Knowledge Hub · Vexcal AV03 Dose Calibrator
Every nuclear-medicine patient dose passes through a dose calibrator before injection. The calibrator is the QA anchor — the reading defines whether the dispensed activity is within prescription tolerance. AERB and AAPM TG-181 frame the QA programme that wraps around the instrument, including the requirement that calibration factors are set per isotope and per source geometry rather than assumed from a manufacturer table.
Why this matters
What it does
A dose calibrator is a pressurised ionisation chamber with electronics that convert the chamber current into an activity reading. Every patient dose drawn in the hot lab passes through it before injection — the calibrator confirms the prescribed activity within tolerance.
Based on: AERB Safety Code for Nuclear Medicine Facility; AAPM TG-181 Quality Assurance for PET Imaging.
Read source ↗Daily, monthly, annual
AERB and AAPM TG-181 expect a stratified QA programme: daily constancy with a long-lived source, monthly linearity, annual accuracy against NIST-traceable references. The Vexcal stores the QA log internally; the radiation-safety officer reviews the trend at month-end and at the annual inspection.
Based on: AERB Safety Code for Nuclear Medicine Facility; AAPM TG-181 Quality Assurance for PET Imaging.
Read source ↗Isotope + geometry
The chamber response per unit of activity depends on the radionuclide **and** on the source geometry — the same Lu-177 activity in a 10 mL P6 vial reads differently from a 3 mL syringe or a tungsten dose pot. The Vexcal does not ship with pre-programmed factors, because an assumed factor would silently produce wrong patient-dose readings whenever the container changed. Instead, the operator establishes a factor per isotope-geometry combination against a NIST-traceable reference of known activity in the same container that will be used clinically — and stores it.
Based on: AAPM TG-181 dose-calibrator QA guidance; AERB Safety Code geometry-factor expectations.
Read source ↗AERB compliance
AERB Safety Code for Nuclear Medicine Facility defines the dose-calibrator QA expectations — daily constancy, monthly linearity, annual accuracy and geometry-specific calibration factors. The Vexcal supports the full workflow with a documented record that satisfies the AERB inspection officer.
Based on: AERB Safety Code for Nuclear Medicine Facility.
Read source ↗Vexcal AV03 at a glance
Ion chamber
Pressurised well-type
Diagnostic + therapeutic
5 sec
Measurement
Fast morning-list throughput
Per-geometry
Calibration factors
Set against NIST-traceable refs
AERB
Compliant
Indian regulatory path
Scope of this page
The dose calibrator is the instrument; the QA programme is the radiopharmacy's. Daily constancy with a long-lived source, monthly linearity testing, annual NIST-traceable accuracy testing — the programme defines the cadence, the action thresholds and the trending log. The instrument supplies the measurement and the audit-trail record.
The AERB Safety Code that frames the dose-calibrator QA programme in India.
Where next