Radiopharmacist's Notes · Vexcal AV03
Three tiers of dose-calibrator QA —daily, monthly, annual.
The radiopharmacist owns the daily constancy. The physicist owns the monthly linearity and the annual NIST-traceable accuracy review. Three columns — what each tier does, who does it, and where the result lands in the AERB inspection dossier.
Three lanes of the dose-calibrator QA programme
Daily constancy on the left, monthly linearity / drift check in the middle, annual NIST-traceable accuracy on the right.
Daily — radiopharmacist (before morning list)
- Power the calibrator and let the chamber warm up (typically 15–30 min)
- Insert the long-lived constancy source (Co-57 or Cs-137) at the standard geometry
- Acquire the constancy reading; compare to the expected decay-corrected activity
- Action: pass if within ±5 % of expected; out-of-tolerance triggers re-measurement and SOP escalation
- Log the reading in the daily QA register; source returned to its shielded holder
Source: AERB Safety Code for Nuclear Medicine Facility; site SOP.
Monthly — physicist / RSO
- Linearity test across the clinical activity range — Tc-99m decay method or shielded-attenuator method
- Check geometry-correction factors against the standard reference vial / syringe
- Inspect QA log for daily-constancy trend across the month
- Action: drift toward ±5 % limit triggers source-side check (decay correction) and instrument-side check (electronics, chamber)
- Sign-off entered in the monthly QA register; flagged drift escalates to vendor service
Source: AAPM TG-181 / TG-211 PET-NM QA guidance; AERB Safety Code.
Annual — physicist (full accuracy test)
- NIST-traceable accuracy test against the full QA reference-source set (Co-57, Co-60, Cs-137, Ba-133)
- Reading must match each source certificate within ±10 % (typical action threshold)
- Energy-response check across the clinical photon-energy span
- Full QA report compiled — daily constancy trend, monthly linearity, annual accuracy
- Report archived for the AERB facility inspection dossier and NABH / JCI accreditation file
Source: AERB Safety Code for Nuclear Medicine Facility; NIST-traceable QA reference sources.
Scope of this page
The cadence and action thresholds above align with AERB Safety Code expectations and AAPM TG-181 / TG-211 guidance. Exact site SOP — who signs off, what the action register looks like, the recovery path after an out-of-tolerance reading — should be authored against the site's QA programme document, not adopted verbatim from this page.
Sources cited on this page
- Atomic Energy Regulatory Board (India). Safety Code for Nuclear Medicine Facility. AERB PDF ↗
- American Association of Physicists in Medicine. AAPM TG-181 / TG-211 PET-NM QA guidance.