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

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.

Knowledge Hub →

Activity measurement in plain English

AERB framing; three-tier QA cadence; why calibration factors are isotope **and** geometry specific.

Product page →

Specs and AERB documentation

Pressurised ionisation chamber, operator-set isotope + geometry factors, AERB import path.