Held at the Christie Hospital, Manchester, on 15 November 2005

Attendees:	Simon Jerome		NPL (Chairman)
	Dagmara Tyler		NPL (Secretary)
	Janis Brown		Mount Vernon Hospital
	Rital Coleman		Southern Scientific Ltd
	Piers de Lavison		NPL
	Ken Frost		Southern Scientific Ltd
	Richard Gadd		University Hospital of North Staffordshire
	Andrew Harris		Sheffield Teaching Hospitals NHS Foundation Trust
	Sue Hooper		Velindre NHS Trust
	Ian Hufton		Royal Liverpool University Hospital
	Dudley Ibbett		Derbyshire Royal Infirmiary
	Steve Jeans		Christie Hospital NHS Trust
	Julian MacDonald		Glan Clwyd Hospital
	Christ Nottage		Essex Rivers Healthcare
	Lorna Patrick		Pharmaceutical Profiles Ltd
	Jacqueline Roberts		Leeds General Infirmiary
	William Thomson		City Hospital NHS Trust, Birmingham
	Farnoosh Zananiri		Bristol General Hospital
	Jill Tipping		Christie Hospital NHS Trust
	Angharad Williams		Glan Clwyd Hospital

Welcome

Simon Jerome (NPL) welcomed the delegates to the third meeting of the RCUF. He gave a brief summary of the terms of reference and what the forum hopes to address.

Matters rising:

• Performance ß chambers - no progress has been made on this.
• ¹⁹²Ir and ¹²⁵I seeds and syringe calibration factors have been placed on the NPL website, via their relevant publications. R-schott factors to be added soon.

Publications available

Each delegate gave a short introduction about themselves at the meeting.

Protocol for establishing and maintaining the calibration of medical radionuclide calibrators and their quality control
- a detailed run-through

Some of the main changes:

Chapter 1

• Measurements that require the source to be taken out between measurements is now known as reproducibility and not precision
• If the source is left in the chamber between measurements, this is now known as repeatability
• Accuracy needs to be checked annually with two reference sources (traceable to NPL).
• If applicable, the reference nuclides should be varied each year If different volumes or containers are being used then subsidiary calibrations need to be carried out. Care needs to be taken when doing this and the uncertainties for low energy sources and ß emitters will be high
• When checking any variations from standard measurements, the source needs to be taken out of the chamber between measurements

Chapter 2

• It is important to both quantify and minimise uncertainties
• Estimation of uncertainty - The international agreement on uncertainty evaluation is based on 'GUM' but this is translated into a UKAS document M3003, 'The Expression of Uncertainty and Confidence in Measurements'. A more readable guide is the NPL publication GPG 11, 'The Beginners Guide to Uncertainty'.
• Uncertainties on calibration certificates are made up of 4 stages:
  Step 1 - identify all components and estimate value at 1σ
  Step 2 - provide standard uncertainty for each component by use of the sensitivity co-efficient
  Step 3 - combine in quadrature
  Step 4 - expand the uncertainty (k=2)

A short discussion followed regarding some of the points above. A question was raised about the time scale between measurements when taking the source out of the chamber. Richard stated that this is usually a small time scale but it does depend on the radionuclide being measured. A draft of the GPG will not be available for consultation.

View Richard Gadd's presentation

Presentations

NPL Calibration Service

Simon Jerome initially asked for feedback regarding the calibration service from the audience. The main issues raised were the long waiting times for certificates and problems with booking ahead.
Simon then gave his presentation in which he addressed the issues raised. He then asked if it would be acceptable to the hospitals to have specific periods each year where NPL would carry out calibrations. After several questions regarding the administration issues and the timing of the calibrations, it was suggested that maybe a trial should be run to test the system. Concerns were raised about the timing and that it may not be convenient for all hospitals. Would calibrations be available outside these set periods? Simon stated that NPL would do its best to accommodate such calibrations but on a one off basis. No firm decisions were made on this topic. It was suggested that NPL could run a 'premium service' including arranging all the transport etc but Simon said that this was not possible.

View Simon Jerome's presentation

^99mTc Comparison -"From primary standards to hospitals"

Lena Johansson (NPL) gave a presentation giving the overview of carrying out a primary standardisation using ^99mTc.

View Lena Johansson's presentation

^99mTc Calibration Service

Simon Jerome (NPL) outlined the plans for NPL running a free ^99mTc calibration service, this would be run in two parts.

A discussion ensued regarding the details of the comparison and whether 'free' included the transport costs. It was suggested that as many as 300 hospitals may be interested if the service is completely free, so a token cost should be considered in the region of £100 - £200. Participants should be told that participation in both parts of the exercise is mandatory. A question was raised asking whether this exercise could be linked to the publication of the GPG but Simon replied that is was unlikely to be possible.

View Simon Jerome's presentation

Internet Metrology

Piers De Lavison (NPL) gave a presentation about the future possibility of 'over the internet calibrations'.

This led to a lengthy discussion regarding the question of liability. If a mistake is made by NPL and a patient receives the wrong amount of a radiopharmaceutical the hospital physicist is liable. NPL to look into the legal issues but Piers re-enforced the fact that nothing would be done without lengthy consultation with the hospitals. The discussion then turned to the issue of the new electrometer for radiocalibrators. Ken Frost (Southern Scientific) told the meeting that the secondary standard electrometer was ready and the tertiary one is imminent. The cost of the up-grade is likely to be ~£400 for tertiary radionuclide calibrators.

View Piers De Lavison's presentation

Any Other Business

Simon Jerome (NPL) stated that NPL has funding to carry out two more standardisations on radionuclides of interest to the nuclear medicine community. For suggestions please contact simon.jerome@npl.co.uk

View Simon Jerome's presentation

The meeting was drawn to a close and the delegates were invited on a tour of the Molecular Imaging Centre.

Dagmara Tyler

RCUF Secretary
Radioactivity and Neutron Group
National Physical Laboratory