Minutes of the 9th Radionuclide Calibrator Users' Forum (RCUF) John Himsworth Sheffield Teaching Hospitals NHSFT john.himsworth@sth.nhs.uk Mira Moran Royal Berkshire Hospital mira.moran@royalberkshire.nhs.uk William Hallett Imanova Ltd william.hallett@imanova.co.uk Alex Smout Royal Surrey County Hospital a.smout@nhs.net Sophie Wiltshire Gloucestershire Hospitals NHS Foundation Trust Sophie.wiltshire@glos.nhs.uk Matthew Talboys Cardiff and Vale ULHB matthew.talboys@wales.nhs.uk Nicholas Vennart University of Hartlepool Hospital nicholas.vennart@nth.nhs.uk Eva Kint AIB-VINCOTTE CONTROLATOM VZW nloos@vincotte.be Tom Meylaers AIB-VINCOTTE CONTROLATOM VZW nloos@vincotte.be Peter O'Sullivan Maidstone and Tunbridge Wells NHS Trust peter.osullivan@nhs.net Annie Olsson Karolinska University hospital Huddinge annie.olsson@karolinska.se Liviu-Cristian Mihailescu SCK-CEN - lmihaile@sckcen.be Emily Joel Barts Health NHS Trust emily.joel@bartshealth.nhs.uk Nadia Nazir Mount Vernon Hospital nadia.nazir@nhs.net Stephen Dainty UHNS s.dainty@me.com Christopher Green Kent & Canterbury Hospital c.green777@btinternet.com Janelle Reyes-Goddard Gloucestershire Hospitals janelle.reyes-goddard@glos.nhs.uk Robert Geake Charring Cross Hospital ROBERT.GEAKE@IMPERIAL.NHS.UK Zacharias Chalampalakis Royal Berkshire Hospital zacharias.chalampalakis@royalberkshire.nhs.uk Peter Crawley Maidstone Hospital peter.crawley@nhs.net Fred Wickham Royal Free London NHS Foundation Trust Caspar.Wickham@nhs.net Emma O'Shaughnessy Poole Hospital NHS Foundation Trust emma.o'shaughnessy@poole.nhs.uk Natalie Bebbington University Hospitals Birmingham Natalie.Bebbington@uhb.nhs.uk Dominic Rushforth The Royal Marsden NHS trust dominic.rushforth@rmh.nhs.uk James Solomon Colchester Hospital University NHS Foundation Trust kimberley.white-overton@colchesterhospital.nhs.uk Paul Hinton Royal Surrey County Hospital paul.hinton@nhs.net Glenn Woolley Royal Free London NHS Foundation Trust glenn.woolley@nhs.net Nafisa Khan Royal Berkshire Hospital nafisa.ajmal@royalberkshirehospital.nhs.uk Helen Davison Royal United Hospital, Bath (NHS) hdavison2@nhs.net Emma Wroe Brighton and Sussex University Hospitals NHS Trust emma.wroe@bsuh.nhs.uk Mike Avison Bradford Royal Infirmary mike.avison@bthft.nhs.uk Chris Nottage Colchester General Hospital chris.nottage@colchesterhospital.nhs.uk Andrew Fenwick National Physical Laboratory andrew.fenwick@npl.co.uk Kelley Ferreira National Physical Laboratory kelley.ferreira@npl.co.uk John Keightley National Physical Laboratory john.keightley@npl.co.uk Geoff Smith National Physical Laboratory geoff.smith@npl.co.uk Samuel Davis Royal Surrey County Hospital spxdavis@gmail.com Sheila MacMahon British Columbia Cancer Agency smacmahon@bccancer.bc.ca Jill Merrett National Physical Laboratory jill.merrett@npl.co.uk Gregory James City Hospital, Birmingham gregory.james@nhs.net Anton Paramithas St. George's Hospital anton.paramithas@stgeorges.nhs.uk 1
Chairman's Welcome and Introduction The Chairman, Andrew Fenwick, NPL, welcomed the delegates to the ninth meeting and summarised the Terms of Reference for the RCUF which remained unchanged. The Agenda was introduced. Presentations: Report on Action Items from 2012 RCUF meeting, Kelley Ferreira, NPL The progress on the actions from the eighth RCUF meeting was presented by Kelley Ferreira, NPL. NPL s progress on the feasibility of an alternative 18 F calibration method using the 68 Ge/ 68 Ga mock syringe source was highlighted. 75 Se-Capsule measurement actions were outlined with further work in dissolving the capsules discussed. The 2nd Radionuclide Calibrator Training Course (RCTC) took place on 27 February 2014 and included a practical session which received a mixed response from participants. This will be refined in future however overall the feedback from the course was very positive. There was mention of the ongoing review of Good Practice Guide 93 (GPG93) and the aims outlined. It was suggested to discuss future comparison exercises during the discussion session later on in the meeting. It was highlighted that up-to-date calibration factors were available along with NPL recommended half-lives and on the NPL website at www.npl.co.uk/fidelis. The outstanding actions were proposed for inclusion in the discussion session. Medical community to continue submitting proposals to NPL for future projects supporting Nuclear Medicine to: radioactivity@npl.co.uk. The practical session in the RCTC will be reviewed along with the option of providing factors for dissolved 75 Se-Capsules. The Absolute Standardisation of 223 Ra by 4π(LS)-γ Coincidence Counting, John Keightley, NPL John Keightley gave an introduction to primary standards, traceability and 4π(LS)-γ coincidence counting along with the application of these methods to the standardisation of 223 Ra. Results were presented and how the results will be used for factors was discussed. Multiple dimensional extrapolations were talked through and an estimated activity concentration given. It was noted that factors will be published for Fidelis and Capintec calibrators within the next few months. Fred Wickham raised the question of whether 223 Ra factors that will be published for commercial calibrators such as Capintec's will vary between calibrators, and how this could be checked. It was pointed out that the factors should be OK due to the way Capintec s are produced, but that a calibration should be carried out at some point to confirm factors in use. Primary Standardisation and IC calibration: Thorium-227, Andy Pearce, NPL Andy Pearce gave an overview of the steps taken in the standardisation and Ion Chamber calibration of 227 Th as the decay parent of 223 Ra. The reasons for the standardisation were outlined along with the complications of getting time dependant calibration factors and the radiochemical steps required for separation. It was mentioned that some results were still being processed 2
although provisional results were given. Attention was given to the attempt to find the effective zerotime from different methods and the summary of progress to date. It was mentioned that the Ion Chamber analysis was waiting on finalised primary standard results. The question was raised that if 227 Th was in clinical use whether clinicians would be responsible for finding the zero time and how the separation would be conducted. Various solutions were suggested and problems raised, including the sticking problems associated with 223 Ra. It was mentioned that NPL will liaise with ALGETA as what is the best way to proceed. Action: NPL to liaise with ALGETA to decide on best way to proceed in regards to working out the zero time for clinical use of 227 Th. Measuring I-123 using a copper filter, Nicholas Vennart, University of Hartlepool Hospital A discussion of the troubles experienced by Hartlepool Hospital in measuring 123 I in a copper filter presented by Nicholas Vennart. An explanation of a difference between different vials when measuring in a copper filter was outlined and it was made clear that there were no problems with other radionuclides. Discussion: A few delegates suggested the use of different calibration figures for different vials. It was suggested that the differences could be explained by sticking and in addition it was mentioned that a paper written by Bill Thomson on Copper filters was available. Progress on Metrology for Molecular Radiotherapy Metro-MRT, Lena Johansson, NPL Lena Johansson gave an overview of the work packages involved in this MetroMRT European collaborative project. Proposals to improve the accuracy of activity measurements for molecular radiotherapy included development of TDCR-Čerenkov detection and an update of the progress of Quantitative Imaging for Molecular Radiotherapy (MRT), including the calibration of SPECT cameras using the Jaszczak phantom and the significance of correction factors applied in SPECT reconstruction. Lena also identified the next steps in the calibration measurements with Lu-177 and the review of a draft calibration procedure written by NPL. It was highlighted that further information can be obtained from the website http://projects.npl.co.uk/metromrt/. A few medical physicists raised queries on what was to happen after 2015 and the problem of the large scope and broad range of the application of the project. Andrew Fenwick pointed out that this project is just the beginning and could not hope to solve all the problems in one go but the hope is that future work will develop from this project including the next phase of European funding known as EMPIR. Emma O Shaughnessy, secretary of the Nuclear Medicine Software Quality Group (NMSQG) mentioned that they have a website comparison chart for the effects of different filters used in different software programmes and that NPL can contact her in regards to software for Quantitative Imaging. NPL raised the query of whether there is a need for PET calibration and the consensus was yes. Problems associated with the dumbing down of PET calibration curves and the difficulty of writing protocols for this were raised. It was mentioned that NCRI are a certified laboratory for uploading images in PET and a similar laboratory is needed for SPECT, it was suggested that NPL could do this in the future. It was mentioned that NPL should get in contact with 3
NCRI (Lucy Pike) as they have a recommended approach to PET scanners. There was also a consensus that a phantom library, possibly held by NPL, would be of interest. Action: NPL to work on a proposal for what to do after 2015 and NPL will also contact NMSQG. Annual Linearity, Alex Smout, Royal Surrey County Hospital Alex Smout, Royal Surrey County Hospital, presented a review of the GPG93 methodology of annual linearity checks along with suggestions for new methods of linearity checks. Problems of the GPG93 methodology were highlighted and a new method using automatic logging was suggested. The problem of linearity checks that were conducted over range changes was highlighted. Further issues were discussed and two solutions were presented. A comparison of the four different types of linearity checks were presented and discussed. Further questions were thrown to the group, including a query about data logging for different types of calibrators. Further discussions took place about the various techniques used to conduct annual linearity checks along with the reaction of different calibrators to range changes. The existence of data logging software for various types of calibrator was confirmed by Anton Paramithas among others. It was agreed that data logging software would be shared between various parties. Range Change Errors on Capintec CRC-15R and CRC-25R Dose Calibrators, John Himsworth Sheffield Teaching Hospital John Himsworth from Sheffield Teaching Hospital, presented a discussion of errors associated at range change level associated with Capintec calibrators. Further investigation into the range change errors presented was shown and further testing of these errors for 111 In presented. The cause of errors was outlined succinctly and conclusions drawn. Discussion: A discussion of different range changes, when these occur and for what nuclides and activities followed. 90 Y Filters, Chris Nottage, Colchester University Hospital Chris Nottage from Colchester University Hospital presented the difficulties of 90 Y calibrations on the Fidelis and the use of plastic filters. Copper filters were compared to plastic filters and the difficulties of making a solid plastic filter using a 3D printer was presented along with differences in response of the calibrator for different colours of filter. Discussion: It was suggested that to solve the problem of the filters not being solid the inner part could be filled with a substance such as water or wax. Further discussion took place of how best to check accuracy of calibrations for 90 Y and the possible use of beta counters. 4
Open discussions session 75 Se General discussions about 75 Se revealed that not many participants had measured this nuclide even though it was pointed out that the capsule could be measured on Capintec calibrators. The discussions revealed that it was not worth dissolving the 75 Se capsule to obtain calibration factors as there would be no need to change factors due to high background and small number of decimal places (the measurements would only be made to check for an order of magnitude mistake). This is despite the suggestion that the reading from a Capintec was stable enough to take a measurement and give confidence when giving the radionuclide to patients. While the general consensus agreed that accuracy was important it was suggested that the factors were not of great clinical concern, therefore there would not be a need to calculate them however it is likely NPL will perform the work anyway for completeness. Colloidal 90 Y It was explained that NPL cannot standardise colloidal 90 Y as it not homogenous, and pointed out that there was a 25% difference between colloidal and liquid sources in the same vial following preliminary attempts to homogenise the solution. The general consensus was that many measurements in hospitals are conducted by simply shaking the colloids and measuring immediately after. However there was an agreement that further work needs to be done and it would be beneficial if NPL offered a colloidal calibration service. NPL will look into providing a colloidal calibration service and deriving factors for the Fidelis and commercial calibrators. Review of GPG93 A review of the usefulness and the content of the GPG93 took place. It was pointed out that it is slightly out of date and various issues were raised including the GPG93 making no addressing of PET and whether the problem of hysteresis is still present. The consensus was that it could be made more user friendly with examples that were generic as opposed to examples that worked specifically for NPL measurements. NPL to talk to Daniel McGowan about raw data for hysteresis. Proposals for future NPL NMO programme - Comparison between NPL and cyclotrons for 18 F The participants expressed their interest in an 18 F comparison between NPL and cyclotrons. The details of how best to achieve this were discussed and participants suggested contacting Lucy Pike or Rosemary Morton (Rosemary.Morton@uhns.nhs.uk) would be beneficial. It was also suggested that NPL contact the MHRA (contacts on the website) to find information about the legal requirements for cyclotrons to follow such a comparison. Andrew Fenwick also mentioned that he may bring up the matter with the IPEM Nuclear Medicine Special Interest Group. NPL to look into the feasibility of starting a comparison with cyclotrons and to contact the relevant people. 5
- Protocol for calibration using the 68 Ge syringe It was mentioned that it would be useful for NPL to work out how to interpret well counter measurements for 68 Ge. The fact that NPL have no well counter was brought up but that NPL would look at the relative differences between each calibrator used. Comparison Exercises in the next 10 years A discussion was opened to find out what the participants thought about which nuclides would be best to conduct comparison exercises on the next ten years. 68 Ga was mentioned as a problem nuclide as it was difficult to measure, due to the 68 Ge breakthrough issue. Other nuclides that were mentioned were 223 Ra, 123 I, 131 I (Capsules), 32 P, 111 In (with/without Copper filters), 51 Cr and 99m Tc. It was mentioned that the 99m Tc comparison would be easily conducted simply by collecting data. A new method by which calibrations would be conducted was proposed that involved obtaining an estimate of the activity from the participants before sending certificates out in order to create a database of values. It was made clear that the results would be kept completely confidential. NPL to implement this database method in the near future with a view to create an annual report and present the results at subsequent RCUF meetings. Grouping of Calibrations within a few months of the year The suggestion that NPL would limit the radionuclide calibration service it offers to set calibration periods throughout the year was discussed. No participants raised any complaints however it was mentioned that the change should be very well advertised and the suggestion was made that calibration periods should be taken place twice annually with sessions in Autumn and Spring (rather than at the start and end of the year). NPL, although still undecided on this, will look into the possibility of grouping calibrations and will communicate decisions back to users. Frequency of RCUF and format of RCTC Whether to make the RCTC an annual event was discussed. The general consensus was that more notice was needed for each RCTC and that making it an annual event was a positive move. Various issues were brought to light, including the uncertainty of university courses (with respect to the ability of participants to attend) and therefore the difficulty in potentially making it a part of university courses. It was generally agreed that specific Universities would need to be contacted to find this information as each university is different. The format of the RCTC practical session was discussed with a split in consensus of whether to keep the practical nature or to just give some data to participants to allow more time for analysis. The option of using linearity data was raised. However it was mentioned that it would be interesting to see a range of calibrators. Another suggestion was made to give worked examples with answers for participants to take away with them. John Keightley suggested that the next RCUF meeting be after the ICRM Life sciences working group, of which the consensus was positive. 6
A few participants asked if the actual agenda of the meeting could be circulated along with email addresses. NPL has uploaded the actual agenda to the RCUF website and has included the email addresses of those present at the beginning of these minutes. AOB The group was asked if there were any further topics for discussion and none were presented. The Chairman thanked the delegates for attending and closed the meeting 7