When medical physicists wore white coats

NHS

Dr Edwin Aird shares his memories of the revolution he has experienced working in the medical physics department.

 

Edwin Aird portrait

While I was an undergraduate at Newcastle University (1962), the 2nd year honours group was invited to visit the Medical Physics Department at Newcastle General Hospital. I was so impressed with the department and the range of things they were doing and the application of physics to medicine that I wrote to Professor Frank Farmer (Head of Department at that time) to ask about working there. He responded with a proposal that I apply for a special research grant that he was hoping for locally and that I write again after my graduation.

The following year I got in touch with Frank Farmer again and was accepted on an MSc grant to study “In-homogeneities in Radiotherapy”; one year in the first instance (on a grant of about £700).

Meeting 1970 1

I can’t now remember my first day exactly; not sure what office I had, but I do remember the Professor’s insistence on donning a white coat (provided and laundered by the hospital) when arriving at work, This ‘uniform’ was thought to be a vital sign to patients that physicists were part of the ‘clinical’ team.

I divided my time in that first year between research and clinical work (interestingly, this was part of the philosophy of some of the early physicists, many of whom in the 1930s and 40s had transferred from academic physics, including Frank Farmer); the situation now couldn’t be more different.

Fig 1

Image 1 The gantry mounted linear accelerator at Newcastle General Hospital [ref 2]

So, on the routine side, I began to learn about radiotherapy: its planning and treatment. Newcastle at that time had two cobalt machines (Mobaltron-60s) and two linear accelerators as well as two Marconi 250kV sets and a Philips SXT (Superficial X-rays). This latter set I used extensively a little later in my career to optimise the characteristics of the Farmer chamber (image 1).

The main linear accelerator was manufactured by Mullard (a branch of Philips), which Frank Farmer had installed as the first gantry-mounted 4MV linac (image 2). There were a few stories about the installation of this linac. In particular I remember this: the team had reached the point where they needed to produce X-rays so needed a high atomic number transmission target. Someone found a sovereign, but forgot the amount of heat produced when the high energy electrons hit it. The sovereign promptly melted and fell out of the linac head. (This linac went on to perform 25 years’ service).

Fig 2

Fig 2 Newcastle Simulator (Frank Farmer at Controls) [ref 3]

For those physicists who find quality assurance (QA) on linear accelerators today a huge burden, my recollection of the checks we performed on this linac amounted to: dose measurements and field size checks. There was little attempt to measure flatness since the accelerated electron beam wasn’t bent before striking the target, so no perturbations in intensity across the field were expected.

 

 

Fig 3

Fig 3 A Head and Neck Xeroradiograph showing potential. Treatment volume [ref 3]

 

Treatment planning was done by hand, often mainly using % depth dose, but also with some isodose curves for more complex plans on tracing paper; on to an outline of the patient performed using lead wire and other devices, e.g. callipers. Newcastle was unique in having developed a home-made simulator (using a radiotherapy SXT unit mounted on a gantry (image 2) that allowed an image to be viewed on a Xerox plate immediately without the need for film development (ref 3, see also image 3).

The first computer in the department, which was to revolutionise treatment planning, came to Newcastle in the early 1970s and was called a PDP 8, the ‘Rad8 system’ developed by Bentley and Milan. (image 4 [ref 4]).

Radium tubes and needles were still extensively used at this time for intracavitary and interstitial brachytherapy. I was also required to calculate the dwell times for gynae radium insertions (using ovoids and central vaginal sources with a modified Manchester system for the gynae and radium needles, mainly in back of tongue with radiographs and Paterson Parker tables). Following the calculation of the radium dwell times I would then go up to the ward to discuss the removal times, for each patient, with sister on the ward. Amazing now to think how much radioactivity (up to 105mg – equivalent to approximately 389 MBq-or more) for gynae insertions was handled by several different groups of staff at that time.

In those early years I also learnt the elements of radiation protection and nuclear medicine. Radiation Protection (guided by a ‘Code of Practice’; an excellent document that was used to help write the ‘Guidance Note’ now used under Ionising radiation Legislation) was regionally organised. Very early in my career (there were only two of us to perform the external radiation work: myself and MJ Day), I found myself organising visits within Northumberland, Cumbria and parts of Durham. (See The Regional Centre below). These were more as inspections than to make many measurements (not the very extensive QA that is performed now, although we did use film or image intensification – only recently developed – to look for faults in lead aprons; and we measured exposure levels in and out of beam with the ‘37D’ (Pitman) dosemeter (originally developed by Sidney Osborne as an excellent versatile instrument for exposure measurements ref 5). I learnt a pattern of inspection of barriers, filtration, lead aprons etc. very quickly. [In the early 1970s the NRPB decided to do their own inspections and were surprised to find that, because the HPA had organised things so well there was little need for NRPB to get too heavily involved].

My memories of nuclear medicine: incredibly slow rectilinear scanners, prior to the commercial development of gamma cameras; kidney function (renogram) using two ‘D’-shaped detectors (scintillation) with manual optimisation of their positions connected to count rate meters and chart recorders.

The regional centre

I’m not sure how many hospitals this covered in my early days in Northumberland, Tyneside, Durham and Cumbria. I know when Keith Boddy implemented Frank Farmer’s plan to have a small physics department (where gamma cameras were installed in district general hospitals) there were thirteen hospitals with physics departments in the region. Prior to this – from about my 3rd year at Newcastle – I was delegated to look after the small centre in Carlisle where there were two Marconi 250kV sets, an SXT and some iodine treatment. In the 1950s this had been the job of Jack Fowler who used some of his time to study arc therapy on 250kV (see ref 6).

Rad 2014 photo

Edwin Aird (right) receiving the BIR Sylvanus Thompson Award from Andy Beavis

In those early years I also found time to help develop differential X-ray absorptiometry to measure antimony in the local Tyneside Antimony workers’ lungs (organised by the Newcastle University Department of Industrial Health). I was also able to build on this experience to develop my own equipment, using characteristic X-rays, to measure bone mineral in the femur. This clinical work allowed me to meet a new set of clinicians (other than radiotherapists – as Clinical Oncologists were then called – and radiologists) involved with bone loss in patients: kidney specialists, endocrinologists and geriatricians. Commercial equipment has since been developed to perform bone mineral and body composition measurements (GE Lunar, Hologic, and Norland).


References:

  1. Aird EGA and Farmer FT. The design of a thimble chamber for the Farmer dosemeter. Phys Med Biol 1972 17: 169–174. https://doi.org/10.1088/0031-9155/17/2/001
  2. Day MJ and Farmer FT. The 4 MeV Linear Accelerator at Newcastle upon Tyne. Br J Radiol 1958; 31: 669–682. https://doi.org/10.1259/0007-1285-31-372-669
  3. Farmer FT, Fowler JF and Haggith JW. Megavoltage Treatment Planning and the Use of Xeroradiography. Br J Radiol 1963; 36: 426–435. https://doi.org/10.1259/0007-1285-36-426-426
  4. Bentley RE and Milan J. An interactive digital computer system for radiotherapy treatment planning. Br J Radiol 1971; 44: 826–833. https://doi.org/10.1259/0007-1285-44-527-826
  5. Osborn SB and Borrows RG. An Ionization Chamber for Diagnostic X-Radiation. Med.Biol1958; 3: 37–43. https://doi.org/10.1088/0031-9155/3/1/305
  6. Fowler JF and Farmer FT. Measured Dose Distributions in Arc and Rotation Therapy: A Critical Comparison of Moving and Fixed Field Techniques. Br J Radiol 1957; 30: 653–659. https://doi.org/10.1259/0007-1285-30-360-653

About Dr Edwin Aird

Edwin Aird was Head of Physics at Mount Vernon Hospital from 1988-2012 and Head of Radiotherapy Physics at St Bartholomew’s Hospital from 1985-1988. He was Head of Radiotherapy Physics at Newcastle General Hospital from 1980-1985. He is an IPEM Chief Examiner 1994-1997 (Physics Training Scheme), FRCR (RT) Examiner 1989-1993, Radiotherapy Degree (External Examiner (Liverpool University): 1993-1996. He is a IAEA: Qualified Expert: 1999-2005 and an LH Gray Trustee: 1999-2003.

He was awarded the BIR Roentgen Prize in 2005 and delivered the Silvanus Thompson: Award and Eponymous Lecture 2013.

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From darkroom to digital: Tracing the transformation of Radiography

NHS

Stewart Whitley reflects on how technology has revolutionised radiographic imaging. 

 

Since the launch of RAD Magazine back in 1975, radiographic imaging as we know it has changed dramatically, far beyond the concept of what anyone could have imagined at that time. And just as smart mobile phone technology has revolutionised how we communicate, so too has the emergence of digital imaging technology transformed the X-ray department while at the same time providing both regional and national connectivity.

Fig 1

Figure 1: At work in the chest room at New Ealing Hospital, London. From RAD Magazine, July 1979

A few of us will remember with fondness those ‘bygone days’ when the darkroom was a hive of activity and was central to all that happened in the X-ray department; all permanent images, and for that matter, reporting was dependent on film/screen technology and film processing chemistry. Back then there was the gradual but necessary progression from manual processing, with those famous drying cabinets, to the first automatic dryers and then the emergence of automatic processing which was the first step in revolutionising film processing and the eventual demise of the darkroom. Even though those wonderful automatic film processors could eventually process film in 90 seconds, a great deal of care and attention was still necessary to keep rollers, processing tanks and processing chemicals in tip-top condition. And what department was without a silver recovery system to generate income? Then everything changed dramatically overnight with the introduction of daylight processing. Different manufacturers had different solutions but the overall effect was to transform the X-ray department and free up the darkroom technician, many of whom became X-ray helpers – the forerunners to the modern image support worker (figure 1). While image acquisition using modern film/screen technology progressed steadily with the introduction of more efficient and higher quality image systems, the focus was on radiation dose reduction, with X-ray manufacturers offering a range of general X-ray and fluoroscopic systems which provided welcome features to reduce patient and staff dose.

Fig 2

Figure 2: Radiologists and radiographers attending a preview of Agfa Gevaert’s daylight processing system in London. From RAD Magazine, March 1977

Older X-ray systems were powered with what would be considered today outdated X-ray generator technology and X-ray tube design, with corresponding limitations on short exposure times and geometric sharpness. Thanks howeverto consistent research and development in generator technology and X-ray tube design, the problem of high tube output and short exposure times with associated production of inherent high heat was resolved. This facilitated multiple exposure equipment for cardiovascular imaging and general angiography with their inherent demands for high quality sharp images at low radiation doses. Such changes have enabled the acquisition of motion-free images of the vascular tree, coronary vessels and heart anatomy, giving spectacular images of cardiac function and anatomy. The X-ray generator control desk is now hardly recognisable from those found in departments back in 1975 – some still had voltage compensation controls and meters for you to manipulate before you started the day (figure 2).

Gone are those massive exposure control dials for individual control of Kv, Ma and time. Such control desks were large and floor standing, unlike modern small desks which rest on a bench or can be wall mounted and synchronised to the X-ray tube housing/light beam display unit. For exposure factor selection, we are no longer confined to manual selection, thanks to the development of anatomical programming selection combined with the introduction of automatic exposure control – something that we take for granted nowadays – but its use still requires skill and knowledge of the location and use of the relevant ionizing chambers to select the most appropriate exposure conditions. Used correctly, image quality will be consistent with the optimum use of radiation dose. The design of X-ray tables and ceiling tube suspension systems has been a gradual process, developing from simple solutions to fully integrated motorised units where preprogramming of the location of the X-ray tube/table of a vertical Bucky is linked to the body part selected for examination, requiring less effort from the radiographer in positioning heavy equipment.

Fig 3

Figure 3: Coventry and Warwickshire Hospital’s ceiling-mounted equipment in its new X-ray unit. From RAD Magazine

We now see the control of exposure factor selection built in to the modern X-ray tube housing/light beam diaphragm display unit. This saves a great deal of time and releases more time for patient care, which has been further enhanced with the introduction of rise and fall tables with floating table tops – something which is taken for granted compared to the old days with fixed-height tables and no facility to move the patient other than brute force (figure 3). Overall, the advances in design with improved ergonomics have been complemented with a range of dose information and dose saving features such as the introduction of DAP meters (now a feature of all X-ray systems), additional selectable X-ray tube filtration for paediatric radiography, and the ability to remove grids in the Bucky systems to lower patient dose.

Over the years, changes in standard radiography requests and techniques have emerged which have been driven by the introduction of new technologies and patient pathways. No longer, for instance, are those well-loved isocentric skull units required because basic skull radiography has become a thing of the past and, if necessary, is replaced with the use of CT. As a result, there has been a loss of this skill, but as one modality is lost others like OPG and cone-beam computed tomography (CBCT) have found their way into the X-ray department. Continuing this theme, fluoroscopy procedures such as barium enema and barium meal procedures are no longer in favour, compared to yesteryear when they were undertaken mostly on equipment based on the undercouch X-ray tube design with over-the-table image intensifier. Not only have such fluoroscopy units in the UK diminished in number but they have been replaced with equipment with a more X-ray tube and image detector unit. This is complemented by a range of image selection features such as digital subtraction and road mapping for angiography, as well as a number of exposure and dose control options from the main control console or on a mobile control desk that can be positioned anywhere in the room.

Image 4

Figure 4: Blackpool Victoria Hospital’s Farage Unit equipped with a new Philips C-arm angiography unit with CBCT capability

Such C-arm systems can also support CBCT. This truly is a leap forward in design and capability, with such configurations providing volumetric CT capabilities which in the angiography suite provide the clinician with a 3D orientation of pathology as well as a feature to plan the optimum orientation for positioning a biopsy needle, without damaging vital organs or arteries (figure 4). Undoubtedly, however, the introduction of digital technology has transformed how we acquire images. The development of both computed radiography (CR) and direct digital radiography (DDR) has been fascinating to observe. In the early days of this development, DDR with large detectors was mostly fixed and integrated into the vertical Bucky and table design while CR was based mainly on conventional cassettes, thus giving the radiographer greater flexibility and the ability to undertake examinations in the conventional way. However, all of that has changed with DDR now presented with mobile flat detectors, built-in wi-fi technology, and in different sizes capable of being used in a similar way to film/screen cassette radiography. This has revolutionised the speed in which images are acquired and, with the development of mobile DDR based X-ray systems, its use in high dependency patient care units such as ITU and SCBU is providing the clinician with instant images, thus assisting them to make immediate and important treatment decisions. Overall the X-ray department has been changed forever – what next?

This article was first published in RAD Magazine, 43, 500, 22, 24. Reproduced with permission.


About Stewart Whitley

Stewart Whitley

Stewart undertook his radiography training in the Royal Army Medical Corps qualifying in 1967 at the Royal Herbert Hospital, Woolwich, London.  After serving in the Army he returned to N. Ireland working first at the Lagan Valley Hospital, Lisburn and then at the Royal Victoria Hospital, Belfast where he qualified as a Radiographer Teacher before moving to Altnagelvin Hospital, Londonderry as Deputy Superintendent Radiographer.

In 1978 he was appointed District Radiographer at Blackpool Victoria Hospital where he remained until the autumn of 2006 when he retired from the NHS as Directorate Manager of Radiology and Physiotherapy Services.

Shortly after leaving the NHS he established UK Radiology Advisory Services, a small company dedicated to providing medical imaging advice and support to various NHS and private sector organisations and educational establishments.

Stewart has a passion for Radiography and his professional body, the Society and College of Radiographers, and has served as a Council Member, Honorary Secretary of the N. Ireland Branch of the Society of Radiographers and as a DCR and HDCR Medical Photography examiner as well as serving on a number of SCOR committees.

He lectures on a number of courses and was an Honorary Lecturer and Coordinator for radiographer lecturers on the FRCR course at Manchester University.

Stewart took on the role of ISRRT’s Director of Professional Practice in April 2018

 

The case of the missing fingers!

NHS

Professor Roger Dale remembers how he got his first job in medical physics and how he thought he’d discovered a radiation martyr.

 

Roger Dale circa 1966

Anxiously seeking a job in medical physics on completion of my first degree in 1966 I quickly became aware that basic grade physicist positions in large centres were difficult to find and, for a while, I was unsure what to do. Being out of work I wrote in some desperation to a (very small) radiotherapy centre in Kent pointing out my predicament and asking if I could join as a porter until such time as I could obtain a physicist position in a larger department. To my great surprise I received a phone call a day or two later from the head radiotherapist (Dr B) inviting me along for an informal chat with him, during which it transpired that the hospital had no requirement for any more porters but did have a vacant establishment for a radiotherapy physicist at principal grade! The principal post had already been offered to a gentleman in New Zealand but it would take a month or two before he could take up the position. Therefore, as there was no physicist in post at that time, Dr B suggested that I join as an acting-temporary(!) basic grade until the principal appointee arrived in the UK. Needless to say, I agreed without hesitation.

The necessary paperwork was sorted out remarkably quickly (the old personnel departments always seemed notably more efficient than the burgeoning HR empires which later followed) and my career in medical physics began, albeit rather shakily. My only ‘supervision’ came from occasional conversations with Mr W, the Chief Technician, whose own duties were entirely focused on running the film badge and thyroid uptake services. He was not at all involved on the radiotherapy side of things so I spent many hours buried deep in the standard radiotherapy physics textbooks of the time. That reading reinforced my desire to stay in medical physics because here were the seemingly abstract physical and mathematical concepts encountered during my degree studies being successfully applied to highly relevant clinical issues. Amongst other things I brushed up on the fundamentals of radium dosimetry, this being necessary since Dr B performed several radium implants each week (remote afterloading systems were only just being introduced back then) and, as I was now the sole medical physicist (of sorts) within a 50 mile radius, he required me to be present during the procedures.

Dr B’s theatre sessions were an eye-opener. Apart from a certain squeamishness at witnessing surgery for the first time, I found his implantation technique quite scary since, although a full range of surgical implements and manipulators were at his disposal, he had a habit of giving all the radium needles a push with his fingers. Worse, it was impossible not to notice that several of his fingers were in fact missing! Even a greenhorn like me knew that physically touching radioactive sources was definitely a practice not to be recommended and the fledgling scientist in me began to ponder on cause and effect.

For several days it worried me that Dr B might be paying a very high price in order to pursue his noble vocation and I was unsure how (or if) I should air my concerns, especially as my status as an unsupervised acting-temporary basic grade physicist of just a few weeks’ standing hardly conferred much authority. Eventually I plucked up the courage to speak to the Chief Technician, telling him how convinced I was that Dr B was suffering radiation damage as a direct result of his operating technique. Mr W’s reaction was not quite what I expected. After some snorts of derision at my expense he then took some delight in pointing out that Dr B had been in the RAMC during the war. He had landed on the Normandy beaches where his jeep had hit a mine, and that was how he had lost several of his fingers. Somewhat chastened, I went away to reflect on the fact that my powers of deductive reasoning might be in need of substantial refinement.

Shortly after this awkward conversation the newly-appointed principal physicist arrived from New Zealand and, contrary to all my expectations, Dr B suggested that I stay on for a while longer to gain some first-hand experience working with the new man. This was to be a tremendous bonus as the knowledge and advice I picked up in the weeks following gave me enough of an advantage to successfully apply for a substantive post (i.e. neither acting nor temporary) in a large London centre, after which I never looked back.

Roger Dale recentToday’s NHS is nothing like the one I joined in 1966 and specialised scientist training is much more formalised and incalculably better. No one these days could be appointed in the manner that I had been but Dr B, like most other NHS professionals then and now, was motivated by good intentions and his thoughtfulness over fifty years ago put me on the path to a rich and fulfilling career in medical physics and radiobiology. I discovered later in life that Dr B had told one of his colleagues that he had helped me because he “wanted to give the lad a chance”. What he gave me was a chance that was truly exceptional and this lad has been immensely grateful ever since.


About Professor Roger Dale

Roger Dale retired from his post at Imperial College Healthcare in 2010 following an NHS career spanning 43 years. His main scientific interest has been the development of radiobiological models which can be used to quantitatively assess the biological impact of radiotherapy and other cancer treatment modalities. He is widely published and the clinical significance of his work has been recognised through the award of a number of prestigious scientific prizes and through his  parallel appointment, in 2005, as Professor of Cancer Radiobiology in the Faculty of Medicine at Imperial College. He continues to be involved in research and teaching.

My first day in radiotherapy physics: reflections of a medical physicist

NHSIn 2010 Karen Goldstone was awarded the MBE for her services to healthcare. Here she reflects on the primitive tools used for radiotherapy patient outlines back in the 1970s and remembers the wise advice she was given on her first day as a radiotherapy physicist.

BIR

I started work in the NHS as a Hospital Physicist in 1970. Prior to that I did the MSc in radiation Physics based at Middlesex Hospital. When doing a placement in nuclear medicine, computer tapes had to be taken to University College about a fifteen minute walk to the other side of Tottenham Court Road and fetched the next day hopefully having run successfully.

In my first post I expected to be doing mainly diagnostic radiology physics but discovered that that was rather a luxury field and so most of my time was spent doing radiotherapy physics. Those were the days when patient outlines were taken using a strip of lead or a flexicurve and planning was done using tracing paper and coloured pencils or biros. There was no computer planning of course and we only had one calculator with a paper roll print out so slide rules were in constant use. The main piece of advice I remember receiving on my first day was that if I discovered I had made a mistake I should own up to it straight away and not seek to cover it up – very wise words.

When not doing radiotherapy physics many hours were spent reading out film densities produced using our homemade “Ardran Cassette” in order to check kVp. This was the beginning of setting up a quality control programme for X-ray units. Another time-consuming activity was sealing lithium borate powder into plastic capsules in order to measure dose to radiologists, carrying out various procedures under fluoroscopic control, and subsequently reading the doses received.

Although diagnostic radiology physics was not seen as important it was an exciting time and I was fortunate enough to hear Godfrey Hounsfield give the 1972 MacRobert Award lecture on “Computerised Transverse Axial Tomography” – an invention that has revolutionised diagnostic imaging.

I started my second post in 1974 in a smaller department but with responsibilities in other, far-flung, hospitals. Here I was the radiotherapy physicist (the only one) and also covered diagnostic radiology and radiation protection, but because it was a smaller department and staff had to be versatile I also did some nuclear medicine and even once some ultrasound.

In the peripheral hospitals in my patch one was still using wet developing, one using just a fluorescent screen for fluoroscopic procedures and one an image intensifier viewed not via a camera but via a mirror arrangement.

How times have changed!


About Karen Goldstone MBE

I worked for forty years in the NHS, in radiotherapy physics, diagnostic X-ray physics and all aspects of radiation protection. In 1983 I set up the East Anglian Regional Radiation Protection Service (EARRPS) based at Addenbrooke’s Hospital in Cambridge, and ran it for almost 30 years. I was both a Radiation Protection Adviser and Laser Protection Adviser. I gave physics lectures to radiologists and was a physics examiner for FRCR both in the UK and Malaysia. With colleagues in EARRPS and Cambridge University I ran a number of Radiation Protection Supervisor courses and gave countless IRMER courses to reluctant clinical staff. I was exceedingly surprised to be awarded the MBE in 2010 for services to healthcare.

Since retiring I have taken up rowing and become a Level 2 rowing coach; I have given two courses on Radiation and Health to the University of the Third Age in Cambridge and am otherwise kept busy with my garden, allotment, grandchildren and church activities. I am still involved on one or two committees for medical physics and radiological protection.