A busy morning - every second Tuesday paediatric scans are carried out, with families travelling from all over the country. The majority of scans today were brain scans for frontal lobe epilepsy and a EEG was carried out first. I can't begin to tell you the pandemonium caused. Each child is accompanied by one or both parents naturally, a paediatric nurse, a EEG technician, an anaesthetist, a staff nurse and a recovery nurse. The children need to be given a general anaethestic for the scan and then recovered in the scan room afterwards. The department is not particularly child friendly, the staff are lovely but it is very clinical - we couldn't find the toys this morning, although the staff were sure we had some. This is one of the few centres which scan children and I believe they want to become a paediatric centre of excellence - so it would be interesting to see how they develop this.

I also saw a 19yr old scanned for treatment response for Hodgkins Disease today and the difference between the progression of HD and NHL was very obvious. HD starts as a unifocal disease in one node and spreads in an orderly fashion to the next - on this particular scan you could see the disease like a necklace of beads running bilaterally down the neck into the mediastinum

There wasn’t time to review individual cases after scans today as the paed cases made us play catch up for the rest of the day. One does have to be careful not to be gratuitously interested in spotting pathology and remember the patients who have so much riding on the outcome of the scan.

This is an example of a PET/CT image showing (from left to right) a low res CT image, a PET image and finally a fused PET/CT image. Increased FDG uptake is visible in the left hilar region and chest wall. Uptake in the bladder, kidneys, testes and orbits is normal

My student liaison asked me whether I was beginning to find it monotonous yet, and if I’m honest the answer would be a little. Despite the ‘high tech’ nature of the job I believe there is far more skill required in general radiography. The staff here are all from different professional backgrounds - the superintendent is pure nuclear medicine, one is bioscience, another diagnostic radiography and another from therapy. The process is identical for every patient and rather like a barium or IVU list you get to say the same thing all day. I do everything the qualified staff do, bar cannulate patients. I interview, put on and take off the scanner, input patient details in the very many places they need to be input and carry out daily QC checks. It is my responsibility to make sure I limit the dose I receive from patients once they are injected and therefore radioactive, and to log my daily dose on the computer with the rest of the staff. The superintendent here is very keen that the staff gain an appreciation of where PET/CT fits into the patient’s journey and encourages all the staff to take turns in attending the multidisciplinary team meetings for individual pathologies, which take place weekly.

I have been reading with interest the blogs of the other students doing PET/CT in the midlands and their practice differs from ours in a number of ways. They see upto 7 patients per day for a limited range of pathologies, whereas we image as many as 21 patients a day for a wider range of conditions, so not all oncology. Our tracer uptake time is 90mins versus 60mins - so with more patients in department for longer we have to be very efficient at getting them through the system to maximise the two scanners. We try and limit our ‘beds’ to 6 for a half body scan which runs from inferior orbital rim to mid thighs. Shorter patients allow us to get away with just 5 beds sometimes. A bed = 5mins scanning time and then it moves position. Less beds means less dose to the patient. For patients over 100kg the bed time gets increased from 5 mins to 6 or 7minutes. Most scans are conducted with the arms up over the head, if for any reason the patient can’t manage this, then all subsequent scans must also be done arms down for consistency. This is for reporting because so much anatomy moves. It is also preferential to keep arms out of the scan because they produce alot of scatter. The only time a scan is conducted routinely arms down is if a melanoma is suspected on the arms. We also seem to inject slightly less - aiming for 350Mbq (+/- 10%) versus 400Mbq.

Day Fourteen

I had a visit to the cyclatron today, which was really interesting. The radiochemists explained the process of producing FGD which is highly labour intensive. The cyclatron was heavily shielded and was still too 'hot' to stand next to, but they've invited me back on Monday when it will be 'cold' and they're going to take the lead and concrete shield off for me to look inside.

Yesterday I sat in on a reporting session, the doctor was very generous with her time and talked me through the whole process. They double report in this clinic. The first report is produced without reading the referral, which was interesting because quite a few of the patients I had interviewed earlier and was aware of their history - so it was amazing to see how quickly the doctor could hit the nail on the head. It really helped me with my cross sectional anatomy as well.

Other than that I have concentrated on reading as much about lymphoma as possible which includes checking the history of every patient that comes through the department. The peak age for NHL is around my own age so it is very humbling to be in the prescence of these people coming to terms with this disease.

Day Seven

An interesting patient pathway:-

Patient B presented to GP with 3 week history of L loin/testicular pain in July ‘07. Patient was referred for an IVU which showed L uretheric obstruction and hydronephrosis for which he underwent a nephrostomy and was stented. A follow-up CT revealed two abdominal masses. A biopsy followed which diagnosed Diffuse Large B Cell Lymphoma (DLBCL) and a PET/CT was requested to see the extent of the disease. The scan revealed multiple areas of FDG uptake with a large primary in the abdomen, surrounding the psoas muscle. It was decided at the lymphoma meeting today that this patient will have two cycles of what is known as CHOP-R. The acronym accounts for the initial letter of the 5 drugs involved, and is the chemotherapy regime for DLBCL . He will then be re PET scanned after the two cycles of chemo to assess response to treatment. PET/CT has clearly played a pivotal role in this patient’s diagnostic and treatment programme. Treatment response scans are a relatively new thing for PET/CT, but they seem to be performed regularly in this trust.

A naked PET/CT machine

Day Six

We were down a scanner today, some staff opted to take annual leave, otherwise there would be too many staff and not enough work. Even so, it was still a slow day. I was able to see inside the scanner as the service engineer took it to bits. He took the time to explain to me what all the various bits of electronic entrails did, and I saw the ring of 32 scintillation crystals with their photomultiplier detectors. I took some photos of it in pieces, now I just have to figure out how to get them off my phone onto the computer!

I also helped with the QC this morning as Monday is the day for any weekly QC tests. I can do the PET phantom tests on my own now. Generally they allow me to do this and to draw up all the saline flushes for the day. I continue to be amazed by how inclusive this team are - they really are very generous and supportive. My supervisor arranged for me to sit in on a reporting session sometime and I'm going to see the cyclatron next week where the radioactive tracers are produced on site.

Tomorrow morning one of the reporting doctors is running a 'lecture' session on some of the interesting cases the team have indicated they would like to know more about - so i'm looking forward to that. There is also the second multidisciplinary lymphoma meeting tomorrow which I will also attend, I'm hoping that some of the patients I saw last week will be discussed. I'm following two patients who have recently been diagnosed with NHL to fulfill my learning contract objectives. One of the reports came back today and it's not terribly conclusive, so I'm now hoping the other one will be more suitable.

I'm writing notes constantly and have accrued a vast amount of new information in my head - I'm not sure I'm able to put it into context yet, hopefully the pieces will fall into place.

Day Four

The department was down two members of staff today so I was able to be more hands on.

A patient came in today who had only just been diagnosed with Non Hodgkin Lymphoma (NHL). Her patient pathway so far has been a visit to her GP 6 weeks ago with a lump in her groin which rapidly increased in size. She was then referred for a lymph node and a bone marrow biopsy, with diagnosis definitively by histopathology. That was Tuesday, today she attended for a PET/CT scan. There was certainly an area of increased FGD uptake in the left groin and also on the right illiac crest, but this is where the bone marrow biopsy was performed. The report should be ready in a couple of days, her case may also be discussed at next week’s lymphoma forum. The patient was asymptomatic but appeared to be in shock from the diagnosis. I interviewed this patient and got her ready for the scan, so definitely will follow the case through as far as my visit allows.

Lymphoma is a general term for a group of cancers that originate in the lymphatic system. They can be divided into two groups Hodgkin Disease (HD) and all other lymphatic cancers called Non Hodgkin Lymphoma (NHL). Lymphomas result when a lymphocyte undergoes a malignant change and begins to multiply creating tumours which enlarge the lymph nodes and other parts of the immune system. NHL is much less predictable than HD and has a greater chance of spreading to extra nodal sites. HD is the more curable of the two and is characterised by an orderly spread from one lymph node to another.

Day Three

Most of the patients attending the PET centre are lymphoma sufferers, which can be split into either Hodgkin Disease or Non-Hodgkin Lymphomas. As with all cancers treatment decisions are based on the stage of the disease. Stage I and II lymphomas receive reduced cycles of chemotherapy. Previously the standard treatment regime was four cycles of chemo, but there are known problems associated with the toxicity of chemotherapy and a possibility of long term complications such as MI and bone marrow suppression. Consequently any opportunity to reduce with certainty the amount of chemo/radiotherapy a patient receives is beneficial. PET/CT has a significant role to play in this because it is so effective in establishing whether treatment has been effective after only two cycles of treatment.

I was invited to attend an interdisciplinary lymphoma forum meeting yesterday where patient cases are discussed with a view to reaching consensus over future treatment. Oncologists, radiologists and histopathologists were all present with CT, fused PET/CT images, histopathology slides showing germ cells before and after treatment - all presented interactively. An interesting ‘discussion’ broke out between a reader in CT and a reader in PET/CT about what is appropriate baseline imaging for lymphoma, the argument being that whilst PET/CT is the gold standard in this particular trust, CT remains the gold standard elsewhere in the UK. It was really satisfying to gain an insight into the process behind clinical decisions, particularly on patients who had been scanned whilst I was in department.

Other cancers, known as solid tumours - breast, colorectal, oesophageal etc are also scanned for. Today there was a research trial sponsored by GlaxoSmith Kline into whether a drug used for diabetes reduces the chance of Alzheimers developing. There is also bone study/osteoporosis research project taking place, trying t o establish whether the effects from a long acting drug (10yrs) are indeed still maintained when withdrawn.

I was allowed to interview some patients today, the PET/CT questionnaire is as extensive as an MRI safety questionnaire but for different reasons. It was great to do something other than observing and it was a compliment that the staff trusted me to do it. My temporary contract has still not come through so until then I need to limit any time spent with patients post injection. Although I’m finding the whole process really interesting, I have had a couple of moments of doubt about my choice, ie, whether I would have been better working in general radiography and compounding my skills. Next week, however, I should be able to be more of a team member and am looking forward to that.

Day One

Quite a different journey to work for me today. I'm on the 07.30am train into central London. By 8.30 I'm sitting in one of the many cafes in the hospital, looking out over the river Thames and the Houses of Parliament. Hundred of staff are arriving - I assume they are staff because I haven't spotted one uniform yet. I wonder if there is a policy whereby you don't travel to work in your uniform. I feel strangely at home. I grew up around this area and went to school just down the road from the hospital. I remember it as less than salubrious but today I am struck by how clean and bright it is, with lots of sculpture and modern art.

All the staff in the PET department were expecting me, an induction pack and badge were waiting and a three week itinery produced. I was really impressed with the organisation, but also the warmth of welcome. I am the first 'formal' student they have had, which really surprised me because the centre has an international reputation for excellence and many PET trials are conducted there. They are keen to know that they are fulfilling my objectives and have asked for feedback on my experience.

It's not a department to work in if you're of a disorganised disposition - timing is everything. Patients arrive and are taken to an interview/injection room. Here a team of two radiographers work together, one checking id and patient history whilst the other canulates the patient. From here the patient changes into a hospital gown and is allocated one of six bays with a bed - this is known as a 'hot' room and is where the radioactive tracer is injected. The idea is to minimise your time in this room, potentially you could have six patients all emitting radiation and that could result in a high cummulative dose. Once injected the patient needs to remain inactive for an hour and half, even reading is not permitted. This is to create optimal conditions for the uptake of tracer to pathology and not muscle. Although this sounds like a lot of sitting around time for the radiographers nothing could be further from the truth. Scans need to be conducted exactly on time, and as one patient’s scan is finishing another patient’s uptake time is completing. About ten minutes before the scan the patient is sent to empty their bladder and then return to rest. Somehow the radiographers know exactly where each patient is in the process, interaction with the patient and thus radiation burden is shared equally between the radiographers and they also had a running mental tally of this.

I’ve ‘acquired’ lots of other bits of information about the modality and will endeavour to put them into context over the coming days.