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.