Neuroendocrine Cancer: Ga68 PET Scan – a game changer?

When I was offered my very first Ga68 PET/CT at a 6 monthly surveillance meeting in May 2018, I was both excited and apprehensive. Let me explain below why I had a mix of emotions.

I was diagnosed in 2010 with metastatic NETs clearly showing on CT scan, the staging was confirmed via an Octreotide Scan which in addition pointed out two further deposits above the diaphragm (one of which has since been dealt with). In addition to routine surveillance via CT scan, I had two further Octreotide Scans in 2011 and 2013 following 3 surgeries, these confirmed the surveillance CT findings of remnant disease. The third scan in 2013 highlighted an additional lesion in my thyroid (still under a watch and wait regime, biopsy inconclusive but read on….).

To date, my 6 monthly CT scans seem to have been adequate surveillance cover and all my tumour and hormone markers remain normal. I’m reasonably fit and well for a 62-year-old.

Then I ventured into the unknown

this is not actually my scan!

I wrote a comprehensive post about the Ga68 PET entitled “…. Into the unknown” – so named because that is how I felt at the time. It’s well-known that the Ga68 is a far superior nuclear scan to the elderly Octreotide type, showing much greater detail with the advantage of providing better predictions of PRRT success if required downstream. It has been a game changer for many and if you look below and inside my article, you will see statistics indicating just how it can ‘change the game’ in somatostatin receptor positive Neuroendocrine Cancer diagnostics and treatment.

The excitement of the Ga68 PET

I was going to get the latest ‘tech’ and thought it could be useful confirmation of what I already knew. I also felt lucky to get one, they are limited in UK and there has to be a clinical need to get access. I was excited because it might just rubber stamp the stability I’ve enjoyed for the past 5 or so years since my last surgery in 2012.

The apprehension of the Ga68 PET

I also felt apprehensive because of the ‘unknown’ factor with cancer, i.e. what is there lurking in my body that no-one knows about, and which might never harm me but this scan will light it up demanding attention. I was also apprehensive in case this more detailed scan found something potentially dangerous. As we know, NETs are mostly slow-growing but always sneaky. Of course, any new tumours found may not actually be new, they were just not seen until the Ga68 PET was able to uncover them.  How annoying!

Is the Ga68 PET Scan a game changer?

To confirm the advantages of SSTR PET over Octreotide scans, a study comprising 1,561 patients reported a change in tumour management occurred in over a third of patients after SSTR PET/CT even when performed after an Octreotide scan.

  • Overall, change in management occurred in 44% (range, 16%-71%) of NET patients after SSTR PET/CT.
  • In 4 of 14 studies, SSTR PET/CT was performed after an 111In-Octreotide scan. In this subgroup, additional information by SSTR PET/CT led to a change in management in 39% (range, 16%-71%) of patients.
  • Seven of 14 studies differentiated between inter- and intramodality changes, with most changes being intermodality (77%; intramodality, 23%). (note: intermodality means changes within the same treatment, intramodality means change to another treatment).

In an older study, this slide from a NET Research Foundation conference shows some more interesting statistics:

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This slide from a recent NET Research Foundation conference confirms the power of more detailed scanning

Was Ga68 PET a game changer for me?

Yes, I believe so.  I’m now in the ‘bone met club’ and although that single metastasis has probably been there for some time, it’s not a ‘label‘ I was keen to add to my portfolio. If I was to be 100% honest, I’m not totally convinced it’s a metastasis. The scan has brought more light onto my thyroid issue.  In fact it indicate even more potential issues above the diaphragm including what looks like a new sighting around my left pectoral.  The can also lghts up a known issue in the left clavicle lymph nodes, first pointed out via Octreotide scan in 2010 and biopsy negative.

In addition to a nuclear scan update (routine surveillance), it also formed part of an investigation into progression of my retroperitoneal fibrosis (initially diagnosed 2010 but potential growth spotted on recent surveillance CT).  The Ga68 PET doesn’t make fibrosis light up (it’s not cancerous) but there are some hotspots in the area of the aorta close to the fibrosis.   Surgery is on hold for now as my kidney function is fine following a renal MAG3 scan which reported no blockages. 

It would appear I’m no longer a boring stable patient

The Ga68 PET Scan confirmed:

Bone Metastases. Report indicates “intense focal uptake“. It always amazes me that people can be thankful for having an extra tumour.  I’m thankful I only have a single bone metastasis (right rib number 11). I had read so many stories of those who got their first Ga68 PET and came back with multiple bone metastases. I’ll accept one and add to my NET CV. I have no symptoms of this bone metastasis and it will now be monitored going forward. I’m annoyed that I don’t know how long it’s been there though!

Confirmation and better understanding of the following:

  1. Thyroid lesion There is some uptake showing. A 2014 Biopsy of this lesion was inconclusive and actual 2018 Ga68 PET report infers physiological uptake. I’m already diagnosed hypothyroidism, possibly connected.  (Edit – on ultrasound in Jan 2019, looks slightly smaller than previous check).
  2. Left Supraclavicular Fossa (SCF) Nodes lighting up “intense uptake“.  I’ve had an exploratory biopsy of the SCF nodes, 5 nodes removed negative. Nothing is ‘pathologically enlarged’ in this area. Monitored every 6 months on CT, annually on ultrasound.  I had 9 nodes removed from the left axillary in 2012, 5 tested positive for NETs and this area did not light up. This whole area on the left above the diaphragm continues to be controversial. My surgeon once said I had an unusual disposition of tumours.  (Edit: Nothing sinister or worryingly enlarged showing on Jan 2019 ultrasound – measuring 6mm).
  3. Report also highlights left subpectoral lymph nodes which is new.  The subpectoral area is very interesting as from my quick research, they are closer to the left axillary (armpit) nodes than they are to the SCF nodesI’m hoping to get an ultrasound of these in January at my annual thyroid clinic (Edit: nothing sinister showing on ultrasound in Jan 2019).
  4. My known liver metastases lit up (remnant from liver surgery 2011) – not marked as intense though. The figure of 3 seems to figure highly throughout my surveillance scans although the PET report said “multiple” and predominately right-sided which fits.
  5. Retroperitoneal area. This has been a problem area for me since diagnosis and some lymph nodes are identified (intense word not used). This area has been highlighted on my 3 octreotide scans to date and was first highlighted in my diagnosis trigger scan due to fibrosis (desmoplasia) which was surrounding the aorta and inferior venous cava, some pretty important blood vessels. I wrote an article on the issue very recently – you can read by clicking here. So this scan confirms there are potentially active lymph nodes in this area, perhaps contributing to further growth of the fibrosis threatening important vessels – read below.

Retroperitoneal Fibrosis (Desmoplasia)

I have learned so much about desmoplasia since this issue arose that I now fully understand why I had to have radical surgery back in 2010 to try to remove as much of the fibrosis as possible from the aortic area. You can read more about this in my article.  Desmoplasia via fibrosis is still very much of an unknown and mystery condition in NETs.

I now know that my fibrosis is classed as clinically significant and according to the Uppsala study of over 800 patients inside my article, I’m in 5% of those affected in this way (2% if you calculate it using just the retroperitoneal area).

It appears this problem has come back with new fibrosis or growth of existing fibrosis threatening to impinge on blood vessels related to the kidneys and also my ureters (kidney to bladder urine flow). The Ga68 PET doesn’t make fibrosis light up (it’s not cancerous) but there are some hotspots in the area of the aorta close to the fibrosis.

I didn’t expect this particular problem to return – it was a bit of a shock. My hormone markers have been normal for 8 years and this just emphasises the importance of scans in surveillance. 

Conventional Imaging is still important though

There’s still quite a lot of hype surrounding the Ga68 PET scan and I get this.  However, it does not replace conventional imaging (CI) such as CT and MRI scans which still have their place in routine surveillance and also in diagnostics where they are normally at least the trigger for ‘something is wrong’. For the vast majority, a CT/MRI scan will find tumours and be able to measure reductions and progress in regular surveillance regimes. There are actually recommended usages for the Ga68 PET scan here.  For example, it is not recommended for routine surveillance in place of CI.

In fact, the retroperitoneal fibrosis has appeared on every CT scan since diagnosis but the changes were highlighted on my most recent standalone CT and it triggered the Ga68 PET (although my new Oncologist did say I was due a revised nuclear scan).  It’s not a ‘functional’ issue (although it is caused by functional tumours). In fact the fibrosis is not mentioned on the Ga68 PET because it is not lighting up – but the lymph nodes surrounding it are mentioned and they are under suspicious as being active.

Read a summary of all conventional scans and nuclear scans by clicking here.

Next Steps

I’ve since has meetings with my Oncologist and Surgeon and a treatment plan is underway. My surgeon explained it all in his wonderfully articulate and brilliant surgical mind. Fortunately it’s not really urgent but pre-emptive treatment may be required at some point as the consequences of kidney/bladder function are quite severe. Following some further checks, the anticipated surgery is on hold for now as my kidney function is fine following a renal MAG3 scan which reported no blockages.  I continue to have monthly renal blood tests and it was hinted another renal MAG3 could be done at the end of the year.

Summary

My game has changed, that’s for sure. I’m now entering a new phase and I’m waiting on details of my revised surveillance regime. However, at least my medical team and I now know what WE are dealing with and the risks vs benefits are currently being assessed. I’m heavily involved in that.

If you can see it, you can detect it. If you can detect it, you can monitor or treat it.

It’s been 5 years since I saw a scalpel (….but my surgeon is still on speed dial)

im-still-here

5 years ago today, I had a bunch of lymph nodes removed. Two separate areas were resected, only one was showing growth but both were showing up as hotspots on an Octreoscan.  I had known since shortly after diagnosis in 2010 that ‘hotspots’ were showing in my left ‘axillary’ lymph nodes (armpit) and my left ‘supraclavicular fossa’ (SCF) lymph nodes (clavicle area). Some 10 months previously, I had a major liver resection and 5 months prior to the liver resection, I had a small intestinal primary removed including work on some associated complications.  There had always been a plan to optimise cytoreduction of my distant metastases, it was just a matter of timing. I still can’t get my head round why metastases from a small intestinal NET managed to get to this area but not others!

Distant nodal metastasis treatment

A total of 9 nodes were removed from my left armpit (a very common operation for breast cancer patients). The surgeon had inspected the area and found some were palpable and my normally stable Chromogranin A marker was showing a small spike out of range.  During the same operation under general anaesthetic, an ultrasound directed SCF nodal ‘exploration’ was carried out.  When biopsied, 5 of the 9 resected axillary nodes were tested positive (Ki-67 <5) but the 5 SCF nodes removed were tested negative. The subsequent Octreoscan still lit up in the left SCF area but the lights on the left axillary area were ‘extinguished’. There is no pathological enlargement or pain in the left SCF area – so this is just monitored.

Side effects

Apart from a very faint scar in the left SCF area, there does not appear to be any side effects from this exploratory surgery.  The left axillary area cut is well hidden by hair growth but I do sense a lack of feeling in the area.  Additionally, I have a very mild case of lymphedema in my left hand which occasionally looks slightly swollen – the consequences of cancer and its treatment.  Fluid build-up, or post-operative seroma, can be a side effect of a lymphadenectomy.  In fact, within a month of the operation, I had to have circa 160mls of fluid removed on 4 occasions from my armpit.  It was uncomfortable and painful, resulting in additional time off work.  The surgeon used a fine needle aspiration to draw out the fluid, a painless procedure. It eventually cleared up and everything was back to normal.  The specialist said my left arm would be slightly more susceptible to infections and suggested to avoid using my left arm for blood draws and other invasive procedures and injuries.

Other close calls (“to cut or not to cut”)

I have a 19mm thyroid lesion which was pointed out to me in 2013. This has been biopsied with inconclusive results.  Although the thyroid is an endocrine gland, it looks like a non-NET problem so far. Thyroid nodules are in fact very common and statistically, 50-70% of all 50-70 year olds will have at least one nodule present (i.e. if you are in your 50s, there is a 50% chance you will have one nodule and so on). The vast majority will never bother a person while they live.  I attend an annual Endocrine MDT where this is monitored in close coordination with the NET MDT. It’s actually managed by the same surgeon who carried out the nodal work above.

I have a 3mm lung nodule, discovered in 2011. Apparently, lung nodules are a pretty common incidental finding with 1 per 500 X-rays and 1 per 100 CT scans finding them.  This is monitored and hasn’t changed since noted.

You may also be interested in my post “Neuroendocrine Cancer – to cut or not to cut”

I watch and wait but I also watch and learn.  Make sure you are under some form of surveillance.

Thanks for reading

Ronny Allan

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Neuroendocrine Cancer: Nodes, Nodules, Lesions

www-cancer-gov_publishedcontent_images_cancertopics_factsheet_sites-types_metastaticA fairly common disposition of metastatic Neuroendocrine Tumours (NETs) is a primary with associated local/regional secondary’s (e.g. lymph nodes, mesentery and others) with liver metastases.  Technically speaking, the liver is distant. However, many metastatic patients have additional and odd appearances in even more distant places, including (but not limited to) the extremities and the head & neck.  In certain NETs, these might be an additional primary (e.g. in the case of Multiple Endocrine Neoplasia (MEN); or they could even be a totally different cancer. The worry with NETs is that the little suckers can sometimes make these surprise appearances given that neuroendocrine cells are everywhere.

Cancer doesn’t just spread through the blood steam, it can also spread through the lymphatic system. This is a system of thin tubes (vessels) and lymph nodes that run throughout the body in the same way blood vessels do. The lymph system is an important part of our immune system as it plays a role in fighting bacteria and other infections; and destroying old or abnormal cells, such as cancer cells. The lymphatic system also contains organs, some of which feature regularly in NETs.  If cancer cells go into the small lymph vessels close to the primary tumour they can be carried into nearby lymph glands where they stick around. In the lymph glands they may be destroyed (that is actually one of the jobs of the lymph glands) but some may survive and grow to form tumours in one or more lymph nodes.

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The Lymphatic System

I also had the usual bulky chains of lymph node metastases in or around the mesentery that frequently appear with an abdominal primary (in my case the small intestine). These were all removed as part of my primary resection. However, I knew since shortly after diagnosis in 2010 that I had ‘hotspots’ in my left ‘axillary’ lymph nodes (armpit) and my left ‘supraclavicular fossa’ (SCF) lymph nodes (clavicle). These were found on Octreoscan but at the time, they were not pathologically enlarged – just ‘lighting up’.  They also light up on Ga68 PET.

In early 2012, 15 months after removal of primary and 10 months after liver resection, one of the axillary lymph nodes became palpable (signs of growth) and this coincided with a small spike in Chromogranin A.  A total of 9 nodes were removed very shortly after this surveillance, 5 of which tested positive for NETs (Ki-67 <5%).  As part of the same operation, 5 SCF left clavicle nodes were removed but tested negative.  On a subsequent Octreoscan, the armpit was clear but the clavicle area still lit up.  However, there is no pathological enlargement or pain – so this is just monitored. Also lights up on Ga68 PET I have a 3mm lung ‘nodule’, discovered in 2011. Apparently, lung nodules are a pretty common incidental finding with 1 per 500 X-rays and 1 per 100 CT scans finding them.  This is monitored.

thyroidI have a 19mm thyroid ‘lesion’ which was pointed out to me in 2013. This has been biopsied with inconclusive results.  Although the thyroid is an endocrine gland, it looks like a non-NET problem to date. Thyroid nodules are in fact very common and statistically, 50-70% of all 50-70 year olds will have at least one ‘nodule’ present (i.e. if you are in your 50s, there is a 50% chance you will have one nodule and so on). The vast majority will never bother a person while they live.  That said, my thyroid blood tests are abnormal and on 20th March 2018, following an Endocrine appointment, I was put on a trial dose of 50mcg of Levothyroxine to counter the thyroid panel results indicating hypothyroidism. Levothyroxine is a thyroid hormone replacement. Early in 2017, during my Endocrine MDT, a surveillance ultrasound spotted a slightly enlarged lymph node on the right side (measuring 9mm x 9mm) described as a ‘level 4’ node (a location indicator meaning the ‘lower jugular group’).  The report was passed to the NET MDT for their consideration with the surgical rep on the Endocrine MDT recommending a conservative approach – the NET MDT agreed. I suspect that’s right, it’s still below the worry threshold, nothing is palpable (no lumps) and I don’t have any specific symptoms.  There could have been a number of reasons for the enlargement and it might even be back to normal size on my next scan (spoiler alert – it was). All my issues have been left-sided to date, so that was interesting. That said, I did have an MRI in 2014 to investigate pain and a swelling at the site of my right ‘sternoclavicular’ joint – subsequently declared a non-issue. Showed as inflammation on recent Ga68 PET.

Life as a metastatic Neuroendocrine Cancer patient is interesting and efficient surveillance is absolutely critical.

You may enjoy my posts:

“Living with Neuroendocrine Cancer – 8 tips for conquering fear”

“Worrier or Warrior”