In this article, CellPath introduce an aid to biopsy processing that protects tissue and facilitates production of maximum diagnostic information- the Lumea BxChip. We also share our conversation with an early adopter of the BxChip, and hear of the success they achieved with their trials.
Needle core biopsies are taken to minimise patient discomfort while still gleaning essential information about a particular tissue. Organs such as prostate, breast, liver and kidney can all be studied using needle core biopsies, thus reducing the need for invasive surgery and extended hospital stays.
While these tiny biopsies are often more convenient for patients, they can create challenges for laboratories where the tissue must be processed and handled extensively. Damage may occur during manipulation with forceps, which is required at several stages of standard processing. Their delicate nature creates additional difficulties as the tissue is also prone to breaking during processing, which could lead to the loss of valuable material and vital diagnostic information. Cores that do contain tumour cells are even more susceptible, due to their high gland to stroma ratio. All of these factors mean that needle core biopsies typically consume a significant amount of time and resources.
In order to ensure fragmented cores do not become mixed, many laboratories choose to process each needle core individually. If biopsies are processed in this way then large amounts of resources are required to produce one block for each core, resulting in a greater workload and slower turnaround times.
Some laboratories prefer to maximise their use of resources and instead process multiple needle core biopsies from the same patient together in the same cassette. If multiple biopsies are processed together, samples can break and become mixed during processing, which could lead to diagnostic confusion.
A difficult compromise
Determining the most appropriate course of action will require compromise, but should resource efficiency ever be prioritised over diagnostic accuracy?
A novel solution to this ongoing compromise has recently arrived in the UK. Launched by CellPath in September 2019 at the IBMS Biomedical Science Congress, the LUMEA BxChip allows multiple needle core biopsies to be processed simultaneously with reduced risk of cores becoming mixed or fragmented.
The BxChip consists of a blue, flexible, tissue-like matrix with six channels. Each channel fits one needle core biopsy, with chips available to fit 12-, 14-, 16- and 18-gauge needle cores. Different tissues will typically be taken using different gauge needles, with prostate, currently the tissue most commonly processed in the BxChip, taken using an 18-gauge needle.
The bright blue colour provides a high-contrast background to ensure tissue cores are clearly visible. On the surface of the chip are identification markers providing orientation information. The addition of these markers is particularly useful to histopathologists as this information is typically lost using other methods because cores are not secured throughout transport and processing. The chip also features evenly spaced, 1-mm tick marks, aiding measurement and reporting of the amount of cancer per core.
To fill the BxChip, cores are placed directly into the channels in the procedure room. Transferring cores straight from the biopsy gun to the chip ensures that the biopsies require no further individual handling. Murugan et al (2019) found a significant reduction (more than threefold) in pre-analytical and analytical time using the BxChip. They also found increased specimen security with nonlinear fragmentation completely absent, in contrast to standard processing.
Once filled, the chip is placed into a cassette and transported to the laboratory in a formalin pot. From here the chip can be treated like any other biopsy, albeit a rectangular blue biopsy. The individual cores are now held safely in the chip and it can be processed according to size. Throughout processing and microtomy, there is no need to adopt any change of process; the benefit being that as many as three sections from each six-core chip can fit on a single standard microscope slide.
When processed, cores are much less likely to fragment, and any fragmentation that does occur will be contained within the same channel. This means that there is much more tissue available to view under the microscope, aiding diagnosis.
The potential savings of resources alone are clear, but when time and tissue availability are also taken into account, it becomes clear that the opportunities offered by the BxChip are worthy of a closer look. That was the attitude held by Dr Mitul Sharma of University Hospital of North Durham.
Pioneers trial BxChip
Prior to release into the UK market, Dr Sharma heard about the BxChip during a conference in the USA, where the chip is used successfully in numerous hospitals. Sensing an opportunity to improve upon current processes, the team at Durham opted to introduce the 18-gauge chip to process prostate cores. Following a successful trial, they have now fully adopted the use of the BxChip for processing all of their prostate biopsies.
Here, laboratory manager Andrew Munro shares their experience of introducing the chip.
What inspired you to use the BxChip?
We were definitely looking for an alternative method to what we were using. We were handling samples too many times and increasing our risk of picking up the wrong cassette, which meant patient samples could be transposed. That’s what led us to try the chip.
Did you have any issues getting other departments to ‘buy in’ to the use of the BxChip with patients?
I don’t know if we were just lucky but radiology was willing to give it a go. When we were going to try it out for real, I went down to the prostate clinic and talked to the radiologists and explained the new way we wanted the cores presented to us. They seemed quite happy to put them straight into the chip. So at least our radiology department was quite happy to try this new system that didn’t seem too onerous to them.
Would you say both you and the radiologists found it easy to use the chip?
There’s a bit of a learning curve for the microtomists and the histopathologists. Our laboratory has quite a mix of both experienced and inexperienced staff. The more-experienced microtomists were happy with knowing how far to cut into these chips, whereas some of the less experienced staff took a bit longer to be confident that they were going far enough into the chip, getting the balance right between a full face section, but not too deep.
What sort of savings have you noticed since using the BxChip?
We worked out that we save £1400 on consumables per annum. Even though the chips appear costly, we’re now using fewer consumables such as slides. However, the time saved by the biomedical scientist and the histopathologist is probably the biggest saving.
Alongside the savings reported by the team at Durham, significant savings can also be made on the cost of immunohistochemistry (IHC) reagents.
Depending on the current process, the number of slides produced per case could reduce from six to one. Reducing the number of slides submitted for IHC processing by such a large amount creates potential for huge savings to be made.
Would you say you need a large workload to warrant the chip or is it manageable to implement as a bonus for occasional cases?
We receive about five prostate cases a week, so we do about 200 a year. We don’t have a particularly large prostate workload but even with that small amount it saves us time. If you had a greater workload it would obviously save you even more time.
Have you noticed any improvement in the amount of fragmentation since using the chip?
Yes, when the prostate cores were placed in our previous five-well cassette, they had more room to move around and break or separate, but when they go into the channels of the chip, the sponge goes on top of them, resulting in less movement for them to break up. Generally, they are now consistently in one piece.
How do other people react to the chip?
It’s one of those things that people want to see. I’ve had a few different trusts emailing because they saw Dr Sharma’s poster (at Leeds Pathology 2019) and started asking about the chip. I’ve said to them that if you really want to understand you need to see it in action. There are challenges of course, but we had such a nightmare with our old system – it was just open to samples being transposed.
Would you recommend the chip to others?
Yes, I would. Some hospitals embed one core per block, leaving them with 10 or 12 blocks, which must create a nightmare. If you’re cutting three levels on each block you end up with more than 30 slides per prostate case, compared with the four that we now produce. If they can get to this level of reducing their slide use, it would be an even bigger bonus.
Future of the BxChip
For University Hospital of North Durham, the trial of the chip was so successful that it has now been implemented for use with all prostate biopsies. Future work in the UK, supported by CellPath, will see the 12-, 14- and 16-gauge chips also trialled, allowing different tissues such as breast, kidney or liver to be processed. The UK market is well positioned to trial innovative methods of time and cost savings, particularly when patients stand to benefit from an increased amount of tissue available for diagnosis. Further studies in the UK will reveal the true cost saving potential available to the NHS.
