[Histonet] Microwave Tissue Processing

Mon Mar 17 06:35:49 CDT 2014

Aikhan
I am happy to share my experience, and very inspirational your concern for the burden on the patient and their families. Your language is just fine ! Do not be concerned. We are on this list to help one another. 
MW processing fairly common here. Some people love it, and some people are not fully confident in it yet. My first advice would be that the biggest issue to adoption seems to be understanding that it works differently than conventional processing, though the end result accomplishes the same purpose. It works very well if people take the time to learn to use it correctly. It is based more on physics of MW energy and tissue components than just passive reagent diffusion like conventional processors. It is wise to take some time to learn about how this works before starting, though getting past this barrier should be easier for you since you are not accustomed to using a conventional processor.
The vendors that I know are Thermo-Shandon, Sakura, Milestone -at least these are the instruments I have personally used ( various models). They all have advantages and disadvantages, it just depends on what your needs are. The Milestone I would say is particularly adopted to very high volumes. The vendors have proprietary technology and some reagents, but most use formalin, but just accelerate the fixation rate with MW energy instead of convection heat and agitation. The big concern is that you are working with much shorter times and so you have to adjust your thinking on this aspect. Also some tissues- liver cores, skins and bloody specimens such as endometrial biopsies will get very dry if you are not careful with the heat and microwave exposure- my theory is that is has to do with the polarity or water content of these tissues. The outer surface becomes almost coagulated and tough, must like over-cooked food in the microwave. 

Important notes are: 
 That generally you cannot REPROCESS microwave processed tissue. So you have to take the time to do it correctly from the beginning, and all tissue can be sucessfully processed when a suitable program is set up.  As you know, you CAN reprocess with conventional, though the results are often not much improved. So carefully consider this as you set up your process ( see below my suggestions for this). The tissue thickness and overall dimensions are even more important with MW than with any type of conventional processing to get uniform and optimal results.  
On the positive side, large samples( cut thinly), breast tissue and other fatty specimens seem to do exceptionally well, much better than conventional. Graded ethanols are typically used for dehydration as in conventional processing. So, really most of the reagents are the same in the instruments I have used, with the exception that isopropanol is substituted for xylene as a transition and clearing reagent. Even though this seems counterintutitive, it actually seems to work pretty well. If you are accustomed to processing manually, you will be amazed at the tissue quality and speed you can gain by using any type of automated processing- you will be leaps and bounds ahead if you are successful in adopting microwave assisted processing. 

Advantages
signifigantly reduce turn around, faster pateint results- some program are less than 1 hour, really speeding up diagnosis. For some patients and samples this may outweigh almost any disadvantagesthe vendors typically can assit with the intial set up and this takes care of many of the issues I mention under disadvantagescleaner, less exposure to hazardous chemicials 
Disadvantages
Takes more time in the inital design of the programs,and validationYou may need to customize or adjust programs for particular tissues more so than conventional, so a little more technical attention and time is needed, in some labs this may be a barrier 
I hope that some of this information can be of help to you. Please let me know if I can assist further in any way. 

Joelle Weaver MAOM, HTL (ASCP) QIHC

Date: Mon, 17 Mar 2014 14:49:12 +0600
Subject: Re: [Histonet] Microwave Tissue Processing
From: aikhanlab <@t> gmail.com
To: joelleweaver <@t> hotmail.com

Hi Joelle Weaver,

>From your posting I learned that you have experience of using Microwave tissue processor for last 8-10 years. I would be grateful if you can help me in light of your experience.

We are giving histopathology service in our country, Bangladesh. 
We have a peculiar situation: Many patients are from rural areas, they come to the city, have to stay till a diagnosis is made, an expensive matter for them bearing all these costs; there's no insurance system here. 

Presently tissue processing is manual in our lab; around 150 paraffin blocks daily. Needing to produce rapid result under financial constraint we are thinking of microwave processing, but we don't have any experience with these.

We know there are other choices as well: conventional carousel (like Shandon Citadel), vacuum single retort (like Sakura tissue-tek) and linear processors (like ATP 700 or ATP 1000).

I would be grateful if you can let us know about your experience with MW processors.

Some of the questions in my mind about MW tissue processor: 
1. What are the reagents required in MW tissue processing. Can we use the same reagent repeatedly in the
    MW processor, like in conventional processors. If so, how many times we can use the same reagent 

    repeatedly.
2. What are the MW processors available in the market: I have googled and found Milestone, Labpulse.
3. As compared to conventional processor, what are the advantages and disadvantages in your opinion.

If you have more to tell us about your experience, please do, I would be happy to learn from you. Please excuse my bad language if something is not clear to you. 

Regards,

aikhan

On Fri, Mar 14, 2014 at 6:02 PM, joelle weaver <joelleweaver <@t> hotmail.com> wrote:

I have used a couple of vendor's MW processing instruments over the past 8-10 years. So it is used, even if it has not become as commonplace as conventional in every setting or market. It seems to be more favored in high volume settings, for pretty obvious reasons.  In teaching and instruction * my opinion * - you should teach them the theory and fundamentals for practice for ALL the possible tissue processing technologies they may encounter, and this is consistent with the approach to practice of the topics on the ASCP exam.They have to know the fundamental basics and then it is easy to expand to more emerging practices and technology. It would be more of a disservice to me if you left anything( either conventional technology or MW out), in your treatment of that topic.

Joelle Weaver MAOM, HTL (ASCP) QIHC

> From: KGoodkowsky <@t> goodwin.edu

> To: histonet <@t> lists.utsouthwestern.edu

> Date: Fri, 14 Mar 2014 11:47:26 +0000

> Subject: [Histonet] Microwave Tissue Processing

>

> Hello all,

> I had an opportunity to demo a microwave tissue processing unit for my students.  Is anyone using microwave technology for tissue processing and if so, could you please provide me some information on your experience with this?  There are many pros that I can see, including its ease of use and quick processing time which fits well with the student lab schedule.  I am wondering, however, what the likelihood will be that students will use this technology once in the field.  I don't want to do them a disservice by not using conventional tissue processing methods.  The majority of hospitals in the CT/MA area use conventional tissue processors.

>

> Thank you.

>

> Sent from my iPad

> Kelli Goodkowsky

> Director Clinical Education, Histologic Science

> Goodwin College

> (860) 727-6917

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