Electrical Impedance Spectroscopy For Skin Cancer Screening

Dr Stephen Hess shares how he integrates the augmented intelligence-based Nevisense device into real-world dermatology practice to enhance clinical decision-making.

Stephen D. Hess, MD, PhD, is a board-certified dermatologist and the owner, president, and medical director of Center City Dermatology, with office locations in Philadelphia and Exton, PA.

Transcript

My name is Dr Stephen Hess. I am a board-certified dermatologist practicing in the Philadelphia region of Pennsylvania.

How did you first decide to incorporate Nevisense into your diagnostic workflow for pigmented lesions?

Dr Hess: So I first learned about Nevisense from a colleague of mine at a conference several years ago, and I was intrigued, so I decided to do a little bit more digging into the data on this device myself, and I read several studies and I was really impressed by the clinical data. When I looked into this, I also realized that this device has actually been approved and used widely in Europe since 2013. So that was reassuring to me. What I found was that the data showed that Nevisense can significantly increase the diagnostic accuracy, especially in challenging pigmented lesions. It does enhance both sensitivity and specificity, and actually it decreases the number needed to biopsy, which is really an important metric when we talk about melanoma testing. So the more I dove into the data, the more impressed I was and I decided that it might be something that would be worth adding to my own practice.

Where does Nevisense fit in your clinical algorithm—before biopsy, after dermoscopy, or in equivocal cases?

Dr Hess: Nevisense is really a tool that I use, particularly in challenging or ambiguous pigmented lesions. So it is not a replacement for my clinical judgment, nor is it a replacement for dermoscopy. So the way that this works is I will, of course, evaluate clinically any suspicious pigmented lesion, and I will also use my dermatoscope. But if a lesion falls into this ambiguous or challenging category, for example, clinically we use the ABCD criteria and maybe a lesion might have 1 or 2 of those features, but not 3 or 4 of them. And maybe under the dermatoscope, the pattern that I'm seeing is not perfectly normal, but it is ambiguous, then I may make the decision to use the Nevisense at that time. So it is a tool that I use alongside my clinical judgment and my dermatoscope to help inform decision-making with respect to either biopsying that lesion or continuing to follow the lesion clinically and not intervene at that time.

How has its use affected your threshold for deciding when to biopsy a lesion?

Dr Hess: Well, it actually affects my threshold in both directions. I would say the more common scenario is a lesion that, again, is somewhat ambiguous, has a few features that are concerning but is not overtly suspicious for melanoma. And the Nevisense may provide information that would indicate that this lesion should be removed. So I would think that's the more common scenario that I see in my practice, so in that sense, my threshold for biopsy has actually decreased. However, there are certainly scenarios where a lesion may look a little bit more clinically concerning to me. And the Nevisense analysis suggests a reassuring score, a lower score on the Nevisense scale, which goes from 0 to 10. And we know when the score is between 0 and 3, the negative predictive value for this being melanoma is greater than 99%. So in that scenario, it may actually increase my threshold for biopsy. So essentially the device can inform decision-making by either lowering or raising the threshold for biopsy depending on the clinical scenario, my judgment, as well as the analysis done by the Nevisense machine.

In what types of lesions or patient cases do you find Nevisense particularly helpful or informative?

Dr Hess: Well, Nevisense is very helpful in patients, for example, with a personal or family history of melanoma, it's also quite useful for those patients with a high burden of what I would call clinically dysplastic or atypical nevi. And in patients who are heavily sun-damaged in each of these scenarios, Nevisense can be very valuable. Also, in many of my patients who may be hesitant to consent to a biopsy, for example, they have a pigmented lesion that's in a cosmetically sensitive area. Perhaps they're needle phobic or needle averse, perhaps they just have biopsy fatigue and they're reluctant to give consent for a biopsy. And in these patients, sometimes the Nevisense device will provide an analysis which may help me convince the patient that a biopsy in this case is warranted. So it is very helpful for those patients. And it's also helpful, for example, in very anxious patients who may be insisting on a biopsy of a lesion that is not all that concerning clinically, but the Nevisense device in those cases may provide a score, a low score that would be reassuring and help me convince the patient that this lesion is very unlikely to be a melanoma, and therefore we can follow it clinically.

This may also happen in younger patients. In fact, when their parents bring them in and are very concerned about a pigmented lesion, sometimes the Nevisense can actually provide reassuring data, and then we don't actually have to intervene and remove that lesion.

Does Nevisense ever change your clinical decision-making—either preventing unnecessary biopsies or prompting earlier intervention?

Dr Hess: Yes, Nevisense can absolutely prompt earlier intervention in some lesions that may be clinically ambiguous or very subtle. And I have absolutely diagnosed melanoma in patients who I otherwise would not have necessarily biopsied. I would've made the judgment to defer the biopsy or perhaps the patient would have declined the biopsy. And in these cases, it did prompt me to intervene earlier. By contrast, I've also had scenarios where lesions look a little more concerning to me, but not concerning enough to be overtly suspicious for cancer, but somewhat more concerning. And the Nevisense device has provided reassuring analysis, and therefore it has changed my decision to elect to follow that lesion clinically rather than removing it. I would add that in the cases where I have identified melanoma earlier, fortunately in all of these cases, the melanomas were detected at a very early stage when they're potentially curable. In other words, the melanomas were detected at stage 0 in situ, or at most T1A lesions. And that's very important because at that stage, melanoma is certainly treatable and potentially curable. So I think early detection of melanoma is really the key point here.

How do you balance the device’s output with your own dermoscopic and clinical assessment?

Dr Hess: So balancing the output of the device with clinical judgment, including visual analysis using the ABCD criteria as well as dermoscopic evaluation, is critical. I want to emphasize that this is not a standalone screening tool and one has to incorporate the Nevisense analysis, the EIS analysis with one's clinical judgment in order to make the decision. So I would never depend solely on the result of the device to make a decision. I think that balance requires experience and good clinical judgment because it's definitely not a standalone screening tool that can be used by itself. It is one piece that we use to make that decision. And combining that information, my clinical judgment, my dermatoscope evaluation, and the Nevisense result is how I come to the decision on how to manage that difficult pigmented lesion.

Have you observed any measurable impact on patient outcomes, such as detection rates or reduced biopsy burden?

Dr Hess: In my practice, Navisense has helped me to detect melanoma earlier in a number of my patients. I have many examples of this. One in particular I might mention was a middle-aged gentleman who had a pigmented lesion on his forearm, and he was convinced that it had been there for many years and hadn't changed. However, it had a few subtle concerning features to me based on clinical evaluation as well as dermoscopy. And when I ran the Nevisense analysis on this, he had a score of an 8 out of 10, which basically meant that there was a significant risk that this lesion could in fact be malignant. So based on that, we made the decision together to do the biopsy, and it turned out that this was a melanoma in situ. So that's one example. But I have also no doubt reduced the number of unnecessary biopsies in my practice.

There are definitely situations, particularly I see this in lesions that had some abnormal clinical features, particularly in younger patients. And sometimes these lesions may be congenital Nevi or sometimes in older adults, these lesions could be perhaps pigmented seborrheic keratosis or antigens. And the Nevisense score is quite reassuring. And in these cases, I've been able to defer biopsy and follow these lesions clinically. And in my experience, since I've been following these patients, none of these that I have deferred biopsy have gone on to develop melanoma. So I think the device works well in both scenarios to enhance early detection of melanoma, but also to reduce unnecessary biopsies. And in fact, there is good clinical data to support this, to support both of those things. And I want to also make the point that for clinicians of all experience levels, this has been shown to be true. So a study was done showing that residents, dermatology residents, dermatology advanced practice providers, including PAs and nurse practitioners, as well as board-certified dermatologists, all improved their diagnostic accuracy by incorporating Nevisense into lesion evaluation.

What has been your experience in communicating the purpose and value of Nevisense to patients during exams?

Dr Hess: Patients are very open to this, and in fact, they love the idea of using a device that provides some objective data to augment my clinical judgment. So the response from my patients has been very, very positive, especially when I explained to them that this is going to increase the diagnostic accuracy. It may allow for earlier detection of melanoma and also may avoid unnecessary biopsies. So my patients really understand the value here. And in fact, since we've incorporated this into my practice, I think this is one of the things that has helped distinguish my practice in the way that we evaluate and screen for melanoma.

What learning curve should dermatologists expect when adopting this tool into practice?

Dr Hess: When first incorporating Nevisense into practice, it is important first and foremost that everyone using the device be trained. So there is some training that has to take place. It's an FDA-required training. I want to mention that the decision to proceed with a Nevisense analysis has to be made by a clinician. However, the procedure itself can be delegated and performed by one of the associated clinical staff in the office. It does not actually have to be performed by the provider. So training is one thing that's really important. The second thing that's important is workflow and how and when is this procedure going to be performed on the patient? So that's another piece of the learning curve. And then interpreting that data and incorporating it into the diagnostic algorithm is important because the score in itself is not going to dictate the decision to biopsy or not. It has to be used in combination with clinical judgment, and that does take some time and experience. But overall, it was fairly seamless and easy to incorporate the device. The company that makes it, SciBase, will provide training for the office staff. And within a couple of weeks we had a great workflow and we're up and running with the device, and now we use it every day.

Are there limitations or caveats with Nevisense that you think are important for clinicians to understand? 

Dr Hess: I think there are definitely some limitations and caveats. And first of all, I want to reemphasize that again, this is not a standalone screening tool. It has to be incorporated into the clinician's judgment based on visual assessment and dermoscopy. Second, there are certain areas where this device cannot be used. For example, you cannot assess lesions on acral skin, such as the palms and soles of the feet. You cannot assess pigmented lesions on mucosal sites or areas where there's active dermatitis or scarring like from a previous biopsy. And you can also not test lesions that are present within a tattoo. So there are some inherent limitations to the device itself. It is approved for use in adults and children, so that is not a limitation, but there are some limitations. 

Are there any insights you would like to share regarding electrical impedance spectroscopy for skin cancer screening?

Dr Hess: Sure. To highlight some of the key features, it's a non-invasive device, so by itself, there are no needles, there's no pain. And one of the other key features is that it uses electrical impedance spectroscopy to analyze the lesion below the surface of the skin. So malignant cells and benign cells actually have different resistance to this electrical impedance, and so the device is actually able to capture data below the surface of the skin, which provides additional information compared to what we can see on the surface of the skin itself. That's the limitation with visual assessment and dermoscopy, we're basically looking at the epidermis of the skin, whereas this device can screen deeper than that. I also want to mention that it's objective data and it gives a score from 0 to 10, and if the score is 3 or less, the negative predictive value for melanoma is greater than 99%, but scores 4 and higher directly correlate with the likelihood that a lesion may be malignant. So that's essentially the nuts and bolts of the device. It's a fairly small device with the footprint slightly larger than a laptop computer, and it can be transported from room to room.

I also want to mention that there is a CPT code for using this device. So in other words, clinicians, when they perform this procedure, they can actually bill the payers for this because there is a CPT code that already exists. So that one can get reimbursed for the work involved in performing this performing the procedure.