Biopotential Assessment—An Alternative in Oral

Biopotential Assessment—An Alternative in Oral
IJHNS
Sonal P Vahanwala
10.5005/jp-journals-10001-1248
Original research
Biopotential Assessment—An Alternative in Oral
Squamous Cell Carcinoma Diagnostics: A Study
1
Sonal P Vahanwala, 2Soumyo Mukherji, 3Arvind Dhawangale, 4Sourabh Agrawal
ABSTRACT
Aim: The aim of this study was to ascertain the relation between
surface electrical potential and the presence of cancer in the
buccal mucosa and their correlation.
Materials and methods: A device was designed to measure
the skin potentials on the face, and various head and neck
carcinomas can be detected in a noninvasive way. The present
study is a case control study in the ratio 1:1, comprising two
groups of 10 individuals each. The two distinct groups of the
study are as follows:
1. Normal subjects group consisting of individuals with no habit
of tobacco, with the absence of any lesion active or passive
on the skin or buccal mucosa.
2. Cancer patients group consisting of individuals attending
the head and neck services at the Tata Memorial Hospital,
Mumbai, with the habit of tobacco consumption and having
a lesion on the buccal mucosa with biopsy confirming
diagnosis of squamous cell carcinoma (SCC).
Results: Sites of SCC were significantly electropositive
compared with control sites in normal tissue. But noncancerous
lesions yielded no potential difference between the lesion and
control sites.
Conclusion: The skin surface potential values are maintained
in an individual with no cancerogenesis, whereas in oral
squamous cell carcinoma (OSCC) the lesion values are more
electropositive than the surrounding areas. This can be used
to detect OSCC.
Significance: The device designed is patient-compliant and can
be used in cancers of breast, colon, etc. More research work is
recommended on skin surface potentials.
Keywords: Electric, Electrodes, Oral squamous cell carcinoma,
Skin surface potentials.
1
Professor and PhD Student, 2Dean and Professor, 3Research
Associate, 4Research Scholar
1
D.Y. Patil University School of Dentistry, Navi Mumbai
Department of BioScience & BioEngineering, Indian Institute of
Technology, Mumbai, Maharashtra, India
2
Student Affairs, Indian Institute of Technology; Department of
BioScience & BioEngineering, Indian Institute of Technology
Mumbai, Maharashtra, India
3,4
Department of BioScience & BioEngineering, Indian Institute
of Technology, Mumbai, Maharashtra, India
Corresponding Author: Sonal P Vahanwala, Professor and
PhD Student, D.Y. Patil University School of Dentistry Navi
Mumbai; Department of BioScience & BioEngineering, Indian
Institute of Technology, Mumbai, Maharashtra, India
168
How to cite this article: Vahanwala SP, Mukherji S, Dhawangale A,
Agrawal S. Biopotential Assessment—An Alternative in Oral
Squamous Cell Carcinoma Diagnostics: A Study. Int J Head
Neck Surg 2015;6(4):168-174.
Source of support: Nil
Conflict of interest: None
INTRODUCTION
The relationship between bioelectricity and electrical
technology has been a long and a two-way street. Its
history1 may be traced back through many centuries, but
the starting point that could be considered is the work
of Galvani in 1760s, who discovered the electric battery
formed by dissimilar metals in an electrolytic solution,
and the stimulation of nerves by the current so generated.
Through the 19th century, the work of Helmholtz, who was
both an eminent physicist and physiologist, put forward
the concept of electrical double layer, which is fundamental
to the understanding of bioelectric potentials existing at
membrane interfaces in all biological systems.
The biological systems 2 have electrical activity
associated with them. This activity can be a constant DC
electric field, a constant flux of charge-carrying particles
or current, or a time-varying electric field or current
associated with some time-dependent biological or
biochemical phenomenon. All healthy living cells have a
membrane potential of about –60 to –100 mV. The negative
sign of the membrane potential indicates that the inside
surface of the cell membrane is relatively more negative
than the immediate exterior surface of the cell membrane.3
In a healthy cell, the inside surface of the cell membrane
is slightly negative relative to its external cell membrane
surface.4 When one considers the transmembrane potential
of a healthy cell the electric field across the cell membrane
is enormous, being up to 10,000,000–20,000,000 V/m.5
The healthy cells intracellularly maintain a high
concentration of potassium and a low concentration of
sodium. But when cells are injured or cancerous, sodium
and water flow into the cells and potassium, magnesium,
calcium, and zinc are lost from the cell interior and the cell
membrane potential falls.6-8 Many authors have reported
that cancer cells have: (a) Higher intracellular sodium, (b)
higher content of unstructured water, (c) lower intracellular potassium, magnesium, and calcium concentrations,
and (d) more negative charges on their cell surface.7-10
The available evidence suggests that cancer develops
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Biopotential Assessment—An Alternative in Oral Squamous Cell Carcinoma Diagnostics: A Study
within a background of dysregulated proliferation encompassing a field. Hence, preliminary studies which use
invasive needle electrode indicate that the region of electrical depolarization extends to the skin surface in quadrants
of the breast which harbors malignancy, Davies.11
The cancer cells have lower transmembrane potentials than normal cells and altered membrane permeability. These cell membrane changes interfere with the
flow of oxygen and nutrients into the cells and impair
aerobic metabolism causing cancer cells to rely more on
anaerobic metabolism for energy production. Anaerobic metabolism, excessive sodium concentrations, low
transmembrane potential, and pH alterations in turn
create intracellular conditions more conducive to cellular
mitosis.
ELECTRICAL DETECTION OF NEAR
SURFACE CARCINOMA
Experimental results have shown that during oncogenesis
there are changes in the ionic composition of the cell.
There are changes in the cell membrane composition
as well. During oncogenesis the intracellular Na+
concentration increases and K+ concentration decreases,
and the permeability for Na+ ions also increases. The
extracellular fluid would then reflect as changes in
the electrical potential of the cell. These changes in the
potential could affect the surrounding electric field and
can be measured on the surface if these changes are close
to the skin surface.
In case of breast cancer, majority of tumors are
superficial and palpable. In such cases skin surface
potential measurements can have diagnostic value,
especially in reducing unnecessary diagnostic tests with
inconclusive findings. Proliferative changes in the breast
epithelium are an intrinsic aspect in the development of
breast cancer and results in regions of epithelial electrical
depolarization within the breast parenchyma, which
extend to the skin surface. Diagnostic information can be
obtained from noninvasive and nonimaging test based
on skin surface electropotentials.
REVIEW OF LITERATURE
As seen in Table 1, the concept budded in the 1990s and
various studies were attempted. It may be concluded
that this technique will be useful for the near surface
carcinoma. Notable among these is HFN cancers –
particularly squamous cell carcinoma (SCC). In India
the prevalence of SCC is relatively high due to tobacco
usage—both as cigarettes and analogues as well as
chewing tobacco. As per the recent Global Tobacco Survey
(GATS) India Report (2010), the current use of smokeless
tobacco among adult males in India is as high as 32.9%
and among females it is 18.4%. Overall 26 of the adult
population consume smokeless types of tobacco. Owing
to the widespread nature of the disease, an inexpensive
modality for detection and amount of intervention will
be particularly useful. This study set out to explain the
electrical potential measurements as an inexpensive and
noninvasive alternate method to traditional methods.
Most of the clinical research has been focused on
evaluating the effectiveness of the test for the differential diagnosis of localized suspicious cancerous lesions.
The next step would be for further development and
clinical assessment of the technology as a new modality for cancer screening. For this application, additional
sensors would be utilized to allow measurement of
electropotentials independent of lesion location and
for asymptomatic individuals. The objective would be
identification of high-risk patients by detecting abnormal
levels of relative depolarization, as reflected by higher
electropotential differentials. These patients could then
be referred for imaging or other tests. Initial pilot studies
Table 1: Early researchers of skin surface potentials in cancer
Study
Measurements of cell membrane potential in
breast tissue and in breast epithelial cells to
explore the relation between cell membrane
potentials, oncogenesis and electrical potentials
previously measured on the breast surface.
A multi-centric study was carried out in 661
women to see whether measurement of the
breast electrical activity with surface sensors
could distinguish benign and malignant breast
disease [Biofield test]
A biofield diagnostic test was done on 182
women scheduled either for mammography or
ultrasound or both
Author
Marino et al
199412
Notes
The potentials were in the range of –16.2 ± 2.8 mV for benign
cases. And –13.3 ± 2.2 mV for malignant breast lesions.
Cuzik et al
199813
They found a highly significant trend of progressive electrical
changes according to the characteristics of biopsied tissue.
Discriminatory information was obtained in both pre-menopausal
and post-menopausal women. The test procedure was similar to
an ECG where in non-invasive sensors were used to measure the
skin surface potentials. The results revealed specificity of 55% and
sensitivity at 90% for palpable lesions.
Subbhuraam This test demonstrated high values of sensitivity 96.23, specificity
VS, 201214
93.80% and accuracy 94.51%. The clinical study results showed
that this modality can help physicians to differentiate benign and
malignant breast lesions.
International Journal of Head and Neck Surgery, October-December 2015;6(4):168-174
169
Sonal P Vahanwala
using a nondirected or screening-type array indicate that
cancers produce higher differentials than benign lesions
or normal tissue.
Another application of this technology would be
for the diagnosis of recurrent cancer. In the irradiated
breast, e.g., mammography has been shown to have
a sensitivity of only 64% for recurrent carcinoma in
patients who previously had undergone conservative
surgery. The Biofield diagnostic array12 could be utilized
for these cases because the region of suspicion, i.e., the
site of the previous cancer, is identifiable. Pilot studies
are currently under way in Europe to determine the
potential effectiveness of the Biofield test for this
application. Monitoring the effectiveness of therapy
may be another potentially useful application of the
technology.
Currently, it is difficult to assess the effectiveness
of therapy prior to mortality reduction endpoints in
randomized trials. An alternative approach might
be to evaluate tissue proliferation before, during, and
after cycles of therapy. There is evidence11 to support
the use of the skin surface potential measurements for
the assessment of tissue proliferation. The evidence
comes from the multicenter trials, in which it was found
that proliferative and atypical benign lesions produced
greater electropotential differentials than nonproliferative benign lesions.
The key aspect of this technology is its ability to
sample electrical potentials concurrently from an array
of many sensors placed on the skin. This allows multiple
comparisons between sensor sites for the detection
of abnormal proliferation, which reveal regions or
pockets of relative depolarization on the surface of the
skin, analogous to pockets of low- and high-pressure
systems seen on weather maps. The technology in its
present form confers a number of inherent advantages.
These include:
• The test is completely noninvasive and there is no
pain associated with the procedure.
• There is no exposure to ionizing radiation or other
energy.
• The test is simple to implement and can be performed
by a technician.
• Conducting the test takes about 15 minutes and the
result is available immediately.
• The test can be repeated as often as needed.
• The test result is objective and does not require an
expert for interpretation.
• The test is cost-effective, hence can be widely used.
• Since the test is noninvasive, simple to use, and
is cost-effective, it could be eventually integrated
into various health care settings where primary or
170
basic evaluation occurs and may provide adjunctive
information for assisting in the resolution of screen
detected abnormalities or suspicious palpable lesions.
Hence, a study to compare the skin surface potentials
in normals and patients suffering from oral squamous
cell carcinoma (OSCC) was undertaken.
MATERIALS AND METHODS
The block diagram shown in Figure 1 provided reading in
each channel to measure the skin surface potentials with
reference point and shows the data using alphanumeric
display.
The above-mentioned surface potential measurement
circuit was made using MSP430F1611 with all necessary
peripherals, analog circuit, and power management unit.
The block diagram shows different parts of the board
with specific tasks. The modules are described as follows:
• Processing unit: The printed circuit board (PCB) was
built around MSP430F1611 microcontroller, typically
designed for acquiring data from external peripheral
devices. The analog data was converted into digital
value by using analog to digital converter (ADC) and
after processing, the data was displayed on a 20 × 4
alphanumeric LCD panel. The inbuilt digital port
and digital to analog converter (DAC) control the
analog signal for processing by using a level shifter
to keep the ADC input value positive. (Successive
approximation register type of ADC can convert only
positive analog input voltage.)
• Multiplexer unit: The circuit consisted of four 4:1
multiplexers that receive analog signal from the
electrodes and feed to the analog section according
to the channel selection provided by the controller.
The multiplexing is achieved by using two integrated
circuits (ICs) 74HC4052 (dual 4:1 multiplexers).
• Analog unit: The circuit was designed to receive ± 60
mV at input side, which converts to the value of
0–2.5 V and fed to the ADC of the microcontroller.
The analog consisted of three parts built using
IC OP07.
• Amplifier section: This section was a noninverting
amplifier with a gain of 3, and the amplifier takes
input from the multiplexer and feeds it to the filter.
– Filter section: This section was second-order
Chebyshev low pass filters with a cutoff frequency
of 1.6 Hz. These filters only pass voltages near
to DC and block all unwanted signals (like
electrocardiogram, electromyography, respiration
interference, power line noise). Then these voltages
are fed to the controller through level shifter.
– Level shifter section: Since the controller ADC would
not be able to handle any negative voltage, so to
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Biopotential Assessment—An Alternative in Oral Squamous Cell Carcinoma Diagnostics: A Study
measure negative voltage the input was shifted to
a positive value using a level shifter.
• Power supply unit: The circuit was designed to work
on the 9 V battery. The regulator IC LM7806 provided
6 V to the analog section. A supply inverter IC ICL7660
provided a negative voltage to the analog section. In
order to provide power to the controller, a low dropout
(LDO) regulator IC LP2981 was used, which provided
3.3 V to the mixed signal processor (MSP).
• Display unit: This section consisted of a 20 × 4 alphanumeric display with digital level shifters. The MSP
fed the information to the level shifter IC 74HC8T245
which shifted the data to 5 V logic from 3.3 V and drive
the LCD display directly.
• Programming: The microcontroller was programmed
to check every input skin potential and show it on the
display.
The present study was a case control study in the
ratio 1:1, comprising two groups of 10 individuals each.
The two distinct groups of the study are:
1. Normal subjects group: This consisted of individuals
with no habit of tobacco, with the absence of any lesion
active or passive on the skin or buccal mucosa. This
group has medically fit subjects.
2. Cancer patients group: This consisted of individuals
attending the head and neck services at the Tata
Memorial Hospital, Mumbai, with the habit of tobacco
consumption. Each individual has a lesion on the
buccal mucosa, with biopsy confirming diagnosis of
SCC.
As shown in Figure 1, a device designed for measuring
skin surface potentials was utilized. It comprised a single
PCB provided with various other components, fabricated
as shown in Figure 2.
After acquiring ethical clearance and patient consent,
each individual from the above group was selected for
the study. Eight channels were placed on the skin surface
of the face bilaterally. First four on the right side followed
by the other four on left. Special care was taken to choose
subjects who were freshly shaven [skin prepared] to
avoid readings with any artifacts or noise in the recordings. The electrodes were stuck separately, such that
there was no overlap of even the adhesive material. All
care was taken to prevent any leakage of the electro-gel
beneath the electrodes, thereby avoiding any shorting in
the circuits. Channels 1 to 4 were placed on the affected
side of the face and channels 5 to 8 were placed on the
contralateral side of the face. Channel 1 paired with
channel 5; channel 2 paired with channel 6; channel 3
paired with channel 7; channel 4 paired with channel 8;
i.e., these channels were placed bilaterally symmetrical
on either side of the face. The reference electrode was
put in the sternum.
In the cancer group, channel 4 was kept on the skin
overlying the suspicious cancer area. All the other
channels were placed on normal overlying skin of
the face. Both the groups were subjected to following
comparisons and assessment of various parameters
was done (Table 2):
Parameter 1:Channel 4 has to be specifically compared
to its anatomically similar contralateral
side which is nondiseased. The difference
of this anatomical site was denoted
by D1.
D1 = channel 4 − channel 8
Parameter 2:Readings of channel 4 have to be compared
with the channels on the same side, i.e., the
diseased side. Hence the average of channels 1 to 3 has to be taken, presuming that
channels 1 to3 clinically do not not overly
on the cancerogenic site. The difference is
denoted by D2.
Thus, D2 = channel 4 − average of channels
1 to 3
Parameter 3:The skin surface potential on both half
of the face has to be evaluated to judge
the difference in the clinically affected
side as compared to sound normal side
of the same individual. This difference is
denoted by D3.
D3 = average of channels 1,2,3,4 − average
of channels 5 to 8
The numerical values obtained thus were subjected
to Student’s t-test.
Table 2: Diagrammatic representation of parameters evaluated after obtaining the readings
D1
(Comparing Ch 4 with 8)
D2
(Comparing Ch 4 with mean of Ch 1 to 3)
D3
(Bilateral comparison)
Normal group
√
[Interpretation 1]
√
[Interpretation 2]
√
[Interpretation 3]
Comparing right half with the left half
Cancer patients
√
[Interpretation 4]
√
[Interpretation 5]
√
[Interpretation 6]
Comparing cancerous
side from the normal side
The numerical values obtained thus were subjected to Student’s t-test
International Journal of Head and Neck Surgery, October-December 2015;6(4):168-174
171
Sonal P Vahanwala
• Data given for two groups were:
Sample size
Mean
Standard deviation
Normal
n1 = 10
X1
SD1
yielded no potential difference between the lesion and
control sites.
Cancer
n2 = 10
X2
SD2
DISCUSSION
STATISTICAL EVALUATION
Applying the Fundamentals of
Null Hypothesis
Null Hypothesis: There is no significant change in the
surface potential measurements
(Normal Group):
D1:Channel 4 − channel 8 = 0
(Not significant)
D2:Channel 4 − (Average of channels 1 to 3) = 0
(Not significant)
D3:That is, Left-hand side of the face and right-hand side
of the face have no difference
LHS − RHS = 0
(Not significant)
Thus, in the normal group subjects obey Null
Hypothesis.
Similarly, when cancerogenesis sets in the area
affected it is unable to maintain the surface potential.
{Cancer Group}:
D1: Channel 4 − channel 8 ≠ 0
(Significant)
D2: Channel 4 − (average of channels 1 to 3) ≠ 0
(Significant)
D3:T hat is, Comparing averages of all channels of
cancerous side vs normal side has no difference
LHS − RHS ≠ 0
(Not significant)
RESULTS
In normal subjects (Table 3), the skin surface potential
values should be equal bilaterally, i.e., not significant as
there was no carcinogenesis. Statistical data reveals that
there was no significant difference between Channel 4
and 8 for 90% confidence interval. These findings
are similar to earlier results that sites of SCC were
significantly electropositive compared with control
sites in normal tissue, but that noncancerous lesions
Oral cancer is a problem of great concern globally.
Nowadays, with the introduction of smokeless tobacco
in the Eastern Asia, the abuse has percolated among
the teenagers and male to female ratio of the habit is
comparable. Cancer is curable if detected early. It is the
dream of every clinician to curb the menace caused
by this life-threatening disease. Extensive survey and
screening protocols are designed to diagnose the disease
at a very early stage.
Wilson and Jungner13 have mentioned about the
criteria for a disease to be categorized to undergo a
screening protocol. Since oral cancer meets at least three
of those criteria, screening measures seem to be seriously
warranted. Owing to the cost implications and the
possibility for over-diagnosis (false positive result), strict
criteria are needed to evaluate the screening program and
to determine its appropriateness. Similar to pap smear,
which has stood the test of time for diagnosing cervical
cancers, there is no test available to diagnose oral cancer.
Vascular-related streaming potentials and neural
activity may contribute to the genesis of the electrical pot­
en­tials, but they arise primarily from Nernst potentials
across various tissue membranes. The altered electrical
potentials reflect the presence of transformed cells during
oncogenesis. This effect is due to change in interstitial K+
concentration that arises from alterations in the activity
of K+ channels. Surface electrical potentials shows a
change in individuals with cancer, if measured on the
skin. It is found that decreased intracellular K+ concentration occurs during oncogenesis, and this account for
the observed association between elevated electrical potentials and cancer. Decreased intracellular K+ suggests
a higher extracellular K+ level, and the cancer site would
therefore tend to be electropositive compared with a control site in normal tissue because addition of relatively
few K+ could produce electrical potentials comparable
in magnitude.
Table 3: Normal group
Para meter
Test for
t
p-value
Interpretation
D1
Channel 4 – channel 8
0.505
0.6357
1) No significant difference between Ch 4 and 8 for
90% confidence interval
D2
Channel 4 –
(average of channels 1 to 3)
0.9834
0.3706
2) No significant difference between channel
4 and average channels 1, 2, 3 for 90% confidence
interval
D3
Comparing left hand side with right hand
side of the face [LHS with RHS]
1.4737
0.2
3) No significant difference between left hand side
with right hand side of the face for 90% confidence
interval
172
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Biopotential Assessment—An Alternative in Oral Squamous Cell Carcinoma Diagnostics: A Study
Table 4: Cancer patients group
Para meter Test for
t
p-value
Interpretation
D1
Channel 4 – Channel 8
2.1965
0.071
4) Significant difference between Channels 4 and 8
for 90% confidence interval
D2
Channel 4 – (average of channels 1 to 3)
2.3129
0.060
5) Significant difference between Ch 4 and average
channels 1 to 3 for 90% confidence interval
D3
Comparing averages of all channels of
cancerous side vs normal side
1.9126
0.105
6) No significant difference between the averages
for Cancerous side and the unaffected contralateral
side for 90% confidence interval
Significant difference for 85% confidence interval
Review of the literature has generated a lot of interest
in modalities of screening, which were noninvasive,
showed patient compliance, and ease of repeatability
in past few years. Skin surface potential measurement
has appeared to be lucrative as a screening tool. Hence
various experiments were conducted, in which the skin
surface potential measurement studies were pursued. It
is hypothesized that, if we were able to detect the surface
potentials on the surface of the skin using electrodes and
quantify them, then that can help in differentiating disease
state like cancers from the normal physiologic conditions
in man. Thus the skin surface potential measurement
(a modality which analyzes the skin surface electrical
potentials measured by an array of electrodes) test holds
a promise in diagnosing breast cancer. Thus if the device
can be used to measure the skin potentials on the face,
various head and neck carcinomas can be detected in a
noninvasive way, given that the skin surface potentials by
and large remain stable and same in a normal individual.
The cells are able to maintain the Na–K influx. Hence the
difference on the left half of the face as compared to right
half of the face should be more or less zero. Statistically
evaluating the results should be not significant.
In normal subjects (Table 3), in the right half of the face,
the skin surface potential values should be equal, i.e., not
significant as there was no carcinogenesis. Statistical data
reveals that there was no significant difference between
Channel 4 and 8 for 90% confidence interval. This was
because the surface potential in normal individual was
physiologically maintained equal bilaterally. The value,
if compared, was almost zero or less than zero. Hence
was not significant.
The present study included all cases of SCC confirmed
by gold standard biopsy. Channel 4 was always kept on
the area where clinically abnormal multiplication of cell –
i.e., cancerogenesis—was suspected. Hence behavior of
Channel 4 was compared to various other channels in
both the groups. Electrical changes may provide a physical
basis for distinguishing between normal and cancerous
growth.14 Our findings are similar to earlier results15 that
sites of SCC were significantly electropositive compared
with control sites in normal tissue, but that noncancerous
lesions yielded no potential difference between the
lesion and control sites. In preliminary studies done by
researchers, elevated surface electrical potentials were
found to be associated with cancerous lesions beneath
the skin in women with palpable breast masses.16 The
aim of the present study was to ascertain the relation
between surface electrical potential and the presence of
cancer in the buccal mucosa. In cancer patients (Table 4),
in the right half of the face, the skin surface potential
values would not be the same and hence should be
statistically significant. Table 4 also reveals that Channel
4 and the contralateral side, Channel 8, showed statistical
significant results. There was a significant difference
between Channel 4 and 8 for 90% confidence interval.
Also, there is a significant difference between Channel 4
and average channels 1 to 3 for 90% confidence interval.17,18
CONCLUSION
The differences in channels of normal subjects are not
statistically significant as the normal skin surface potential is always maintained at a particular level. So, the
skin surface potential values appear close to each other
and their differences are not statistically significant.
This implies that they are close to zero. The affected area
shows significant difference with the ipsilateral channels
as well as the contralateral channels. That means if clinically known cancer lesion is given, prediction of the skin
surface potential of the area can be made and then quantified. The affected side may be at the same skin surface
potential because of process of cancerogenesis. Hence the
difference of the affected side appears “not significant”
statistically, according to the findings of interpretation.
It is significant only at 85% confidence interval. Larger
sample size is hence required to prove a statistical relevance. Trials need to be carried out on cancers occurring
in the other parts of the body like breast, colon.
CLINICAL SIGNIFICANCE
Our findings are similar to earlier results that sites of SCC
were significantly electropositive compared with control
sites in normal tissue, but that noncancerous lesions
yielded no potential difference between the lesion and
International Journal of Head and Neck Surgery, October-December 2015;6(4):168-174
173
Sonal P Vahanwala
control sites. In preliminary studies done by researchers,
elevated surface electrical potentials were found to be
associated with cancerous lesions beneath the skin in
women with palpable breast masses. If clinically known
cancer lesion is given, prediction of the skin surface
potential of the area can be made and then quantified.
ACKNOWLEDGMENT
Author would like to thank Dr. Pankaj Chaturvedi,
Professor, Tata Memorial Hospital and Research Centre,
Head and Neck Services, Mumbai for his help and
support in carrying out the study.
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