Dr JJ Masani explores the science and technique behind removing moles using radiosurgery
Radiosurgery (synonymous terms: radio-wave surgery, micro-wave surgery, high- frequency surgery, electro-surgery, Bovie’s Current) has a high frequency current of 2 to 4 MHz (million times/sec), and is cold to touch at the cutting electrode, thus produces less tissue damage.1 Domestic mains electric current of 50Hz (1 Hz = 1 wave form per second) creates copulation with high temperature, as well as tissue damage.1 The cutting electrode has less lateral heat than most lasers, creating excellent cutting ability, less tissue damage, less post-operative pain and above all, less scarring when removing moles. As there is no necrosis or carbonisation, the specimen can be sent for histopathology. There is also no pressure applied to skin, as with a scalpel. Radiowave surgery should not be confused with electric cautery, where the equipment uses heat (50 to 400 Hz) – the cutting electrode of radiosurgery is stone cold.1 Besides excision of moles, radio-wave surgery can be used (with no scarring to minimal scarring) in senile angiomas, xanthomas, keloids, rhinophymas, spider veins, epilation of hair and skin tightening). In my opinion we are, as aesthetic physicians, dermatologists and surgeons, underusing this innovative technology. There seems to be a lack of knowledge on radiosurgery as it is not yet taught in medical schools. Compared to scalpel technology, the equipment is expensive and the technique is quite different.
The application of heated stones to obtain haemostasis has been used since ancient times.2 Later, during the nineteenth century, surgeons used cautery and electricity within medicine. Although radiosurgery was introduced before the 1920s, credit is given to physicist William Bovie, who developed the first prototype of the modern radiosurgery generator for diathermy. This allowed Dr Harvey Cushing, a neurosurgeon, to successfully remove a vascular myeloma from the head of a 64-year-old patient on 1st October 1926 in Boston. Liebel-Flarsheim Co then purchased the patent for the Bovie Unit for $1, and proceeded to make millions.2
|COMPARISON OF LATERAL HEAT AND TISSUE DAMAGE BY ENERGY SOURCES2|
|1. Radio-Wave Surgery||0.02 mm damage|
|2. CO2 Laser||0.5 mm damage|
|3. Holmium Laser||0.5 mm damage|
|4. ND: YAG||2.3 mm damage|
Patients with cardiac pacemakers are an absolute contraindication as radiowaves interfere with cardiac pacemakers – they too work on the principles of electromagnetic radiation.3 Some newer pacemakers are not altered by radiosurgery wave forms, and this should be checked with the cardiologist prior to treatment. A patient must not wear jewellery or be in contact with metal due to the risk of burns caused by an alternate current path or "capacitive coupling". Radiowaves are non-ionizing, thus cause no damage to animal DNA or surrounding tissue, just like mobile phones. 4
However, all general rules of safety with electro-magnetic equipment must be followed. phones. This includes making sure no alcohol is used for cleaning and there is no presence of ignitable gases in the operating room.
The first principle of all electromagnet wave form is that electrons move in an electromagnetic medium, always completeing a circuit.2 See Figure 1 where the lead wire from the generator producing radiowaves (2 MHz to 4 MHz high frequency) passes to the active electrode with a loop, which is used in a feathering manner to cut the mole. The loop is at room temperature. The radiowave then travels through the body on to the antenna (like the aerial of a radio or a mobile phone) and back to the generator. The second principle to understand is that there is a frequency and a wavelength to consider in any electromagnetic radiation, with domestic power having a long wavelength, low frequency and is hot to touch. Radio-frequency, on the other hand, is a shorter wavelength with high frequency and is cold to touch. Up to visible light the infrared spectrum is non-ionising to our DNA, and beyond UV light it is ionising to our DNA and harmful.2 To understand the principle of an electric circuit, one could compare it with our WC where the cistern, which is full of water, has potential energy (voltage), and when we pull the flush, water runs down the pipe (current - measured with amperes) and the force with which it runs is classed as watts or power, or if timed in one second, a joule. Thus Voltage x Amperes = Watts. (Remembered by the pneumonic: VAW) Ohms is the resistance offered by what we clear in the WC, or in case of radiowave surgery, is our body offering the resistance. The soiled water then goes to the cesspit, gets purified and returns to the cistern, thus completing the circuit. (As demonstrated in Figure 2).
After taking a detailed medical history and carrying out an examination of the patient, I proceed to use the Dermascope to distinguish between benign and malignant moles (BCC, SCC, melanomas). Appropriate training and experience in the use of the Dermascope brings about a better diagnosis of the naevi and its nature, prior to excision. Good quality images can now be taken using a Dermascope with the iPhone 4, 5 or 6, and other smart phones with an adaptor costing less than £30.00. See Figure 3.
If the lesion is recognised as malignant, or after histopathology is diagnosed as malignant, then the general rules of surgical principals apply and excision has to be wider than the margins, as well as deeper, to reach subcutaneous tissue. This too could be carried out by radio-surgery using a tungsten wire instead of a loop, but the patient must then be told that a scar will result owing to a wider and deeper excision, and sutures or a skin graft may apply.
Once the naevi is diagnosed as benign, one can use the radiowave generator and tungsten loop to feather and shave the naevi until the pigment is removed without hitting the dermis to avoid scarring. The tissue scooped can be sent for histopathology as there is no carbonisation of tissue. Similarly senile angiomas, xanthomas, keloids, rhinophymas, spider veins and warts can be excised without scarring.1
Clinical Data: Possible Seborrhoeic keratosis. Excised by radio surgery. Present for one month.
Macroscopic: Lesion from scalp: A rough pale hairy slightly friable skin lesion 5 x 4 x 3 mm. Bisected.
Microscopic: Skin shows an irritated seborrhoeic keratosis. There are no atypical features, and the lesion has been excised.
Diagnosis: Skin from scalp – Seborrhoeic keratosis.
Dzingel, R, ‘Radio Surgery in Dermatology’, Cosmetic Medicine, 25 (2004), p.1430-4031.
Masarweh, N et al, ‘Electro-Surgery: History, Principles and Current and Future Uses’, American College of Surgeons Publications, (2006), p. 520.
‘Electromagnetic interference’, MHRA, (2014) http://www.mhra.gov.uk/Safetyinformation/Generalsafetyinformationandadvice/Technicalinformation/Electromagneticinterference/ Last accessed: 12/12/14.
‘Cell Phones and Cancer Risk’, National Cancer Institute, (2013) http://www.cancer.gov/cancertopics/factsheet/Risk/cellphones Last accessed: 12/12/14.