Superficial X-ray Therapy Research Articles

A Personal Approach to the Treatment of Verrucae

AbstractVerrueae or warts of the soles are notoriously stubborn to all forms of treatment. They tend to recur and as many as 20 per cent may show this tendency. The many methods of dealing with them, ranging from the orthodox to Tom Saw-year’s method of burying a dead cat in the Church graveyard at midnight, are in themselves an admission of failure leading to frustration in both patient and doctor alike. In a minority of cases superficial X-ray therapy is tried as a last resort and should this fail the unhappy patient resorts to insoles, plasters, chiropody and finally to treating himself. It is true to say, whilst no patient likes having verrueae, no doctor enjoys treating them.

A new superficial X-ray therapy unit

There is currently a shortage of commercially available superficial X-ray therapy units in the range 50–150 kV, both for new departments and for the replacement of old equipment. As a result of this shortage, an X-ray unit designed for industrial radiography has been used as the basis of a new superficial X-ray therapy unit. A detailed specification (Royal Marsden Hospital, internal report, 1969) was first written for such a unit covering all aspects of performance (beam qualities, exposure rates, field sizes, treatment distances, safety interlocks, etc.) and the new unit was built to this specification. The design and construction of the unit and its performance as a therapy set are described. The X-ray generator is a modified Pantak 150 kV unit type LC 150 incorporating a Thermax SLT/T X-ray insert tube. The HT generator and the cables are those in use on the 150 kV industrial units. The control console and the oil cooler were designed by Pantak Ltd. for this X-ray unit on the basis of our specification...

治療のための撮影法 : 電子線の制動X線による撮影

In case of superficial x-ray therapy the position and size of the field is decided on the treatment-bed by radiography with supervoltage x-ray, in order to coincide it with the tumor region accurately. On the contrary it is not necessary to use this procedure in electronbeam therapy, because the tumor is usually superficial and easily palpable. But I believe, that in electron therapy also it is important to know that the localization of the tumor, the beam direction and the relation between the tumor and the neighboring sensitive organs. Therefore I consider the same technical procedure by the use of secondary radiation (Bremsstrahlen) during electron beam therapy as the localization-radiography by supervoltage x-ray. In this paper my experimental results are described.

Simple and rapid method of checking the output of superficial X-ray and grenz-ray therapy machines

A number of superficial X-ray and grenz-ray therapy machines in radiotherapy departments are in use which are neither equipped with an integrating dosemeter nor have a dose-rate monitor fitted into the tube housing. Such machines, according to para. 4.1.22 (ii) of the current Code of Practice (1964), require the installation of a device with which the radiographer can make daily checks of the output. Such a device should be very simple and rapid in use, robust and reliable. Only a modest degree of accuracy and sophistication in ionisation chamber design and electronic circuitry is indicated. A system for achieving these requirements is described which is inexpensive and will commend itself to those radiotherapy departments having limited technical resources.

X-RAY CONTAMINATION IN TOTAL-SKIN ELECTRON THERAPY OF LYMPHOMA CUTIS AND EXFOLIATIVE DERMATITIS.

Low-megavoltage electron beams have 4 been utilized during the past fifteen years as one of the major therapeutic modalities in the management of patients with lymphoma cutis (1, 13, 14). Treatment with total-skin electron irradiation has resulted in symptomatic relief of pruritus and burning and frequently has promoted involution of plaques, skin ulcers, and tumors. Low-megavoltage electron beams have been employed in psoriasis and atopic dermatitis but with more variable results (4, 13, 15). The use of conventional superficial x-ray therapy in lymphoma cutis results in a significant degree of cumulative total-body irradiation. An advantage of electron therapy has been that the penetration of electrons can be controlled, concentrating the ionizing radiation to the pathologically involved epidermis and dermis with relative sparing of the underlying hematopoietic and visceral organs. Cumulative experience with this therapeutic modality, however, suggests that a small fraction of radiation delivered to the skin is in the form of x-rays (7, 13, 14). The advantage of therapy with electron beams is diminished if this x-ray contamination represents a significant proportion of the total ionizing radiation. The purpose of this paper is to present an heretofore unreported source of x-ray contamination occurring during the course of large-field electron-beam therapy. Technics and Instrumentation Thirty-four patients with lymphoma cutis (mycosis fungoides, premycosis fungoides, and lymphosarcoma) and severe exfoliative dermatitis have been treated at the University of California at Los Angeles Center for the Health Sciences during the past two years. Morgan and Dowdy (12) and Haimson and Karzmark (5) have previously described in detail the technical aspects of the 6-Mev linear accelerator employed, 2 and have documented the negligible fraction of x- ray associated with the 6-Mev electron beam. The electrons are magnetically deflected away from a gold target and are scattered through an 0.008-in. nickel window. The beam is collimated entirely within the head by a tungsten primary collimator and tungsten-faced movable jaws. The patients are positioned at a distance of 600 cm, at which point the useful diameter of the beam is about 6 feet, with a uniformity of ± 7 per cent. Seven patients received low-megavoltage electron therapy with an initial energy of 6.5 Mev and a maximum penetration of approximately 2.5 cm of tissue at a distance of 600 cm, with the 50 per cent depth dose at 19 mm. Thirteen were treated with the same 6.5-Mev source but with the maximum penetration reduced to approximately 2 cm with the 50 per cent depth dose at 14 mm. The reduction was accomplished by interposing a 1¼4-in. sheet of Masonite over the exit portal of the collimating system. Further reduction of penetration to approximately 1 cm with a 50 per cent depth dose at 5 mm was employed for 18 patients3 by interposing 3¾4-in. of Masonite added filtration.

RADIATION CANCER OF THE SKIN.

The World literature, while replete with cases of radiation dermatoses, contains a paucity of reports of the more serious sequelae of such cutaneous injuries. Until 1942, approximately only 125 cases of occupational cancer and 63 of therapeutic carcinoma resulting from radiation had been reported from all countries (16, 19, 21, 24). The 36 cases of Cannon, Randolph, and Murray (5) comprise the largest series of radiation cancers. The present reported series includes 59 examples of roentgen and radium carcinoma of the skin resulting from post-irradiation dermatitis. Newly imposed standards of protection and education in precautionary measures have not prevented adventitial x-ray exposures in the dental and medical professions, therapeutic sequelae in patients, and beta-ray burns in workers engaged in atomic energy and medical research programs. The extended employment of x rays, radium, and radioactive substances in medicine for diagnostic and therapeutic purposes and their applicability in industry and governmental projects enhance the hazard. We continue to see patients with radiodermatitis and radiocarcinoma in both clinical and office practice. Twice as many cases of roentgen dermatitis were observed at Massachusetts General Hospital in the decade 1948-1957 as in the preceding ten years (5). In the average fluoroscopic examination of the gastrointestinal tract, including spot-films, it is estimated that the patient receives in the neighborhood of 67 R. In a dental film, 1 to 4 R are received. Thus, with a complete oral x-ray study utilizing 12 to 16 films, the total dose received could amount to 12 to 64 R. When repeated diagnostic procedures are performed, the multiplication of the roentgen factors involved becomes sufficiently alarming to warrant a plea for caution (11). Source of Exposure Our 59 patients may be divided into two groups: (a) 28 in whom radiation cancer developed as a result of adventitial exposure and (b) 31 with radiation cancers of the skin following exposure to deep or superficial x-ray therapy administered for benign dermatoses or malignant tumors (Table I). In those instances resulting from therapeutic x radiation the history usually showed some 6 to 12 superficial radiation exposures given within a period of six months to a year. In 2 patients, there was a history of a single superficial therapeutic exposure for benign dermatitis. One radiation cancer subsequently developed after a single radium application to a small hemangioma of the skin. Those patients engaged in the professional use of x rays and radium had spent from two to forty-three years in association with these modalities, the average being twenty-two years. Incidence In a review of 700 cases of radiodermatitis collected from the literature, the overall incidence of cancer was 24 per cent (7, 11, 13, 14, 21).

POTENTIATION OF HYPERPIGMENTATION FROM X-RADIATION. EFFECTS OF DEMETHYLCHLORTETRACYCLINE THERAPY.

It is well known that hyperpigmentation may develop in darker-skinned races after even small doses of x-radiation. The skin of lightly pigmented Negroes may become nearly black after a few weekly doses of 75 roentgens (r) of superficial x-ray therapy. This effect occurs without visible inflammatory change. During the past few years, attention has been called to photosensitivity, or more properly, phototoxic cutaneous reactions in patients exposed to sunlight during demethylchlortetracycline administration.1,2The effect has been shown to be a quantitative one,3ie, developing mainly when a minimum of 600 mg of this drug was given daily. It was further shown by Schorr and Monash4to be potentiated by both ultraviolet rays of wavelength between 2,800 Angstroms (A) and 3,200 A, and by rays with longer wavelength than 3,150 A which pass through common window glass. Report of Case Recently, I observed the development of moderately severe

THE GRENZ-RAY OUTPUT CHARACTERISTICS OF A SUPERFICIAL THERAPY MACHINE.

In a superficial X-ray therapy unit, the Dermopan, recently installed at this hospital, an unexpected relationship was observed between X-ray output and tube current when the latter was varied from the specified value at the 10 kV setting. It is thought worth while to record this observation, since failure to appreciate this behaviour could lead to serious errors in dosage. It will also be seen that, by means of a simple adjustment of the control circuit of the machine, this characteristic can be turned to good account by providing improved dose control. The equipment uses a self-rectified tube with a beryllium window. A selector switch on the control panel provides for operation at 10, 29, 43 or 50 kVp. An electrical interlock system ensures that the tube can be energised only when the filter appropriate to the selected kilovoltage is in place. A fine control of line voltage is provided. A tube current of precisely 25 mA is specified at all four X-ray qualities. Tube current control is smooth and adequat...

Sebum Production During 16-Epiestriol Administration

The development of acne during puberty is intimately associated with and dependent upon the sebaceous gland hypertrophy that occurs at this time. It is our feeling that sebum provides the fuel for the development in a susceptible individual of the inflammatory lesions characteristic of the disease. 1 Our data indicates that the severest cases of acne occur in patients with large sebaceous glands and high sebum production. 2 Although there are undoubtedly other governing factors in the pathogenesis of the disease, the fact remains that suppression of the large postpubertal glands can favorably alter the course of the disease. For example, fractional superficial x-ray therapy exerts its beneficial effect on acne by suppression of sebaceous gland size. However, the response is only temporary, and after completion of a safely tolerated course of x-ray, the glands promptly regenerate, and as such the disorder may reappear. 3 It is well known that

The Evolution of a Superficial X-Ray Therapy Technique for Carcinoma of the Skin

SUMMARY A basic technique for treatment of carcinoma of the skin is described. Essential objects are high cure rate and minimal late radiation scarring. Eight fractions of 450 rads are used in an overall time of three weeks. Three doses are given weekly except in the third week when the middle dose is omitted. A routine of held size reduction in successive weeks is practised to diminish edge effects on scars. Quality of radiation is varied according to depth of infiltration present. Dosage is reduced for moderately large lesions, and treatment is spread over 4 or 5 weeks for really large lesions. Very significant improvement in resultant radiation scars have followed adoption of the methods described.

Treatment of superficial thrombophlebitis.

To The Editor: Superficial thrombophlebitis occurring in the legs associated with varicose veins is a chronic condition which does not readily respond to treatment. It often necessitates frequent office visits and sometimes complete bedrest or hospitalization. Many forms of therapy have been advocated, especially the daily intramuscular injections of trypsin in oil, which is the treatment presently in vogue. Patients have worn supporting bandages for months, have had anticoagulant therapy, superficial x-ray therapy to the areas of inflammation, rest in bed, elevation of the legs and applications of heat, and stripping operations on the veins The foregoing procedures have resulted in improvement or cure, but the treatment has been prolonged and the relief of discomfort has not been rapid. In my use of these forms of therapy I have not been impressed with the rapidity of improvement in symptoms such as pain, tenderness and local muscle spasm. Recently, in an attempt to limit the pain and muscle spasm which accompanied this condition, I injected small amounts of hydrocortisone acetate suspension (25 mg. per cc.) combined with tetracaine hydrochloride (Pontocaine, 0.15 per cent solution). Each injection contained 0.5 cc. of the hydrocortisone suspension and 1.0 cc. of the tetracaine solution, and was given directly into the painful indurated area of the thrombotic process with a fine needle. The results were very satisfactory. The pain and tenderness improved rapidly, and the next day every patient so treated announced that there had been great improvement. I originally started treatment on many of these patients with daily intramuscular injections of trypsin, rest, elevation and a support bandage; but after starting the use of hydrocortisone in tetracaine locally, the results were immediate and gratifying. I have used this treatment in over 20 cases without any ill effects, and there has been no sloughing of tissue or ulceration. Two injections at intervals of two to three days were sufficient in the great majority of cases; a few patients required three injections. Observations made three months after treatment revealed complete recovery and no relapse in any of the patients treated. Conclusions: Treatment of superficial thrombophlebitis by the local injection of hydrocortisone suspension combined with tetracaine solution has yielded good results. Pain, swelling, and disability have been greatly improved, and there have been no untoward effects. The response to treatment is rapid, compared to that following other methods, and I have adopted this procedure as the one of choice in the treatment of superficial thrombophlebitis of the legs.

An interlock system for a superficial x-ray set.

When superficial X-ray therapy sets are operated with a number of different combinations of kilovoltage and external filtration to produce different qualities of radiation it is desirable that some form of interlocking should be incorporated to prevent the application of an incorrect kilovoltage to the X-ray tube when a particular filter is in use. A method providing for automatic selection of kilovoltage when a filter is inserted in the filter carriage has been described by Herbert and Marshall (1951). The method described here, which is used on a superficial X-ray set with a Variac voltage control, employs only micro-switches throughout, provides for visual indication of the filter in use, and allows the voltage applied to the primary of the H.T. transformer to be read directly. Three qualities of radiation are normally used, obtained by the following combinations of kilovoltage and external filter: (a) 60 kV, no external filter; (b) 100 kV, 1 mm Al; (c) 140 kV, 2 mm Al.

Isodose curves for superficial therapy.

Isodose curves for the low voltages and small fields used in superficial x-ray therapy have been the subject of few publications. Excellent central-axis depth-dose data are available as a result of work by Andrews and Braestrup, by Braestrup, and by Johns, Epp, and Fedoruk. In 1941, Lamerton published isodose curves for four widely used fields at a single half-value layer, and in 1943 Mayneord made available additional material at two lower voltages. Having recently completed work on isodose curves for the small fields used in intracavitary therapy, the authors considered it worthwhile to explore the fields and radiation qualities usually associated with superficial therapy. It was thought that some significant information might be developed regarding the radiation at the edges of such fields and that this might be of value in correlating the size of the lesion and the size of field required for an adequate dose. Instruments and Equipment In the study covering intracavitary fields, a modified Royal Cancer Hospital probe was used. This probe made use of an ionization chamber having a 1-mm. wall of air-equivalent material. It was felt that, for use with the low voltages and filtrations commonly associated with superficial therapy, a thinner wall would be advisable. Accordingly, the 1-mm. wall was reduced to a thickness of 0.28 mm. A check of the uniformity of the wall thickness was made by rotating the chamber in a low-voltage x-ray beam. The internal dimensions of the chamber were: length, 5 mm. and diameter, 3 mm., giving a volume of 0.035 c.c. after deduction of the volume of the central electrode. The chamber was calibrated against a 25-r Victoreen thimble chamber previously calibrated at the National Bureau of Standards. A plot of the wave-length dependence of the chamber is shown in Figure 1. The question of the shadow cast by the metal stem of such a probe must always be considered for small fields at low voltages. This so-called “stem effect” may have an influence on both the surface dose and that at a depth. The effect that the metal stem of the Royal Cancer probe might have on our work was studied by placing the chamber 0.5 cm. below the surface of a phantom and, with the chamber as the axis, rotating through 360° a heavy lead diaphragm having a 5 × 2.5-mm. slot centered 1.75 cm. from the axis of rotation. The dose rate read by the chamber under such conditions would be due to radiation scattered into the chamber from the area irradiated through the slot, and any appreciable stem effect should show up in a polar plot of the ionization recorded by the chamber. It was found that in the area shaded by the stem there was an appreciable reduction of the ionization current. For this reason it was felt advisable to modify the probe in order to remove so far as possible this stem effect.

Simple scheme for deriving x-ray skin-surface dose times.

WHEN A superficial x-ray therapy plant is calibrated using a thimble ionization chamber, it is the free-air output of x-rays that is determined. Such free-air doses of x-rays are unsuitable for dermatologic practice, a fact that will be appreciated by contrasting the effect of delivering 100 r in air to areas of different size. If the treated area is the size of a face, back-scatter of x-rays from the body tissues will increase the dose at the surface of the skin to as much as 135 r, whereas delivery of the same air dose to an area of 1 square centimeter may result in a skin-surface dose as low as 101 r. Obviously, the effects on the skin will vary, even though the air dose delivered was the same in each instance. In order to obtain constant therapeutic effects, all doses given in dermatologic x-ray treatments should therefore be

Low voltage x-ray therapy with a beryllium window tube. I. Introduction and advantages.

X-ray therapy with a beryllium window tube enables high dose rates and control of depth penetration to be obtained without undue restriction of field size. It provides a means of administering low voltage near distance X-ray therapy and superficial therapy with advantages, e.g., in treating haemangioma in a few seconds, and in the eye and gonadal regions, where penetration is undesirable. The mode of prescription of penetration is the half value depth (H.V.D.) in tissue for convenience. The integral dose is 1/10 of 85 kV superficial X-ray therapy. Over 200 cases have been treated without radionecrosis.

Approximate Theoretical Solution of a problem of Scattering of Soft X rays (λ Between 0·25 and 0·56 Å) and its Consequences in Medical Radiology

(A) Statement of a physical problem of X ray scattering. Fundamentals of an approximate theoretical solution of the problem. Test of the solution by comparison with experimental data. (B) Discussion of the requirements of superficial X-ray therapy. Survey of a method to establish rational techniques of X-ray therapy in skin diseases. (C) Evaluation of densities and contrasts in radiographs of a typical object. Discussion of the changes in the image resulting from three different changes of the technique of exposure, viz.: (a) use of a film with greater gradation, (b) reduction of the size of the beam, (c) increase of wavelength of the X radiation. It is found that change (a) enlarges all contrasts in the same proportion, that change (b) enlarges all contrasts, but preferably those in the lighter regions of the image, and that (c) gives a considerable enlargement of contrasts in the darker regions of the image whereas it reduces the contrasts in the lighter regions.

Some Observations on Superficial and Medium X-Ray Therapy

Some Observations on Superficial and Medium X-Ray Therapy

The Physical and Biological Basis of Grenz-ray Therapy

To produce a therapeutic-biological action by means of X rays, a certain amount of physical energy must be absorbed in the radiated strata. In skin diseases this reaction occurs in the affected layers. But physiological experiment as well as clinical experience have shown that in many general conditions, disturbances of the more deep-seated organs can be influenced by way of the surface. Great interest has been displayed during the last twelve years in that part of the long-wave X-ray therapy which is known as Grenz or Bucky rays. It is proposed to discuss the literature and also the writer's own experience, and the results of his experimental work since 1930. In many University hospitals on the Continent and in America, superficial X-ray therapy is carried out mainly, if not entirely, by means of Grenz rays. Grenz-ray therapy has many advantages when compared with treatment by X rays. In the first place, the degree of healing is usually much more satisfactory. The technique is easier. The apparatus is not costly to purchase, as is the case with X rays, and it can be maintained with but little expense. With Grenz-ray therapy there is a very low incidence of residual damage, and lastly, there is no difficulty in repeating treatment in the case of recurrence of the disease. Grenz-ray treatment may be applied locally or generally. The local treatment is applied directly to the affected part of the organism. This is the case especially in skin diseases.