Radium Needles Research Articles

High-resolution dosimetry with stimulated phosphorescence.

Thermally stimulated radiophosphorescence has been studied as a means of high-resolution dosimetry. Small grains of CaSO4:Mn phosphor, embedded in a thin Teflon tape, constitute the dosimeter. The light emitted after irradiation is measured with a photomultiplier coupled to the eyepiece of a scanning microscope. With CaSO4:Mn, the phosphorescence at room temperature is sufficient for measurement after doses in excess of 3000 rads. The spatial resolution of the technique is about 0.2 mm. The method has been tested by measuring the dose distributions from a radium needle and a beta-emitting eye applicator.

A technical note on precision implantation for interstitial oral radiation

A method for precise radium needle implantation in the therapy of tumors of the tongue and floor of the mouth is described. The device is fabricated as a two-piece acrylic splint that may be applied easily either under local or general anesthesia. It provides the radiation therapist with parallel positioning of the needles and an optimum distribution pattern. Fabrication and clinical application of the device are presented.

Radiation from radium needles

Radiation from radium needles

Fibrosarcoma: a complication of interstitial radiation therapy for a benign haemangioma occurring after 18 years.

A fibrosarcoma developed in the soft tissue of the lower extremity 18 years after extensive radiation treatment of a haemangioma with radium needles and radon need implants. The radiation therapy of haemangiomata, must be assessed in light of its potential for such catastrophic results. The adverse effects of therapeutic radiation have been known for some time and more recently it has been shown that the incidence of radiation-induced malignancy is growing (Arlen, 1971). Radiation is still used to treat benign conditions, especially haemangiomata of the skin and soft tissues despite an international awareness of the sequela (Maddin, 1970; Mustard, Ravitch and Snyder, 1969). We would like to report the following case; the first, we believe, to develop from an implant.

An afterloading technique for radium needles in the treatment of carcinoma of the oral cavity.

The authors describe a technique for afterloading a radium implant. A mold made from the patient's oral lesion and surrounding tissue is used in planning and carrying out implantation into the lesion. Advantages of this system include more precise implantation, decreased irradiation of personnel, and an improved teaching model.

Long time studies of advanced cancer of the ear treated with electrosurgery plus radiation.

This paper follows our first report on the same subject presented before the American Radium Society 24 years ago, in 1948.Records of 62 cases treated from 1940 to 1958 were collected and divided into 3 groups.The first group of 14 cases includes proven cures alive from 12 to 25 years (Table I). Two were excluded because 1 died of cancer of the skull near the original ear lesion at 15 years and 1 died of pulmonary metastases at 12 years with no evidence of cancer of the ear present. This leaves 12, or 85 per cent, of the original 14 cases well from 12 to 25 years. All of these, except 1, were treated by the removal of the original lesion with electrosurgery plus the implantation of low intensity radium needles beneath the remaining malignant tissue for 7 days. The 1 exceptional case had a large squamous cell carcinoma surrounding the original site of the ear plus extension into the mastoid and bone surrounding the internal ear. Treatment was started with 3,600 r (air) given through a large port to the ent...

A protected loading device for thin 192 Ir wires.

192Ir wire sources are increasingly used in various centres for interstitial radiotherapy, the advantages of flexibility and of afterloading removing some of the disadvantages of the use of radium needles (Pierquin 1964; Pierquin, Chassagne and Cox 1971; Paine 1972). One of the difficulties experienced by users of the thinner (0·3 mm diameter) wires has been the problem of loading so thin a wire under protected conditions into the plastic tubing in which it is handled by the Radiotherapist when current techniques are used. This tubing has an outside diameter of 1 mm and internal diameter of 0·5 mm and is thus too thin for the manoeuvre to be safely accomplished in a reasonably short time by eye with the use of long forceps. It is also necessary to place a small constriction or seal in the tubing at either end of the active wire so as to prevent it from slipping along the tubing during manipulation of the tubing into the patient. Most centres using these techniques have found it necessary to evolve some ki...

Some considerations on radiation therapy of tongue cancer.

In the 9-year period, 1960 to 1968, 117 patients with cancer of the tongue were treated by radiation therapy. Radiation techniques mainly used were interstitial radon seed or radium therapy to the primary lesion. As for 102 primary cases, the cumulative 5-year survival rate was 43 ± 5.5% according to the life-table method. When the primary lesion is relatively small, the radon seed implantation technique has advantages over radium needles in terms of patient comfort and easy applicability. It is highly suggestive that prophylactic lymph node irradiation decreases node metastases and improves the prognosis. Though radionecrotic complications were observed later in about 10% of the cases, successful management was done with the cooperation of oral surgeons.

Radiotherapeutic Principles and Viewpoints

Squamous cell carcinoma is an important and common cancer of the oral cavity and the lower lip. Although variable degrees of differentiation do occur, the predominant histopathological finding is in the direction of a moderate to a well-differeniated tumor. On the lower lip, in the oral cavity (in which the common location is the oral portion of the tongue), the floor of the mouth, and the lower gingiva (mandible), the squamous cell carcinoma is a radioresponsive and radiocurable neoplasm. The therapeutic armamentarium currently available for attack on these lesions is diverse; it includes radiations uniquely advantageous for obtaining control of these tumors. They range from low-voltage x-ray suitable for superficial lip carcinomas, to orthovoltage radiation for advanced lip lesions and per oral techniques, to supervoltage radiation; the latter minimizes acute and chronic cutaneous radiation reactions and, significantly, relatively spares the bone tissues. In addition, low-intensity radium needles or radioactive substitutes

The use of a surgical splint in the treatment of oral carcinoma

A case has been presented to illustrate a technique of using an acrylic guide for the placement of radium needles in the treatment of an oral carcinoma. The appliance allows for the proper spacing and parallelism of the needles to ensure efficient radiation of the lesion.

Long time studies of metastatic cervical lymph nodes treated with irradiation.

This paper is written in an effort to show that many patients with metastatic cervical lymph nodes can be cured for long periods of time with our combined low intensity radium needle implantations plus orthovoltage roentgen-ray therapy. The entire treatment for one area is given in 7 days. The equipment is relatively inexpensive and the hospital stay of only 8 days reduces this expense so that most patients can afford it.It must be admitted that experience and know-how play an important role in this type of therapy and it is also very important to know what a well trained surgeon can do in eliminating troublesome radiation sequelae.

The relative biological effect of 252Cf radiation on HeLa cells in culture.

CALIFORNIUM 252 undergoes spontaneous fission with a half-life of two and six-tenths years. The fission-spectrum neutrons are densely ionizing and therefore may be more efficient than x rays or gamma rays in eradicating malignant tumors, particularly those containing anoxic foci. The use of this nuclide for interstitial and intracavitary radiotherapy was suggested by Schlea and Stoddard (1), and sources have been fabricated for this purpose at the Savannah River Laboratory of the USAEC (2). Ten of the above sources, each originally about 4.5 µg, were obtained by us for the purpose of performing pretherapeutic radiobiological experiments. The determinations of relative effectiveness of 252Cf vis-à-vis conventional forms of protracted irradiation is necessary prior to clinical application. Materials And Methods HeLa S3 cells were cultured in Puck's N16 medium containing 10 per cent fetal calf serum, and 5,000 units of penicillin and 5,000 µg of streptomycin per 100 ml, Six-to seven-day-old stock cultures with confluent growth were used for preparation of clone cultures; the medium was discarded, cells washed once with isotonically buffered Versene 1: 5,000 and treated for five to ten minutes at 37°C with GIBCO EDTA-Trypsin solution (IX). The cell suspension was transferred to a 10 ml screw-cap centrifuge tube and centrifuged five minutes at 700 r.p.m.; the medium was carefully removed and cells resuspended in 2 ml of N 16 medium and cell count made in a counting chamber. If necessary, a further dilution of cells in medium was made and approximately 3,000 cells added to 2.7 ml of medium in Falcon plastic, 25 cc tissue culture flasks. The cultures were gassed with 5 per cent CO2-air mixture, shaken gently to distribute the cells, and placed on a level surface in a 37°C incubator. The preirradiation growth period was about seventeen hours in most instances. Ten needles containing ~4.5µg 252Cf each with a linear intensity of 2.25 µg/cm active length were arranged in a planar array to provide a homogeneous irradiation field over an area of 16 cm2 at a distance of 9.2 mm corresponding to the inner surface of the floor of the tissue culture flask. The dose rate at this distance was 16.1 rads/hr. initially and decreased slightly by completion of the experiments. A similar arrangement of radium needles (total of 40 mg) provided a dose rate of 31 rads/hr. to the floor of the tissue culture flask. Cells were also irradiated acutely with 250 kVp x rays (h.v.l, = 1.2 mm Cu, dose rate = 111 rads/min.). Results The survival curves for HeLa S3 cells irradiated with 252Cf at ~16 rads per hour, radium at 31 rads per hour, and acute 250-kVp x rays are illustrated in Figure 1.

Californium 252 as an external source of neutrons for radiotherapy treatment.

Californium 252 is a neutron emitter releasing 2·34×1012 n sec−1 g−1 by spontaneous fission. The half-life for neutron production is 2·65 years. Several authors (Oliver, 1968; Schlea and Stoddard 1965; Wright, Boulogne, Reinig and Evans, 1967) have discussed the application of 252Cf needles to intracavitary and interstitial radiotherapy in place of the more conventional radium needles. 1 μg of californium should give about the same dose-rate as 1 mg of radium in this treatment. There is now some interest in the possibility that 252Cf might also be suitable as an external source of radiation for radiotherapy in the form of a “tele-neutron unit”, analogous to the conventional cobalt machines. The purpose of this report is to examine if this is in fact a feasible proposition. It is assumed that 252Cf neutrons have been accepted as suitable from considerations of OER, RBE and depth dose. The question is, can an adequate treatment dose-rate be obtained at a reasonable cost while providing sufficient shielding round the source to conform with protection regulations? Since at present the Code of Practice (1964) does not contain any definite recommendations for protection from a tele-neutron unit, it has been assumed that the dose-rate at the surface of the shield must not exceed 2 mrem/hour.

Peroral irradiation of carcinoma of the oral tongue.

THE TREATMENT of squamous–cell carcinoma of the oral part of the tongue has developed in the hands of many workers along surgical lines; others emphasizing radiation therapy have evolved a variety of technics. At the University of Michigan orthovoltage radiation (200–220 kV) was the only agent available for ex–ternal irradiation until 1955. Since it was not possible to deliver a high dose to a tumor of the tongue using opposing or multiple fields without producing undesirable radiation damage of the jaw, a peroral technic with malleable thin–walled lead cones was developed for the treatment of certain lingual lesions and frequently was used as the sole method of radiotherapy. It avoided radiation exposure of the mandible, the soft tissues of the face, and the major salivary glands. This method produced encouraging results which persuaded us to favor it over radium needle implants as the preferred mode of treatment in selected carcinomas of the tongue. This technic is certainly not original with us, having been first attempted by Brickner (5) in 1903 and used rather extensively by Martin (13). Ebenius (9), Baclesse et al. (4), and Ennuyer and Bataini (10) also described such technics; Castigliano and Sklaroff (7) conceived and used cones individually fashioned for each lesion. Among others, Sharp et al. (19), Ash and Millar (3), and Frazell and Lucas (12) employed this technic in conjunction with interstitial and external irradiation. More recently Phillips (17) reported on use of the method for various oral carcinomas. This report reviews our experience with peroral radiotherapy of squamous-cell carcinoma of the oral part of the tongue from 1940 through 1960. We have classified the extent of the neoplasm according to the following TNM classification adhering to the principle of using the category of lesser extent in doubtful situations: T1—tumor less than 3 em in diameter. T2—tumor 3 to 5 ern in diameter with a possible minimal extension to the floor of the mouth or deep muscle infiltration. T3—tumor more than 5 em which may extend to include half of the tongue, with possible limited extension to the floor of the mouth. T4—tumor involving more than half of the tongue or massive extension to the floor of the mouth with involvement of the mandible, extension into the base of the tongue, or marked extension into the tonsillar structures. The cervical node involvement was classified in the following way: N0—no palpable adenopathy. N1—homolateral adenopathy, mobile. N2—bilateral or contralateral adenopathy, mobile. N3—fixed adenopathy, homolateral or bilateral.

Californium-252 neutron sources for medical applications

Californium-252 neutron sources are being prepared to investigate the value of this radio-nuclide in diagnosing and treating diseases. A gram of 252Cf emits 2.34 × 10 12 neutrons per sec through spontaneous fission. A source resembling a cell-loaded radium needle was developed for neutron therapy. Four micrograms of 252Cf were electrodeposited on a platinum-iridium wire, 0·51 mm in dia. and 20 mm in length, and the wire was doubly encapsulated. Since therapy needles are normally implanted in the body, very conservative design criteria were established to prevent leakage of radioactive material. A more intense source, containing 100 μg of 252Cf was prepared for neutron radiography experiments. This source is pelletized 252Cf oxide in a platinum metal matrix doubly encapsulated in stainless steel. The active source volume was approximately 6 mm 3. Methods are being developed to prepare very intense californium sources that could be used eventually for neutron radiography and for diagnosis by activation analysis.

Derivation of isodose charts for radium tubes

In estimating dosage in gynaecological radium treatments, it is sometimes desirable to have isodose charts for the individual radium γ-ray sources, in order to carry out a summation of dose-rates at selected points after the positions of the sources have been ascertained. Isodose charts for a large number of clinical radium tubes and needles manufactured by the Radiochemical Centre, Amersham, are available from the International Atomic Energy Agency through its Radiation Data Scheme (I.A.E.A., 1964). These charts are replicas of the charts derived by Kemp and Hall (1952) by means of a specially constructed analogue calculator (Kemp, 1944; 1945; 1950), and give isodose distributions in rontgens per hour. This calculator took into account obliquity effects in γ-ray transmission through the walls of the container and also the heterogeneity of the γ rays from radium, for which a value of 8·4 R-cm2/mg-h was used for the specific γ-ray constant (with 0·5 mm Pt filter). Tissue absorption and scatter effects were...

Dosimetry of an implantable 252Cf source.

Implantable californium-252 needles have been developed as neutron sources for radiotherapy (1). These needles, designed as a versatile replacement for radium needles, have several theoretical advantages. The therapeutic effectiveness of fast neutrons, with their high linear energy transfer, may be greater than that of gamma rays on an equal dose basis (2). Fission spectrum neutrons provide a more localized dose to the tissue volume under treatment because of their low penetrability. Consequently, larger doses to the tumor can be given without an attendant increase in dose to surrounding healthy tissue. Californium, which emits 2.33 × 106 neutrons/(sec.) (πg) by spontaneous fission and has an effective half-life of 2.566 years, may be prepared in a variety of source geometries. Sufficient 252Cf for clinical use could become available by 1975 at a cost of about one dollar per microgram (3). The potential hazard associated with container rupture and release of contaminating materials is insignificant compared to that of radium sources. Before californium can be clinically evaluated, detailed descriptions of the dose distribution near californium sources must be determined. Preliminary dosimetry studies have been reported (1). More comprehensive studies have now been completed and are presented in this paper as neutron and gamma-ray depth-dose curves and isodose charts for a typical 252Cf needle. Materials and Methods Neutron and gamma-ray doses were measured in close proximity to a 4.5-πg 262Cf needle having a diameter of 1.65 mm and an active length of 20 mm (Fig. 1). All dose rates were measured in a torso-shaped phantom (20 × 30 × 60 cm high) filled with tissue-equivalent (T-E) solution (4). Two systems, activation threshold materials and semiconductor diode dosimeters, measured the incident fast neutron fluence in the presence of thermal neutrons and gamma rays (5). An equivalent fast neutron dose was calculated, using the kerma/ fluence relationship described by Williamson and Mitacek (6). Activation threshold materials for detecting fast neutron fluence have been used for years in reactor technology and in dosimetry. An adaptation of the dosimetry technics of Wright, Hoy, and Splichal (7) was employed for these measurements, which simulate an in vivo situation. The threshold materials (foils), described in Table I, were selected for their response to neutrons in a desired energy range. If an effective cross section weighted for the incident neutron energy distribution is determined, these three materials can measure the incident neutron fluence between 2.0 eV and 8.0 MeV. The fluence calculated for this interval is converted to neutron dose by where φCu, φIn, and φS are the fluenees in their respective energy ranges, and the coefficients are the average kerma/fluence factor, weighted for the californium fission spectrum. The foil system described has a minimum detectability limit of about 10 rads.

Report on a radium safe and lead testing system.

A radium safe has been constructed, using 46 standard 2 × 4 × 8-inch lead bricks stacked together. Troughs were dug in four of the bricks and fitted with plastic trays. These constitute the drawers which are surrounded with aluminum shells to prevent marring and are fitted with stops so that they cannot come completely out. The drawers are separated by 1/8-inch steel plate, and the entire safe is surrounded by the same material. The outside surface is an aluminum shell, and the door is 1/8-inch steel fitted with a rubber gasket so that the safe is almost air-proof. The base is 1/2-inch steel plate, and the safe sits on a dolly with four wheels mounted in high-strength bearings so that the 1,200 pound unit can be moved. A small hole was drilled in the top of the safe (through the aluminum and steel sections) for connection to a vacuum pump. Short lengths of plastic tubing are connected to both the safe and the pump. The two pieces of plastic tubing are in turn connected with aluminum tubing which is fitted into holes drilled through two rubber stoppers. These stoppers will fit into either end of a 3/4-inch diameter aluminum cylinder about three inches long. Activated charcoal is placed in the cylinder with a plug of cotton at each end. The purpose of this system is to provide routine leak-testing of a radium supply without undue exposure to the person doing the testing. A charcoal filter can easily be inserted in the vacuum line. Only a few seconds of pumping time are required to determine leakage, using an end-window G-M tube and Baird-Atomic Counter with a normal background of about 20 counts per minute. It is planned to modify the filter construction in the future for use with a well-type scintillation counter. Accumulated data which were taken with a 1.33 mg leaking radium needle, show relations between count-rate, pumping time, and leakage time. A net count rate of 22 counts per minute was obtained from a fifteen-second pumping when the needle had been in a sealed container seven days after being exhausted of its free radon. Obviously, if a leak is detected, the operator must receive some exposure in isolating the defective needle by using the old test tube (or equivalent) system.

Radioisotope techniques. Intracavitary placement of radium, interstitial implantations, instillations.

Radiation therapy of any tumor, and particularly bladder cancer, is best accomplished whenever possible by an interior radiation technique, ie, a single radium capsule placed in the center of a 30-cc Foley balloon (the Walter Reed technique), or by inserting radium needles or radioactive tantalum ( 182 Ta) wire sources into the tumor. These produce higher cure rates than external irradiation, while minimizing irradiation of adjacent normal tissues. Despite the superior results of these interior techniques, 13-16 they are used in few clinics. Their unpopularity is probably due to the complexity of the techniques and the considerable time and effort required of the radiotherapist-urologist team to executive them. The most commonly employed program for treating papilloma and low-grade papillary carcinoma consists of repeated transurethral resections followed by external irradiation when the neoplasm becomes aggressive. Its popularity, despite the relatively poor results, is probably due to its relative simplicity. It is unfortunate

In-safe threading and sterilization of radium needles.

Radium needles must be threaded, sterilized, and, unless storage facilities are available in the operating room, they must be transported there for use. Exposure to personnel may be reduced if these operations are conducted without removing the needles from storage. A safe designed for this purpose will be described. It consists of three parts: (a) a lead box (with lid), inside which there fit (b) a central core of lead with holes to contain the needles, and (c) a lead brick wall attached to the side of the box behind which the operator stands. The lead box is water-tight, permitting flooding with sterilizing solution for cold sterilization of the needles. It may be drained through a valve near its bottom so the needles may be stored dry. Since the lid and walls are only 2 cm thick, this box alone cannot provide adequate protection from the amount of radium it was designed to contain (130 mg). Providing additional protection is one of the functions of the lead core that fits inside the box. This lead core...