Radium Needles Research Articles

Parametrial implant in Stage III B cancer of the cervix. III. A five-year study.

Since 1975, the Department of Radiation Therapy, University of Maryland Hospital initiated a policy of supplementing the dose to the affected parametrium by using radium needles implants in conjunction with a protruding tandem preferably, or Manchester ovoid in the case of absence of the lower segment of the uterus. The authors have noted a remarkable improvement in local control as well as an improved three-year survival rate with minimal immediate complications. Additional Stage IIIB (FIGO) cases were collected and they were treated by the same technique and have a close follow-up since 1975. Forty-nine cases studied, 32 (65%) survived with disease-free status for a minimum of five years with no loss to follow-up. Local control was excellent, as expected, at the level of 84% (41/49). There were 8% major complications as a consequence of radiation treatment and the majority of them required surgical intervention with excellent success. Paraaortic metastasis remains a major problem and requires further study. The current plan will include retroperitoneal exploratory laparotomy and para-aortic node sampling with extension of the external beam portals to include the positive node region and followed by interstitial and intracavitary brachytherapy.

Prosthetic requirements for selective placement of interstitial needles in the treatment of osteogenic sarcoma of the mandible

Dentists may perform an important adjunctive role in support of other medical specialists. In a combined treatment of osteogenic sarcoma of the mandible, a course of radiation to the mandible is followed by resection. A prosthesis for selective placement of interstitial radium needles is fabricated. The rationale for treatment and the prosthesis design requirements have been presented.

Preoperative radiation therapy in squamous cell carcinoma of the anterior two-thirds of the tongue at the norwegian radium hospital

We examined the records of 118 patients with squamous cell carcinoma of the anterior two-thirds of the tongue treated during a 15 year period between 1958 and 1972 at The Norwegian Radium Hospital. They were staged according to the UICC 1978 system. Preoperative irradiation was employed in all patients, either with a radium needle implant or with external high energy irradiation or both. After a median delay of 3 months, surgical resection of the residual infiltrate was carried out. Histological examination of the resected tongue specimen was reported negative for residual tumor in 72 % of T 1N 0, 48 % of T 2N 0, and 29 % of T 3N 0 patients. The local control of the tumor of the tongue after negative post-irradiation histology was 91 % for T 1N 0 68 % for T 2N 0, and 50 % for T 3N 0 patients. The local control of the tumor of the tongue after positive post-irradiation histology was 89 % for T 1N 0, 43 % for T 2N 0, and 30% for T 3N 0 patients. Surgery was, therefore, most effective in preventing local recurrence in the earlier stages. The local control of the neck after negative post-irradiation histology was 72 % for T 1N 0, 53 % for T 2N 0, and 3 out of 4 for T 3N 0 patients. The local control of the neck after positive post-irradiation histology was 22 % for T 1N 0, 43% for T 2N 0, and 50 % for T 3N 0 patients. More extensive use of external beam irradiation was noted in patients with advanced tumors. The five year survival of patients with negative post-irradiation histology was, for T 1N 0 65% absolute and 73% relative; for T 2N 0 53% absolute and relative; for T 3N 0 50% absolute and relative. The five year survival of patients; with positive post-irradiation histology was, for T 1N 0 39% absolute and 59% relative; for T 2N 0 29% absolute and 40 % relative; for T 3N 0 30 % absolute and relative. The difference observed between the groups of patients with negative and positive post-irradiation histology with respect to the control of the tumor in the neck and to the survival were statistically significant for T 1N 0 patients.

Duration and Timing of Spermatogenesis in a Stock of the Mussel Mytilus Californianus

Determining the duration and timing of spermatogenesis in Mytilus californianus Conrad became key questions in our study of carcinogen-mutagen indices in the marine environment. We had postulated that the murine sperm deformation assay of Bruce, Furrer & Wyrobek (1974) should have marine analogues, and we assayed a number of marine invertebrates sampled near potentially carcinogenic waste flows, and by γ-ray dose-response experiments. Our field results demonstrated some deformation but only at a very low level (less than 5 % in Mytilus edulis L.). Development of a γ-ray doseresponse (90–900 rads) procedure for M. californianus by radium needle inserted through a drilled hole closed with a plastic plug, and subsequent biopsy of gonadal tissue at measured distances from the site of irradiation, did not show deformations from a pilot test in June 1979. If a viable dose-response procedure was to be developed it was necessary to establish seasonal reproductive timing so that specimens could be collected or cultured to maximize spermatogenesis and hence response potential, and also to establish the duration of spermatogenesis so that response measures via a gonadal tissue extraction could be appropriately timed.

Interstitial radiation therapeutic techniques at Mount Vernon Hospital.

Retrospective analysis of 56 cases of carcinoma on the lateral border of the anterior two thirds of the tongue treated at Mount Vernon Hospital using radium needle implant alone yielded 5-year actuarial survivals of 75.3 per cent in 25 T1N0 cases and 81.8 per cent in 25 T2N0 cases. Five-year actuarial local recurrence of 17.5 per cent was recorded in the T1 group and 35 per cent in the T2 group. Local recurrences were attributed to failure of the implant to encompass extensions of the tumour along the lateral border or into the musculature of the tongue. Five-year actuarial local recurrence of 66.2 per cent was recorded in 18 patients with carcinoma of the breast treated by radium needle implant alone; 4 of these 9 local recurrences occurred at some distance from the treated area and could not be classed as marginal recurrences. A preliminary investigation carried out in 1981 indicated that significant improvements in source distribution, particularly at poorly accessible sites, could be achieved using afterloading techniques. In addition the use of 192Ir as a source could result in improvements in staff protection.

Experimental study of the response characteristics of large Ge(Li) detectors

The relative efficiencies of a cylindrical Ge(Li) detector having an estimated active volume of 77 cm 3 were measured in the full-energy, single-escape and double-escape peaks produced by γ rays of energies 2–12 MeV. These relative efficiencies at 2–10 MeV are expressed theoretically in terms of the absolute efficiencies calculated for all interactions except coherent scattering, the probability that a 0.511 MeV annihilation photon escapes from the active volume of the crystal, and an empirical reduction factor which is energy dependent. The escape probability is constant at 0.676±0.006. The γ-ray absorption coefficient for all interactions producing the full-energy peak is derived by comparison with the known pair-production coefficient and tabulated for γ rays of energies 2–10 MeV. The above Ge(Li) detector and a second one having an estimated active volume of 114 cm 3 were scanned horizontally with a fine pencil of γ rays from a 10 mg radium needle. The relative angular efficiencies measured in the full-energy peaks at 1120, 1764, 2204 and 2447 keV were used to evaluate the angular attenuation factor Q k for k = 1, 2, 4 and 6. The experimental and calculated factors agree if the effective outer radius of the detector is taken to be 87% of the nominal value. Radiography was found useful in checking the dimensions and axial position of one of the detectors in its aluminum housing.

A non-looping afterloading technique for interstitial implants of the base of the tongue

A new afterloading technique for interstitial radiation therapy of tongue cancer is described which eliminates many of the problems associated with radium needle and “loop” implants. It is particularly advantageous for the more posteriorly situated tumors, where loops are technically difficult to execute and pose difficulty in afterloading. The technique employs polyethylene afterloading catheters with one end sealed. An adequate dose to the dorsum of the tongue (which in the loop technique is delivered by the apex of the loop) is ensured by means of an intta-oral afterloading catheter, which is anchored on the dorsum of the tongue by suturing it to the tips of vertical afterloading catheters traversing the substance of the tongue. Since these manipulations can be performed outside the patient's mouth the procedure is much easier than making loops in the depths of the oral cavity. Afterloading is quiFk and simple because all the catheters are without bends or kinks and the removal of the implant is also straightfoirward. Pre-insplant planning is performed with the help of a planar implant guide, and the technique offers considerable flexibility for adequately encompassing tumors of different sizes in all three dimensions.

Radium needle spacing effect on the dose distribution of planar implants.

In an earlier paper we investigated the influence of the crossing needle location on the dose distribution of radium implants with one uncrossed end (Doss and Richman, 1979). It was found that in all cases considered the optimum coverage of radiation dose occurred when the crossing needle was either at or slightly beyond the physical ends of the parallel needles. The quality of the implant was judged by plotting the fraction of the implant area receiving 85% of the maximum dose against the distance of the crossing needle beyond the physical ends. Implant geometries which achieve a dosage of 6000 cGy (rad) in seven days were sought.

Parametrial implants in the treatment of stage IIIB carcinoma of the cervix. II. Analysis of success and failure.

Local failure (in the cervix and pelvic wall) continues to be a major reason for poor results following conventional radiation treatment of Stage IIIB (FIGO) carcinoma of the cervix. Attempting to minimize this local failure, in 1975 and early 1976, the Radiation Therapy Department, University of Maryland Hospital, began using a parametrial implant technique in a selected group of patients who had met the criteria for implant in Stage IIIB carcinoma of the cervix. Essentially, prior to radium implant, all patients received whole-pelvis irradiation (4000-5000 rad TP/four to five weeks) plus an appropriate parametrial boost to the affected side (pelvic wall to 5500 rad/over five and a half weeks). Two types of radium were given: 1) a protruding tandem with parametrial implant by means of radium needles; and 2) a radium implant to the lower segment of uterus and affected parametrium plus a vaginal colpostat in cases of severe shortening (or absence) of the uterine cavity or when we were unable to identify the uterine cavity. A total of 31 cases were treated with one or the other of these techniques and have been followed for a minimum of three years. Results show an absolute disease-free survival rate of 64.5% (20 of 31) with a determinate disease-free survival rate of 71.4% (20 of 28). The overall local control rate is 84% (26 of 31). Analysis of local and paraaortic failures as well as distant metastases and complications are presented in detail.

Radium implant to the parametrium in the treatment of stage IIIB carcinoma of the cervix: Analysis of dosimetry

Radium needle implant to the parametrium in order to supplement the dose rates to the cervix, parametrium and pelvic wall from a protruding intrauterine tandem was simulated using the skeleton of an adult pelvis in a water phantom. The results of direct dosimetry are presented. The parametrial implant approach was instituted in our clinic in 1975 to minimize local failures, especially parametrial, in Stage IIIB carcinoma of the cervix. The technique is used with patients who cannot accomodate two vaginal ovoids with the intrauterine tandem for conventional intracavitary radium therapy because of the extent of the neoplastic disease. Our dosimetric results showed an increase in the parametrial and pelvic wall dose rates of better than 60% with a typical implant of six half-intensity (0.33 mg/cm.) needles to the affected parametrium; the bladder and rectum dose rates increased by less than 17%. There was a relatively minimal (8–13%) increase in the dose rates to other pelvic node-bearing sites. Results for a minimal implant to both proximal parametria and a clinical example of the parametrial implant application are also presented.

Application of stereo X-ray photogrammetry (SRM) in the determination of absorbed dose values during intracavitary radiation therapy

The method of stereo X-ray photogrammetry is described, using a Stereo X-ray comparator, as well as some clinical applications. The X-ray equipment consists of two X-ray tubes and a pneumatically driven cassette changer, developed to reduce effects of patient or organ motion between stereo radiographs. The accuracy of the set-up is demonstrated with measurements on a geometrical model and on a gelatine phantom containing radium needles. The clinical use is reported in determining dose rates to points of the intestinal wall during intracavitary radiotherapy of gynecological cancer. In a number of cases the stereo measurements have resulted in a change in the application time or in the charge or position of the applicator, possibly preventing later complications, as a result of a high dose. Future applications for implant dosimetry ( 192Ir, 125I) are suggested.

Treatment of stage IIIB carcinoma of the cervix: improvement in local control by radium needles implant to supplement the dose to the parametrium.

From 1971 to 1974 at the University of Maryland Hospital a total of 53 cases Stage III B cancer of the cervix (FIGO) were treated by a technique consisting of total pelvis irradiation (4000–5000 rad/4–5 weeks) plus a boost to the affected parametrium up to 5500 rad/5 1/2 weeks followed by usual Fletcher-Suit intrauterine and vaginal radium. An overall absolute three year survival rate (NED) of 49% (26/53) was obtained. Local failure and especially parametrial failure was 51% (27/53). All local failure occurred within one year after the completion of the therapy. Further analysis showed that all local and parametrial failure cases at the time of radium insertion had evidence of residual disease in parametria as well as midline lesion under EUA. Because of the findings suggestive of inadequate radium dosage, a group of patients treated from 1975 to early 1976 who were diagnosed jointly by Gynecologic and Radiation Oncologists as Stage III B (FIGO) had a radium needle implant to the affected parametrium as a booster to the routine radium. Whole pelvis irradiation was given to 4000–5000 rad/4–5 weeks and pelvic wall boost to 5500 rad/5 1/2 weeks as usual prior to radium therapy. 18 cases of Stage IIIB cervical CA. were treated by radium needles implant in conjunction with protruding tandem and have had a careful follow-up ranging from 15 months to 36 months. Fourteen of 18 cases treated in this fashion showed a complete disappearance of the neoplastic disease (14/18 = 78%). One case was lost to follow-up and three cases showed local failure within 6 months after therapy (4/18 = 22%). Technique and dosimetry with less than expected complications will be discussed in detail.

A versatile radium storage safe

The radium safe described provides secure, conveniently supervised and monitored storage for more than 200 radium needles and tubes (500 mg) and is adaptable for storing other brachytherapy radionuclides. Distinctive features of the safe are: (1) the light-weight, rotating drum which holds the sources, (2) the ease, safety and rapidity with which sources can be inventoried, removed or returned to the safe, and (3) a port through which radon leak tests can be made with minimal exposure to radiation. The geometry of the safe is cylindrical.

Dystrophic calcification in the tongue: A late sequel to radiation therapy

I nterstitial radiotherapy consists of the direct implantation of radioactive sources into and around malignant tissues. Removable implants are used to deliver a specific dose, after which the radioactive source is removed, while permanent implants are left in place. The principal value of interstitial therapy is in delivering a high radiation dose to a small volume. This technique is useful in the treatment of selected small lesions and in boosting the radiation dose in conjunction with external beam therapy. Less frequently, it is used as a means of re-treatment following local recurrence in patients who are not surgical candidates and in whom external beam therapy would not be suitable.le3 Advantages of interstitial implants are their limited side effects and a paucity of late sequelae.“-” Some disadvantages of interstitial therapy include heterogeneous dose distribution, the occasional tendency for a localized area to receive an intense radiation dose (hot spot), which may lead to necrosis, and the invasive nature of the procedure itself.3* 4 Because of the uneven dosage from interstitial implants and the risk of not covering an adequate area of involvement, external irradiation in combination with interstitial implants is sometimes used for oral tumors.4. 6 Recently developed sophisticated computer dosimetry programs have facilitated the calculation of dose distribution within the tumor volume.7 Radium needles (removable), gold198 seeds (permanent), and radon-222 seeds (permanent) have been used as implants in the treatment of oral carcinomas for over 50 years. More recently, iridium192 wire and seeds and iodine125 seeds have become frequently used as implants because of their advantages of economy, relatively short half-life, and improved radiation safety.2, H Among the well-documented side effects of head and neck irradiation are xerostomia, mucositis, chondritis, and dental caries. The development of osteonecrosis as a complication of radiation has been less frequently observed since the advent of supervoltage

Chromosome Aberrations Induced in Human Lymphocytes by Radiation from252Cf

In vitro dose--response curves of unstable chromosome aberrations in human lymphocytes have been obtained for 252Cf neutron radiation. The aberration yields fitted best to the linear function Y=aD, which is consistent with the single-track model of aberration formation for high LET radiation. The curves have been compared with others previously produced in this laboratory for several energies of neutrons and for 60Co gamma radiation. The r.b.e. for 252Cf with respect to 60Co is 27 at very low doses, decreasing to 6 at an aberration yield equivalent to 400 rad of 18 rad/hour gamma radiation. A profile of chromosome-aberration induction with depth in a perspex phantom was obtained by placing blood samples at several distances over the range 0.65-2.0 cm from the californium source. This profile was compared with depth-damage calculations for a radium needle. The r.b.e. of 252Cf radiation relative to 226Ra gamma radiation increased with the distance from the source, implying that californium is more effective at greater distances in destroying the ability of cells to divide, which may be an advantage in the treatment of large tumours.

Combined low dose-rate hyperthermal treatment: A model for interstitial therapy

This-d generation transplants of spontaneous mouse mammary tumors were subjected to a continuous hyperthermal and low dose-rate treatment at dose rates comparable to interstitial radium needle therapy. Radiation was delivered via co-60 and heating was by immersion in a water bath. Treatment temperatures were fl:om 37.5 to 42.OoC with treatment times up to 36 hours. As judged by tumor regrowth times, the combined treatment was about 6 times more effective at 42.0 than at 37.5oC. There was little increase in sensitivity from 37.5-410, but the sensitivity doubled for each 0.42OC increase in temperature above 41.OoC.

The reconstruction and dose-rate calculation of radium needle implants.

A comprehensive computer program has been developed for carrying out the various tasks associated with radium needle implants. Data input for the program are obtained by digitizing an orthogonal pair of radiographs with an analogue tracing system. Corresponding needles in the two radiographs are automatically located, and the implant may be rotated to any desired position in three dimensional space, at the same time presenting a view of the rotation on a storage oscilloscope. Automatic determination of the mean plane of a planar implant is possible, and the dose-rate distribution may be calculated in any specified plane. A Paterson--Parker exposure rate calculation may be performed with a biological dose and treatment time correction incorporated. The program is written in Fortran and runs on a small interactive computer system.

A comprehensive radiotherapy planning system implemented in Fortran on a small interactive computer.

A suite of Fortran programs for carrying out the various dose computational aspects of radiotherapy has been developed on an enhanced RAD8 computing system. The hardward configuration of the computer is described and the main features of the programs in the suite are discussed. The include: (a) beam data input systems for use with linear accelerators and cobalt units; (b) static and rotational teletherapy planning, with computer optimization in the static planning; (c) irregular field calculations with isodose visualization; (d) interstitial calculations including routines which will reconstruct a radium needle implant in three dimensions in addition to presenting the isodose distribution in any desired plane. The problems of implementing the programs on another computer system are discussed.

Treatment of carcinoma of the oral tongue by radium needle implantation

Forty-nine patients had a radium implant for carcinoma of the oral tongue. In thirty-four of the forty-nine (70 per cent), local three year control of the cancer was achieved. Three patients in whom the radiation failed were rescued by subsequent surgery. The five year absolute survival in this series was 63.8 per cent. In conclusion, we believe that improved survival rates without functional and cosmetic defect can be obtained by closer cooperation between surgeons and radiotherapists.

A preloaded radium needle implant device for maintenance of needle spacing.

A small stainless steel bar was machined to accept radium needles. The stainless steel bar will hold a rack of two, three, four, or five radium needles in a single plane. The crossing needle may be affixed to the bar so that textbook-like geometry is possible. The stainless steel bar remains in place during the entire implant. Spacing between needles is close to perfect. The time required to insers the implant is reduced compared to free-hand insertions, and less variation in dose is seen on computer-assisted calculations. Two years' experience in the use and development of the radium needle holder will be reviewed.