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PubMed1996

Answers to applicant selection from a directory of residency programs in obstetrics and gynecology.

OBJECTIVE: To answer six questions applicants commonly ask of programs, using the data base of a directory of residency programs in obstetrics and gynecology. METHODS: We analyzed data from a directory of 258 civilian residency programs in the United States compiled from a 1994-1995 survey. We expanded the analysis to compare small and large residency programs on the six questions. RESULTS: The average-size program of four residents per year received 50 applications for each position, offered interviews to less than a third of its applicants, and interviewed 15 applicants for each position. An interview gives an applicant a 7% chance of matching with a program. Small programs (fewer than four residents per year) interviewed more of their applicants than did large programs. Programs reported that their residents' scores on part I ranged from the 25th to the 90th percentile, and on part II from the 38th to the 92nd percentile. In general, residents in large programs scored better on these tests than did residents in small programs. Most programs (74%) considered electives beneficial in obtaining a residency position and reported a higher percentage of elective takers than programs without this policy. One in four residents in a program either took a senior elective there, graduated from the same institution, or both. Residents from programs offering fellowship training were twice as likely to pursue fellowship training than residents from programs with no fellowships. Large programs were four times more likely to sponsor fellowships than were small programs. CONCLUSION: Getting an interview in a residency program is a major accomplishment, whereas becoming known in a program may improve the applicant's odds of matching there. Applicants should review a program's policy on electives and selection record. Those considering fellowships should probably apply to programs that offer them. The directory offers a valuable data source for comparing residency programs in obstetrics and gynecology.

Directories as Topic↗

PubMed1994

Dosimetric considerations of commercially fabricated esophageal applicators.

Two commercially fabricated esophageal applicators for low dose rate intraluminal brachytherapy were compared using the dose non-uniformity ratio (DNR). One of the applicators has a single afterloading catheter while the other applicator has six afterloading catheters to accommodate low dose rate 192Ir ribbon or wire sources. Five sets of source configurations, each with a different ribbon length in the range of 5-17 cm were analysed using the DNR. The DNR shows the delivery of relatively higher total doses at higher dose rates to tissues closer to the applicators. The difference in the inhomogeneity of dose rates and the treatment volume exposed to higher dose rates than the prescribed dose rate between the two applicators are minimal. The dose homogeneity is better for the single-source applicator while the worst dose homogeneity for the six-source applicator is caused by the placement of each source closer to the surface of the applicator. The implications of higher dose rates were discussed using the alpha/beta model.

Brachytherapy↗

PubMed1990

The influence of application rate on the bacterial mutagenicity of soil amended with municipal sewage sludge.

The mutagenic potential of two soils amended with a municipal sewage sludge at two application rates was monitored over a 2-year period using Salmonella/microsome mutagenicity assay. Samples were collected from undisturbed monolith lysimeters of Weswood sandy clay (Fluventic Ustochrept) and Padina sandy loam (Grossarenic Paleustalf) amended with dried sewage sludge at 50 and 100 Mg/ha. Soil samples were collected and sequentially extracted with methylene chloride and methanol. The residues from these extracts were tested for mutagenicity at five doses with and without metabolic activation in Salmonella strain TA98. In general, the mutagenic potential of the amended soils of both application rates for the first 8 weeks following sludge application increased and then slowly decreased. The maximum mutagenic response observed in the soil extracts was 222 revertants at a dose of 10 mg of residue. This response was induced by the methanol extract from the Weswood soil collected 56 days after the application of 50 Mg/ha sewage sludge as compared to the 100 Mg/ha application which induced 202 revertants/mg. The mutagenicity of all fractions extracted from the sludge-amended soil at both application rates collected 717 days after application were not appreciably different from extracts from the unamended soils. The data indicate that chemicals that were mutagenic in bacteria persist in the soil and that at the higher application rates, as much as 2 years may be required for the mutagenic potential of the soil to return to background levels.

Journal Article↗

PubMed1988

Development of an 241Am applicator for intracavitary irradiation of gynecologic cancers.

Sealed sources of 241Am that emit primarily 60 keV photons produce relative dose distributions in water comparable to those from 137Cs or 226Ra sources and can produce dose rates of up to 100 cGy/hr at 1 cm in water. Also, 241Am gamma rays can be effectively shielded by thin layers of high atomic number materials (HVL is 1/8th mm of lead) placed on the applicator or inside some body cavities (for example, hypaque in bladder, barium sulphate in rectum). These properties of 241Am sources open a new approach to optimizing intracavitary irradiation of various cancers by allowing a reduction in dose and volume of irradiated critical organs or by increasing tumor doses. The relative ease with which highly effective shielding is achievable with 241Am sources would allow the design and fabrication of partially shielded applicators which can produce asymmetric dose distributions to allow unidirectional irradiation of localized lesions. Design and dosimetry characteristics of a gynecological applicator containing 241Am sources are presented. The applicator consists of a 2, 3, or 4 segment vaginal plaque (loaded with 2 and 5 Ci 241Am sources) and a tandem made up of a single 8 Ci 241Am source. Dose rates at 2 cm from the plaques are 42.0, 47.4, 58.3 and 56.7 cGy/hr for 5-5, 5-4-5, 5-5-5, and 5-4-4-5 Ci plaques, respectively. The 5-4-5 Ci plaque in combination with the 8 Ci tandem produces dose rates of 60.0 and 22.8 cGy/hr to points A and B, respectively. Surface dose rates on the plaque applicators are 143, 124, 142 and 132 cGy/hr for 5-5, 5-4-5, 5-5-5 and 5-4-4-5 Ci applicators, respectively. The shielding effect of a 0.5 mm thick lead foil on one side of the 5-4-5 Ci applicator is found to be a factor of 16.8; for example, the dose rate at 2 cm from the unshielded side is 42.0 cGy/hr compared to a dose rate of 2.5 cGy/hr at 2 cm from the shielded side. Initial clinical experience with this applicator in the treatment of recurrent gynecological lesions is also presented.

Americium↗

PubMed1993

Beam shaping for microwave waveguide hyperthermia applicators.

PURPOSE: Hyperthermia treatments commonly use single element microwave waveguide applicators. The microwave beam patterns produced by these applicators are often non-uniform. As a result, hot spots are formed in the heated tissue and therapeutic temperatures are reached in only small areas of the treatment field. We have constructed new coupling boluses that improve the heating patterns of external microwave applicators. METHODS: The microwave beam transmitted through the bolus is modified by microwave absorbing saline/gelatin pads. The pads can be designed to result in a uniform heating pattern over a large area or alternatively, complex heating patterns can be generated for specific clinical applications. An analysis of the effect of bolus design parameters on microwave absorption patterns is presented. The heating patterns of the MA-100 and MA-120 microwave waveguide applicators have been measured in muscle and fat phantom materials with both the manufacturer's boluses and the new boluses. RESULTS: In the case of the MA-100, the area above the 70% heating level measured in a muscle phantom was increased by a factor of 2.3 by an absorbing pad bolus. Similarly, the heating area of the MA-120 was increased by a factor of 2.6 by an absorbing pad bolus. The boluses were tested in a clinical setting by measuring tissue temperature profiles in patients under different bolus arrangements. The area over which therapeutic temperature was achieved was increased considerably when the absorbing bolus was used. A second bolus was designed for the MA-120 to produce a ring heating pattern for the treatment of a breast cancer patient who had developed recurrences at the periphery of a skin graft. The heating pattern produced in a muscle phantom is compared with tissue temperature profiles measured during the hyperthermia treatment of this patient. CONCLUSIONS: Microwave absorbing filters using saline pads significantly improve the heating patterns of microwave waveguide hyperthermia applicators. This improvement was confirmed in clinical application where much greater areas of homogeneous heating were observed. The technology was extended to produce complex heating patterns for special clinical applications.

Breast Neoplasms↗

PubMed2005

Systemic versus local application of gentamicin in prophylaxis of implant-related osteomyelitis in a rat model.

Administration of perioperative antibiotic prophylaxis is a routine procedure in orthopedic surgery. Besides systemic prophylaxis, only few techniques are established for local application of antibiotics to reduce infection related to orthopedic implants. The aim of this study was to evaluate the efficacy of locally versus systemically applied gentamicin in a rat model (n = 60). For local application, the antibiotic was delivered from a biodegradable poly(D,L-lactide) (PDLLA) coating of titanium implants. The efficacy of local prophylaxis was compared to a systemic single shot application of gentamicin as well as a combination of both administrations. Half of the animals received a weight-adopted single shot application of gentamicin 30 min prior to surgery. At surgery, the medullary cavities of the tibiae were contaminated with Staphylococcus aureus (10(2) colony forming units /CFU) and titanium Kirschner wires were implanted into the medullary canals. The implants were either uncoated, PDLLA coated, or coated with PDLLA + 10% w/w gentamicin. The animals were followed up for 42 days. X-ray examinations were performed; body weight, temperature, and the clinical condition were determined. After sacrifice, infection was evaluated by histological and microbiological analysis. All animals treated with uncoated or PDLLA-coated Kirschner wires without systemic application of the antibiotic developed osteomyelitis and all cultures of implants were tested positive on S. aureus. Implant-related osteomyelitis could be prevented by prophylaxis of systemically applied gentamicin in 15% of animals. In contrast, local application of gentamicin delivered from a PDLLA coating was more effective. Onset of infection could be prevented in 90% of animals treated with gentamicin coated Kirschner wires, and in 80% of the animals that were treated with a combination of local and systemic application. The local application from PDLLA-coated implants might support systemic antibiotic prophylaxis in preventing implant-associated osteomyelitis.

Animals↗

PubMed2004

Transcutaneous IL-2 uptake mediated by Transfersomes depends on concentration and fractionated application.

INTRODUCTION: Transfersomes (TF) are new, ultradeformable carriers with characteristics that enable them to penetrate the skin spontaneously. TFs are able to transport noninvasively both low- and high-molecular-weight molecules into the body. MATERIALS AND METHODS: TFs contain phosphatidylcholine and sodium cholate. Recombinant human interleukin-2 (Proleukin, Chiron) was added to the TFs and incubated for 24 h at 4 degrees C. The immunotransfersomes (ITF) were isolated from free interleukin-2 (IL-2) by filtration (Centrisart, Sartorius). Twenty-five thousand, 50,000 and 150,000 IU pure IL-2 and ITFs, which had been incubated with the same concentrations of IL-2, were applied subcutaneously (s.c.) (n = 8) and epicutaneously (e.c.) (n = 8) to mice. The IL-2 serum concentrations in the mice were then measured by ELISA after 2, 4, 6, 8, 10 and 24 h. Fractionation of the transdermal IL-2 application was also examined as a means of improving uptake. RESULTS: In concentrations of 25,000 and 50,000 IU IL-2, the subcutaneous application of ITFs resulted in a longer lasting IL-2 serum concentration than did the subcutaneous application of pure IL-2. While at 25,000 IU, the epicutaneous application of ITFs resulted in serum concentrations comparable to those resulting from s.c. application, at 50,000 and 150,000 IU, only 50% and 22.6% of the maximum serum concentration resulting from the s.c. application of pure IL-2 was obtained. Fractionating the transdermal IL-2 application improved uptake. CONCLUSION: We were able to show that biologically active IL-2 can be bonded to TFs up to 75%. It is possible to transport IL-2 through the skin using TFs. Both the concentration-dependent saturation of the TFs with IL-2 and fractionation of the application resulted in differing degrees of transcutaneous IL-2 uptake.

Administration, Cutaneous↗

PubMed2004

Assessment of application-rate dependent effects of a long-term fire retardant chemical (Fire Trol 934) on Typha domingensis germination.

Although long-term fire retardants (LTR) gain increasingly acceptance as effective tools for wildfire management, recent studies indicate their potential harmfulness in the environment, especially in aquatic ecosystems. This study comprises a first laboratory impact assessment of LTR action in temporal Mediterranean wetlands, using seed germination of Typha domingensis as indicator of impact. Our aim was to identify application rates upon which seed germination could be significantly affected. We tested for low (1 l m(-2)) and high (3 l m(-2)) application rates of Fire Trol 934 which are recommended by the manufacturers as a function of fuel characteristics. In addition, we simulated the impact of a higher application rate of 5 l m(-2) because inhomogeneous dispersal of the LTR during fire control and prevention operations can result in locally elevated applications. Results of a microcosm experiment indicate that application rates of 1 or 3 l m(-2) can impact Typha germination rates in the short-term via indirect LTR-mediated effects on water quality, which suppressed necessary cues for germination. However, a subsequent experiment with Petri dishes, using seeds isolated from the LTR treated sediments did not show significantly different germination rates between the control and the treatments with application rates of 1 or 3 l m(-2). This suggests that retardant pre-application germination success could be recovered in nature once the retardant is eliminated. By contrast, seeds almost completely failed to germinate in the microcosm experiment and the subsequent Petri dish essay when an application rate of 5 l m(-2) was used. This suggests a critical level upon which Typha seed germination may be perpetually limited. Research should be extended to other plant species to provide fire managers with guidelines for environmentally safe use of LTR in the Mediterranean region.

Dose-Response Relationship, Drug↗

PubMed2005

Inhalational and dermal exposures during spray application of biocides.

Data on inhalational and potential dermal exposures during spray application of liquid biocidal products were generated. On the one hand, model experiments with different spraying devices using fluorescent tracers were carried out to investigate the influence of parameters relevant to the exposure (e.g. spraying equipment, nozzle size, direction of application). On the other hand, measurements were performed at selected workplaces (during disinfection operations in food and feed areas; pest control operations for private, public and veterinary hygiene; wood protection and antifouling applications) after application of biocidal products such as Empire 20, Responsar SC, Omexan-forte, Actellic, Perma-forte; Fendona SC, Pyrethrum mist; CBM 8, Aldekol Des 03, TAD CID, Basileum, Basilit. The measurements taken in the model rooms demonstrated dependence of the inhalation exposure on the type of spraying device used, in the following order: "spraying with low pressure" < "airless spraying" < "fogging" indicating that the particle diameter of the released spray droplets is the most important parameter. In addition inhalation exposure was lowest when the spraying direction was downward. Also for the potential dermal exposure, the spraying direction was of particular importance: overhead spraying caused the highest contamination of body surfaces. The data of inhalational and potential dermal exposures gained through workplace measurements showed considerable variation. During spraying procedures with low-pressure equipments, dose rates of active substances inhaled by the operators ranged from 7 to 230 microg active substance (a.s.)/h. An increase in inhaled dose rates (6-33 mg a.s./h) was observed after use of high application volumes/time unit during wood protection applications indoors. Spraying in the veterinary sector using medium-pressure sprayers led to inhaled dose rates between 2 and 24mga.s./h. The highest inhaled dose rates were measured during fogging (114 mg a.s./h) and after-high-pressure applications in the antifouling sector (110-300 mg a.s./h). The potential dermal exposure of spray operators was lowest (dose rates from 0.2 to 7 mg a.s./h) in the areas of food and feed disinfection and private and public hygiene during spraying with low-pressure devices. During fogging, wood protection and antifouling applications, high-potential dermal exposures of the operators were determined. Dermal dose rates varied between 100 and 34,000 mg a.s./h.

Air Pollutants, Occupational↗

PubMed2006

A random clinical trial study to assess the efficiency of topical applications of podophyllin resin (25%) versus podophyllin resin (25%) together with acyclovir cream (5%) in the treatment of oral hairy leukoplakia.

OBJECTIVE: The objective of this study was to assess the efficiency of topical applications of podophyllin resin (25%) (P) versus podophyllin resin (25%) together with acyclovir cream (5%) (PA) in the treatment of oral hairy leukoplakia (OHL) in accordance with the following criteria: (1) number of applications necessary for the total clinical resolution of OHL; (2) correlation between the decrease of lesion size and the number of applications; (3) total clinical resolution of OHL; and (4) clinical reevaluation 12 months after the end of treatment. STUDY DESIGN: Forty-six OHLs were treated with P (P group) or with PA (PA group). Applications were performed weekly. Student t, Fisher exact, and Pearson correlation tests were used for statistical analysis. RESULTS: All 24 lesions from the PA group presented total clinical resolution while 4 lesions from the P group did not. The P group required up to 25 applications performed weekly while the PA group required up to 18. Observed was a negative significant association between the size of the lesions and the number of applications performed weekly in the PA group. CONCLUSIONS: The present study demonstrated the following: (1) P and PA topical treatments presented a similar average number of applications performed weekly; (2) both groups showed the same clinical response at 12 months post-therapy; and (3) PA presented a 100% clinical resolution and a continuous decrease in OHL size over the course of weekly applications.

Acyclovir↗

PubMed2005

Applicator exposure to acetochlor based on biomonitoring.

Biomonitoring was used to assess the combined dermal, oral, and inhalation exposure associated with the agricultural use of Harness Plus, an emulsifiable concentrate formulation of the herbicide acetochlor. Twenty Spanish farmers handled and applied acetochlor to maize in the spring of 2003, following the product label recommendations. Open- and closed-cabin applications were equally represented. Urine was collected during six consecutive days, starting the day prior to application. Daily composites were analyzed for 2-ethyl-6-methyl-aniline, a common chemophore representing the major urinary acetochlor metabolites. All applicators showed detectable concentrations in urine after application. Although, the open-cabin applicators treated fewer hectares, they showed significantly higher exposure compared to the closed-cabin applicators (average exposure: 0.004 and 0.002 mg/kg bw/day, respectively). Linear regression analysis suggested that untracked incidents had a significant impact on the total exposure. Other events that may have contributed to the observed exposure are repair of faulty equipment, accidental spillages, splashes, and inadequate use of protective gloves. The average margins of exposure (MOE) for farmers ranged from 23,000 (open cabin) to about 44,000 (closed cabin). For professional applicators the MOEs were 10-fold lower. These MOEs clearly indicate that no adverse health effects should be expected from agricultural acetochlor applications.

Administration, Oral↗

PubMed1998

Correlation between local vascular and sensory changes following tissue inflammation induced by repetitive application of topical capsaicin.

The aim of the present study was to investigate local vascular and sensory changes and their correlation in order to obtain a better understanding of the mechanisms of allodynia, hyperalgesia and vascular changes following tissue inflammation induced by repetitive application of capsaicin cream. This type of application was utilized as a controlled model of inflammation which was altered in intensity due to its repetitive applicability. Ten healthy volunteers participated in two experiments separated by at least five days. Each experiment consisted of a baseline session followed by five additional sessions. Before these sessions either 1.5 g capsaicin (1%) or placebo cream was applied to the volar site of the forearm for 15 min. The areas of stroking allodynia and pin-prick hyperalgesia were mapped and the intensity of spontaneous pain (VAS) was assessed after each application of the cream. In addition, the visible flare, temperature (IR-Thermography), and blood- flow (Laser-Doppler) were measured. The first application of capsaicin was perceived as painful; it induced both secondary hyperalgesia and allodynia. Compared to placebo, the first application of capsaicin cream also resulted in an increased blood-flow, elevated temperature and visible flare. The highest values of these sensory and vascular parameters were reached after the third application. A direct correlation between visible flare, secondary mechanical hyperalgesia and allodynia following repetitive application of capsaicin indicates that both common central and peripheral mechanisms were involved in these changes.

Administration, Topical↗

PubMed2003

The antinociceptive effect of iontophoretic direct application of diclofenac to arthritic knee-joints of rats.

This study compared the antinociceptive effect produced by cathodic iontophoresis of sodium diclofenac close to an arthritic knee-joint in rats with that of systemic application. Arthritic nocifensive incapacitation was induced by LPS (1 microg) injection into a knee-joint previously (72 h) primed with carrageenan (300 microg). Diclofenac (0.1, 0.25 and 0.5 mg/kg) given intraperitoneally 1 h after LPS injection caused dose-dependent inhibition of incapacitation. Diclofenac iontophoresis was performed by varying either the current density (0.1, 0.2, and 0.3 mA/cm2) or the duration of application (4, 10, 20 and 30 min) of a polyvinylpirrolydone-hydroxymethylcellulose gel containing 1% sodium diclofenac. A clear, current density-dependent effect was observed for 0.1, 0.2 and 0.3 mA/cm2 (10 min period), which was similar to the effect observed for the intraperitoneal application of 0.1, 0.25 and 0.5 mg/kg doses. Combining different application periods with different current densities, in a manner that resulted in the same total current (1.6 mA*min) application, did not produce similar therapeutic effects, but the antinociceptive effect was directly proportional to the current density. The ipsilateral iontophoresis (0.25 mA/cm2 x 10 min or 0.5 mA/cm2 x 4 min) of diclofenac produced an effect significantly greater than the same contralateral application (p<0.05). In conclusion, our results suggest that the therapeutic effect depends on the current density but not on the application time, and also that the iontophoretic, direct application to the inflamed knee-joint enhances the therapeutic effect probably as a result of the direct delivery of the drug.

Analgesics↗

PubMed2001

Variations of intracavitary applicator geometry during multiple HDR brachytherapy insertions in carcinoma cervix and its influence on reporting as per ICRU report 38.

PURPOSE: This paper examines the extent of variation in the applicator geometry during multiple high dose rate (HDR) intracavitary brachytherapy (ICBT) applications and its impact on reporting as per ICRU report 38. MATERIALS AND METHODS: Eighty orthogonal radiographs from 20 consecutive patients of carcinoma cervix (FIGO stages, IIA-IIIB) having four HDR ICBT applications of 6 Gy each at weekly intervals following teletherapy were evaluated. The applicator consisted of a flexible intrauterine tandem (IUT) independent of the ovoid assembly. The applicator geometry was evaluated in terms of: alpha angle, beta angle, intrauterine length (IUTL), interovoid (IOV), os to right ovoid (ORT) and os to left ovoid (OLT) distances along with vertical (VDL) and anteroposterior displacements (ADL) of the os with respect to the ovoids. The Cartesian co-ordinates (X, Y, and Z) of the IUT tip, centre of both ovoids and os were also measured. Doses to right point A (ARD), left point A (ALD), along with a reference volume of 6 Gy for ICRU height (IRH), width (IRW), thickness (IRT) and volume (IRV) were estimated for each application. RESULTS: Highly significant differences (P<0.001) between four insertions in any given patient across 20 patients for alpha angle, beta angle, IUTL, IOV, ORT, VDL, co-ordinates of the IUT, ovoids and os were observed, except for ADL (P=0.041) and OLT (P=0.247). As a consequence, variations were observed in ARD (P=0.027), ALD (P=0.017); IRH, IRW, IRT and IRV (all P<0.001). Applicator factors which influenced the various dose specification parameters were: beta angle and ORT for both ARD and ALD; UTLN, VDL and ORT for IRH; UTLN and IOV for IRW; UTLN for IRT and VDL for the 6 Gy IRV. CONCLUSIONS: A significant variation of the applicator geometry and its movement was observed in patients undergoing multiple HDR ICBT. This could have implications for reporting dose and volume specifications as required by ICRU report 38.

Brachytherapy↗

PubMed1999

Jaw electromyographic activity induced by the application of algesic chemicals to the rat tooth pulp.

The aim of this study was to determine if the application of mustard oil (MO), a small-fiber excitant and inflammatory irritant, or other algesic chemicals (capsaicin, CAP, and bradykinin, BK) to the rat maxillary molar tooth pulp induces electromyographic (EMG) activity of the masseter and digastric muscles, and also to determine if endogenous opioid mechanisms may be involved in any documented EMG changes. Application of MO to the tooth pulp induced a significant increase in EMG activity of the ipsilateral masseter up to 30 min. The application of mineral oil to the pulp or MO application to the pulp-extirpated tooth did not induce any significant EMG increases. The application of CAP or BK to the pulp in contrast had much weaker effects on EMG activity of the jaw muscles. CAP produced a small but prolonged increase in masseter EMG activity, and BK induced a short-lasting increase in digastric EMG activity. The systemic administration of the opiate antagonist naloxone significantly reactivated (i.e. rekindled) the EMG response evoked by MO application to the pulp. Naloxone did not produce any such significant rekindling effect on EMG activity following CAP, BK or mineral oil application to the pulp or following MO application to the pulp-extirpated tooth. The MO, BK and especially CAP groups showed histological evidence of vasodilatation and polymorphonuclear leukocyte infiltration in the pulp tissue and a significant increase in plasma extravasation of Evans Blue dye, whereas mineral oil did not induce these changes. These findings suggest that pulp afferent inputs to the central nervous system evoked by BK. CAP and especially MO may induce enhanced jaw muscle activity. In addition, the naloxone data suggest that an opioid suppresive mechanism may be induced by the pulpal afferent inputs evoked by MO, and may serve to limit the jaw muscle activity elicited by these inputs.

Animals↗

PubMed1997

Three-dimensional applicator system for carcinoma of the uterine cervix.

PURPOSE: Intracavitary dose prescription for cancer of the uterine cervix has been based on the use of plane orthogonal films. Computed tomography (CT) and magnetic resonance imaging can provide three-dimensional (3D) anatomic information with which more sophisticated treatment planning can be carried out. This work describes a new tandem and ovoids design that permits modern 3D dosimetry and has the same placement flexibility for the physician as the applicators currently being used. METHODS AND MATERIALS: The external shape of the Fletcher-Suit-Delclos (FSD) minicolpostat tandem and ovoids system has been used as a model to build a prototype of a new applicator. The prototype colpostats are constructed out of aluminum and steel. The tandems are made of aluminum. The Fletcher shields are eliminated. A new method of using tungsten for dose attenuation and shielding has been designed. Longitudinal alignment of the tungsten shields makes the new system possible. This applicator is CT-compatible. RESULTS: Dose calculations for the new design are compared to a commercial version of the FSD applicator. Both the aluminum prototype and a simple extension of the prototype to a plastic applicator system are considered. It is shown that the principal difference in dose is that the dose is reduced in the region inferior to the center of the ovoids. All configurations (plastic caps on or off) are equivalently shielded for the new device. In addition, an intermediate mini-ovoid configuration can be used clinically via the introduction of a D-shaped cap. The latter reduces the high dose to the vaginal mucosal surfaces. CONCLUSION: For a single ovoid, a comparison of dose with the FSD shows differences; however, the difference in dose is insignificant when the complete applicator, tandem, and ovoids are compared. With this new applicator, it is now possible to accumulate very accurate and detailed 3D dose-distribution data for the critical structures and other points of interest in the vicinity of the applicator. These data will permit future analysis of the correlation of dose and outcome for carcinoma of the cervix.

Brachytherapy↗

PubMed1997

A simple, inexpensive applicator for irradiation of localized areas of the vagina with intracavitary brachytherapy.

PURPOSE: To describe the construction of a simple, inexpensive applicator for irradiation of localized areas of the vagina with intracavitary brachytherapy. METHODS AND MATERIALS: It was desirable to avoid an interstitial implant in an elderly patient with a stage T2 vaginal cancer. The final phase of radiation therapy was delivered with a custom made intracavitary cylinder that allowed the high-dose area to be limited to the portion of the vagina at high risk for residual disease. The applicator was fabricated from a clear cast acrylic (Lucite) rod with dimensions 3.5 cm diameter x 5.0 cm long. The applicator contained 11 parallel grooves, each 1.8 mm deep x 2.2 mm wide, machined along the surface of the cylinder parallel its long axis at 1.0 cm increments. Plastic needles (15 gauge) were inserted into the grooves along the surface of the acrylic cylinder and held in place with heat shrink tubing. The applicator was easily inserted and positioned without anesthesia. Standard low dose rate 192Ir ribbons were inserted into the plastic needles after positioning the applicator in the vagina. RESULTS: Construction of this applicator system requires a few weeks notice and approximately $150. Fabrication of the grooved cylinder is a routine task for a workshop with a milling machine. A step-by-step description of how to construct and use the applicator is provided along with the telephone numbers of commercial vendors to call to order all necessary materials. CONCLUSION: This article describes a simple, inexpensive method for constructing a customized vaginal applicator that can be used to treat a limited area of the vagina with intracavitary brachytherapy.

Aged↗

PubMed2002

An Internet-based approach to advising radiology residency applicants.

RATIONALE AND OBJECTIVES: The authors created a computerized database Web site enabling radiology residency applicants to utilize the experience of recent graduates from their school in maximizing the effectiveness of the residency advisory process. Objectives of this database Web site are (a) to provide general information regarding radiology as a specialty; (b) to allow students to gauge their chances of matching based on the experience of recent graduates from their school; (c) to provide advisors with a faster, more accurate assessment of a student's matching potential; and (d) to decrease the number of residency applications submitted through the Electronic Residency Application Service. MATERIALS AND METHODS: Thirty graduates from the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School (UMDNJ-RWJMS) from 1999 to 2001 who applied to radiology residency were successfully contacted by telephone or e-mail. Data were gathered regarding their academic performance and activities, residency application, and final match outcome and were entered into a spreadsheet for analysis. This information, along with student-to-student advice regarding the match, was also entered into an interactive Web site for use by UMDNJ-RWJMS medical students, radiology advisors, and deans. RESULTS: The Web site model was applied to radiology residency applicants from UMDNJ-RWJMS. This database Web site provided general radiology information and allowed students and advisors to gauge their chances of matching based on the experience of past applicants from their school. CONCLUSION: This database Web site can provide a realistic comparison of a student's academics with those of previous applicants. Yearly analysis of school-specific data can help advisors follow applicant trends and modify their own advice. The database Web site can be easily duplicated and, if applied to other schools and specialties, could potentially benefit students nationally.

Educational Measurement↗