Needle imaging during ultrasound-guided permanent prostate implants.

As demonstrated by water phantom experiments and clinical observations, the reverberation artifact associated with the ultrasound needle image during permanent prostate implants is extremely useful in determining precise radioactive seed positioning. It also serves as an independent quality assurance check of the number of seeds in the strand.

Problems with rigid seed strand lodging during prostate implantation: a proposed mechanism and solution.

Since the introduction of rigid strands of radioactive seeds embedded in absorbable suture material, many brachytherapists have experienced problems with the strands lodging inside the implant needle during the deposition process. By using a scanning electron microscope, we examined some potential factors which could lead to this problem. It seems plausible that the lodging is due to two factors: prostate tissue hindering the motion of the strand initially, and friction between the strand braids and the inner surface of the needle. Both result in an "accordion effect" as the stylet applies pressure on the strand. Based on this assumption, a solution was found. A combination of using needles with a polished inner surface, and repeated clockwise and counterclockwise 360 degrees twisting of the needle about the stylet during the deposition process allows for smooth deposition of the strand at the intended location. By using this technique, one is able to exploit the potential dosimetric advantages of rigid seed strand implants without additional problems.

Improvement in dosimetry of ultrasound-guided prostate implants with the use of multiple stabilization needles.

The use of three stabilization needles for ultrasound-guided permanent prostate implants results in better dosimetric coverage of the prostate, all other variables being equal. This technique prevents rocking motion of the prostate when anterior needles are inserted and thus improves accuracy of seed placement and shortens the length of the procedure. On post-implant CT-based dosimetric evaluation, the three stabilization needles technique provides better coverage, with the prescription isodose line encompassing 95% of the target volume compared to 90% for the implant utilizing two stabilization needles. Further improvements in the technique are currently under investigation, with the goal of consistently achieving truly "conformal anatomical prostate brachyradiotherapy."

A simple method for verifying activity of iodine-125 seeds in rigid absorbable suture.

A simple system which facilitates the verification of the calibration of iodine-125 sources in rigid absorbable suture, on the remote traceability basis, was developed. It consists of a plastic jig accommodating a sterile closed-end 16 gauge plastic catheter. The iodine-125 source in rigid absorbable suture is placed into the sterile closed-end 16 gauge plastic catheter. The jig fits in a standard dose calibrator. The sterility of the strand is maintained while a reasonable number of seeds used for an actual implant can be easily measured. This is an improvement over the current recommended practice of assaying just one separate seed of the same strength designation. This system brings the calibration procedure for the rigid sterile seed strands in line with the AAPM TG-40 recommendation for the rest of radioactive seed products.

A spreadsheet technique for dosimetry of transperineal prostate implants.

Although conceptually straightforward, dosimetry of permanent 125I seed prostate implants is not necessarily easy to implement in clinical practice, especially for institutions that are unwilling or unable to modify their commercial RTP systems. Spreadsheet techniques that aid in both preimplant treatment planning and post-implant dosimetric evaluation have been developed. The first spreadsheet converts the seed distribution expressed in terms of template grid coordinates to the format suitable for input into the RTP system, and determines the positions and loading patterns of individual needles. The second spreadsheet macroprogram is designed, as a modification of the Roy et al. [Int. J. Radiat. Oncol. Biol. Phys. 26, 163-169 (1993)] technique, to interactively determine physical seed locations from the post-implant CT images. Although less automated than described elsewhere, this approach was found acceptable for clinical practice at our institution.

An unusual late presentation of imperforate hymen.

BACKGROUND: The imperforate hymen is a rare gynecologic abnormality that may not be detected until the onset of menses, when hematocolpos causes symptoms due to an expanding pelvic mass. CASE: A 19-year-old woman had primary amenorrhea, originally misdiagnosed as müllerian agenesis. Because of a combination of late onset of menses, vaginal dilation, and sexual intercourse, her hematocolpos remained relatively asymptomatic. CONCLUSION: Proper diagnosis of the imperforate hymen could have been made earlier by contrasting the ultrasound findings with the absence of associated genitourinary and skeletal anomalies. Magnetic resonance imaging can detect a uterus not previously seen on ultrasound. An early imaging study may further prevent the misdiagnosis of congenital absence of the uterus.

Portable dental kit for nursing homes.

With the increased dentulism in older adults, more patients living in long term care facilities will be requiring dental care. A portable kit is presented here that allows a care-giver to provide limited interim treatment prior to the availability of definitive care by a dental practitioner. Included are some aids for improving the patient's ability to perform oral maintenance.

Behavioral and clinical concerns for the geriatric dental patient.

Treatment of older adult patients involves more than clinical competence. A working knowledge of the nature of this population is crucial if impediments to care are to be removed. Medical status, psychological status, socioeconomic level, current drug regimens and mobility contribute to the successful pursuit and delivery of dental care. Misconception on the part of the practitioner can easily reinforce barriers to care rather than remove them. Today's dentist has an obligation to contribute to the maintenance of the patient's quality of life, not just their dentition.

Are you a laggard?

Continuing education is an accepted and expected practice in dentistry today. Professional responsibility dictates contemporary knowledge be utilized in our patient treatment. As society becomes more health conscious, demands are being made for mandated participation in continuing education. For continuing education to be of value, it must present information and experiences that address both the needs of the adult learner and the profession. A variety of learning activities should be accepted for continuing education credit. Of the identifiable types of active practitioners, the laggard presents the most substantial problem. Mandatory education is one proposed method of drawing the laggard back into the life-long learning arena.

Serum pituitary and steroid hormone levels in the adult male: one value is as good as the mean of three.

The result of the hormone concentration of one blood sample was used to determine the accuracy of predicting not only the hormone concentrations of a second and third sample drawn 15 minutes apart, but also the mean value of the three samples. Three blood specimens from 73 men involved in two previously reported studies (A and B) were assayed individually for luteinizing hormone, follicle-stimulating hormone, prolactin, testosterone, androstenedione, dehydroepiandrosterone sulfate, estradiol, and cortisol. The predictive correlation of one single hormone value, when compared with the mean of three values, was 0.90 or greater, except for prolactin in study A (0.86) and testosterone in study B (0.86). Since the hormone level obtained for one sample has such a high predictive value for the hormone levels of the other two samples, drawing more than one sample is redundant.

A note on a simple procedure for redistributing a teacher's student contacts.

A class of twelve third-grade students in a rural school of two grades per teacher was observed to determine the frequency of student-teacher contacts for each student. Requiring each child to go to a play area when he completed his work resulted in changing the distribution of these contacts so that the better students used fewer teacher contacts. In addition, the number of completed assignments of all students increased and data are presented which imply that the poorer students of the class received more of the teacher's available time than previously. The application of this procedure to special pupil populations would probably be very useful. A number of advantages and limitations of the procedure are described.