Optimal equations for describing the relationship between prostate volume, number of sources, and total activity in permanent prostate brachytherapy.

OBJECTIVES: To determine whether there is an optimal type of mathematical equation for predicting seed and activity requirements for permanent prostate brachytherapy. METHODS: Four institutions with extensive brachytherapy experience each submitted details of more than 40 implants. The data was used to generate power and linear equations to reflect the relationship between preimplant volume and the number of seeds implanted, and preimplant volume and the total implant activity. We compared the R and standard error of the generated equations to determine which type of equation better fit the data. RESULTS: For the limited range of prostate volumes commonly implanted (20-60 mL), power and linear equations predict seed and activity requirements comparably well. CONCLUSIONS: Linear and power equations are equally suitable for generating institution-specific nomograms.

Inter-institutional variation of implant activity for permanent prostate brachytherapy.

PURPOSE: Despite the existence of guidelines for permanent prostate brachytherapy, it is unclear whether there is interinstitutional consensus concerning the parameters of an ideal implant. METHODS AND MATERIAL: Three institutions with extensive prostate brachytherapy expertise submitted information regarding their implant philosophy and dosimetric constraints, as well as data on up to 50 radioiodine implants. Regression analyses were performed to reflect each institution's utilization of seeds and implanted activity. RESULTS: Despite almost identical implant philosophy, target volume, and dosimetric constraints, there were statistically significant interinstitutional differences in the number of seeds and total implant activity across the range of prostate volumes. For larger volumes, the variation in implanted activity was 25%; for smaller glands, it exceeded 40%. CONCLUSIONS: There remain wide variations in implanted activity between institutions espousing seemingly identical implant strategies, prescription, and dosimetry constraints. Brachytherapists should therefore be wary of using nomograms generated at other institutions.

Radiation Therapists' Experiences with Complementary Alternative Medicine Use by their Patients: A Preliminary Study.

Complementary and alternative medicine (CAM) is increasingly popular among patients receiving radiation therapy. However, there is little empirical evidence relating to the interactions of radiation therapists and their patients regarding the use of CAM during treatment. The study objectives were to quantify how often the issue of CAM use arises in the therapists' daily practice, to explore radiation therapists' knowledge and attitudes about CAM use by their patients, and to identify areas for future education and development for therapists. This article describes a two-centre survey conducted at the Vancouver Cancer Centre in British Columbia and Princess Margaret Hospital in Ontario. The survey used an email survey instrument, "SurveyMonkey," which was emailed to all therapists working at both centres (n = 230). The survey had a 5-point Likert scale ranging from "strongly disagree" to "strongly agree." There were also associated open-ended questions to allow for individual comments. The total response rate from the two centres was 49%. Results indicated that the topic of CAM does arise, although the frequency of interaction between patient and therapist varies between centres. Therapists reported feeling comfortable with their knowledge of 3 from a list of 27 common CAM therapies. They would recommend/support their patients' use of 11 CAM therapies in total. Therapists and patients use a variety of information sources about CAM, but would welcome more information/education in this area. Overall, therapists felt that the radiation oncologist was the most appropriate person to discuss the use of CAM with patients. Radiation therapists need more information about CAM in the form of continuing education to meet the needs of their patients. Further research is warranted, as this is a very preliminary look at a large and somewhat controversial topic.