Surface Dosimetry of Patients Undergoing Total Body Irradiation: A Retrospective Analysis for Quality Assurance.

Total body irradiation (TBI) is used prior to bone marrow transplantation as part of the conditioning regimen in selected patients. A linear accelerator-based technique was used at our treatment centre between June, 2004 and August, 2015. Patients were treated supine with extended source-to-surface distance (SSD) lateral fields, and prescription dose was 12 Gy delivered in six fractions, two fractions per day. Dose was prescribed to midplane at the level of the umbilicus and monitor units were calculated manually based on measured beam data. Dose variation within 10% of the prescribed midplane dose is considered acceptable for TBI treatment. This was achieved in our clinic by using compensators to account for missing tissue in the head and neck and lower leg regions. Lung attenuators were routinely used to correct for internal inhomogeneity, which resulted from low density lung tissue. The purpose of this study was to determine whether dose variation was within acceptable limits for these patients as part of a quality assurance process. Following chart review, 129 patients who received six-fraction TBI from 2004 to 2015 were included in this study. Patients receiving single fraction treatment were excluded. Metal oxide semiconductor field effect transistors (MOSFET) dosimetry was used to measure surface dose at four or five locations during patients' first fraction of TBI. Dosimetry was repeated during the second fraction for any site with variation greater than 10%. Statistical analysis was carried out on patient data, diagnosis and dosimetry measurements. Of the 129 patients who met the inclusion criteria, 50 were diagnosed with acute myelogenous leukemia, 30 with acute lymphoblastic leukemia and 11 with chronic myelogenous leukemia. The rest of the patients were diagnosed with lymphoma or myelodysplastic syndromes. The mean percent variation in dosimetry measurements taken at the specific locations ranged between 3.5% and 8.3%. The highest variation was found in measurements performed on the cheek. A high percentage of all dosimetry readings (85.5%) was within the acceptable range of +10% from the expected value. The highest number of individual readings taken at a specific location that fell outside this range were found at the cheek. We conclude that the linear accelerator delivered TBI at our centre meets the acceptable limits of dose variation over an 11-year period.

Patient preferences in early glottic cancer treatment.

Patients with early-stage glottic cancer are primarily treated with one of three options: endoscopic laser excision, external-beam radiation, or open conservation surgery. We sought to determine patient preferences for treatment when presented with a choice between CO2 laser resection and radiation (open conservation surgery was not offered because the endoscopic approach is preferred at our institution). This prospective cohort study was conducted at the Dalhousie University Faculty of Medicine in Halifax, Canada. Our patient population was made up of 54 men and 10 women, aged 30 to 84 years (mean: 65.0 ± 11.2). Their disease were staged as follows: carcinoma in situ, n = 11; T1a = 21; T1b = 6; and T2 = 26. Patients were quoted identical cure rates for the two treatment modalities. The controversial issue of voice outcomes was discussed, but no leading information was given to the study cohort. All 64 patients chose CO2 laser resection as opposed to radiation therapy for definitive treatment.

A national survey of the availability of intensity-modulated radiation therapy and stereotactic radiosurgery in Canada.

BACKGROUND: The timely and appropriate adoption of new radiation therapy (RT) technologies is a challenge both in terms of providing of optimal patient care and managing health care resources. Relatively little is known regarding the rate at which new RT technologies are adopted in different jurisdictions, and the barriers to implementation of these technologies. METHODS: Surveys were sent to all radiation oncology department heads in Canada regarding the availability of RT equipment from 2006 to 2010. Data were collected concerning the availability and use of Intensity Modulated Radiation Therapy (IMRT) and stereotactic radiosurgery (SRS), and the obstacles to implementation of these technologies. RESULTS: IMRT was available in 37% of responding centers in 2006, increasing to 87% in 2010. In 2010, 72% of centers reported that IMRT was available for all patients who might benefit, and 37% indicated that they used IMRT for "virtually all" head and neck patients. SRS availability increased from 26% in 2006 to 42.5% in 2010. Eighty-two percent of centers reported that patients had access to SRS either directly or by referral. The main barriers for IMRT implementation included the need to train or hire treatment planning staff, whereas barriers to SRS implementation mostly included the need to purchase and/or upgrade existing planning software and equipment. CONCLUSIONS: The survey showed a growing adoption of IMRT and SRS in Canada, although the latter was available in less than half of responding centers. Barriers to implementation differed for IMRT compared to SRS. Enhancing human resources is an important consideration in the implementation of new RT technologies, due to the multidisciplinary nature of the planning and treatment process.

PET/CT aids the staging of and radiotherapy planning for early-stage extranodal natural killer/T-cell lymphoma, nasal type: a case series.

Extranodal natural killer/T-cell lymphoma (ENKTL), nasal type, is a rare form of non-Hodgkin lymphoma. Treatment of ENKTL primarily relies on radiation; thus, proper delineation of target volumes is critical. Currently, the ideal modalities for delineation of gross tumor volume for ENKTL are unknown. We describe three consecutive cases of localized ENKTL that presented to the Nova Scotia Cancer Centre in Halifax, Nova Scotia. All patients had a planning CT and MRI as well as a planning FDG-PET/CT in the radiotherapy treatment position, wearing immobilization masks. All patients received radiation alone. In two patients, PET/CT changed not only the stage, but also the target volume requiring treatment. The third patient was unable to tolerate an MRI, but was able to undergo PET/CT, which improved the accuracy of the target volume. PET/CT aided the staging of and radiotherapy planning for our patients and appears to be a promising tool in the treatment of ENKTL.

Sex or survival: short-term versus long-term androgen deprivation in patients with locally advanced prostate cancer treated with radiotherapy.

BACKGROUND: Combined long-term androgen deprivation (LTAD) and radiation conveys a prostate cancer-specific survival advantage over combined short-term androgen deprivation (STAD) and radiation. The seminal question is whether or not the gains are worth the adverse effects of LTAD with respect to patient preferences. METHODS: Preferences for LTAD compared with STAD were elicited by direct patient interview using the probability trade-off method. "Time trade-off utilities" (TTOu) for erectile dysfunction and osteoporosis were elicited using the time trade-off method. Participants' current prostate cancer-specific health state was assessed using the Patient-Oriented Prostate Utility Scale-Psychometric. Participants' current sexual function was assessed using the International Index of Erectile Function (IIEF). RESULTS: All participants were willing to trade survival rather than undergo LTAD compared with STAD. The mean minimally required increment in prostate cancer-specific survival (MRIS) was 8.2%. The mean TTOu for impotence was 0.78, and the mean TTOu for osteoporosis was 0.71. The MRIS was correlated with the Sexual Desire domain score of the IIEF (Spearman rank-correlation coefficient, r = 0.50; P<.0001). CONCLUSIONS: Patients desired more prostate cancer-specific survival than what was afforded by LTAD and radiotherapy compared with STAD and radiotherapy.

Incomplete and inconsistent information provided to men making decisions for treatment of early-stage prostate cancer.

OBJECTIVES: To determine whether there is a gap between what patients know about early-stage prostate cancer and what they need to know to make treatment decisions, and whether the information patients receive varies depending on their treating physician. METHODS: Needs assessment was performed using a questionnaire consisting of 41 statements about early-stage prostate cancer. Statements were divided into six thematic subsets. Participants used a 5-point Likert scale to rate statements in terms of knowledge of the information and importance to a treatment decision. Information gaps were defined as significant difference between the importance and knowledge of an item. Descriptive statistics were used to describe demographic subscale scores. The information gap was analyzed by a paired t test for each thematic subset. One-way analyses of variance were used to detect any differences on the basis of treating physician. RESULTS: Questionnaires were distributed to 270 men (135 treated by radical prostatectomy, 135 by external beam radiotherapy). The return rate was 51% (138 questionnaires). A statistically significant information gap was found among all six thematic subsets, with five of the six P values less than 0.0001. Statistically significant variation was observed in the amount of information patients received from their treating physicians among four of the thematic subsets. CONCLUSIONS: There is an information gap between what early-stage prostate cancer patients need to know and the information they receive. Additionally there is a difference in the amount of information provided by different physicians.

Testosterone and erectile function recovery after radiotherapy and long-term androgen deprivation with luteinizing hormone-releasing hormone agonists.

OBJECTIVE: To study the recovery of testosterone levels and erectile function in men who received radiotherapy plus long-term adjuvant androgen deprivation (LTAD) with luteinizing hormone-releasing hormone (LHRH) agonists. PATIENTS AND METHODS: From April 2000 to July 2001, men who had completed prostate radiotherapy with > or = 2 years of LTAD, and had their last LHRH agonist injection at least 6 months before, were invited to participate. At study entry, the men completed the International Index of Erectile Function (IIEF), and their serum total testosterone (TT), prostate-specific antigen, LH, follicle-stimulating hormone, haemoglobin, and body mass were measured. This assessment was repeated at 1 year. RESULTS: In all, 20 men were recruited, with a mean (range) age of 70 (55-81) years. Defining a normal TT level as > or = 8.0 nmol/L, the median time to a normal level was 2.3 years (95% confidence interval (CI), 1.9-4.2). The median duration of castrate TT levels was 8 months (95% CI, 6.2-14.9). LH recovered before TT, suggesting that the rate-limiting step in the recovery of TT may be at the testicular level. The median time to recovery of normal LH levels was 3.8 months, compared to 8.0 months to reach supracastrate TT levels, and 2.3 years to reach normal TT levels. Age and the LH/TT ratio were associated with the time to recovery of both supracastrate and normal levels of TT. The IIEF was completed by 17 men; there were no significant changes in the scores in any domain of the IIEF during the study. CONCLUSIONS: Most men recover supracastrate testosterone levels after LTAD and external beam radiotherapy, but recovery of 'normal' testosterone levels is slow. Few men recover potency and sexual desire. The patients age and LH/TT ratio may be predictive of the time to recovery of both supracastrate and normal testosterone levels.