Publications (51) View all
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Article: Regional treatment margins for prostate brachytherapy.
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ABSTRACT: PURPOSE: This study quantified the treatment margin (TM) around the prostate that received 100% of the prescribed dose and analyzed postimplant dosimetry in different regions of the prostate for (125)I seed implants. METHODS AND MATERIALS: An average target volume (ATV) was created from postoperative MRI scan contours drawn independently by five radiation oncologists in 40 patients. The MRI was fused with the postoperative CT for dosimetry purposes. The TM, defined as the radial distance between the ATV and the 100% isodose line, was measured at 16 points at the base, midgland, and apex. The ATV was divided into four quadrants: anterior-superior, posterior-superior, anterior-inferior, and posterior-inferior quadrants. The values of the dose that covers 90% of the ATV (D90) and the percentage of the ATV receiving the prescribed dose (V100) received by the whole prostate and its four quadrants were documented. RESULTS: The range of the mean TM, in millimeter, was -8.88 to 3.68, 1.12 to 10.42, and 6.27 to 18.25 at the base, midgland, and apex, respectively. The mean D90 was 135.8, 162.8, 191.0, and 194.6 Gy for the anterior-superior, posterior-superior, anterior-inferior, and posterior-inferior quadrants, respectively. CONCLUSIONS: Despite having a relatively uniform preoperative planning target volume, this study identified variable TMs postoperatively in different regions of the prostate. In particular, the anterior base is most underdosed, whereas the lateral regions of the midgland and apex have generous TMs. Postimplant dosimetric parameters were lowest in the anterior-inferior quadrant.Brachytherapy 05/2013; · 1.47 Impact Factor -
Article: Cancer Cachexia in the Age of Obesity: Skeletal Muscle Depletion Is a Powerful Prognostic Factor, Independent of Body Mass Index.
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ABSTRACT: PURPOSEEmerging evidence suggests muscle depletion predicts survival of patients with cancer. PATIENTS AND METHODS At a cancer center in Alberta, Canada, consecutive patients with cancer (lung or GI; N = 1,473) were assessed at presentation for weight loss history, lumbar skeletal muscle index, and mean muscle attenuation (Hounsfield units) by computed tomography (CT). Univariate and multivariate analyses were conducted. Concordance (c) statistics were used to test predictive accuracy of survival models.ResultsBody mass index (BMI) distribution was 17% obese, 35% overweight, 36% normal weight, and 12% underweight. Patients in all BMI categories varied widely in weight loss, muscle index, and muscle attenuation. Thresholds defining associations between these three variables and survival were determined using optimal stratification. High weight loss, low muscle index, and low muscle attenuation were independently prognostic of survival. A survival model containing conventional covariates (cancer diagnosis, stage, age, performance status) gave a c statistic of 0.73 (95% CI, 0.67 to 0.79), whereas a model ignoring conventional variables and including only BMI, weight loss, muscle index, and muscle attenuation gave a c statistic of 0.92 (95% CI, 0.88 to 0.95; P < .001). Patients who possessed all three of these poor prognostic variables survived 8.4 months (95% CI, 6.5 to 10.3), regardless of whether they presented as obese, overweight, normal weight, or underweight, in contrast to patients who had none of these features, who survived 28.4 months (95% CI, 24.2 to 32.6; P < .001). CONCLUSIONCT images reveal otherwise occult muscle depletion. Patients with cancer who are cachexic by the conventional criterion (involuntary weight loss) and by two additional criteria (muscle depletion and low muscle attenuation) share a poor prognosis, regardless of overall body weight.Journal of Clinical Oncology 03/2013; · 18.37 Impact Factor -
Article: Hope in Newly Diagnosed Cancer Patients.
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ABSTRACT: CONTEXT: Hope is important to cancer patients as it helps them deal with their diagnosis. Little is known about hope in newly diagnosed cancer patients. OBJECTIVES: Based on the Transcending Possibilities conceptual model of hope, the purpose of this study was to examine the relationship of hope with pain, energy, and psychological and demographic characteristics in newly diagnosed adult oncology outpatients. METHODS: Data from 310 New Patient Assessment Forms from cancer outpatients' health records were collected. Health records from the first six months of 2009 were reviewed and data were collected on hope, energy, pain, depression, anxiety, feeling overwhelmed, and demographic variables. A generalized linear modeling approach was used to study the relationship of hope scores with these variables. Hypothesized variables and variables that were significant at the P = 0.01 level from the univariate analysis were entered into the multivariate model, with hope scores as the dependent variable. RESULTS: Hope scores were significantly negatively related to age (P = 0.02). More specifically, oncology patients who were 65 years of age or older had significantly less hope than those under the age of 65 years (P = 0.01). Gender (P = 0.009) also was a significant factor, with men having higher hope scores than women. No other variables were significant. CONCLUSION: Older adults comprise the majority of persons in Canada with cancer. The lower hope scores found in this age group compared with their younger counterparts underscore the importance of further research. This study provides a foundation for future research in this important area for oncology patients.Journal of pain and symptom management 03/2013; · 2.42 Impact Factor -
Article: Phase I study of hypofractionated intensity modulated radiation therapy with concurrent and adjuvant temozolomide in patients with glioblastoma multiforme.
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ABSTRACT: Purpose: To determine the safety and efficacy of hypofractionated intensity modulated radiation therapy (Hypo-IMRT) using helical tomotherapy (HT) with concurrent low dose temozolomide (TMZ) followed by adjuvant TMZ in patients with glioblastoma multiforme (GBM).Methods and materials: Adult patients with GBM and KPS > 70 were prospectively enrolled between 2005 and 2007 in this phase I study. The Fibonacci dose escalation protocol was implemented to establish a safe radiation fractionation regimen. The protocol defined radiation therapy (RT) dose level I as 54.4 Gy in 20 fractions over 4 weeks and dose level II as 60 Gy in 22 fractions over 4.5 weeks. Concurrent TMZ followed by adjuvant TMZ was given according to the Stupp regimen. The primary endpoints were feasibility and safety of Hypo-IMRT with concurrent TMZ. Secondary endpoints included progression free survival (PFS), pattern of failure, overall survival (OS) and incidence of pseudoprogression. The latter was defined as clinical or radiological suggestion of tumour progression within three months of radiation completion followed by spontaneous recovery of the patient. RESULTS: A total of 25 patients were prospectively enrolled with a median follow-up of 12.4 months. The median age at diagnosis was 53 years. Based on recursive partitioning analysis (RPA) criteria, 16%, 52% and 32% of the patients were RPA class III, class IV and class V, respectively. All patients completed concurrent RT and TMZ, and 19 patients (76.0%) received adjuvant TMZ. The median OS was 15.67 months (95% CI 11.56 - 20.04) and the median PFS was 6.7 months (95% CI 4.0 -- 14.0). The median time between surgery and start of RT was 44 days (range of 28 to 77 days). Delaying radiation therapy by more than 6 weeks after surgery was an independent prognostic factor associated with a worse OS (4.0 vs. 16.1 months, P = 0.027). All recurrences occurred within 2 cm of the original gross tumour volume (GTV). No cases of pseudoprogression were identified in our cohort of patients. Three patients tolerated dose level I with no dose limiting toxicity and hence the remainder of the patients were treated with dose level II according to the dose escalation protocol. Grade 3--4 hematological toxicity was limited to two patients and one patient developed Grade 4 Pneumocystis jiroveci pneumonia. CONCLUSION: Hypo-IMRT using HT given with concurrent TMZ is feasible and safe. The median OS and PFS are comparable to those observed with conventional fractionation. Hypofractionated radiation therapy offers the advantage of a shorter treatment period which is imperative in this group of patients with limited life expectancy.Radiation Oncology 02/2013; 8(1):38. · 2.32 Impact Factor -
Article: The Quality of Life of Male Spouses of Women With Breast Cancer: Hope, Self-efficacy, and Perceptions of Guilt.
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ABSTRACT: BACKGROUND:: The quality of life of male spouses of partners with breast cancer may determine the support they are able to give their wives. Little is known about the factors associated with their quality of life. OBJECTIVE:: The purpose of this study was to examine the relationship of the quality of life of male spouses of partners with breast cancer with the following factors: (a) demographic variables of male spouses and their partners, (b) levels of hope of male spouses and their partners, (c) self-efficacy and loss and grief of male spouses, and (d) quality of life of partners with breast cancer. METHODS:: Six hundred surveys were mailed to women with breast cancer (stage 1-3) and their male spouses. A total of 110 surveys were completed. RESULTS:: With the use of generalized linear modeling, participating male spouses with higher quality of life scores: (a) were older (P = .01), (b) had higher hope scores (P = .01), (c) had lower feelings of guilt scores (P < .01) (subscale of loss and grief), (d) had higher general self-efficacy scores (P < .01), and (e) had partners with breast cancer with higher quality of life scores (P < .01). CONCLUSIONS:: Hope, self-efficacy, feelings of guilt, age, and their partners' quality of life were significantly related to quality of life of the male spouses of women with breast cancer. IMPLICATIONS FOR PRACTICE:: The findings underscore the importance of assessing for and fostering hope and self-efficacy as well as decreasing guilt in male spouses of women with breast cancer to improve their quality of life.Cancer nursing 01/2013; · 1.88 Impact Factor
