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Churilla T.M.,Commonwealth Medical College | Donnelly P.E.,Hospital for Special Surgery | Leatherman E.R.,West Virginia University | Adonizio C.S.,Commonwealth Medical College | And 2 more authors.
Breast Journal | Year: 2015

Mastectomy and breast conservation therapy (BCT) are equivalent in survival for treatment of early stage breast cancer. This study evaluated the impact of radiation oncologist accessibility on choice of breast conserving surgery (BCS) versus mastectomy, and the appropriate receipt of radiotherapy after BCS. In the National Cancer Institute Survival, Epidemiology, and End Results data base, the authors selected breast cancer cases from 2004 to 2008 with the following criteria: T2N1M0 or less, lobular or ductal histology, and treatment with simple or partial mastectomy. We combined the Health Resources and Services Administration Area Resource File to define average radiation oncologist density (ROD) by county over the same time period. We evaluated tumor characteristics, demographic information, and ROD with respect to BCS rates and receipt of radiation therapy after BCS in univariable and multivariable analyses. In 118,773 cases analyzed, mastectomy was performed 33.2% of the time relative to BCS. After adjustment for demographic and tumor variables, the odds of having BCS versus mastectomy were directly associated with ROD (multiplicative change in odds for a single unit increase in ROD [95% CI] = 1.02 [1.01-1.03]; p < 0.001). Adjuvant radiation therapy was not administered in 28.2% of BCS cases. When adjusting for demographic and tumor variables, the odds of having BCS without adjuvant radiation were inversely associated with ROD (0.95 [0.94-0.97]; p < 0.001). We observed a direct relationship between ROD and BCS rates independent of demographic and tumor variables, and an inverse trend for omission of radiotherapy after BCS. Access to radiation oncologists may represent an important factor in surgical choice and receiving appropriate BCT in early stage breast cancer. © 2015 Wiley Periodicals, Inc. Source


Yuan J.,Northeast Radiation Oncology Center | Chen W.,Northeast Radiation Oncology Center
Medical Physics | Year: 2010

Purpose: The authors propose an algorithm based on the k-d tree for nearest neighbor searching to improve the γ calculation time for 2D and 3D dose distributions. Methods: The γ calculation method has been widely used for comparisons of dose distributions in clinical treatment plans and quality assurances. By specifying the acceptable dose and distance-to-agreement criteria, the method provides quantitative measurement of the agreement between the reference and evaluation dose distributions. The γ value indicates the acceptability. In regions where γ1, the predefined criterion is satisfied and thus the agreement is acceptable; otherwise, the agreement fails. Although the concept of the method is not complicated and a quick nave implementation is straightforward, an efficient and robust implementation is not trivial. Recent algorithms based on exhaustive searching within a maximum radius, the geometric Euclidean distance, and the table lookup method have been proposed to improve the computational time for multidimensional dose distributions. Motivated by the fact that the least searching time for finding a nearest neighbor can be an O (log N) operation with a k-d tree, where N is the total number of the dose points, the authors propose an algorithm based on the k-d tree for the γ evaluation in this work. Results: In the experiment, the authors found that the average k-d tree construction time per reference point is O (log N), while the nearest neighbor searching time per evaluation point is proportional to O (N1/k), where k is between 2 and 3 for two-dimensional and three-dimensional dose distributions, respectively. Conclusions: Comparing with other algorithms such as exhaustive search and sorted list O (N), the k-d tree algorithm for γ evaluation is much more efficient. © 2010 American Association of Physicists in Medicine. Source


Lawton C.A.,Medical College of Wisconsin | Yan Y.,Radiation Therapy Oncology Group Statistical Center | Lee W.R.,Duke University | Gillin M.,University of Houston | And 6 more authors.
International Journal of Radiation Oncology Biology Physics | Year: 2012

Purpose: External-beam radiation therapy combined with low - doserate permanent brachytherapy are commonly used to treat men with localized prostate cancer. This Phase II trial was performed to document late gastrointestinal or genitourinary toxicity as well as biochemical control for this treatment in a multi-institutional cooperative group setting. This report defines the long-term results of this trial. Methods and Materials: All eligible patients received external-beam radiation (45 Gy in 25 fractions) followed 2-6 weeks later by a permanent iodine 125 implant of 108 Gy. Late toxicity was defined by the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer late radiation morbidity scoring scheme. Biochemical control was defined by the American Society for Therapeutic Radiology and Oncology (ASTRO) Consensus definition and the ASTRO Phoenix definition. Results: One hundred thirty-eight patients were enrolled from 20 institutions, and 131 were eligible. Median follow-up (living patients) was 8.2 years (range, 2.7-9.3 years). The 8-year estimate of late grade >3 genitourinary and/or gastrointestinal toxicity was 15%. The most common grade >3 toxicities were urinary frequency, dysuria, and proctitis. There were two grade 4 toxicities, both bladder necrosis, and no grade 5 toxicities. In addition, 42% of patients complained of grade 3 impotence (no erections) at 8 years. The 8-year estimate of biochemical failure was 18% and 21% by the Phoenix and ASTRO consensus definitions, respectively. Conclusion: Biochemical control for this treatment seems durable with 8 years of follow-up and is similar to high - dose external beam radiation alone or brachytherapy alone. Late toxicity in this multi-institutional trial is higher than reports from similar cohorts of patients treated with high - dose external-beam radiation alone or permanent low - doserate brachytherapy alone, perhaps suggesting further attention to strategies that limit doses to normal structures or to unimodal radiotherapy techniques. © 2012 Elsevier Inc. Source


Churilla T.M.,Commonwealth Medical College | Lesko S.L.,Commonwealth Medical College | Lesko S.L.,Northeast Regional Cancer Institute | Brereton H.D.,Commonwealth Medical College | And 5 more authors.
BMJ Open | Year: 2011

Objectives: Low serum vitamin D levels have been associated with risk for certain malignancies, but studies have not directly analysed levels between community oncology and primary care practices. The purpose of this study was to compare serum vitamin D levels in patients at a community oncology practice with non-cancer patients at a primary care practice. Design: Retrospective case-control study. 25-Hydroxyvitamin D levels were ordered for screening in both cancer and non-cancer patients. Levels were compared in univariate and multivariate analyses adjusted for age, body mass index and season of blood draw. Setting: A community-based radiation oncology centre and a community-based primary care practice: both located in Northeastern Pennsylvania, USA. Participants: 170 newly diagnosed cancer patients referred for initial consultation at the community oncology centre from 21 November 2008 to 18 May 2010, and 170 non-cancer patients of the primary care practice who underwent screening for hypovitaminosis D for the first time from 1 January 2009 to 31 December 2009. Primary and secondary outcome measures: The primary outcome measure was mean serum vitamin D level, and the secondary outcome measures were frequencies of patients with vitamin D levels <20 ng/ml and levels <30 ng/ml. Results: The oncology patients had a significantly lower mean serum vitamin D level (24.9 ng/ml) relative to a cohort of non-cancer primary care patients (30.6 ng/ml, p<0.001) from the same geographical region. The relationship retained significance after adjustment for age, body mass index and season of blood draw in multivariate analysis (p=0.001). Levels <20 and <30 ng/ml were more frequent in the oncology patients (OR (95% CI)=2.59 (1.44 to 4.67) and 2.04 (1.20 to 3.46), respectively) in multivariate analysis. Conclusions: Cancer patients were found to have low vitamin D levels relative to a similar cohort of noncancer primary care patients from the same geographical region. Source


Churilla T.M.,Commonwealth Medical College | Brereton H.D.,Commonwealth Medical College | Brereton H.D.,Northeast Radiation Oncology Center | Klem M.,Northeast Radiation Oncology Center | And 2 more authors.
Nutrition and Cancer | Year: 2012

The purpose of this study was to correlate serum vitamin D levels with potential clinical variables and to determine the extent of vitamin D deficiency in a large, outpatient oncology practice. One hundred ninety-five consecutive patients referred for consultation at a community radiation oncology center from October 8, 2008 to March 17, 2010 had vitamin D levels ordered. Patients who were deficient in vitamin D were treated with replacement therapy. Demographic and medical data were collected prospectively and subsequently analyzed. Pretreatment baseline patient and tumor characteristics were evaluated with respect to vitamin D concentrations. One hundred and sixty patients were analyzed. A total of 74% of patients had 25-hydroxyvitamin D concentrations considered either deficient (<20 ng/mL) or suboptimal (20-30 ng/mL). Replacement therapy raised serum vitamin D levels by an average of 15 ng/mL (95% CI = 11-18, P < 0.01). Lower than median serum vitamin D levels were associated with stage III disease in univariate analysis [OR = 2.6 (95% CI = 1.1-6.2), p = 0.04] as well as multivariate analysis adjusted for age, sex, body mass index, and season of draw [OR = 3.3 (95% CI = 1.1-9.7), P = 0.03]. Three-quarters of patients in our series had suboptimal or deficient circulating concentrations of 25-hydroxyvitamin D. Low serum vitamin D levels, independent of age, sex, and body mass index, predicted advanced stage disease. © 2012 Copyright Taylor and Francis Group, LLC. Source

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