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Full-Text Articles in Medical Sciences

Dosimetric Planning Study Of Respiratory-Gated Volumetric Modulated Arc Therapy For Early-Stage Lung Cancer With Stereotactic Body Radiation Therapy, Ilma Xhaferllari, Jeff Chen, Michael Macfarlane, Edward Yu, Stewart Gaede Apr 2015

Dosimetric Planning Study Of Respiratory-Gated Volumetric Modulated Arc Therapy For Early-Stage Lung Cancer With Stereotactic Body Radiation Therapy, Ilma Xhaferllari, Jeff Chen, Michael Macfarlane, Edward Yu, Stewart Gaede

Edward Yu

Purpose: To evaluate the dosimetric potential of respiratory-gated volumetric modulated arc therapy (VMAT) to reduce the dose to normal lung when treating early-stage non-small cell lung cancer (NSCLC) with stereotactic body radiation therapy (SBRT). Methods and materials: Twenty patients with inoperable stage I/II NSCLC with motion greater than 5 mm were retrospectively planned with 4-dimensional computed tomography–based gated and nongated VMAT. Each plan was optimized using two 225° arcs with 10-MV flattening filter– free beams with maximum dose rate of 2400 MU/min. A host script was generated and used to optimize all 40 plans to minimize dosimetric bias. The main …


Prognostic Factors For Male Breast Cancer: Similarity To Female Counterparts, Edward Yu, Larry Stitt, Olga Vujovic, Kurian Joseph, Avi Assouline, Joseph Au, Jawaid Younus, Francisco Perera, Patricia Tai May 2013

Prognostic Factors For Male Breast Cancer: Similarity To Female Counterparts, Edward Yu, Larry Stitt, Olga Vujovic, Kurian Joseph, Avi Assouline, Joseph Au, Jawaid Younus, Francisco Perera, Patricia Tai

Edward Yu

Abstract. Aim: To assess whether prognostic factors in male (MBC) and female (FBC) breast cancer have similar impact on survival. Patients and Methods: Charts for men and women diagnosed with breast cancer referred to the London Regional Cancer Program (LRCP) were reviewed. Patients with distant metastatic diseases were excluded. Data on prognostic factors including age, nodal status, resection margin, use of hormonal therapy, chemotherapy with/without hormone and radiation therapy (RT), overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS) were analyzed. Survival estimates were obtained using Kaplan-Meier methodology. The Cox regression interaction was used to compare male and female …


Prophylactic Cranial Irradiation For Patients With Limited-Stage Small-Cell Lung Cancer With Response To Chemoradiation, Patricia Tai, Avi Assouline, Kurian Joseph, Larry Stitt, Edward Yu Dec 2012

Prophylactic Cranial Irradiation For Patients With Limited-Stage Small-Cell Lung Cancer With Response To Chemoradiation, Patricia Tai, Avi Assouline, Kurian Joseph, Larry Stitt, Edward Yu

Edward Yu

Background Previous clinical studies have generally reported that prophylactic cranial irradiation (PCI) was given to patients with a complete response (CR) to chemotherapy and chest radiotherapy in limited-stage small-cell lung cancer (SCLC). It is not clear if those with incomplete response (IR) would benefit from PCI. Patients and Methods The Saskatchewan experience from 1981 through 2007 was reviewed. Patients were treated with chest radiotherapy and chemotherapy with or without PCI (typical doses: 2500 cGy in 10 fractions over 2 weeks, 3000 cGy in 15 fractions over 3 weeks, or 3000 cGy in 10 fractions over 2 weeks). Results There were …


Male Breast Cancer, Edward Yu May 2012

Male Breast Cancer, Edward Yu

Edward Yu

No abstract provided.


Long-Term Outcome Of Breast Cancer Patients With One To Two Nodes Involved-Application Of Nodal Ratio, Patricia Tai, Kurian Joseph, Ali El-Gayed, Edward Yu Dec 2011

Long-Term Outcome Of Breast Cancer Patients With One To Two Nodes Involved-Application Of Nodal Ratio, Patricia Tai, Kurian Joseph, Ali El-Gayed, Edward Yu

Edward Yu

Abstract: Nodal ratio (NR) is defined as the number of involved nodes to the number of nodes examined. There is limited information on the application of NR on population data. Previous reports in breast cancer generally analyzed one to three positive axillary nodes as a single group. This study investigates whether one to three positive axillary nodes is a homogeneous group in prognosis by comparing one to two positive nodes to three positive nodes. The population-based registry of a Canadian province from 1981 through 1995 was searched. As the reliability of nodal assessment depends on the number of nodes sampled, …


Optimal Strategy For Prophylactic Cranial Irradiation In Limited Stage Small Cell Lung Cancer, Edward Yu, Patricia Tai, Avi Assouline, Kurian Joseph Dec 2011

Optimal Strategy For Prophylactic Cranial Irradiation In Limited Stage Small Cell Lung Cancer, Edward Yu, Patricia Tai, Avi Assouline, Kurian Joseph

Edward Yu

No abstract provided.


Mesothelioma - Epidemiology And Management, Patricia Tai, Edward Yu, Avi Assouline, Kurian Joseph Sep 2011

Mesothelioma - Epidemiology And Management, Patricia Tai, Edward Yu, Avi Assouline, Kurian Joseph

Edward Yu

Mesothelioma is an uncommon tumor. It has a latency period of 20-40 years. The most important risk factor is asbestos exposure. Prognosis of mesothelioma is generally poor with high case-fatality rate, and research to improve the outcome of this disease is on-going worldwide. Due to its rarity, management by a multidisciplinary team with experience is recommended. Carefully selected patients may benefit from tri-modality (surgery, radiotherapy and chemotherapy) treatment. The management of pleural and peritoneal mesothelioma is summarized in this review. Recent advances in chemotherapy and biologic response modifiers are promising.


Lung Cancer Epidemiology – A Global View, Patricia Tai, Edward Yu, Rashmi Koul, Arbind Dubey Sep 2011

Lung Cancer Epidemiology – A Global View, Patricia Tai, Edward Yu, Rashmi Koul, Arbind Dubey

Edward Yu

Smoking, air pollution and radon exposure are causally related to lung cancer. This review analyzes trends of smoking habits by age, sex and ethnicity and their correlation with incidence and mortality of lung cancer. Unfortunately the use of tobacco by adolescents is on the rise. Most developed countries are still showing the rising trend of mortality in female smokers. In Asia, cigarette smoking has become a major health risk with one in three of all cigarettes in the world today are smoked in China. Estimated one hundred million young ( < 29 years old) Chinese smokers will eventually die from lung …


Lung Cancer Brachytherapy: Robotics-Assisted Minimally Invasive Approach, Edward Yu, Craig Lewis, Ana Trejos, Rajni Patel, Richard Malthaner Sep 2011

Lung Cancer Brachytherapy: Robotics-Assisted Minimally Invasive Approach, Edward Yu, Craig Lewis, Ana Trejos, Rajni Patel, Richard Malthaner

Edward Yu

New technological concepts have been evolving to manage the relative poor prognosis of lung cancer. Brachytherapy is becoming an option for both unresectable and early resectable lung cancer. Three-dimensional ultrasound (US) of lung tumours and image-guided minimally invasive robotics-assisted brachytherapy are feasible for dosimetry planning and management of lung tumours. The present article reviews the current knowledge of lung brachytherapy and discusses its potential in future management of lung cancer.


The Impact Of Post-Mastectomy Radiation Therapy On Male Breast Cancer Patients--A Case Series, Edward Yu, Hiromichi Suzuki, Jawaid Younus, Tarek Elfiki, Larry Stitt, Gary Yau, Olga Vujovic, Francisco Perera, Michael Lock, Patricia Tai Mar 2011

The Impact Of Post-Mastectomy Radiation Therapy On Male Breast Cancer Patients--A Case Series, Edward Yu, Hiromichi Suzuki, Jawaid Younus, Tarek Elfiki, Larry Stitt, Gary Yau, Olga Vujovic, Francisco Perera, Michael Lock, Patricia Tai

Edward Yu

OBJECTIVE: To assess the impact of radiation management on male breast cancer (MBC) at London Regional Cancer Program (LRCP). METHODS AND MATERIALS: Men with a diagnosis of breast cancer referred to LRCP were reviewed. The seventh American Joint Committee on Cancer staging system was used. Patients treated with and without post-mastectomy radiation therapy (PMRT) were analyzed. Disease-free survival (DFS) was defined as time duration from diagnosis to first recurrence. Overall survival (OS) was defined as time duration from pathologic diagnosis to death or last follow-up with any death defined as an event. Survival estimates were obtained using Kaplan-Meier methodology. RESULTS: …


A Fully Automated Non-External Marker 4d-Ct Sorting Algorithm Using A Serial Cine Scanning Protocol, Greg Carnes, Stewart Gaede, Edward Yu, Jake Van Dyk, Jerry Battista, Ting-Yim Lee Apr 2009

A Fully Automated Non-External Marker 4d-Ct Sorting Algorithm Using A Serial Cine Scanning Protocol, Greg Carnes, Stewart Gaede, Edward Yu, Jake Van Dyk, Jerry Battista, Ting-Yim Lee

Edward Yu

Current 4D-CT methods require external marker data to retrospectively sort image data and generate CT volumes. In this work we develop an automated 4D-CT sorting algorithm that performs without the aid of data collected from an external respiratory surrogate. The sorting algorithm requires an overlapping cine scan protocol. The overlapping protocol provides a spatial link between couch positions. Beginning with a starting scan position, images from the adjacent scan position (which spatial match the starting scan position) are selected by maximizing the normalized cross correlation (NCC) of the images at the overlapping slice position. The process was continued by 'daisy …


The Use Of Ct Density Changes At Internal Tissue Interfaces To Correlate Internal Organ Motion With An External Surrogate, Stewart Gaede, Gregory Carnes, Edward Yu, Jake Van Dyk, Jerry Battista, Ting-Yim Lee Jan 2009

The Use Of Ct Density Changes At Internal Tissue Interfaces To Correlate Internal Organ Motion With An External Surrogate, Stewart Gaede, Gregory Carnes, Edward Yu, Jake Van Dyk, Jerry Battista, Ting-Yim Lee

Edward Yu

The purpose of this paper is to describe a non-invasive method to monitor the motion of internal organs affected by respiration without using external markers or spirometry, to test the correlation with external markers, and to calculate any time shift between the datasets. Ten lung cancer patients were CT scanned with a GE LightSpeed Plus 4-Slice CT scanner operating in a ciné mode. We retrospectively reconstructed the raw CT data to obtain consecutive 0.5 s reconstructions at 0.1 s intervals to increase image sampling. We defined regions of interest containing tissue interfaces, including tumour/lung interfaces that move due to breathing …


Post-Operative Extended Volume External Beam Radiation Therapy In High Risk Esophageal Cancer Patients: A Prospective Experience, E. Yu, P. Tai, J. Younus, R. Malthaner, P. Truong, L. Stitt, G. Rodrigues, R. Ash, R. Dar, B. Yaremko, A. Tomiak, B. Dingle, M. Sanatani, M. Vincent, W. Kocha, D. Fortin, R. Inculet Dec 2008

Post-Operative Extended Volume External Beam Radiation Therapy In High Risk Esophageal Cancer Patients: A Prospective Experience, E. Yu, P. Tai, J. Younus, R. Malthaner, P. Truong, L. Stitt, G. Rodrigues, R. Ash, R. Dar, B. Yaremko, A. Tomiak, B. Dingle, M. Sanatani, M. Vincent, W. Kocha, D. Fortin, R. Inculet

Edward Yu

Background and purpose: Extended volume external beam radiation therapy (RT) following esophagectomy is controversial. This prospective study evaluates the feasibility of extended volume RT treatment in high-risk esophagectomy patients with cervical anastomosis receiving post–operative combined chemo-radiation therapy. Patients and methods: From 2001-2006, 15 patients with resected esophageal cancer were prospectively accrued to this pilot study, to evaluate the adverse effects of extended volume RT. Eligibility criteria were pathologically proven esophageal malignancy, T3-4, N0-1, disease amenable to surgical resection and esophagectomy with or without resection margin involvement. Patients with distant metastases (M1) and patients treated with previous RT were excluded. All …


The Effect Of Timing Of Radiotherapy After Breast-Conserving Surgery In Patients With Positive Or Close Resection Margins, Young Age, And Node-Negative Disease, With Long Term Follow-Up, Olga Vujovic, Anil Cherian, Edward Yu, A. Dar, Larry Stitt, Francisco Perera Oct 2006

The Effect Of Timing Of Radiotherapy After Breast-Conserving Surgery In Patients With Positive Or Close Resection Margins, Young Age, And Node-Negative Disease, With Long Term Follow-Up, Olga Vujovic, Anil Cherian, Edward Yu, A. Dar, Larry Stitt, Francisco Perera

Edward Yu

Purpose: The aim of this study was to determine the effect of timing of radiotherapy after conservative breast surgery on local recurrence in women with positive resection margins and young age, treated without systemic therapy. Methods and materials: A total of 568 patients with T1 and T2, N0 breast cancer were treated with breast-conserving surgery and breast irradiation, between January 1, 1985, and December 31, 1992, at the London Regional Cancer Centre. 63 patients (11.1%) had positive/close resection margins (< 2 mm) and 48 patients (8.4%) were age < or = 40 years. For patients with positive resection margins, the time intervals from breast surgery to breast irradiation used for analysis were, 0 to 8 weeks, > 8 to 12 weeks and > 12 weeks. For patients < or = 40 years, the intervals used for analysis were 0 to 8 weeks and > 8 weeks. Results: Median follow up was 11.2 years. For patients …


Comparative Planning Evaluation Of Intensity-Modulated Radiotherapy Techniques For Complex Lung Cancer Cases, Slav Yartsev, Jeff Chen, Edward Yu, Tomas Kron, George Rodrigues, Terry Coad, Kristina Trenka, Eugene Wong, Glenn Bauman, Jake Van Dyk Jan 2006

Comparative Planning Evaluation Of Intensity-Modulated Radiotherapy Techniques For Complex Lung Cancer Cases, Slav Yartsev, Jeff Chen, Edward Yu, Tomas Kron, George Rodrigues, Terry Coad, Kristina Trenka, Eugene Wong, Glenn Bauman, Jake Van Dyk

Edward Yu

Background and purpose: Lung cancer treatment can be one of the most challenging fields in radiotherapy. The aim of the present study was to compare different modalities of radiation delivery based on a balanced scoring scheme for target coverage and normal tissue avoidance. Patients and methods: Treatment plans were developed for 15 patients with stage III inoperable non-small cell lung cancer using 3D conformal technique and intensity-modulated radiotherapy (IMRT). Elective nodal irradiation was included for all cases to create the most challenging scenarios with large target volumes. A 2 cm margin was used around the gross tumour volume (GTV) to …


Does Sex Influence The Impact That Smoking, Treatment Interruption And Impaired Pulmonary Function Have On Outcomes In Limited Stage Small Cell Lung Cancer Treatment?, Gregory Videtic, Pauline Truong, Robert Ash, Edward Yu, Walter Kocha, Mark Vincent, Anna Tomiak, A Dar, Frances Whiston, Larry Stitt Jun 2005

Does Sex Influence The Impact That Smoking, Treatment Interruption And Impaired Pulmonary Function Have On Outcomes In Limited Stage Small Cell Lung Cancer Treatment?, Gregory Videtic, Pauline Truong, Robert Ash, Edward Yu, Walter Kocha, Mark Vincent, Anna Tomiak, A Dar, Frances Whiston, Larry Stitt

Edward Yu

PURPOSE: To look for survival differences between men and women with limited stage small cell lung cancer (LS-SCLC) by examining stratified variables that impair treatment efficacy. METHODS: A retrospective review of 215 LS-SCLC patients treated from 1989 to 1999 with concurrent chemotherapy-radiotherapy modelled on the 'early-start' thoracic radiotherapy arm of a National Cancer Institute of Canada randomized trial. RESULTS: Of 215 LS-SCLC patients, 126 (58.6%) were men and 89 (41.4%) were women. Smoking status during treatment for 186 patients (86.5%) was: 107 (58%) nonsmoking (NS) (76 [71%] male [M]; 31 [29%] female [F]) and 79 (42%) smoking (S) (36 M …


Planning Evaluation Of Radiotherapy For Complex Lung Cancer Cases Using Helical Tomotherapy, Tomas Kron, Grigor Grigorov, Edward Yu, Slav Yartsev, Jeff Chen, Eugene Wong, George Rodrigues, Kris Trenka, Terry Coad, Glenn Bauman, Jake Van Dyk Aug 2004

Planning Evaluation Of Radiotherapy For Complex Lung Cancer Cases Using Helical Tomotherapy, Tomas Kron, Grigor Grigorov, Edward Yu, Slav Yartsev, Jeff Chen, Eugene Wong, George Rodrigues, Kris Trenka, Terry Coad, Glenn Bauman, Jake Van Dyk

Edward Yu

Lung cancer treatment is one of the most challenging fields in radiotherapy. The aim of the present study was to investigate what role helical tomotherapy (HT), a novel approach to the delivery of highly conformal dose distributions using intensity-modulated radiation fan beams, can play in difficult cases with large target volumes typical for many of these patients. Tomotherapy plans were developed for 15 patients with stage III inoperable non-small-cell lung cancer. While not necessarily clinically indicated, elective nodal irradiation was included for all cases to create the most challenging scenarios with large target volumes. A 2 cm margin was used …


Radiation Treatment Of Lung Cancer--Patterns Of Practice In Canada, Patricia Tai, Edward Yu, Jerry Battista, Jake Van Dyk Apr 2004

Radiation Treatment Of Lung Cancer--Patterns Of Practice In Canada, Patricia Tai, Edward Yu, Jerry Battista, Jake Van Dyk

Edward Yu

BACKGROUND AND PURPOSE: To assess the patterns of practice among Canadian radiation oncologists who treat lung cancers. PATIENTS AND METHODS: A questionnaire detailing different aspects of radiation treatment of lung cancer was mailed to all radiation oncologists treating lung cancer in Canada. Seventy-two percent (74/103) of radiation oncologists who treat lung cancer from all 34 Canadian cancer centres replied to the questionnaire. RESULTS: (a) Radiotherapy regimens in Canadian cancer centres are in accordance with several major randomised studies. There is still some variation in treatment practice that may be due to unresolved controversies or limited resources. The most frequently used …


Improving The Consistency In Cervical Esophageal Target Volume Definition By Special Training, Patricia Tai, Jake Van Dyk, Jerry Battista, Edward Yu, Larry Stitt, Jon Tonita, Olusegun Agboola, James Brierley, Rashid Dar, Christopher Leighton, Shawn Malone, Barbara Strang, Pauline Truong, Gregory Videtic, C. Wong, Rebecca Wong, Youssef Youssef Jun 2002

Improving The Consistency In Cervical Esophageal Target Volume Definition By Special Training, Patricia Tai, Jake Van Dyk, Jerry Battista, Edward Yu, Larry Stitt, Jon Tonita, Olusegun Agboola, James Brierley, Rashid Dar, Christopher Leighton, Shawn Malone, Barbara Strang, Pauline Truong, Gregory Videtic, C. Wong, Rebecca Wong, Youssef Youssef

Edward Yu

PURPOSE: Three-dimensional conformal radiation therapy requires the precise definition of the target volume. Its potential benefits could be offset by the inconsistency in target definition by radiation oncologists. In a previous survey of radiation oncologists, a large degree of variation in target volume definition of cervical esophageal cancer was noted for the boost phase of radiotherapy. The present study evaluated whether special training could improve the consistency in target volume definitions. METHODS AND MATERIALS: A pre-training survey was performed to establish baseline values. This was followed by a special one-on-one training session on treatment planning based on the RTOG 94-05 …


Monte Carlo Simulations Of Dna Damage From Incorporated Cold Iodine Following Photoelectrically Induced Auger Electron Cascades, V. Moiseenko, S. Karnas, E. Yu, J. Battista Dec 2001

Monte Carlo Simulations Of Dna Damage From Incorporated Cold Iodine Following Photoelectrically Induced Auger Electron Cascades, V. Moiseenko, S. Karnas, E. Yu, J. Battista

Edward Yu

Radiation-induced damage in nucleosomal DNA from Auger electron cascades due to incorporated cold IUdR has been modelled through Monte Carlo simulations. Probabilities of DNA double strand break (DSB) production following a vacancy in the K, L, M and N shells of iodine are estimated. DSB complexity from the base damage accompanying a break was also estimated. Multiple DSB events were analysed for correlated breaks due to nucleosome periodicity. The probability of an Auger cascade causing at least one DSB strongly depended on the shell in which the initial vacancy was produced. This probability was approximately 0.35 for K and L …


Monte Carlo Simulations And Measurement Of Dna Damage From X-Ray-Triggered Auger Cascades In Iododeoxyuridine (Iudr), S. Karnas, V. Moiseenko, E. Yu, P. Truong, J. Battista Aug 2001

Monte Carlo Simulations And Measurement Of Dna Damage From X-Ray-Triggered Auger Cascades In Iododeoxyuridine (Iudr), S. Karnas, V. Moiseenko, E. Yu, P. Truong, J. Battista

Edward Yu

We investigated the DNA damage from Auger electrons emitted from incorporated stable iodine (127I), following photoelectric absorption of external x-rays. The effectiveness of the Auger electrons in producing DNA double-strand breaks (DSB) was determined theoretically, using Monte Carlo simulations of the radiation physics and chemistry, and was shown to be in reasonable agreement with DNA damage measured using the comet assay. The DSB yields were measured in CHO cells for 60Co (as a non-Auger-promoting radiation) and for tungsten-filtered 100 kVp x-rays capable of producing Auger electron emission. The theoretical study showed that on average, 2.5 Auger electrons were emitted for …


Using Treatment Interruptions To Palliate The Toxicity From Concurrent Chemoradiation For Limited Small Cell Lung Cancer Decreases Survival And Disease Control, Gregory Videtic, Karen Fung, Anna Tomiak, Larry Stitt, A. Dar, Pauline Truong, Edward Yu, Mark Vincent, Walter Kocha Jul 2001

Using Treatment Interruptions To Palliate The Toxicity From Concurrent Chemoradiation For Limited Small Cell Lung Cancer Decreases Survival And Disease Control, Gregory Videtic, Karen Fung, Anna Tomiak, Larry Stitt, A. Dar, Pauline Truong, Edward Yu, Mark Vincent, Walter Kocha

Edward Yu

BACKGROUND AND PURPOSE: We analyzed the impact on survival outcomes of treatment interruptions due to toxicity arising during the concurrent phase of chemotherapy/radiotherapy (ChT/RT) for our limited-stage small-cell cancer (LSCLC) population over the past 10 years. MATERIALS AND METHODS: From 1989 to 1999, 215 patients received treatment for LSCLC, consisting of six cycles of alternating cyclophosphamide/doxorubicin or epirubicin/vincristine (CAV; CEV) and etoposide/cisplatin (EP). Thoracic RT was started with EP at either the second or third cycle (85% of patients). RT dose was either 40 Gy in 15 fractions over 3 weeks or 50 Gy in 25 fractions over 5 weeks, …


Radiation Treatment For Cervical Esophagus: Patterns Of Practice Study In Canada, 1996, Patricia Tai, Jake Van Dyk, Edward Yu, Jerry Battista, Matthew Schmid, Larry Stitt, Jon Tonita, Terry Coad May 2000

Radiation Treatment For Cervical Esophagus: Patterns Of Practice Study In Canada, 1996, Patricia Tai, Jake Van Dyk, Edward Yu, Jerry Battista, Matthew Schmid, Larry Stitt, Jon Tonita, Terry Coad

Edward Yu

PURPOSE: To assess the patterns of practice among Canadian radiation oncologists who treat esophageal cancers, using a trans-Canada survey, completed at the end of 1996. METHODS AND MATERIALS: One of 3 case presentations of different stages of cervical esophageal cancer was randomly assigned and sent to participating radiation oncologists by mail. Respondents were asked to fill in questionnaires regarding treatment techniques and to outline target volumes for the boost phase of radiotherapy. Radiation oncologists from 26 of 27 (96%) of all Canadian centers participated. RESULTS: High-energy X-rays (>/= 10 MV) were employed by 68% of the respondents in part …


Optimal Photon Energies For Iudr K-Edge Radiosensitization With Filtered X-Ray And Radioisotope Sources, S. Karnas, E. Yu, R. Mcgarry, J. Battista Sep 1999

Optimal Photon Energies For Iudr K-Edge Radiosensitization With Filtered X-Ray And Radioisotope Sources, S. Karnas, E. Yu, R. Mcgarry, J. Battista

Edward Yu

The purpose of this work is to determine the most physically effective radiation energy for K-edge absorption of x- or gamma-rays by iododeoxyuridine (IUdR) on Chinese hamster ovary (CHO) cells. Brachytherapy sources (Sm-145, I-125, Yb-169 and Am-241) and x-ray beams (30 kVp, 100 kVp and 100 kVp with gold, gadolinium, lead or tungsten filtration) were investigated for their preferential absorption qualities by IUdR sensitized DNA. The 30 kVp, 100 kVp and 100 kVp with tungsten filtration were then used to irradiate CHO cells, with or without IUdR incorporation (i.e. 10(-5) M of IUdR for 3 days). Radiation absorption calculations were …


Variability Of Target Volume Delineation In Cervical Esophageal Cancer, Patricia Tai, Jake Van Dyk, Edward Yu, Jerry Battista, Larry Stitt, Terry Coad Aug 1998

Variability Of Target Volume Delineation In Cervical Esophageal Cancer, Patricia Tai, Jake Van Dyk, Edward Yu, Jerry Battista, Larry Stitt, Terry Coad

Edward Yu

PURPOSE: Three-dimensional (3D) conformal radiation therapy (CRT) assumes and requires the precise delineation of the target volume. To assess the consistency of target volume delineation by radiation oncologists, who treat esophageal cancers, we have performed a transCanada survey. MATERIALS AND METHODS: One of three case presentations, including CT scan images, of different stages of cervical esophageal cancer was randomly chosen and sent by mail. Respondents were asked to fill in questionnaires regarding treatment techniques and to outline boost target volumes for the primary tumor on CT scans, using ICRU-50 definitions. RESULTS: Of 58 radiation oncologists who agreed to participate, 48 …


Vitamin D And Parotid Gland Function In The Rat, C. Peterfy, A. Tenenhouse, E. Yu Mar 1988

Vitamin D And Parotid Gland Function In The Rat, C. Peterfy, A. Tenenhouse, E. Yu

Edward Yu

1. We previously reported that parotid gland secretion is decreased in rats deprived of vitamin D (Glijer, Peterfy & Tenenhouse, 1985). In the present study we examine whether this effect is a direct result of the absence of vitamin D or due to the secondary systemic effects of vitamin D deficiency. 2. Offspring of rats maintained on a calcium-supplemented (1.2%), vitamin-D-deficient diet were weaned onto the same diet and examined after 8 weeks. Using this method it was possible to maintain serum calcium and parathyroid hormone concentrations within normal limits. Serum 25-hydroxyvitamin D (25(OH)D3) was not detectable, but 1,25-dihydroxyvitamin D …


Uptake, Storage And Secretion Of 5-Hydroxytryptamine And Its Amino Acid Precursor By Dispersed Rat Pancreas Acinar Cells, Ligia Stern, A. Tenenhouse, E. Yu Jun 1983

Uptake, Storage And Secretion Of 5-Hydroxytryptamine And Its Amino Acid Precursor By Dispersed Rat Pancreas Acinar Cells, Ligia Stern, A. Tenenhouse, E. Yu

Edward Yu

Rat pancreas acinar cells contain 5-hydroxytryptamine (5-HT; 10.86 +/- 2.52 ng/i.u. amylase), all of which can be accounted for by the 5-HT recovered from the zymogen granule fraction of these cells (10.70 +/- 3.06 ng/i.u. amylase). When incubated with [14C]5-HT dispersed acinar cells take up the amine and concentrate it in zymogen granules. These cells will also take up [14C]5-HTP (5-hydroxytryptophan), decarboxylate it and store the [14C]5-HT so produced in zymogen granules. 5-HTP itself is not taken up by the granules. 5-HT is incorporated into zymogen granules early in their formation; no amine is accumulated by mature zymogen granules and …