Publications by authors named "Elisa K Chan"

New treatment paradigms for resectable nonsmall cell lung cancer (NSCLC), with an emphasis on personalised care and a multidisciplinary approach, have significantly improved patient outcomes. The incorporation of immune checkpoint inhibitors into neoadjuvant, perioperative and adjuvant treatment algorithms is reshaping the standard of care for resectable NSCLC. Adjuvant targeted therapy trials have also paved the way for a much-needed personalised approach for patients with actionable genomic alterations.

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Purpose: Moist desquamation (MD) is a concerning acute side effect of radiation therapy for breast cancer, often seen in skin folds for patients having large or pendulous breasts. In vivo skin dosimetry, clinical assessments, and patient-reported skin reactions were used to determine a relationship between dose-area metrics and the development of MD, to lend insight into skin tolerances and possibly guide future treatment planning dose constraints.

Methods And Materials: Skin dose was measured using GafChromic film on the inner surface of an early prototype carbon-fiber accessory for breast support to remove the inframammary fold in 20 patients at high risk of developing MD undergoing adjuvant whole breast radiation therapy.

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There has been an increasing interest in patient-reported outcome (PRO) measures in both the clinical and research settings to improve the quality of life among patients and to identify when clinical intervention may be needed. The primary purpose of this prospective study was to validate an acute breast skin toxicity PRO measure across a broad sample of patient body types undergoing radiation therapy. Between August 2018 and September 2019, 134 women undergoing adjuvant breast radiotherapy (RT) consented to completing serial PRO measures both during and post-RT treatment and to having their skin assessed by trained trial radiation therapists.

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Background: A novel device for supine positioning in breast radiotherapy for patients with large or pendulous breasts has been developed and tested in phase II studies. This trial is designed to assess the efficacy of the device to reduce skin toxicity and unwanted normal tissue dose in comparison to the current clinical standard for supine breast support during breast radiotherapy.

Methods: Patients at high risk for moist desquamation, having infra-mammary fold or lateral ptosis, will be randomized into two arms.

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Purpose: Higher energy (>6 MV) photons reduce dose inhomogeneity with breast tangent beams, thereby reducing late breast toxicity, but skin and superficial tissue sparing by higher energy beams raises concerns about local recurrence (LR) risk. This study aimed to determine whether beam energy and surgical bed-to-skin distance affect LR.

Methods And Materials: This population-based study included newly diagnosed invasive breast cancers without skin involvement (pT1-4a, any-N, M0) treated with breast-conserving surgery and adjuvant whole breast radiation therapy without bolus or beam spoilers.

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Purpose: This pilot study (ClinicalTrials.gov NCT04543851) investigates a novel breast positioning device using a low density, high tensile carbon-fiber cradle to support the breast, remove the inframammary fold, and reduce dose to organs at risk for whole breast radiation therapy in the supine position.

Methods And Materials: Thirty patients with inframammary folds ≥1 cm or lateral ptosis in supine treatment position were planned with standard positioning and with a carbon-fiber Adjustable Reusable Accessory (CARA) breast support.

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Purpose: Bolus use during postmastectomy radiation therapy doubles the risk of grade 2 and 3 skin toxicity. Despite its unknown benefit, bolus is often prescribed during postmastectomy radiation therapy for patients without skin involvement.

Methods And Materials: For women with breast cancer receiving photon 3-dimensional conformal radiation therapy, bolus was used routinely for chest walls but was omitted for breast reconstructions by about half of radiation oncologists from 2007 to 2011.

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Objective: To determine whether signed family physician reminder letters to women overdue for screening mammography prompts rescreening.

Methods: A randomized double-blind trial conducted in 2013 among women aged 51-73 and overdue for screening by 6-24 months. The study was carried out by the publicly funded British Columbia Cancer Agency Screening Mammography Program, which routinely sends standard reminder postcards to women who are due for mammography.

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Purpose: The Cancer and Leukemia Group B (CALGB) 9343 trial randomized elderly women with estrogen receptor-positive, stage 1 breast cancer to receive either hormone therapy (HT) or HT and radiation therapy (HT-RT) after lumpectomy and showed no difference in survival. After this publication, a practice guideline made HT alone a standard treatment option in British Columbia. The subsequent population-based pattern of practice was studied.

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We describe a Canadian phase III randomized controlled trial of stereotactic body radiotherapy (SBRT) versus conventionally hypofractionated radiotherapy (CRT) for the treatment of stage I medically inoperable non-small-cell lung cancer (OCOG-LUSTRE Trial). Eligible patients are randomized in a 2:1 fashion to either SBRT (48 Gy in 4 fractions for peripherally located lesions; 60 Gy in 8 fractions for centrally located lesions) or CRT (60 Gy in 15 fractions). The primary outcome of the study is 3-year local control, which we hypothesize will improve from 75% with CRT to 87.

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Background And Purpose: Ongoing concern remains regarding cardiac injury with hypofractionated whole breast/chest-wall radiotherapy (HF-WBI) compared to conventional radiotherapy (CF-WBI) in left-sided breast cancer patients. The purpose was to determine if cardiac mortality increases with HF-WBI relative to CF-WBI.

Materials And Methods: Between 1990 and 1998, 5334 women with early-stage breast cancer received post-operative radiotherapy to the breast/chest wall alone.

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Purpose: To determine late urinary toxicity (>12 months) in a large cohort of uniformly treated low-dose-rate prostate brachytherapy patients.

Methods And Materials: From 1998 to 2009, 2709 patients with National Comprehensive Cancer Network-defined low-risk and low-tier intermediate-risk prostate cancer were treated with Iodine 125 ((125)I) low-dose-rate prostate brachytherapy; 2011 patients with a minimum of 25 months of follow-up were included in the study. Baseline patients, treatment, implant factors, and late urinary toxicity (Radiation Therapy Oncology Group [RTOG] grading system and International Prostate Symptom Score [IPSS]) were recorded prospectively.

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Objectives: To evaluate the cosmetic effect of a tumor-bed boost after hypofractionated whole breast irradiation (HF-WBI+B) using a patient-reported questionnaire.

Materials And Methods: Between 2000 and 2005, 4392 women aged 75 years and younger with unilateral early-stage breast cancer received HF-WBI alone or HF-WBI+B. From each group, 800 randomly sampled surviving and nonrelapsed women were invited to complete the Breast Cancer Treatment Outcomes Scale questionnaire.

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Purpose: The risk of cardiac injury with hypofractionated whole-breast/chest wall radiation therapy (HF-WBI) compared with conventional whole-breast/chest wall radiation therapy (CF-WBI) in women with left-sided breast cancer remains a concern. The purpose of this study was to determine if there is an increase in hospital-related morbidity from cardiac causes with HF-WBI relative to CF-WBI.

Methods And Materials: Between 1990 and 1998, 5334 women ≤ 80 years of age with early-stage breast cancer were treated with postoperative radiation therapy to the breast or chest wall alone.

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Purpose: To determine whether acute urinary toxicity rates improve with the overall experience of a large prostate brachytherapy program.

Methods And Materials: From 1998 to 2009, 2937 patients were treated with prostate brachytherapy at the British Columbia Cancer Agency. Baseline patient, treatment, and implant factors were recorded prospectively.

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Purpose: The objective of this study was to compare recurrent tumor locations after radiation therapy with pretreatment delineations of high-grade gliomas from magnetic resonance imaging (MRI) and 3,4-dihydroxy-6-[(18)F]fluoro-L-phenylalanine ((18)F-FDOPA) positron emission tomography (PET) using contours delineated by multiple observers.

Methods And Materials: Nineteen patients with newly diagnosed high-grade gliomas underwent computed tomography (CT), gadolinium contrast-enhanced MRI, and (18)F-FDOPA PET/CT. The image sets (CT, MRI, and PET/CT) were registered, and 5 observers contoured gross tumor volumes (GTVs) using MRI and PET.

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The relationship between rectal dose distribution and the incidence of late rectal complications following external-beam radiotherapy has been previously studied using dose-volume histograms or dose-surface histograms. However, they do not account for the spatial dose distribution. This study proposes a metric based on both surface dose and distance that can predict the incidence of rectal bleeding in prostate cancer patients treated with radical radiotherapy.

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Purpose: The purpose of this study was to assess the efficacy of a 2×2 Gy (total dose, 4 Gy) palliative radiation therapy (RT) regimen for treating patients with indolent non-Hodgkin lymphoma (NHL) in terms of response rate, response duration, and symptom relief.

Methods And Materials: A retrospective chart review was conducted. Between 2003 and 2007, 54 patients with NHL were treated to 85 anatomical sites with a 2×2 Gy palliative regimen.

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Background: Systemic chemotherapy is being used increasingly in patients with colorectal cancer. The effects of prior systemic adjuvant or palliative chemotherapy on morbidity following hepatic resection for metastases are not well defined.

Objectives: To assess the peri-operative impact of systemic chemotherapy on liver resection for colorectal cancer hepatic metastases.

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