Publications by authors named "Yiat Horng Leong"
Article Synopsis
- - Survivors of head and neck cancers (HNC) in Singapore have a higher risk of stroke, and a study aimed to understand this risk among different subpopulations of HNC survivors from January 2005 to December 2020.
- - The study used data from national cancer and stroke registries, focusing on demographic and treatment factors to analyze stroke outcomes over a median follow-up period of about 42.5 months.
- - Out of nearly 10,000 HNC survivors studied, 3.4% suffered a stroke, showing a significant stroke risk increase with an SIRR of 2.46, indicating they were over twice as likely to have a stroke compared to the general population.
Recent technological advances have allowed the possibility of performing patient-specific quality assurance (QA) without time-intensive measurements. The objectives of this study are to: (1) compare how well the log file-based Mobius QA system agrees with measurement-based QA methods (ArcCHECK and portal dosimetry, PD) in passing and failing plans, and; (2) evaluate their error sensitivities. To these ends, ten phantom plans and 100 patient plans were measured with ArcCHECK and PD on VitalBeam, while log files were sent to Mobius for dose recalculation.
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- - Radiotherapy resistance is a significant challenge in cancer treatment, particularly in cervical cancers, and this study identifies the GAGE antigen as a key factor in this resistance.
- - Elevated levels of the GAGE12 protein lead to enhanced radio resistance by promoting specific chromatin changes that improve DNA repair and increase chromatin accessibility.
- - The study suggests using GAGE as a biomarker to identify patients likely to respond poorly to radiotherapy, and highlights the potential of targeting GAGE to enhance treatment effectiveness.
Radiation oncology training in Singapore - A non-Australasian RANZCR training site.
J Med Imaging Radiat Oncol
July 2021
The Radiation Oncology Department at The National Cancer Institute, Singapore (NCIS) and the Royal Australian and New Zealand College of Radiology (RANZCR) has had a well-established relationship that began as a partnership to grow a pool of local radiation oncologists to meet a nation's demand for radiotherapy services. This journey has surpassed its initial aims and now has produced a generation of radiation oncologists leading a national cancer institute. We recount the history and progress of this partnership here, as well as the unique success of its product; the only RANZCR-accredited radiation oncology training site outside of Australia and New Zealand since 2002.
View Article and Find Full Text PDFPhase 1 Study of Low-Dose Fractionated Whole Abdominal Radiation Therapy in Combination With Weekly Paclitaxel for Platinum-Resistant Ovarian Cancer (GCGS-01).
Int J Radiat Oncol Biol Phys
March 2021
Purpose: Low-dose fractionated whole abdominal radiation therapy (LDFWART) has synergistic activity with paclitaxel in preclinical models. The aim of this phase 1 trial was to determine the recommended phase 2 dose and preliminary activity of weekly paclitaxel (wP) concurrent with LDFWART in patients with platinum-resistant ovarian cancer (PROC).
Methods And Materials: Patients were enrolled at de-escalating dose levels of wP (part A), starting at 80 mg/m, concurrent with fixed-dose LDFWART delivered in 60 cGy fractions twice-daily, 2 days per week, for 6 continuous weeks.
Article Synopsis
- - The study aimed to compare the incremental clinical benefits (ICB) and costs of three treatment approaches for locally advanced nasopharyngeal cancer: induction chemotherapy (IC) added to concurrent chemoradiotherapy (CCRT), concurrent chemotherapy (CC) added to radiotherapy (RT), and CC plus adjuvant chemotherapy (AC) added to RT.
- - Three clinical trials for IC, three for CC, and four for CC + AC were analyzed, revealing that all approaches had similar ICB scores and incremental drug costs, with no significant differences found statistically.
- - The conclusions indicate that the ICB and drug costs associated with these treatment methods do not significantly differ, suggesting that choosing between them may depend more on patient
Emerging radiotherapy technologies and trends in nasopharyngeal cancer.
Cancer Commun (Lond)
September 2020
Article Synopsis
- Technology has significantly advanced radiotherapy treatments for nasopharyngeal cancer (NPC), leading to improved outcomes over recent decades.
- Key emerging trends include personalized medicine, advanced imaging, better treatment planning, adaptive re-planning, the use of particle therapy, and the integration of artificial intelligence in clinical settings.
- The expectation is that these innovations will greatly enhance the effectiveness and safety of NPC radiotherapy in the coming decade.
Purpose: To determine the efficacy and toxicity of re-irradiation for patients with recurrent GBM.
Materials And Methods: We searched various biomedical databases from 1998 to 2018, for eligible studies where patients were treated with re-irradiation for recurrent GBM. Outcomes of interest were 6 and 12-month overall survival (OS-6, OS-12), 6 and 12-month progression free survival (PFS-6, PFS-12) and serious (Grade 3 +) adverse events (AE).
Article Synopsis
- - Neoadjuvant chemoradiotherapy (CRT) followed by total mesorectal excision (TME) surgery for locally advanced rectal cancer shows improved local control and reduced toxicity compared to adjuvant CRT, based on a study of 117 patients treated at National University Hospital in Singapore.
- - The study found a median follow-up of 34 months, with 11.5% of patients achieving a pathological complete response, while 72.6% experienced tumor or nodal downstaging; however, only 5.2% and 3.1% reported Grade 3 acute and late toxicities, respectively, with no Grade 4 toxicities.
- - Five-year outcomes indicated low local recurrence (
Background: The purpose of this clinical review was to summate the published data for the long-term outcomes of reirradiation with intensity-modulated radiotherapy (IMRT) for locally recurrent nasopharyngeal carcinoma (NPC).
Methods: We searched biomedical literature databases for eligible studies published from January 2005 to September 2016. Outcomes of interests were 5-year local failure-free survival, distant failure-free survival, overall survival (OS), and toxicities.
Purpose: To determine the feasibility and safety of outpatient combined intracavitary and interstitial brachytherapy for cervix cancer with sedation and local anesthesia.
Material And Methods: We included patients diagnosed with non-metastatic cervix cancer and have completed brachytherapy between December 2015 and December 2016. Moderate to deep sedation was achieved using intravenous midazolam, propofol, fentanyl, and oxycodone.
Introduction: This study reports the outcomes of patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation followed by surgery in a local population of Singapore.
Materials And Methods: The records of 85 patients who underwent neoadjuvant chemoradiation for locally advanced rectal cancer followed by surgery at the Tan Tock Seng Hospital (TTSH) between November 2002 and January 2012 were reviewed. The treatment protocol comprised radiotherapy to a total dose of 50.