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Featured researches published by Linh Nguyen.


Urology | 1998

Late Effects After Radiotherapy for Prostate Cancer in a Randomized Dose-Response Study: Results of a Self-Assessment Questionnaire

Linh Nguyen; Alan Pollack; Gunar K. Zagars

OBJECTIVES To evaluate the late effects more than 2 years after radiotherapy using a patient-reported questionnaire in patients with prostate cancer enrolled in a randomized dose-response study comparing 70 Gy (conventional) and 78 Gy (conformal) radiotherapy (RT). METHODS The first 112 patients in the study were sent questionnaires to evaluate late bladder, rectal, and sexual function. There were 101 evaluable responses, with 50 in the conventional (Conven-RT) arm and 51 in the conformal (3DCRT) arm. RESULTS The overall rate of persistent incontinence was 29%, with 36% reporting urgency-related and 8% stress-related incontinence at some time after radiation. Use of a urinary protective device was required in 2%. The majority noticed leakage less than once per day (52%). In comparing the Conven-RT group with the 3DCRT group, similar incontinence rates were seen. However, fewer of those who received 3DCRT reported daily leakage of urine (33% versus 63%, P = 0.044). The majority (78%) of patients experienced no or mild change in bowel function after RT. Urgency of bowel movements (BMs) was of concern for 27% of patients; however, 90% reported their BMs were controlled without accidents, and 1% were taking antidiarrheal medications once a week or daily. The Conven-RT group had more moderate or major changes in bowel function than the 3DCRT group (34% versus 10%), more frequent BMs (47% versus 27%), and more urgent BMs (37% versus 18%) (P < or = 0.040 for all three comparisons). Hematochezia was uncommon, occurring once a week in 7% and daily in 4% of patients. Before RT, 80% of patients were potent, with erections adequate for intercourse at least a few times over the prior year. After RT, potency was decreased to 51%, with erections adequate for intercourse at least a few times since the completion of RT. CONCLUSIONS The overall rates of significant complications were extremely low. Although 30% reported incontinence, relatively few patients (2%) required pads. This rate compares favorably with the 31% of patients requiring protection after radical prostatectomy reported previously. Despite the higher treatment doses in the 3DCRT arm, slightly fewer long-term bowel side effects were noted. These data indicate that 78 Gy may safely be delivered using the conformal RT boost treatment technique described.


Lancet Oncology | 2002

Radiotherapy for cancer of the head and neck: altered fractionation regimens

Linh Nguyen; K. Kian Ang

A greater understanding of radiobiology led to the development of two classes of radiation fractionation schedules for the treatment of head and neck cancers. The aim of accelerated fractionation is to reduce tumour proliferation, which is a major cause of relapse, by shortening the total duration of radiotherapy. By contrast, hyperfractionation exploits the differential sensitivity of tumour cells and normal tissues to radiation, to increase the therapeutic gain. The results of clinical trials of various types of altered fractionation schedules in head and neck carcinomas are examined in this review. Acceleration of radiation by 1 week without dose reduction and hyperfractionation are consistently better than standard fractionation for locoregional control of intermediate to advanced carcinomas without an increase in late toxic effects. However, improvement in survival of patients has not been consistent. Clinical investigations show that improvement in locoregional disease control and consistent gain in survival have been achieved with combinations of radiotherapy and concurrent chemotherapy in patients with mostly stage IV carcinomas. However, these benefits have been at the expense of increased late morbidity. Consequently, concurrent radiochemotherapy is now preferred for non-surgical treatment of patients with locally advanced carcinomas, whereas altered fractionation is generally selected for patients with intermediate-stage tumours or who are medically unfit to receive chemotherapy. Further data is needed before the combination of altered fractionation with chemotherapy can be recommended outside of a study setting.


International Journal of Radiation Oncology Biology Physics | 2001

Can positron emission tomography improve the quality of care for head-and-neck cancer patients?

Naomi R. Schechter; Ann M. Gillenwater; Robert M. Byers; Adam S. Garden; William H. Morrison; Linh Nguyen; Donald A. Podoloff; K. Kian Ang

PURPOSE Fluoro-2-deoxy-d-glucose-positron emission tomography (FDG-PET) is a functional imaging modality that measures the relative uptake of 18FDG with PET. The purpose of this review is to assess the potential contribution of FDG-PET scans to the treatment of head-and-neck cancer patients. METHODS AND MATERIALS Data were assessed from the literature with attention to what additional information may be gained from the use of FDG-PET in four clinical settings: (1) detection of occult metastatic disease in the neck, (2) detection of occult primaries in patients with neck metastases, (3) detection of synchronous primaries or metastatic disease in the chest, and (4) detection of residual/recurrent locoregional disease. RESULTS Although the data are somewhat conflicting, FDG-PET appears to add little additional value to the physical examination and conventional imaging studies (supplemented by biopsy when appropriate) for the detection of subclinical nodal metastases, unknown primaries, or disease in the chest. However, FDG-PET scans are quite useful in differentiating residual/recurrent disease from treatment-induced normal tissue changes. A positive FDG-PET scan at 1 month after radiotherapy is highly indicative of the presence of residual disease, and a negative scan at 4 months after treatment is highly predictive of tumor eradication. CONCLUSIONS Large-scale studies using newer generation equipment and more defined methods are needed to more rigorously assess the potential of FDG-PET in the detection of subclinical primary or simultaneous secondary tumors and of nodal or systemic spread. Currently, however, FDG-PET can contribute to the detection of residual/early recurrent tumors, leading to the timely institution of salvage therapy or the prevention of unnecessary biopsies of irradiated tissues, which may aggravate injury.


Cancer | 2012

Achievement of personalized pain goal in cancer patients referred to a supportive care clinic at a comprehensive cancer center

Shalini Dalal; David Hui; Linh Nguyen; Ray Chacko; Cheryl Scott; Lynn Roberts; Eduardo Bruera

Cancer pain initiatives recommend using the personalized pain goal to tailor pain management. This study was conducted to examine the feasibility and stability of personalized pain goal, and how it compares to the clinical pain response criteria.


International Journal of Radiation Oncology Biology Physics | 2000

The outcome of combined-modality treatments for stage I and II primary large B-cell lymphoma of the mediastinum

Linh Nguyen; Chul S. Ha; Mark A. Hess; Jorge Romaguera; John T. Manning; Fernando Cabanillas; James D. Cox

PURPOSE Primary mediastinal large B-cell lymphoma (PML) has clinicopathologic features distinct from those of other diffuse large-cell lymphomas. However, the optimal treatment for this tumor is evolving, and in particular, the role of radiation therapy remains undefined. We conducted a retrospective review to evaluate the role of radiation therapy in this disease. METHODS AND MATERIALS The medical records of 40 consecutive patients with Ann Arbor Stage I or II PML treated at our institution from January 1980 to December 1995 were reviewed. There were 18 patients with Stage I disease and 22 patients with Stage II disease; 62.5% were women and 37.5% were men. The median age was 32.4 years (range, 17-74 years). The tumor scores were 0 in 1 patient, I in 5 patients, II in 13 patients, III in 7 patients, IV in 4 patients, and unknown in 10 patients. The International Prognostic Index (IPI) was 0 in 10 patients, I in 26 patients, II in 2 patients, and unknown in 2 patients. All patients were treated with doxorubicin-based chemotherapy, and 35 patients received radiation therapy. For most patients who received radiation therapy, an involved field or a modified-mantle field was used, and a dose of 40 Gy in 20 fractions or 39.6 Gy in 22 fractions was administered. Univariate analysis was performed to identify prognostic factors. RESULTS The median follow-up in surviving patients was 56 months (range, 19-194 months). The actuarial 5-year relapse-free survival (RFS) rate and overall survival (OS) rate for all patients were 67% and 72%, respectively. Thirty-five patients achieved a complete response; 32 of these patients received radiation therapy. The patterns of failure for the complete responders were as follows: locoregional failure alone for 1 patient (at the margin of the radiation field); distant failure alone for 5 patients; and both locoregional (in-field) and distant failure for 1 patient. There were no failures after 2.5 years. None of the 5 patients who never achieved a complete response had local control, and all died with disease. Only 2 of the 5 completed the planned course of radiation therapy; both had massive mediastinal disease. There was no treatment-related death from the initial chemotherapy or radiation therapy. One patient developed a second malignancy (sarcoma) within the radiation field after 13 years. The tumor score was a significant predictor of RFS (p = 0.016) and OS (p = 0.006), but the IPI did not prove to be a significant predictor. CONCLUSION We recommend consolidative radiation therapy in view of the excellent local control and the lack of significant toxicity. Modified mantle or involved field appears to be an adequate volume, and 39.6-40 Gy appears to be an adequate dose. The tumor score is a significant prognostic factor.


Cancer | 2010

Timing of palliative care referral and symptom burden in phase 1 cancer patients: a retrospective cohort study.

David Hui; Henrique A. Parsons; Linh Nguyen; Shana L. Palla; Sriram Yennurajalingam; Razelle Kurzrock; Eduardo Bruera

Phase 1 trials offer patients with advanced cancer the opportunity to pursue life‐prolonging cancer treatments. In the current study, the timing of referral and symptom burden between patients referred to palliative care by phase 1 oncologists and those referred by non‐phase 1 oncologists were compared.


International Journal of Radiation Oncology Biology Physics | 1999

Effectiveness of accelerated radiotherapy for patients with inoperable non-small cell lung cancer (NSCLC) and borderline prognostic factors without distant metastasis: a retrospective review

Linh Nguyen; Ritsuko Komaki; Pamela K. Allen; Randi Schea; Luka Milas

PURPOSE The standard treatment for patients with unresectable or medically inoperable non-small cell lung cancer (NSCLC) and good prognostic factors (e.g., weight loss [WL] < or = 5% and Karnofsky performance status [KPS] > or = 70) is induction chemotherapy followed by definitive radiotherapy to the primary site at 1.8-2.0 Gy per fraction with a total dose of 60-63 Gy to the target volume. Patients with poor prognostic factors usually receive radiotherapy alone, but the fractionation schedule and total dose have not been standardized. To attempt to optimize irradiation doses and schedule, we compared the effectiveness of accelerated radiotherapy (ACRT) alone to 45 Gy at 3 Gy per fraction with standard radiation therapy (STRT) of 60-66 Gy at 2 Gy per fraction in regard to tumor response, local control, distant metastasis, toxicity, and survival. METHODS AND MATERIALS Fifty-five patients treated with radiation for NSCLC at The University of Texas M. D. Anderson Cancer Center between 1990 and 1994 were identified. All 55 patients had node-positive, and no distant metastasis (N+, M0) of NSCLC. Two cohorts were identified. One cohort (26 patients) had borderline poor prognostic factors (KPS less than 70 but higher than 50, and/or WL of more than 5%) and was treated with radiotherapy alone to 45 Gy over 3 weeks at 3 Gy/fraction (ACRT). The second cohort (29 patients) had significantly better prognostic factors (KPS > or = 70 and WL < or = 5%) and was treated to 60-66 Gy over 6 to 6 1/2 weeks at 2 Gy per fraction (STRT) during the same period. RESULTS In the first cohort treated by ACRT, the distribution of patients by AJCC stage was IIB 8%, IIIA 19%, and IIIB 73%. Sixty-two percent had KPS <70, and 76% had a WL of >5%. The maximum response rate as determined by chest X-ray was 60% among 45 of 55 patients who were evaluable for response: combined complete responses (20%) and partial responses (40%). Overall survival in these patients was 13% at 2 and 5 years, with a locoregional control rate of 42% and a freedom from distant metastasis rate of 54%. The ACRT cohort treated with 3 Gy per fraction had significantly lower KPS scores (p = 0.003) and greater WL (p = 0.063) than the cohort STRT treated with 2 Gy per fraction. However, treatment results and toxicity were not significantly different between the two cohorts in spite of significantly better prognostic factors in the STRT cohort. CONCLUSIONS Despite having worse prognostic factors, the cohort treated with radiotherapy alone to 45 Gy at 3 Gy per fraction over 3 weeks (ACRT) had response rates, locoregional control, and overall survival comparable to those in the cohort treated by a total dose of 60-66 Gy at 2 Gy per fraction over 6 to 6 1/2 weeks (STRT). Given that accelerated treatment schedules decrease treatment time and cost less, these may, in the current health care environment, be important factors for health care providers to consider in treating patients who have locally advanced NSCLC and borderline poor prognostic factors.


Journal of Pain and Symptom Management | 2013

Self-Reported Constipation in Patients with Advanced Cancer: A Preliminary Report

Wadih Rhondali; Linh Nguyen; J. Lynn Palmer; Duck Hee Kang; David Hui; Eduardo Bruera

CONTEXT Constipation is often inadequately assessed and underdiagnosed in patients with advanced cancer. Many studies use patient-reported constipation (PRC) as an outcome. OBJECTIVES The aim was to compare the accuracy of PRC as compared with the modified Rome III (ROME) criteria and to determine the agreement between PRC, physician assessment of constipation, and objective assessment of constipation by modified ROME criteria among outpatients with advanced cancer. METHODS Patients with advanced cancer attending a supportive care clinic were screened. Constipation was assessed using the modified ROME criteria, patient report (yes or no and rated 0-10; 10=worst possible symptom), and physician assessments (yes or no and rated 0-10). RESULTS One hundred patients were enrolled, and 50 of 100 patients (50%) met the modified ROME criteria for constipation. Disagreement between ROME criteria and the patient report (yes/no) was found in 33 patients (33%) and between ROME criteria and the physician assessment (yes/no) in 39 patients (39%). The best combination of sensitivity (0.84) and specificity (0.62) was found with scores ≥3/10 for PRC. CONCLUSION We found a high frequency of constipation. The limited agreement with modified ROME criteria suggests that a patients self-report as yes or no is not useful for clinical practice. Patient self-rating on a 0 to 10 scale (score of three or greater) seems to be the best tool for constipation screening among this population. More research is needed to identify the best way to assess constipation in patients with advanced cancer.


Palliative & Supportive Care | 2015

The routine use of the Edmonton Classification System for Cancer Pain in an outpatient supportive care center.

Joseph Arthur; Sriram Yennurajalingam; Linh Nguyen; Kimberson Tanco; Gary Chisholm; David Hui; Eduardo Bruera

OBJECTIVE There is no standardized and universally accepted pain classification system for the assessment and management of cancer pain in both clinical practice and research studies. The Edmonton Classification System for Cancer Pain (ECS-CP) is an assessment tool that has demonstrated value in assessing pain characteristics and response. The purpose of our study was to determine the relationship between negative ECS-CP features and some pain-related variables like pain intensity and opioid use. We also explored whether the number of negative ECS-CP features was associated with higher pain intensity. METHOD The electronic charts of 100 patients at an outpatient supportive care clinic in a comprehensive cancer center were reviewed for variables like patient characteristics, initial ECS-CP assessment, morphine equivalent daily dose (MEDD), opioid rotation, Edmonton Symptom Assessment Score (ESAS), and use of adjuvant analgesics. RESULTS Some 91 of the 100 charts were eligible for analysis. The most common primary cancer type was gastrointestinal (22.1%). The median pain intensity was 6, and the median MEDD was 45 mg. Neuropathic pain was associated with higher median pain intensity (7 vs. 5, p = 0.007) and median MEDD requirement (83 vs. 30, p = 0.013). Psychological distress was associated with higher median pain intensity (7 vs. 5, p = 0.042). Incident pain was also associated with a trend toward higher pain intensity (6 vs. 5, p = 0.06). A higher number of negative ECS-CP features was associated with higher pain intensity (p = 0.01). SIGNIFICANCE OF RESULTS The ECS-CP was successfully completed in the majority of patients, demonstrating its utility in routine clinical practice. Neuropathic pain and psychological distress were associated with higher pain intensity. Also, neuropathic pain was associated with a higher MEDD. A higher sum of negative ECS-CP features was associated with higher pain intensity. Further studies will be needed to verify and explore these observations.


International Journal of Radiation Oncology Biology Physics | 1999

Paclitaxel restores radiation-induced apoptosis in a bcl-2-expressing, radiation-resistant lymphoma cell line

Linh Nguyen; Anupama Munshi; Marvette L. Hobbs; Mike D Story; Raymond D Meyn

PURPOSE To restore radiation-induced apoptosis in a bcl-2-expressing, radiation-resistant murine lymphoma cell line (LY-ar) by pretreatment with paclitaxel (Taxol). Because this cell line also has high intracellular levels of glutathione (GSH), reportedly due to the bcl-2 expression and involved in the cells antioxidant functions, paclitaxel treatment was correlated with GSH levels. METHODS AND MATERIALS LY-ar cells were pretreated with paclitaxel and then irradiated with 5 Gy. Apoptosis was measured by DNA fragmentation 6 h later. Dose response and time course experiments were performed. Intracellular GSH levels were measured after treatment. Cell survival analysis was performed for various paclitaxel concentrations +/- 5 Gy. RESULTS LY-ar cells pretreated with 0 nM, 10 nM, 25 nM, and 50 nM paclitaxel for 20 h underwent apoptosis at 2%, 15%, 25%, and 22%, respectively. With the addition of 5-Gy irradiation, LY-ar cell apoptosis increased to 4%, 30%, 49%, and 57%. Maximal apoptosis was detected with a paclitaxel pretreatment time of 20 h. Intracellular GSH levels were reduced by nearly 50% with paclitaxel pretreatment. Surviving fractions (SFs) with 0 nM, 10 nM, 25 nM, and 50 nM paclitaxel and 0 Gy were 1.0, 0.50, 0.08, and 0.05, respectively. SFs with 0 nM, 10 nM, 25 nM, and 50 nM paclitaxel and 5 Gy were 0.009, 0.003, 3 x 10(-5), and 1 x 10(-5), respectively. CONCLUSION Radiation-induced apoptosis in LY-ar cells was restored by pretreatment with paclitaxel. This correlated with lowered levels of intracellular GSH. Cell survival analysis indicated that the combination of Taxol and radiation on cell killing was greater than additive.

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Eduardo Bruera

University of Texas at Austin

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David Hui

The Chinese University of Hong Kong

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Shana L. Palla

University of Texas MD Anderson Cancer Center

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Shalini Dalal

University of Texas MD Anderson Cancer Center

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Wadih Rhondali

University of Texas MD Anderson Cancer Center

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Gary Chisholm

University of Texas MD Anderson Cancer Center

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Joseph Arthur

University of Texas MD Anderson Cancer Center

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Ray Chacko

University of Texas MD Anderson Cancer Center

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Sriram Yennurajalingam

University of Texas MD Anderson Cancer Center

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Sun Hyun Kim

University of Texas MD Anderson Cancer Center

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