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Dive into the research topics where Loren K. Mell is active.

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Featured researches published by Loren K. Mell.


Journal of Clinical Oncology | 2010

Predictors of Competing Mortality in Advanced Head and Neck Cancer

Loren K. Mell; James J. Dignam; Joseph K. Salama; Ezra E.W. Cohen; Blase N. Polite; Virag Dandekar; Amit D. Bhate; Mary Ellyn Witt; Daniel J. Haraf; Bharat B. Mittal; Everett E. Vokes; Ralph R. Weichselbaum

PURPOSE Death from noncancer causes (competing mortality) is an important event in head and neck cancer, but studies identifying predictors of this event are lacking. We sought to identify predictors of competing mortality and develop a risk stratification model for competing events. PATIENTS AND METHODS Cohort study of 479 patients with stage III to IV carcinoma of the head and neck diagnosed between August 1993 and November 2004. Patients were treated on consecutive prospective clinical trials involving organ-preserving chemoradiotherapy and surgery. We used multivariable competing risks regression models to analyze factors associated with the cumulative incidence of competing mortality, locoregional and distant failure, and second malignancies as first events. Results Median follow-up was 52 months median for survivors. The 5-year cumulative incidence of competing mortality was 19.6% (95% CI, 15.8 to 23.4). On multivariable analysis, competing mortality was associated with female sex (hazard ratio [HR], 1.72; 95% CI, 1.13 to 2.63), increasing age (HR, 1.30; 95% CI, 1.04 to 1.62), increasing Charlson Comorbidity Index (HR, 1.24; 95% CI, 1.05 to 1.47), decreasing body mass index (HR, 0.33; 95% CI, 0.13 to 0.84), and decreasing distance traveled to the treating center (HR, 0.65; 95% CI, 0.44 to 0.98). Patients with zero, one, two, and > or = three risk factors had 5-year competing mortality of 8.9% (95% CI, 3.0% to 14.8%), 12.4% (95% CI, 7.0% to 17.8%), 22.1% (95% CI, 14.5% to 29.7%), and 39.3% (95% CI, 28.6% to 50.1%), respectively. CONCLUSION Competing mortality in advanced head and neck cancer is associated with several demographic and health status characteristics. Analyses of risk factors for competing mortality may be useful in outcomes reporting and designing clinical trials.


International Journal of Radiation Oncology Biology Physics | 2003

PRELIMINARY ANALYSIS OF CHRONIC GASTROINTESTINAL TOXICITY IN GYNECOLOGY PATIENTS TREATED WITH INTENSITY-MODULATED WHOLE PELVIC RADIATION THERAPY

Arno J. Mundt; Loren K. Mell; John C. Roeske

PURPOSE To provide a preliminary analysis of chronic gastrointestinal (GI) toxicity in gynecology patients treated with intensity-modulated whole pelvic radiation therapy (IM-WPRT). METHODS AND MATERIALS Between February 2000 and August 2001, 36 gynecology patients received IM-WPRT. All patients underwent a contrast-enhanced computed tomography scan, and a clinical target volume (CTV) was contoured consisting of the upper vagina, parametria, uterus (if present), and presacral and pelvic lymph node regions. The CTV was expanded by 1 cm to create a planning target volume (PTV). Seven or 9-field IM-WPRT plans were generated. IM-WPRT plans were highly conformal, providing excellent coverage of the PTV and considerable sparing of normal tissues, including the small bowel and rectum. Chronic GI toxicity was scored: 0 (no symptoms), 1 (mild symptoms, no medications required), 2 (moderate symptoms, medications required), and 3 (severe symptoms, hospitalization, surgery required). Chronic GI toxicity in 30 gynecology patients treated with conventional WPRT patients before the implementation of IM-WPRT was also evaluated. Median follow-up in the IM-WPRT and WPRT groups were 19.6 and 30.2 months, respectively. RESULTS The IM-WPRT and WPRT groups were well balanced in terms of most patient and treatment factors, including age, site, stage, chemotherapy, WPRT dose, and brachytherapy, except for a higher frequency of surgery (75 vs. 54%, p = 0.02) in the IM-WPRT group. Overall, IM-WPRT patients had a lower rate of chronic GI toxicity (11.1 vs. 50.0%, p = 0.001) than WPRT patients. The percentage of IM-WPRT patients with Grade 1, 2, and 3 toxicity were 8.3%, 2.8%, and 0%, respectively. Corresponding percentages in the WPRT group were 30.0%, 16.7%, and 3.3%, respectively. The only other factor correlated with chronic GI toxicity was age (p = 0.02). On multivariate (logistic regression) analysis controlling for age and other clinical factors, IM-WPRT retained its statistical significance (p = 0.01; odds ratio 0.16; 95% confidence interval 0.04, 0.67) CONCLUSIONS Our results suggest that IM-WPRT is associated with less chronic GI toxicity than conventional WPRT in patients with gynecologic malignancies. However, longer follow-up and more patients are clearly needed to ascertain whether the benefits of IM-WPRT treatment seen here translate into true long-term reductions in chronic GI toxicity.


Journal of Clinical Oncology | 2007

Concurrent Chemotherapy and Intensity-Modulated Radiation Therapy for Anal Canal Cancer Patients: A Multicenter Experience

Joseph K. Salama; Loren K. Mell; David A. Schomas; Robert C. Miller; Kiran Devisetty; Ashesh B. Jani; Arno J. Mundt; John C. Roeske; Stanley L. Liauw; Steven J. Chmura

PURPOSE To report a multicenter experience treating anal canal cancer patients with concurrent chemotherapy and intensity-modulated radiation therapy (IMRT). PATIENTS AND METHODS From October 2000 to June 2006, 53 patients were treated with concurrent chemotherapy and IMRT for anal squamous cell carcinoma at three tertiary-care academic medical centers. Sixty-two percent were T1-2, and 67% were N0; eight patients were HIV positive. Forty-eight patients received fluorouracil (FU)/mitomycin, one received FU/cisplatin, and four received FU alone. All patients underwent computed tomography-based treatment planning with pelvic regions and inguinal nodes receiving a median of 45 Gy. Primary sites and involved nodes were boosted to a median dose of 51.5 Gy. All acute toxicity was scored according to the Common Terminology Criteria for Adverse Events, version 3.0. All late toxicity was scored using Radiation Therapy Oncology Group criteria. RESULTS Median follow-up was 14.5 months (range, 5.2 to 102.8 months). Acute grade 3+ toxicity included 15.1% GI and 37.7% dermatologic toxicity; all acute grade 4 toxicities were hematologic; and acute grade 4 leukopenia and neutropenia occurred in 30.2% and 34.0% of patients, respectively. Treatment breaks occurred in 41.5% of patients, lasting a median of 4 days. Forty-nine patients (92.5%) had a complete response, one patient had a partial response, and three had stable disease. All HIV-positive patients achieved a complete response. Eighteen-month colostomy-free survival, overall survival, freedom from local failure, and freedom from distant failure were 83.7%, 93.4%, 83.9%, and 92.9%, respectively. CONCLUSION Preliminary outcomes suggest that concurrent chemotherapy and IMRT for anal canal cancers is effective and tolerated favorably compared with historical standards.


International Journal of Radiation Oncology Biology Physics | 2011

Consensus Guidelines for Delineation of Clinical Target Volume for Intensity-Modulated Pelvic Radiotherapy for the Definitive Treatment of Cervix Cancer

Karen Lim; William Small; L. Portelance; Carien L. Creutzberg; Ina M. Jürgenliemk-Schulz; Arno J. Mundt; Loren K. Mell; Nina A. Mayr; Akila N. Viswanathan; Anuja Jhingran; Beth Erickson; Jennifer F. De Los Santos; David K. Gaffney; Catheryn M. Yashar; Sushil Beriwal; Aaron H. Wolfson; Alexandra Taylor; Walter R. Bosch; Issam El Naqa; Anthony Fyles

PURPOSE Accurate target definition is vitally important for definitive treatment of cervix cancer with intensity-modulated radiotherapy (IMRT), yet a definition of clinical target volume (CTV) remains variable within the literature. The aim of this study was to develop a consensus CTV definition in preparation for a Phase 2 clinical trial being planned by the Radiation Therapy Oncology Group. METHODS AND MATERIALS A guidelines consensus working group meeting was convened in June 2008 for the purposes of developing target definition guidelines for IMRT for the intact cervix. A draft document of recommendations for CTV definition was created and used to aid in contouring a clinical case. The clinical case was then analyzed for consistency and clarity of target delineation using an expectation maximization algorithm for simultaneous truth and performance level estimation (STAPLE), with kappa statistics as a measure of agreement between participants. RESULTS Nineteen experts in gynecological radiation oncology generated contours on axial magnetic resonance images of the pelvis. Substantial STAPLE agreement sensitivity and specificity values were seen for gross tumor volume (GTV) delineation (0.84 and 0.96, respectively) with a kappa statistic of 0.68 (p < 0.0001). Agreement for delineation of cervix, uterus, vagina, and parametria was moderate. CONCLUSIONS This report provides guidelines for CTV definition in the definitive cervix cancer setting for the purposes of IMRT, building on previously published guidelines for IMRT in the postoperative setting.


Pediatrics | 2005

Association between streptococcal infection and obsessive-compulsive disorder, Tourette's syndrome, and tic disorder.

Loren K. Mell; Robert L. Davis; David S. Owens

Objective. Reports have suggested that streptococcal infection may be etiologically related to pediatric autoimmune neuropsychiatric disorders (PANDAS), but there are few good epidemiologic studies to support this theory. Using population-based data from a large West-Coast health maintenance organization, we assessed whether streptococcal infection was associated with increased risk for obsessive-compulsive disorder (OCD), Tourettes syndrome (TS), or tic disorder. Methods. This is a case-control study of children 4 to 13 years old receiving their first diagnosis of OCD, TS, or tic disorder between January 1992 and December 1999 at Group Health Cooperative outpatient facilities. Cases were matched to controls by birth date, gender, primary physician, and propensity to seek health care. Results. Patients with OCD, TS, or tic disorder were more likely than controls to have had prior streptococcal infection (OR: 2.22; 95% CI: 1.05, 4.69) in the 3 months before onset date. The risk was higher among children with multiple streptococcal infections within 12 months (OR: 3.10; 95% CI: 1.77, 8.96). Having multiple infections with group A β-hemolytic streptococcus within a 12-month period was associated with an increased risk for TS (OR: 13.6; 95% CI: 1.93, 51.0). These associations did not change appreciably when limited to cases with a clear date of onset of symptoms or with tighter matching on health care behavior. Conclusion. These findings lend epidemiologic evidence that PANDAS may arise as a result of a postinfectious autoimmune phenomenon induced by childhood streptococcal infection.


Cancer | 2005

Intensity‐modulated radiation therapy use in the U.S., 2004

Loren K. Mell; Amit K. Mehrotra; Arno J. Mundt

Intensity‐modulated radiation therapy (IMRT) is a novel approach to the planning and delivery of radiation therapy. The prevalence of IMRT use among radiation oncologists in the U.S. appears to be increasing, despite limited data evaluating its risks and benefits.


Journal of The National Comprehensive Cancer Network | 2015

Head and neck cancers, version 1.2015 featured updates to the NCCN guidelines

David G. Pfister; S.A. Spencer; David M. Brizel; Barbara Burtness; Paul M. Busse; Jimmy J. Caudell; Anthony J. Cmelak; A. Dimitrios Colevas; Frank R. Dunphy; David W. Eisele; Robert L. Foote; Jill Gilbert; Maura L. Gillison; Robert I. Haddad; Bruce H. Haughey; Wesley L. Hicks; Ying J. Hitchcock; Antonio Jimeno; Merrill S. Kies; William M. Lydiatt; Ellie Maghami; Thomas V. McCaffrey; Loren K. Mell; Bharat B. Mittal; Harlan A. Pinto; John A. Ridge; Cristina P. Rodriguez; Sandeep Samant; Jatin P. Shah; Randal S. Weber

These NCCN Guidelines Insights focus on nutrition and supportive care for patients with head and neck cancers. This topic was a recent addition to the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Head and Neck Cancers. The NCCN Guidelines Insights focus on major updates to the NCCN Guidelines and discuss the new updates in greater detail. The complete version of the NCCN Guidelines for Head and Neck Cancers is available on the NCCN Web site (NCCN.org).


International Journal of Radiation Oncology Biology Physics | 2008

Dosimetric comparison of bone marrow-sparing intensity-modulated radiotherapy versus conventional techniques for treatment of cervical cancer.

Loren K. Mell; H Tiryaki; K Ahn; Arno J. Mundt; John C. Roeske; Bulent Aydogan

PURPOSE To compare bone marrow-sparing intensity-modulated pelvic radiotherapy (BMS-IMRT) with conventional (four-field box and anteroposterior-posteroanterior [AP-PA]) techniques in the treatment of cervical cancer. METHODS AND MATERIALS The data from 7 cervical cancer patients treated with concurrent chemotherapy and IMRT without BMS were analyzed and compared with data using four-field box and AP-PA techniques. All plans were normalized to cover the planning target volume with the 99% isodose line. The clinical target volume consisted of the pelvic and presacral lymph nodes, uterus and cervix, upper vagina, and parametrial tissue. Normal tissues included bowel, bladder, and pelvic bone marrow (PBM), which comprised the lumbosacral spine and ilium and the ischium, pubis, and proximal femora (lower pelvis bone marrow). Dose-volume histograms for the planning target volume and normal tissues were compared for BMS-IMRT vs. four-field box and AP-PA plans. RESULTS BMS-IMRT was superior to the four-field box technique in reducing the dose to the PBM, small bowel, rectum, and bladder. Compared with AP-PA plans, BMS-IMRT reduced the PBM volume receiving a dose >16.4 Gy. BMS-IMRT reduced the volume of ilium, lower pelvis bone marrow, and bowel receiving a dose >27.7, >18.7, and >21.1 Gy, respectively, but increased dose below these thresholds compared with the AP-PA plans. BMS-IMRT reduced the volume of lumbosacral spine bone marrow, rectum, small bowel, and bladder at all dose levels in all 7 patients. CONCLUSION BMS-IMRT reduced irradiation of PBM compared with the four-field box technique. Compared with the AP-PA technique, BMS-IMRT reduced lumbosacral spine bone marrow irradiation and reduced the volume of PBM irradiated to high doses. Therefore BMS-IMRT might reduce acute hematologic toxicity compared with conventional techniques.


Journal of Clinical Oncology | 2011

Population-Based Study of Competing Mortality in Head and Neck Cancer

Brent S. Rose; Jong-Hyeon Jeong; Sameer K. Nath; Sharon M. Lu; Loren K. Mell

PURPOSE Patients with head and neck cancer (HNC) are at high risk of death resulting from noncancer causes and second malignancies (ie, competing mortality). Variation in competing mortality risk complicates individual treatment choices and design and interpretation of clinical studies. METHODS Using the Surveillance, Epidemiology, and End Results registry, we identified 34,568 patients with nonmetastatic squamous cell carcinoma of the head and neck diagnosed between 1994 and 2003. We developed a multivariable competing-risk regression model to stratify patients according to competing mortality risk and evaluate the impact of this risk on power loss in clinical studies. RESULTS The 5-year cumulative incidences of all-cause mortality, HNC-specific mortality, and competing mortality were 51.3% (95% CI, 50.8% to 51.9%), 23.8% (95% CI, 23.3% to 24.2%), and 27.6% (95% CI, 26.8% to 28.3%), respectively. Factors associated with increased competing mortality were increasing age, male sex, black race, unmarried status, localized disease, higher socioeconomic status, nonsurgical treatment, and hypopharyngeal, nasopharyngeal, and oral cavity subsites. The 5-year cumulative incidences of competing mortality for patients in low-, medium-, and high-risk score tertiles were 20.0% (95% CI, 18.8% to 21.3%), 27.7% (95% CI, 26.3% to 29.1%), and 33.7% (95% CI, 32.2% to 35.2%), respectively. Compared with patients with low competing mortality risk, relative sample sizes required to show benefit of a treatment regarding all-cause mortality were 12% and 42% higher in the medium- and high-risk groups, respectively. CONCLUSION Multiple factors affect risk of competing mortality among patients with HNC. Risk stratification would be useful to identify patients most likely to benefit from treatment intensification.


International Journal of Radiation Oncology Biology Physics | 2011

Clinical Outcomes of Intensity-Modulated Pelvic Radiation Therapy for Carcinoma of the Cervix

Michael D. Hasselle; Brent S. Rose; J.D. Kochanski; Sameer K. Nath; Rounak Bafana; Catheryn M. Yashar; Yasmin Hasan; John C. Roeske; Arno J. Mundt; Loren K. Mell

PURPOSE To evaluate disease outcomes and toxicity in cervical cancer patients treated with pelvic intensity-modulated radiation therapy (IMRT). METHODS AND MATERIALS We included all patients with Stage I-IVA cervical carcinoma treated with IMRT at three different institutions from 2000-2007. Patients treated with extended field or conventional techniques were excluded. Intensity-modulated radiation therapy plans were designed to deliver 45 Gy in 1.8-Gy daily fractions to the planning target volume while minimizing dose to the bowel, bladder, and rectum. Toxicity was graded according to the Radiation Therapy Oncology Group system. Overall survival and disease-free survival were estimated by use of the Kaplan-Meier method. Pelvic failure, distant failure, and late toxicity were estimated by use of cumulative incidence functions. RESULTS The study included 111 patients. Of these, 22 were treated with postoperative IMRT, 8 with IMRT followed by intracavitary brachytherapy and adjuvant hysterectomy, and 81 with IMRT followed by planned intracavitary brachytherapy. Of the patients, 63 had Stage I-IIA disease and 48 had Stage IIB-IVA disease. The median follow-up time was 27 months. The 3-year overall survival rate and the disease-free survival rate were 78% (95% confidence interval [CI], 68-88%) and 69% (95% CI, 59-81%), respectively. The 3-year pelvic failure rate and the distant failure rate were 14% (95% CI, 6-22%) and 17% (95% CI, 8-25%), respectively. Estimates of acute and late Grade 3 toxicity or higher were 2% (95% CI, 0-7%) and 7% (95% CI, 2-13%), respectively. CONCLUSIONS Intensity-modulated radiation therapy is associated with low toxicity and favorable outcomes, supporting its safety and efficacy for cervical cancer. Prospective clinical trials are needed to evaluate the comparative efficacy of IMRT vs. conventional techniques.

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Arno J. Mundt

University of California

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Brent S. Rose

University of California

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S Jiang

University of Texas Southwestern Medical Center

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Kaveh Zakeri

University of California

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Ruben Carmona

University of California

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John Einck

University of California

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