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Dive into the research topics where Robert W. Clough is active.

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Featured researches published by Robert W. Clough.


Radiotherapy and Oncology | 1999

Oxygenation of head and neck cancer: changes during radiotherapy and impact on treatment outcome.

David M. Brizel; Richard K. Dodge; Robert W. Clough; Mark W. Dewhirst

BACKGROUND AND PURPOSE To evaluate the long term clinical significance of tumor oxygenation in a population of head and neck cancer patients receiving radiotherapy and to assess changes in tumor oxygenation during the course of treatment. METHODS AND MATERIALS Patients with head and neck cancer receiving primary RT underwent pretreatment polarographic tumor oxygen measurement of the primary site or a metastatic neck lymph node. Treatment consisted of once daily (2 Gy/fraction to a total dose of 66-70 Gy) or twice daily irradiation (1.25 Gy/fraction to 70-75 Gy) to the primary site. Twenty-seven patients underwent a second series of measurements early in the course of irradiation. RESULTS Sixty-three patients underwent pretreatment tumor oxygen assessment (primary site, n = 24; nodes, n = 39). The median pO2 for primary lesions was 4.8 mmHg, and it was 4.3 mmHg for cervical nodes. There was a weak association between anemia and more poorly oxygened tumors, but many non-anemic patients still had poorly oxygenated tumors. Repeat assessments of tumor oxygenation after 10-15 Gy were unchanged compared to pretreatment baselines. Poorly oxygenated nodes pretreatment were more likely to contain viable residual disease at post-radiation neck dissection. Median follow-up time for surviving patients was 20 months (range 3-50 months). Hypoxia (tumor median pO2 <10 mmHg) adversely affected 2 year local-regional control (30 vs. 73%, P = 0.01), disease-free survival (26 vs. 73%, P = 0.005), and survival (35 vs. 83%, P = 0.02). CONCLUSION Tumor oxygenation affects the prognosis of head and neck cancer independently of other known prognostic variables. This parameter may be a useful tool for the selection of patients for investigational treatment strategies.


International Journal of Radiation Oncology Biology Physics | 2000

Elevated tumor lactate concentrations predict for an increased risk of metastases in head-and-neck cancer

David M. Brizel; Thies Schroeder; Richard L. Scher; Stefan Walenta; Robert W. Clough; Mark W. Dewhirst; Wolfgang Mueller-Klieser

PURPOSE Hypoxia shifts the balance of cellular energy production toward glycolysis with lactate generation as a by-product. Quantitative bioluminescence imaging allows for the quantitation of lactate concentrations in individual tumors. We assessed the relationship between pretreatment tumor lactate concentrations and subsequent development of metastatic disease in patients with newly diagnosed head-and-neck cancer. METHODS AND MATERIALS At the time of biopsy of the primary site, a separate specimen was taken and flash-frozen for subsequent quantitation of lactate concentration using a luciferase bioluminescence technique. The two-dimensional spatial distribution of the bioluminescence intensity within the tissue section was registered directly using a microscope and an imaging photon counting system. Photon intensity was converted to distributions of volume-related tissue concentrations (micromol per gram wet weight). Treatment consisted of either surgery and postoperative radiotherapy or primary radiotherapy, based on presenting disease stage and institutional treatment policies. The subsequent development of metastatic disease constituted the primary clinical endpoint. RESULTS Biopsies obtained from 40 patients were evaluable in 34. The larynx was the most frequent primary site (n = 25). Other sites included oropharynx (n = 5), hypopharynx (n = 3), and oral cavity (n = 1). Most patients (74%) presented with an advanced stage T3 or T4 primary tumor. Nodal involvement was present in 19 (54%) patients. The median tumor lactate concentration was 7.1 micromol/g. Tumors were classified as having either low or high lactate concentrations according to whether these values were below or above the median. The median follow-up time for surviving patients is 27 months. Two-year actuarial survival was 90% for patients with low-lactate-concentration tumor vs. 35% for patients with high-lactate-concentration primaries (<0.0001). Two-year metastasis-free survival was adversely influenced by high tumor lactate concentrations (90% vs. 25%, p < 0.0001). The median lactate concentration for tumors that subsequently metastasized was 12.9 micromol/g vs. 4.8 micromol/g for patients who remained continuously free of disease (p < 0.005). Lactate concentration was not correlated with presenting T stage or N stage. DISCUSSION Elevated tumor lactate concentrations are associated with the subsequent development of nodal or distant metastases in head-and-neck cancer patients. This more aggressive malignant phenotype is probably associated with hypoxia-mediated radioresistance and the upregulation of metastasis-associated genes.


Cancer | 1999

Plasma transforming growth factor-β1 level before radiotherapy correlates with long term outcome of patients with lung carcinoma

Feng-Ming Kong; Randy L. Jirtle; Dale H. Huang; Robert W. Clough; Mitchell S. Anscher

Plasma transforming growth factor‐β1 (TGFβ1) levels are increased in many malignancies at the time of diagnosis, including all forms of lung carcinoma. Therefore, the potential use of TGFβ1 as a plasma marker to predict the long term outcome of lung carcinoma patients treated with radiotherapy (RT) was evaluated.


International Journal of Radiation Oncology Biology Physics | 2009

Concurrent Chemoradiotherapy in Resected Extrahepatic Cholangiocarcinoma

John W. Nelson; A. Paiman Ghafoori; Christopher G. Willett; Douglas S. Tyler; Theodore N. Pappas; Bryan M. Clary; Herbert Hurwitz; Johanna C. Bendell; Michael A. Morse; Robert W. Clough; Brian G. Czito

PURPOSE Extrahepatic cholangiocarcinoma is a rare malignancy. Despite radical resection, survival remains poor, with high rates of local and distant failure. To clarify the role of radiotherapy with chemotherapy, we performed a retrospective analysis of resected patients who had undergone chemoradiotherapy. METHODS AND MATERIALS A total of 45 patients (13 with proximal and 32 with distal disease) underwent resection plus radiotherapy (median dose, 50.4 Gy). All but 1 patient received concurrent fluoropyrimidine-based chemotherapy. The median follow-up was 30 months for all patients and 40 months for survivors. RESULTS Of the 45 patients, 33 underwent adjuvant radiotherapy, and 12 were treated neoadjuvantly. The 5-year actuarial overall survival, disease-free survival, metastasis-free survival, and locoregional control rates were 33%, 37%, 42%, and 78%, respectively. The median survival was 34 months. No patient died perioperatively. Patient age </=60 years and perineural involvement adversely affected survival on univariate analysis. Patients undergoing R0 resection had a significantly improved rate of local control but no survival advantage. Despite having more advanced disease at presentation, patients treated neoadjuvantly had a longer survival (5-year survival 53% vs. 23%, p = 0.16) and similar rates of Grade 2-3 surgical morbidity (16% vs. 33%, p = 0.24) compared with those treated in the postoperative setting. CONCLUSION These study results suggest a possible local control benefit from chemoradiotherapy combined with surgery in patients with advanced, resected biliary cancer. Furthermore, our results suggest that a treatment strategy that includes preoperative chemoradiotherapy might result in improved tumor resectability with similar surgical morbidity compared with patients treated postoperatively, as well as potentially improved survival outcomes. Distant failure remains a significant failure pattern, suggesting the need for more effective systemic therapy.


Journal of Clinical Oncology | 2001

73.6 Gy and Beyond: Hyperfractionated, Accelerated Radiotherapy for Non–Small-Cell Lung Cancer

Patrick D. Maguire; Lawrence B. Marks; Gregory S. Sibley; James E. Herndon; Robert W. Clough; K. Light; Maria L. Hernando; Philip A. Antoine; Mitchell S. Anscher

PURPOSE To assess results with twice-daily high-dose radiotherapy (RT) for non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Between 1991 and 1998, 94 patients with unresectable NSCLC were prescribed > or = 73.6 Gy via accelerated fractionation. Fifty were on a phase II protocol (P group); 44 were similarly treated off-protocol (NP group). The clinical target volume received 45 Gy at 1.25 Gy bid (6-hour interval). The gross target volume received 1.6 Gy bid to 73.6 to 80 Gy over 4.5 to 5 weeks using a concurrent boost technique. Overall survival (OS) and local progression-free survival (LPFS) were calculated by the Kaplan-Meier method. Median follow-up durations for surviving P and NP patients were 67 and 16 months, respectively. RESULTS Total doses received were > or = 72 Gy in 97% of patients. The median OS by stage was 34, 13, and 12 months for stages I/II, IIIa, and IIIb, respectively. LPFS was significantly longer for patients with T1 lesions (median, 43 months) versus T2-4 (median, 7 to 10 months; P =.01). Results were similar in the P and NP groups. Acute grade > or = 3 toxicity included esophagus (14 patients; 15%), lung (three patients; 3% [one grade 5]), and skin (four patients; 4%). Grade > or = 3 late toxicity in 86 assessable patients included esophagus (three patients; 3%), lung (15 patients; 17% [three grade 5]), skin (five patients; 6%), heart (two patients; 2%), and nerve (one patient; 1%). CONCLUSION This regimen yielded favorable survival results, particularly for T1 lesions. Acute grade > or = 3 toxicity seems greater than for conventional RT, though most patients recovered. Late grade > or = 3 pulmonary toxicity occurred in 17%. Because of continued locoregional recurrences, we are currently using doses > or = 86 Gy.


International Journal of Radiation Oncology Biology Physics | 2010

INTENSITY-MODULATED RADIATION THERAPY FOR ANAL MALIGNANCIES: A PRELIMINARY TOXICITY AND DISEASE OUTCOMES ANALYSIS

Joseph M. Pepek; Christopher G. Willett; Q. Jackie Wu; S Yoo; Robert W. Clough; Brian G. Czito

PURPOSE Intensity-modulated radiation therapy (IMRT) has the potential to reduce toxicities associated with chemoradiotherapy in the treatment of anal cancer. This study reports the results of using IMRT in the treatment of anal cancer. METHODS AND MATERIALS Records of patients with anal malignancies treated with IMRT at Duke University were reviewed. Acute toxicity was graded using the NCI CTCAEv3.0 scale. Overall survival (OS), metastasis-free survival (MFS), local-regional control (LRC) and colostomy-free survival (CFS) were calculated using the Kaplan-Meier method. RESULTS Forty-seven patients with anal malignancy (89% canal, 11% perianal skin) were treated with IMRT between August 2006 and September 2008. Median follow-up was 14 months (19 months for SCC patients). Median radiation dose was 54 Gy. Eight patients (18%) required treatment breaks lasting a median of 5 days (range, 2-7 days). Toxicity rates were as follows: Grade 4: leukopenia (7%), thrombocytopenia (2%); Grade 3: leukopenia (18%), diarrhea (9%), and anemia (4%); Grade 2: skin (93%), diarrhea (24%), and leukopenia (24%). The 2-year actuarial overall OS, MFS, LRC, and CFS rates were 85%, 78%, 90% and 82%, respectively. For SCC patients, the 2-year OS, MFS, LRC, and CFS rates were 100%, 100%, 95%, and 91%, respectively. CONCLUSIONS IMRT-based chemoradiotherapy for anal cancer results in significant reductions in normal tissue dose and acute toxicities versus historic controls treated without IMRT, leading to reduced rates of toxicity-related treatment interruption. Early disease-related outcomes seem encouraging. IMRT is emerging as a standard therapy for anal cancer.


International Journal of Radiation Biology | 2000

Radiation-induced pulmonary injury: symptomatic versus subclinical endpoints.

Lawrence B. Marks; Ming Fan; Robert W. Clough; Michael T. Munley; G. Bentel; R.E. Coleman; R.J. Jaszczak; Donna Hollis; Mitchell S. Anscher

Purpose : To assess the relationship between radiation (RT)induced pulmonary symptoms and subclinical changes in pulmonary functions tests (PFT) and radiographs. Materials and methods : A total of 184 patients irradiated between 1992 and 1998 were prospectively evaluated for RT-induced pulmonary symptoms, changes in computed tomography (CT) density, reductions in single photon emission CT (SPECT) perfusion, and changes in pulmonary functions tests (forced expiratory volume in 1s [FEV 1 ] and diffusion capacity to carbon monoxide [DLCO]). Comparisons between the evaluable patients with (N = 34) and without (N = 106) RT-induced pulmonary symptoms were made. Results : Within 6 months of RT, 80% of the RT-induced symptoms were noted. There was no association between the presence or absence of RT-induced pulmonary symptoms and the frequency of RT-induced radiographic changes (p = 0.53), or in the dose–response curve for RT-induced reductions in regional perfusion. Overall, RT-induced changes in SPECT images were more commonly seen than increased density changes on CT (p < 0.001). Most patients with pulmonary symptoms had relatively low pre-RT PFTs and experienced further declines following RT. Conclusions : Regional radiographic changes in CT-defined tissue density or SPECT-defined tissue perfusion are similar in patients with and without RT-induced pulmonary symptoms because these endpoints do not consider the volume of lung affected. RT-induced pulmonary symptoms are better related to post-RT PFT because they are an assessment of whole lung function. Additional studies are necessary to better define models that can predict the degree of radiation-induced changes in whole lung function.PURPOSE To assess the relationship between radiation (RT)-induced pulmonary symptoms and subclinical changes in pulmonary functions tests (PFT) and radiographs. MATERIALS AND METHODS A total of 184 patients irradiated between 1992 and 1998 were prospectively evaluated for RT-induced pulmonary symptoms, changes in computed tomography (CT) density, reductions in single photon emission CT (SPECT) perfusion, and changes in pulmonary functions tests (forced expiratory volume in 1 s [FEV1] and diffusion capacity to carbon monoxide [DLCO]). Comparisons between the evaluable patients with (N=34) and without (N=106) RT-induced pulmonary symptoms were made. RESULTS Within 6 months of RT, 80% of the RT-induced symptoms were noted. There was no association between the presence or absence of RT-induced pulmonary symptoms and the frequency of RT-induced radiographic changes (p=0.53), or in the dose-response curve for RT-induced reductions in regional perfusion. Overall, RT-induced changes in SPECT images were more commonly seen than increased density changes on CT (p<0.001). Most patients with pulmonary symptoms had relatively low pre-RT PFTs and experienced further declines following RT. CONCLUSIONS Regional radiographic changes in CT-defined tissue density or SPECT-defined tissue perfusion are similar in patients with and without RT-induced pulmonary symptoms because these endpoints do not consider the volume of lung affected. RT-induced pulmonary symptoms are better related to post-RT PFT because they are an assessment of whole lung function. Additional studies are necessary to better define models that can predict the degree of radiation-induced changes in whole lung function.


Journal of Clinical Oncology | 2006

Combined-Modality Therapy Versus Radiotherapy Alone for Treatment of Early-Stage Hodgkin's Disease: Cure Balanced Against Complications

Bridget F. Koontz; John P. Kirkpatrick; Robert W. Clough; Robert G. Prosnitz; Jon P. Gockerman; Joseph O. Moore; Leonard R. Prosnitz

PURPOSE The treatment of early-stage Hodgkins disease (HD) has evolved from radiotherapy alone (RT) to combined-modality therapy (CMT) because of concerns about late adverse effects from high-dose subtotal nodal irradiation (STNI). However, there is little information regarding the long-term results of CMT programs that substantially reduce the dose and extent of radiation. In addition, lowering the total radiation dose may reduce the complication rate without compromising cure. This retrospective study compares the long-term results of STNI with CMT using modestly reduced RT dose in the treatment of early-stage HD. PATIENTS AND METHODS Between 1982 and 2002, 111 patients with stage IA and IIA HD were treated definitively with RT (mean dose, 37.9 Gy); 70 patients were treated with CMT with low-dose involved-field radiotherapy (LDIFRT; mean dose, 25.5 Gy). Median follow-up was 11.7 years for RT patients and 8.1 years for the CMT group. RESULTS There was a trend toward improved 20-year overall survival with CMT (83% v 70%; P = .405). No second cancers were observed in the CMT group; in the RT group the actuarial frequency of a second cancer was 16% at 20 years. There was no difference in the frequency of cardiac complications (9% v 6%, RT v CMT). CONCLUSION In this retrospective review, CMT with LDIFRT was effective in curing early-stage HD and was not associated with an increase in second malignancies. For RT alone, a moderate dose seemed to reduce cardiac complications but did not lessen second malignancies compared with higher doses used historically.


International Journal of Radiation Oncology Biology Physics | 2001

Acute urinary toxicity following transperineal prostate brachytherapy using a modified quimby loading method

Song K Kang; Rachel H. Chou; Richard K. Dodge; Robert W. Clough; Hi-Sung L Kang; M.Gray Bowen; Beverly Steffey; S Das; S. Zhou; Arthur W Whitehurst; Niall J Buckley; Jay H Kim; Raymond E Joyner; Ignacio Sarmina; Gustavo S. Montana; Sally S. Ingram; Mitchell S. Anscher

PURPOSE To examine the acute urinary toxicity following transperineal prostate implant using a modified Quimby loading method with regard to time course, severity, and factors that may be associated with a higher incidence of morbidity. METHODS AND MATERIALS One hundred thirty-nine patients with prostate adenocarcinoma treated with brachytherapy from 1997 through 1999 had follow-up records available for review. Patients considered for definitive brachytherapy alone included those with prostate specific antigen (PSA) < or = 6, Gleason score (GS) < or = 6, clinical stage < T2b, and prostate volumes generally less than 40 cc. Patients with larger prostate volumes were given neoadjuvant antiandrogen therapy. Those with GS > 6, PSA > 6, or Stage > T2a were treated with external beam radiation therapy followed by brachytherapy boost. Sources were loaded according to a modified Quimby method. At each follow-up, toxicity was graded based on a modified RTOG urinary toxicity scale. RESULTS Acute urinary toxicity occurred in 88%. Grade I toxicity was reported in 23%, grade II in 45%, and grade III in 20%, with 14% requiring prolonged (greater than 1 week) intermittent or indwelling catheterization. Overall median duration of symptoms was 12 months. There was no difference in duration of symptoms between patients treated with I-125 or Pd-103 sources (p = 0.71). After adjusting for GS and PSA, multivariate logistic regression analysis showed higher incidence of grade 3 toxicity in patients with larger prostate volumes (p = 0.002), and those with more seeds implanted (p < 0.001). Higher incidence of prolonged catheterization was found in patients receiving brachytherapy alone (p = 0.01), with larger prostate volumes (p = 0.01), and those with more seeds implanted (p < 0.001). CONCLUSION Interstitial brachytherapy for prostate cancer leads to a high incidence of acute urinary toxicity, most of which is mild to moderate in severity. A prolonged need for catheterization can occur in some patients. Patients receiving brachytherapy alone, those with prostate volumes greater than 30 cc, and those implanted with a greater number of seeds have the highest incidence of significant toxicity.


International Journal of Radiation Oncology Biology Physics | 2002

Gastrointestinal toxicity of transperineal interstitial prostate brachytherapy.

Song K Kang; Rachel H. Chou; Richard K. Dodge; Robert W. Clough; Hi-Sung L Kang; Carol A. Hahn; Arthur W Whitehurst; Niall J Buckley; Jay H Kim; Raymond E Joyner; Gustavo S. Montana; Sally S. Ingram; Mitchell S. Anscher

PURPOSE To characterize the severity and time course of rectal toxicity following transperineal prostate brachytherapy using prospectively recorded data, and to determine factors associated with toxicity. METHODS AND MATERIALS One hundred thirty-four patients with prostate cancer treated with transperineal brachytherapy from 1997 to 1999 had rectal toxicity data available for analysis. Patients with Gleason score (GS) > 6, prostate-specific antigen (PSA) > 6, or stage > T2a were treated initially with external beam radiation therapy followed by brachytherapy boost; patients with none of these features were treated with brachytherapy alone. Both iodine-125 and palladium-103 sources were used, and loaded according to a modified Quimby distribution. At each follow-up, toxicity was recorded according to a modified RTOG gastrointestinal scale. RESULTS Thirty-nine percent of patients experienced gastrointestinal toxicity, mostly Grade 1. Median duration of symptoms was 6 months. Two patients experienced Grade 3 toxicity, both of whom had minimal symptoms until their 12-month follow-up. There was no Grade 4 or 5 toxicity. The addition of external beam radiation therapy (p = 0.003), higher clinical stage (p = 0.006), and Caucasian race (p = 0.01) were associated with increased incidence of toxicity. CONCLUSION Most patients with rectal toxicity have very mild symptoms. There is a small risk of severe late toxicity. External beam radiation, higher stage, and race are associated with toxicity.

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Lawrence B. Marks

University of North Carolina at Chapel Hill

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Mitchell S. Anscher

Virginia Commonwealth University

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S. Zhou

University of Nebraska Medical Center

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