Yazar "Hubbs, Jessica L." seçeneğine göre listele

Listeleniyor 1 - 5 / 5
  • Küçük Resim Yok
    Öğe
    Assessing the impact of radiation-induced changes in soft tissue density/thickness on the study of radiation-induced perfusion changes in the lung and heart
    (Amer Assoc Physicists Medicine Amer Inst Physics, 2012) Lawrence, Michael V.; Saynak, Mert; Fried, David V.; Bateman, Ted A.; Green, Rebecca L.; Hubbs, Jessica L.; Jaszczak, Ronald J.
    Purpose: Abnormalities in single photon emission computed tomography (SPECT) perfusion within the lung and heart are often detected following radiation for tumors in/around the thorax (e. g., lung cancer or left-sided breast cancer). The presence of SPECT perfusion defects is determined by comparing pre- and post-RT SPECT images. However, RT may increase the density of the soft tissue surrounding the lung/heart (e. g., chest wall/breast) that could possibly lead to an apparent SPECT perfusion defect due to increased attenuation of emitted photons. Further, increases in tissue effective depth will also increase SPECT photon attenuation and may lead to apparent SPECT perfusion defects. The authors herein quantitatively assess the degree of density changes and effective depth in soft tissues following radiation in a series of patients on a prospective clinical study. Methods: Patients receiving thoracic RT were enrolled on a prospective clinical study including pre- and post-RT thoracic computed tomography (CT) scans. Using image registration, changes in tissue density and effective depth within the soft tissues were quantified (as absolute change in average CT Hounsfield units, HU, or tissue thickness, cm). Changes in HU and tissue effective depth were considered as a continuous variable. The potential impact of these tissue changes on SPECT images was estimated using simulation data from a female SPECT thorax phantom with varying tissue densities. Results: Pre- and serial post-RT CT images were quantitatively studied in 23 patients (4 breast cancer, 19 lung cancer). Data were generated from soft tissue regions receiving doses of 20-50 Gy. The average increase in density of the chest was 5 HU (range 46 to -69). The average change in breast density was a decrease of -1 HU (range 13 to -13). There was no apparent dose response in neither the dichotomous nor the continuous analysis. Seventy seven soft tissue contours were created for 19 lung cancer patients. The average change in tissue effective depth was +0.2 cm (range -1.9 to 2.2 cm). The changes in HU represent a <2% average change in tissue density. Based on simulation, the small degree of density and tissue effective depth change is unlikely to yield meaningful changes in either SPECT lung or heart perfusion. Conclusions: RT doses of 20-50 Gy can cause up to a 46 HU increase in soft tissue density 6 months post-RT. Post-RT soft tissue effective depth may increase by 2.0 cm. These modest increases in soft tissue density and effective depth are unlikely to be responsible for the perfusion changes seen on post-RT SPECT lung or heart scans. Further, there was no clear dose response of the soft tissue density changes. Ultimately, the authors findings suggest that prior perfusion reports do reflect changes in the physiology of the lungs and heart. (C) 2012 American Association of Physicists in Medicine. [http://dx.doi.org/10.1118/1.4766433]
  • Küçük Resim Yok
    Öğe
    Factors Associated With the Development of Brain Metastases Analysis of 975 Patients With Early Stage Nonsmall Cell Lung Cancer
    (Wiley, 2010) Hubbs, Jessica L.; Boyd, Jessamy A.; Hollis, Donna; Chino, Junzo P.; Saynak, Mert; Kelsey, Chris R.
    BACKGROUND The risk of developing brain metastases after definitive treatment of locally advanced nonsmall cell lung cancer (NSCLC) is approximately 30%-50%. The risk for patients with early stage disease is less defined. The authors sought to investigate this further and to study potential risk factors. METHODS The records of all patients who underwent surgery for T1-T2 N0-N1 NSCLC at Duke University between the years 1995 and 2005 were reviewed. The cumulative incidence of brain metastases and distant metastases was estimated by using the Kaplan-Meier method. A multivariate analysis assessed factors associated with the development of brain metastases. RESULTS Of 975 consecutive patients, 85% were stage I, and 15% were stage II. Adjuvant chemotherapy was given to 7%. The 5-year actuarial risk of developing brain metastases and distant metastases was 10% (95% confidence interval [CI], 8-13) and 34% (95% CI, 30-39), respectively. Of patients developing brain metastases, the brain was the sole site of failure in 43%. On multivariate analysis, younger age (hazard ratio [HR], 1.03 per year), larger tumor size (HR, 1.26 per cm), lymphovascular space invasion (HR, 1.87), and hilar lymph node involvement (HR, 1.18) were associated with an increased risk of developing brain metastases. CONCLUSIONS In this large series of patients treated surgically for early stage NSCLC, the 5-year actuarial risk of developing brain metastases was 10%. A better understanding of predictive factors and biological susceptibility is needed to identify the subset of patients with early stage NSCLC who are at particularly high risk. Cancer 2010;116:5038-46. (C) 2010 American Cancer Society
  • Küçük Resim Yok
    Öğe
    THE LACK OF IMPACT OF PRE-OPERATIVE PET ON THE RISK, AND PACE, OF SUBSEQUENT FAILURE FOLLOWING SURGERY FOR EARLY STAGE NON-SMALL CELL LUNG CANCER?
    (Lippincott Williams & Wilkins, 2013) Saynak, Mert; Veeramachaneni, Nirmal K.; Hubbs, Jessica L.; Zagar, Timothy; Sheikh, Arif; Khandani, Amir H.; Haithcock, Benjamin
    [Abstract Not Available]
  • Küçük Resim Yok
    Öğe
    Local failure after complete resection of N0-1 non-small cell lung cancer
    (Elsevier Ireland Ltd, 2011) Saynak, Mert; Veeramachaneni, Nirmal K.; Hubbs, Jessica L.; Nam, Jiho; Qaqish, Bahjat F.; Bailey, Janet E.; Chung, Wonil
    Purpose: To estimate the risk of local-regional failure (LRF) after surgery for operable NSCLC, and the effect of clinical/pathologic factors on this risk. Methods: Records of 335 patients undergoing complete resection (lobectomy, pneumonectomy) for pathological T1-4 N0-1 NSCLC (without post-operative radiation) from 1996 to 2006 were reviewed. Crude and actuarial estimated failure rates were computed; local-regional sites included ipsilateral lung, surgical stump, hilar, mediastinal, or supraclavicular nodes. Failure times in sub-groups were calculated with the Kaplan-Meier method and compared via log-rank test. Independent factors adversely affecting LRF were determined with Cox regression. Results: The median follow-up duration for event-free surviving patients was 40 months (range: 1-150). The crude and actuarial 5-year probability of any failure (LR or distant) were 33% and 43%, respectively. Of all failures; 37% were LR only, 35% LR and distant and 28% distant only. The 5-year crude and actuarial probability of LRF were 24% and 35% (95% Cl: 29-42%). Five-year crude LRF rates for T1-2N0, T1-2N1, T3-4N0 and T3-4N1 disease were 19% (41/216), 27% (16/59), 37.5% (15/40) and 40% (8/20), respectively. The corresponding actuarial estimates were T1-2N0 28%, T1-2N1 39%, T3-4N0 50% and T3-4N1 67%. In Cox multiple regression analysis, lymphovascular space invasion (p = 0.03, HR: 1.7) and tumor size (p = 0.01, HR: 1.67 for 5 cm increment) were associated with an increased risk of LRF. Conclusion: Five-year LRF rates are >= 19% in essentially all patient subsets. (C) 2010 Elsevier Ireland Ltd. All rights reserved.
  • Küçük Resim
    Öğe
    Solitary Fibrous Tumors of Chest: Another Look with the Oncologic Perspective
    (2017) Saynak, Mert; Veeramachaneni, Nirmal K.; Hubbs, Jessica L.; Okumuş, Dilruba; Marks, Lawrence B.
    Solitary fibrous tumors are mesenchymal lesions that arise at a variety of sites, most commonly the pleura. Most patients are asymptomatic at diagnosis, with lesions being detected incidentally. Nevertheless, some patients present due to symptoms from local tumor compression (eg. of the airways and pulmonary parenchyma). Furthermore, radiological methods are not always conclusive in making a diagnosis, and thus, pathological analysis is often required. In the past three decades, immunohistochemical techniques have provided a gold standard in solitary fibrous tumor diagnosis. The signature marker of solitary fibrous tumor is the presence of the NAB2-STAT6 fusion that can be reliably detected with a STAT6 antibody. While solitary fibrous tumors are most often benign, they can be malignant in 10-20% of the cases. Unfortunately, histological parameters are not always predictive of benign vs malignant solitary fibrous tumors. As solitary fibrous tumors are generally regarded as relatively chemoresistant tumors; treatment is often limited to localized treatment modalities. The optimal treatment of solitary fibrous tumors appears to be complete surgical resection for both primary and local recurrent disease. However, in cases of suboptimal resection, large disease burden, or advanced recurrence, a multidisciplinary approach may be preferable. Specifically, radiotherapy for inoperable local disease can provide palliation/shrinkage. Given their sometimes -unpredictable and often- protracted clinical course, long-term follow-up post-resection is recommended.