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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Digital image analysis for tumor cellularity and gleason grade to tumor volume analysis in prostate cancer

Chaniotakis, Sotiris 11 July 2018 (has links)
PURPOSE: This study was undertaken to compare HALO™ software image analysis measurements of cellularity with visual estimations from the pathologist and to outline a protocol for future experimental determinations of cellularity using HALO™. Secondly, this study investigated the clinically challenging prostate cancers of Gleason score 7 by analyzing a large database of radical prostatectomy (RP) specimens with regard to their Gleason grade composition and percentage tumor volume composition. The importance of these values of tumor cellularity, prostate volume, and tumor volume data were discussed in terms of future diagnostic endeavors. Finally, this study provided a brief background on prostate cancer, prostate cancer epidemiology, digital pathology, and the limitations and difficulties in the technological transition to digital pathology. All work for this study was done at Dana-Farber Cancer Institute (Boston, MA). METHODS: In the first part of this study, histological slides were acquired by radical prostatectomy (RP) and contained 12 tumor foci of varying degrees and sizes. These slides were scanned and imported into the HALO™ image analysis software. The tumor foci, previously demarcated by a pathologist, were annotated by hand in HALO™. An algorithm for image analysis was created by training classifiers to recognize and differentiate between epithelial tissue, stromal tissue, glass, and other. This process was accomplished by classifying 62 regions which were tested for accuracy before becoming the components of an algorithm to analyze the entire annotation layer. Each tumor focus was analyzed individually, and the results were exported into Microsoft® Excel from which relevant data were extracted. Cellularity was calculated by the percentage of tumor area that the algorithm characterized as epithelial. Cellularity values derived from HALO™ measurements for each tumor focus were compared with the visual estimations of cellularity provided by the pathologist using Pearson's correlation analysis. In the second part of this study, a database of 1386 slides containing tumors with Gleason scores between 6 and 9 was compiled from 140 RP cases. The average percentages of Gleason grades 3, 4, and 5 in each case were determined. The percentage of each slide that was occupied by the tumor was also averaged for each case, yielding an average percentage of tumor volume for each case. The average Gleason grade 3, 4, or 5 percentage for each case was plotted against the associated average tumor volume percentage of that case. The cases of Gleason score 7 (3+4, 4+3) were then isolated and plotted in a similar manner. Pearson’s correlation analysis was used to determine the degree of linear correlation between the two variables in each plot. Results: In the first part of this study, a statistically significant positive correlation between the cellularity estimations of the pathologist and the HALO™ cellularity measurements was found (r = 0.92, p < 0.01, n =12). In the second part of this study, there was a statistically significant negative correlation between average Gleason grade 3 percentage per case and average tumor volume percentage per case (r = -0.55, p <0.001, n = 140). There was also a statistically significant positive correlation between average Gleason grade 4 percentage per case and average tumor volume percentage per case (r = 0.55, p <0.001, n = 140). After slides containing Gleason score 6 (3+3) tumor were removed from the data, a statistically significant negative correlation remained between average Gleason grade 3 percentage per case and average tumor volume percentage per case (r = -0.51, p <0.001, n = 78), and a statistically significant positive correlation remained between average Gleason grade 4 percentage per case and average tumor volume percentage per case (r = 0.5, p <0.001, n = 101). A statistically significant relationship between average Gleason grade 5 percentage and average tumor volume percentage was not found (r = 0.32, p = 0.14, n = 23). CONCLUSIONS: In the first part of this study, the strong positive correlation between HALO™ cellularity values and visual estimations by the pathologist suggests that image analysis may be an effective tool for determining cellularity in digital histological images. More research using larger sample sizes is recommended to further validate the correlation between algorithm-derived cellularity from HALO™ and visual estimation by the pathologist. In the second part of this study, it appears that the volume of prostate tumors of Gleason score 7 may have prognostic power, considering that an increased percentage composition of Gleason grade 4 correlated with larger tumor volumes. Because this result may have significant clinical implications, further research specifically on tumors of Gleason score 7 is suggested to verify this relationship.
2

Prognostic Value of Quantitative Parameters of ¹⁸F-FDG PET/CT for Patients With Angiosarcoma / ¹⁸F-FDG PET/CTの定量指標を用いた血管肉腫患者の予後予測

Kato, Ayako 23 September 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22739号 / 医博第4657号 / 新制||医||1046(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 武藤 学, 教授 佐藤 俊哉, 教授 椛島 健治 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DGAM
3

Experimental model for the irradiation-mediated abscopal effect and factors influencing this effect / 放射線照射に伴う遠達効果実験モデルの樹立と遠達効果に影響を及ぼす因子

Baba, Kiichiro 24 November 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22826号 / 医博第4665号 / 新制||医||1047(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 溝脇 尚志, 教授 武田 俊一, 教授 増永 慎一郎 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
4

Preoperative metabolic tumor volume of intrahepatic cholangiocarcinoma measured by 18F-FDG-PET is associated with the KRAS mutation status and prognosis / 肝内胆管癌において、術前18F-FDG-PETによるMetabolic tumor volumeは腫瘍のKRAS遺伝子変異状態および術後予後と相関する / # ja-Kana

Ikeno, Yoshinobu 25 September 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21337号 / 医博第4395号 / 新制||医||1031(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 武藤 学, 教授 富樫 かおり, 教授 川口 義弥 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
5

Natural history and prognostic factors in localized prostate cancer

Andrén, Ove January 2008 (has links)
<p>The natural history of localized prostate cancer is not fully understood. In most patients the tumor will never progress to a lethal disease, while a subset of patients will ultimately die of the disease. Efficient tools to separate indolent from lethal disease is currently lacking which means that many patients will be offered treatment without any benefit, but still be at risk of experiencing treatment related side effects.</p><p>The aims of these studies were to get more insight into the natural history of untreated localized prostate cancer, to assess the prognostic value of established clinical parameters such as Gleason score, nuclear grade and tumor volume and, moreover, some new prognostic markers Ki-67, AMACR and MUC-1. We also aimed to study time trends in the detection of incidental tumors in Sweden.</p><p>Patients with localized disease (n=223) and no initial treatment were followed for 21 years. Most patients had a favorable outcome. However, a subset of patients developed lethal disease even beyond 15 years of follow-up and these patients define the group that may benefit most from treatment with curative intent. Patients with poorly differentiated tumors experienced a 9 time higher risk of dying in prostate cancer.</p><p>The studies on prognostic markers are based on a cohort of patients (n=253) with incidental prostate cancer detected by transurethral resection for presumed benign hyperplasia. All patients were left without initial treatment. Gleason grade, nuclear grade and tumor volume turned all out to be independent prognostic factors. MUC-1, AMACR and Ki-67 also carried prognostic information. However, after adjustment for Gleason grade, nuclear grade and tumor volume only MUC-1 and AMACR remained as statistically significant prognostic factors. When tested for sensitivity and specificity they all failed and, consequently, they seem to be of less value in daily practice for cancelling an individual patient regarding the choice of treatment.</p><p>Time trends in incidental prostate tumors in Sweden were analyzed in a cohort of patients with prostate tumors detected by transurethral resection (TUR-P). Through linkage of the national registration number (NRN) with several registers, e.g. the Swedish Cancer Registry, the National Inpatient registry and the Cause of Death Registry we identified, during the period 1970 through 2003, in total 23288 patients with incidental prostate cancer, who constituted the study group. As comparison group we choose all patients diagnosed with prostate cancer between 1970-2003 excluding those with incidental cancer, in total 112204 patients. Our result confirms earlier findings that there has been a dramatic change over time in incidence of incidental prostate cancers in Sweden, which parallels the introduction of prostate specific antigen. We also found that the cumulative incidence of prostate cancer death is high in the incidental group, opposing earlier findings that incidental tumours are a non-lethal disease.</p> / issn 1642-4063
6

Radiolabeled acetate PET in oncology imaging : studies on head and neck cancer, prostate cancer and normal distribution

Sun, Aijun January 2010 (has links)
The use of positron emission tomography (PET) for imaging in oncology has grown rapidly in recent years. 2-[18F]-fluorodeoxyglucose (FDG) is the most common tracer of PET, although drawbacks exist. Radiolabeled 1-[11C]-acetate (C-AC) is a simple probe for evaluation of perfusion, anabolism (lipogenesis) and catabolism (oxidative metabolism) in all living tissues. This study explored the potential of AC PET in head and neck cancer, benign and malignant lymph nodes in prostate cancer and normal distribution.  In head and neck cancer, C-AC PET detected more primaries and lymph node metastases than FDG PET. The mean primary tumor volumes delineated by C-AC was 51% larger than that of FDG before radiotherapy (RT). Both FDG and C-AC PET tumor volumes must be carefully validated before used in clinical routine. Baseline tumor clearance rate (kmono) was higher in complete responders (CR) than that in partial responders (PR). kmono tended to correlate inversely with FDG SUV at baseline. Radiosensitive tumors might rely predominantly on oxidative metabolism for their biogenetic needs. kmono increased in PR during RT. The potential reversibility of impaired kmono in radioresistant tumors imply that treatment targeting the intermediary metabolism might improve the outcome. Tumor relative perfusion index (rF) and kmono were coupled in CR throughout the RT, but not in PR. Dynamic C-AC PET provides a new non-invasive method to simultaneously evaluate the tumor oxidative metabolism and perfusion which link the RT response in patients by a single tracer injection. In prostate cancer, elevated C-AC accumulation is common in benign inguinal lymph nodes, probably due to increased lipogenesis rather than lymphatic drainage. CT Hounsfield unit of benign nodes was lower than that of metastases, suggesting that density measurement using CT might improve the specificity of nodal staging of prostate cancer. A novel tracer 2-[18F]-fluoroacetate (F-AC) was synthesized and used for dynamic PET-CT imaging in animals. Compared with C-AC PET-CT, F-AC showed prolonged blood retention, no detectable trapping in myocardium and salivary glands, rapid excretion from liver to bile and urine and de-fluorination resulting in intensive skeletal activity. F-AC does not mimic the normal physiologic path of C-AC and appears to be of little use for assessment of perfusion, intermediary metabolism or lipogenesis.
7

Natural history and prognostic factors in localized prostate cancer

Andrén, Ove January 2008 (has links)
The natural history of localized prostate cancer is not fully understood. In most patients the tumor will never progress to a lethal disease, while a subset of patients will ultimately die of the disease. Efficient tools to separate indolent from lethal disease is currently lacking which means that many patients will be offered treatment without any benefit, but still be at risk of experiencing treatment related side effects. The aims of these studies were to get more insight into the natural history of untreated localized prostate cancer, to assess the prognostic value of established clinical parameters such as Gleason score, nuclear grade and tumor volume and, moreover, some new prognostic markers Ki-67, AMACR and MUC-1. We also aimed to study time trends in the detection of incidental tumors in Sweden. Patients with localized disease (n=223) and no initial treatment were followed for 21 years. Most patients had a favorable outcome. However, a subset of patients developed lethal disease even beyond 15 years of follow-up and these patients define the group that may benefit most from treatment with curative intent. Patients with poorly differentiated tumors experienced a 9 time higher risk of dying in prostate cancer. The studies on prognostic markers are based on a cohort of patients (n=253) with incidental prostate cancer detected by transurethral resection for presumed benign hyperplasia. All patients were left without initial treatment. Gleason grade, nuclear grade and tumor volume turned all out to be independent prognostic factors. MUC-1, AMACR and Ki-67 also carried prognostic information. However, after adjustment for Gleason grade, nuclear grade and tumor volume only MUC-1 and AMACR remained as statistically significant prognostic factors. When tested for sensitivity and specificity they all failed and, consequently, they seem to be of less value in daily practice for cancelling an individual patient regarding the choice of treatment. Time trends in incidental prostate tumors in Sweden were analyzed in a cohort of patients with prostate tumors detected by transurethral resection (TUR-P). Through linkage of the national registration number (NRN) with several registers, e.g. the Swedish Cancer Registry, the National Inpatient registry and the Cause of Death Registry we identified, during the period 1970 through 2003, in total 23288 patients with incidental prostate cancer, who constituted the study group. As comparison group we choose all patients diagnosed with prostate cancer between 1970-2003 excluding those with incidental cancer, in total 112204 patients. Our result confirms earlier findings that there has been a dramatic change over time in incidence of incidental prostate cancers in Sweden, which parallels the introduction of prostate specific antigen. We also found that the cumulative incidence of prostate cancer death is high in the incidental group, opposing earlier findings that incidental tumours are a non-lethal disease.
8

Radiolabeled acetate PET in oncology imaging studies on head and neck cancer, prostate cancer and normal distribution /

Sun, Aijun, January 2010 (has links)
Diss. (sammanfattning) Umeå : Umeå universitet, 2010.

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