Thesis (Ph. D.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 172-202).

Inaug.-diss.--Berlin. / Lebenslauf. "Literaturverzeichnis": p. [40]-41.

Thesis (M. Nurs.)--University of Hong Kong, 2006.

Merkel cell polyomavirus (MCPyV) is an oncogenic virus exist in about 80% of Merkel Cell Carcinoma (MCC), an aggressive human skin cancer. Evidence of MCPyV existing in other kind of skin neoplasms such as cutaneous squamous cell carcinomas (SCCs) has been reported. Since the major type of cervical cancer is SCCs, MCPyV may be associated with cervical cancer tumorigenesis. A Japanese research group has documented the presence of MCPyV DNA in both cervical SCCs and cervical adenocarcinomas (ACs) from Japanese patients. Nevertheless, the association between MCPyV and cervical cancer remains inconclusive and the prevalence of MCPyV in cervical cancer may show demographic variation. This study is aimed to examine whether MCPyV is present in some of the most common gynaecological cancers, namely cervical cancer, ovarian cancer, endometrial cancer, and gestational choriocarcinoma, in Hong Kong patients. Genomic DNA was obtained from 50 cases of cervical cancer, 20 cases of ovarian cancer, and 35 common gynaecological cancers cell lines. Genomic DNA extracted from four MCC samples were used as positive controls. The integrity of the samples was first checked by β-globin PCR. Detection of MCPyV was then performed by MCPyV Large T antigen (LT-ag) PCR. Our PCR analysis showed that only 1 out of 50 (2%) of the cervical cancer samples was positive for MCPyV DNA. The PCR product was purified and cloned for sequencing analysis. Comparing the LT-ag sequence obtained from the only MCPyV positive cervical cancer with reference sequence and with the MCPyV sequence from one of the control cases revealed the presence of different MCPyV variants in Hong Kong patients. None of the ovarian cancer, endometrial cancer, or choriocarcinoma was positive for MCPyV. Our data did not support the notion that MCPyV is associated with gynaecological malignancies. MCPyV may hence be a fairly specific oncogenic agent for Merkel cell carcinoma. / published_or_final_version / Pathology / Master / Master of Medical Sciences

Thesis (M.Med.Sc.)--University of Hong Kong, 2004. / Also available in print.

MSc., Faculty of Science, University of the Witwatersrand, 2011 / Aim: This study aimed at evaluating the accuracy of the treatment setup margin in external beam radiotherapy in cervical cancer patients treated supine with or without the CIVCO “kneefix and feetfix”TM immobilizing devices. Methods and materials: 2 groups of 30 cervical cancer patients each, who were treated supine with two parallel opposed fields or a four-field “box” technique were selected randomly. The treatment fields were planned with a 2 cm setup margin defined radiographically. The first group was treated without any immobilization and the second group was treated with the “kneefix and feetfix”TM immobilization device. Both groups of patients were selected from the patients treated on one of two linear accelerators (linac), which had weekly mechanical quality control (QC). All patients had pre-treatment verifications on the treatment machine in which a megavoltage Xray film was taken to compare with the planning simulation film. Both films were approved by the radiation oncologist managing the patient. In this study the position of the treatment couch as at the approved machine film was taken as the intended or planned position for the immobilized patients. The digital readouts of the daily treatment position of the couch were recorded for each patient as the absolute X (lateral), Y (longitudinal), and Z (vertical) position of the couch from the record and verify system interfaced to the treatment machine. A total of 1241 (582 for the immobilized and 659 for the non-immobilized patient group) daily treatment setup positions were recorded in terms of the X, Y and Z coordinates of the couch corresponding to the Medio-lateral (ML), Supero-inferior (SI) and Antero-posterior (AP) directions of the patient, respectively. The daily translational setup deviation of the patient was calculated by taking the difference between the planned (approved) and daily treatment setup positions in each direction. Each patient’s systematic setup error (mi) and the population mean setup deviation (M), was calculated. Random ( ) and systematic ( ) setup errors were then calculated for each group in each direction. The translational setup variations found in the AP, iii ML, SI directions were compared with the 2 cm x 2 cm x 2 cm Planning Target Volume (PTV). Couch tolerance limits with the immobilization device were suggested based on the ± 2SD (standard deviation) obtained for each translational movement of the treatment couch. Result: The random and systematic errors for the immobilized patient group were less than those for the non-immobilized patient group. For the immobilized patient group, the systematic setup error was greater than the random error in the ML and SI direction as shown in Table I. Table I: The random and systematic errors in the setup in the Antero-posterior (AP), Medio-lateral (ML) and Supero-inferior (SI) directions and the suggested couch tolerance limits for both patient groups. Almost all treatment setup positions had less than 2 cm variation in the AP setup for both patient groups however; one third of the immobilized positions had more than 2 cm variation in the setup in the ML and SI directions. Conclusion: The “kneefix and feetfix”TM immobilizing device resulted in a minor improvement in both the random and systematic setup errors. The systematic setup errors need to be investigated further. There are measurable patient rotations of more than 2 cm in the setup margin with the immobilizing device and this should be confirmed with an imaging study. The 2 cm margin in the ML and SI directions Immobilized patient group Non-immobilized patient group AP (cm) ML (cm) SI (cm) AP (cm) ML (cm) SI (cm) Random error (!) 0.30 1.35 1.26 0.37 2.74 7.83 Systematic error (") 0.19 1.55 1.64 0.33 1.70 8.11 Suggested couch tolerance limits (±2SD) 0.70 4.04 4.08 0.88 4.76 N/A iv established at simulation should not be changed for these patients. A 1 cm tolerance in the AP setup margin could be introduced at this institution.

published_or_final_version / Obstetrics and Gynaecology / Master / Master of Philosophy

No description available.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

published_or_final_version / abstract / toc / Obstetrics and Gynaecology / Doctoral / Doctor of Philosophy