Call number: LD2668 .T4 1959 R37

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.

Thesis (Ph. D.)--University of Chicago, Committee on Human Development, Dept. of Psychology, June 2001. / Includes bibliographical references. Also available on the Internet.

published_or_final_version / Obstetrics and Gynaecology / Master / Master of Philosophy

Intermedin (IMD) is a peptide hormone discovered in 2004 belonging to the calcitonin/calcitonin gene-related peptide superfamily. It signals through a Gprotein coupled receptor by the coupling of a calcitonin receptor-like receptor (CRLR) and one of the receptor activity-modifying proteins (RAMPs) 1-3. Due to its similarity to adrenomedullin in structure and functions, IMD is also known as adrenomedullin 2 (ADM2). Among members of the superfamily, IMD shares the highest degree of homology with ADM, which is a multifunctional vasodilator ubiquitously expressed in various tissues and organs and has been studied by our group for its reproductive functions. It is hypothesized that IMD may be present in the reproductive systems of the rat and exert some effects on reproductive functions. The objectives of this study were to investigate the expression of IMD and its receptor components in the male and female reproductive systems of the rat, the changes in expression across the oestrous cycle, and its effect on uterine contraction. The gene expression levels of Imd and its receptor components and peptide levels of IMD were measured by RT-PCR and enzyme immunoassay respectively. The effect of IMD on the uterine contraction was studied by the organ bath technique. Imd mRNA and IMD levels were detected in the testis, epididymis, ventral prostate, coagulating gland, and seminal vesicle of the male rat and the ovary, oviduct, and uterus of the female rat, suggesting possible roles for IMD in both the male and female reproductive systems. In the male, the Imd mRNA levels were the highest in the seminal vesicle but lowest in the testis and the epididymis and IMD peptide levels were the highest in the coagulating gland but lowest in the epididymis. In the female, the Imd mRNA and IMD peptide levels were the highest in the oviduct and the uterus respectively while both the Imd and IMD levels were the lowest in the ovary. Imd mRNA and IMD levels displayed cyclic changes in various female reproductive tissues across the oestrous cycle. In the ovary, positive immunostaining was detected in the follicles and corpora lutea with more staining in the latter. The Imd mRNA level was significantly higher at prooestrus than dioestrus while the IMD peptide level was significantly higher at metoestrus than dioestrus. In the oviduct, the Imd mRNA level was the lowest at dioestrus but the IMD peptide level was the highest at dioestrus. Positive immunostaining was observed in the ciliated epithelial cells. Uterine Imd mRNA level was the highest at prooestrus while the IMD level was the highest at dioestrus. IMD was found in the luminal and glandular epithelia. IMD significantly reduced the uterine contraction amplitude and frequency but not the basal tone. CGRP receptor antagonist hCGRP8-37 and ADM receptor antagonist hADM22-52 partially abolished the inhibitory effect of IMD on uterine contraction while the IMD specific receptor antagonist hIMD17-47 completely blocked the actions. Enzyme inhibitors of NO (L-NAME) and PI3K (Wortmannin) pathways diminished the IMD-mediated effects on uterine contraction while cAMP/PKA blocker KT5720 had no effect. / published_or_final_version / Physiology / 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

No description available.

No description available.