Introduction: Colorectal cancer is the second most common cause of death in women, and the third most common cause in men. The main treatments available following surgery are chemotherapy and radiotherapy which are not always effective and have side effects. Modern medicine aims to develop targeted cancer therapies that are efficient and cause less side effects to patients. However, this approach requires a thorough understanding of the molecular events that cause cancer cell to grow and divide in order to identify suitable targets. The process of translating the findings into clinical studies can be high cost and technically demanding. However, development of a tissue microarray (TMA), allows immunohistochemical (IHC) staining of multiple cases simultaneously, thereby greatly reducing costs and time. Methods: A TMA was produced from approximately 400 cases of colorectal cancer, along with collection of associated clinical and pathological data. Sections from the TMA were tested for quality by staining with haematoxylin and eosin (H & E), in addition to IHC markers to molecularly classify the colon cancers. Results: The cores from the 384 cases of cancer were successfully transferred to 18 recipient TMA blocks. H & E staining showed good morphological preservation of the cases, reflecting the tumour in the donor blocks. IHC testing was able to successfully classify cases into distinct molecular groupings. Conclusions: The development of a TMA of colorectal cancers provides a valuable tool for the efficient and subsequent molecular classification of colorectal cancer using immunohistochemistry.
Novel germanium (Ge)-doped silica glass fibres tailor-made in Malaysia are fast gaining recognition as potential media for thermoluminescence (TL) dosimetry, with active research ongoing into exploitation of their various beneficial characteristics. Investigation is made herein of the capability of these media for use in diagnostic imaging dosimetry, specifically at the radiation dose levels typically obtained in conduct of Computed Tomography (CT). As a first step within such efforts, there is need to investigate the performance of the fibres using tightly defined spectra, use being made of a Philips constant potential industrial x-ray facility, Model MG165, located at the Malaysian Nuclear Agency Secondary Standards Dosimetry Lab (SSDL). Standard radiation beam qualities (termed RQT) have been established for CT, in accord with IEC 61267: 2003 and IAEA Technical Reports Series No. 457: 2007. A calibrated ionisation chamber has also been utilised, forming a component part of the SSDL equipment. The fabricated fibres used in this study are 2.3 mol% flat fibre (FF) of dimensions 643 × 356 μm2 and 2.3 mol% cylindrical fibre (CF) of 481 μm diameter, while the commercial fibre used is 4 mol% with core diameter of 50 μm. The dopant concentrations are nominal preform values. The fibres have been irradiated to doses of 20, 30 and 40 milligray (mGy) for each of the beam qualities RQT 8, RQT 9 and RQT 10. For x-rays generated at constant potential values from 100 to 150 kV, a discernible energy-dependent response is seen, comparisons being made with that of lithium fluoride (LiF) thermoluminescence dosimeters (TLD-100). TL yield versus dose has also been investigated for x-ray doses from 2 to 40 mGy, all exhibiting linearity. Compared to TLD-100, greater sensitivity is observed for the fibres.