Description: Segment 1 Dr Thomlinson begins by talking about the changes in a tumour that may take place in intervals between treatments. He discusses clonogenic cells and how they react to fractionated doses of radiation. Thomslinson then talks about delaying the growth of a tumour with this method of radiotherapy and how experiments on animal tumours have helped with this research. He discusses these experiments and the results are shown in graphs. Time start: 00:00:00:00 Time end: 00:05:07:00 Length: 00:05:07:00 Segment 2 Another graph shows the response of carcinoma of the bladder to doses of radiation. A further chart shows the response curve of a breast tumour. Thomlinson says how more needs to be known about the growth rate of tumours in order to treat them effectively, though both of the above patients' tumours shrunk considerably. Next, he talks about the change in oxygenation that occurs during fractionated radiotherapy. Graphs show that fully oxygenated cells need less radiation than ones absent of oxygen. Time start: 00:05:07:00 Time end: 00:09:52:00 Length: 00:04:45:00 Segment 3 Another graph shows the gain in radiosensitivity of cells in relation to the tension of oxygen. Thomlinson discusses this data and goes on to talk about research into anoxic (devoid of oxygen) cells and their influence in cancer treatment. He then describes how oxygen reaches the cell of a tumour, with the aid of a series of diagrams. Time start: 00:09:52:00 Time end: 00:15:45:00 Length: 00:05:53:00 Segment 4 Thomlinson discusses how in abnormal tissues capillaries may be forced apart (shown in a diagram), leading to an area of anoxic tissue. Photomicrographs of squamous carcinoma cells from a human bronchus are shown, and Thomlinson points out a necrotic region affected by misplaced capillaries. He then discusses how blood flow slows in other types of tumour, another reason for shortage of oxygen. Time start: 00:15:45:00 Time end: 00:19:55:00 Length: 00:04:10:00 Segment 6 Thomlinson discusses the problems of measuring oxygen tension and anoxic cells in tumours. He goes on to talk about how tests on animal tumours have helped with this research. Footage of a rat with a tumour being clamped (to occlude the blood supply) is seen, as well as footage of it in a pressure vessel (to change the oxygen level in the air). The results of these experiments on the tumours are shown in a series of graphs. Time start: 00:26:06:00 Time end: 00:30:16:00 Length: 00:04:10:00. Segment 7 Thomlinson describes a case in which the patient was given a chemical radiosensitiser that acted specifically on anoxic cells. He also talks about re-oxygenation and how this affects radiation treatment of tumours. He discusses how radiation therapy can reverse the slow blood flow caused by the tumour. Time start: 00:30:16:00 Time end: 00:35:04:21 Length: 00:04:48:21. Segment 8 Thomlinson goes on to talk about the increase in blood vessels and the evening out of blood flow as tumours shrink due to treatment. He says that he wishes to study fractionated radiotherapy to determine the sizes and intervals of the doses to create the best treatment and eliminate hypoxic cells in the tumour. A series of charts shows how fractionated radiotherapy has helped tumours in humans and animals. Thomlinson discusses the courses of radiation given to each patient. Time start: 00:35:04:21 Time end: 00:41:31:00 Length: 00:06:26:04. Segment 9 Thomlinson next talks about how the original size of the tumour affects the course of radiation and about what happens to tumour cells when they die. He also discusses phagocytosis, anothe way in which tumour volume can be diminished. Time start: 00:41:31:00 Time end: 00:44:44:00 Length: 00:03:13:00. Segment 10 Thomlinson discusses the non-cellular materials that make up tumours, such as keratin, cartilage and mucous. Thomlinson then draws a graph showing the size of tumours in relation to time. He details three parts of volume change: growth before treatment, regression after treatment, renewed growth (if treatment fails). Time start: 00:44:44:00 Time end: 00:48:38:24 Length: 00:03:54:24