Background and Purpose: Loco-regional radiotherapy after breast conserving surgery significantly reduces the risk of recurrence but may induce complications in the lungs. The complications are related to the lung volume irradiated and the lung dose delivered. The purpose of this study was to evaluate three tangential breast irradiation techniques i.e. conventional technique, gantry tilting technique and half-beam block technique in terms of the percentage of irradiated lung volume and high dose lung volume for patients of different sizes.

Materials and Method: Treatment planning of the three tangential breast irradiation techniques was performed using the CT scans of 20 patients with early-stage breast cancer after lumpectomy.

Results: When compared with conventional technique, both half beam block technique and gantry tilting technique irradiated a significantly smaller percentage of lung volume and delivered a smaller percentage of high dose (above 30 Gy) volume in the lung. Patients with large breasts had a significantly higher percentage of lung volume irradiated to above 30Gy than those patients with small and medium breasts. The combined effect of tangential separation and technique only produced significant effect on the percentage of total lung volume irradiated but not on the high dose volume.

Conclusions: Gantry tilting and half-beam block techniques can reduce a significant amount of lung volume and high dose lung volume. Half-beam block technique is recommended for small and medium breast size while for large breast size, gantry tilting technique is preferred.

Ten patients with prostate cancer were each planned with 3 conventional and 3 conformal isocentric treatment techniques to compare the relative radiation doses to the bladder and rectal walls, and femoral head using dose volume histograms (DVH). The DVH were calculated for each organ and each technique, and the plans were ranked using the area under the curve method and also by the relative radiation dose given to specific normal tissue volumes.

The results show that for the planning target volume chosen, the 4 field non-coplanar technique delivers the least dose to the bladder, the 6 field coplanar technique delivers the least dose to the rectum and the 3 field oblique technique delivers the least dose to the femoral heads. The 4-field technique with no shielding contributes the most dose to the bladder and rectum and the 6 field coplanar technique contributes the most dose to the femoral heads.

No technique was shown to be optimal for all the organs at risk, but both the 6 field and 4 field non-coplanar field arrangements were shown to be superior techniques for minimising both the bladder and rectal dosage. The choice of technique will therefore depend on other factors such as the total prescribed dose, the ease of set-up and the ease of verification of isocentre reproducibility.

Three-dimensional conformal radiotherapy (3DCRT) has been introduced to treat nasopharyngeal carcinoma (NPC) in Hong Kong. Three more commonly used techniques, which are labelled as 3-field, 4-field and 6-field techniques, are currently employed as a booster treatment and no standard 3DCRT technique has yet been established. This study is aimed to evaluate and compare the dose distributions for the three common 3DCRT techniques so as to provide basis for the development of a routine protocol in future.

For each 3DCRT technique, eight patients with T3 tumours treated between 1997 to 1998 were recruited. Treatment planning was performed with the patients' CT images loaded into the 3-D treatment planning systems. The planning target volume (PTV) and eight organs at risk were delineated for dose assessment. Treatment plans were produced based on the criteria of the corresponding 3DCRT techniques. Dose volume histograms, 2-D and 3-D dose displays were used for dose evaluation.

All three techniques produced reasonable homogenous dose to the PTV. There was no significant difference in the mean doses of the PTV, spinal cord, lens, eyeball, temporal lobe and pituitary. The 3-field technique was superior in sparing the thyroid and optic nerve. The 6-field technique offered lower brain stem dose, and the 4-field technique was in between the two. The use of a vertex field slightly improved dose homogeneity of PTV and reduced the brain stem dose, but the doses to the optic nerve, thyroid, pituitary and temporal lobe were increased.

Purpose: A randomized study to investigate the routine use of a simulator-based CT (Sim-CT) for planning purposes.

Materials and methods: 24 patients accepted for pelvic radiotherapy were randomized to receive either a Sim-CT or a DCT planning CT scan. The execution time was measured for different steps in both procedures. A questionnaire was developed to gain information about the psychological status and physical comfort.

Results: The set-up (of hardware, software and patient) took significantly longer for the Sim-CT procedure (p<0.05). An average of 5.7 min was found in comparison with 3.2 min for the DCT group. A similar result (p<0.0005) was observed for the scan time (resp. 15.9 versus 5.1 min). However the total time of the procedure (including patient preparation) was significantly lower (p<0.005) for the Sim-CT group (resp. 21.6 versus 31.7 min). Physical comfort score showed that some patients experienced more discomfort during the Sim-CT procedure than during DCT.

Conclusions: The scan acquisition time and set-up time of Sim-CT procedure was significantly higher than DCT however the total time was less for Sim-CT group. The overall reduction in time with Sim-CT is counterbalanced by increased patient discomfort.

This study aims to examine two related contemporary issues in cancer care; why people with cancer use complementary therapies [CM] and what lessons there may be in this for Cancer Centre Services. The report will be presented in two parts. Part 1 is in the current issue and Part 2 will follow in the next. In Part 1 the main questions are identified and contextualised with the current literature on complementary therapy use. In Part 2 the method, results and analysis the survey and interviews will be explored. 148 patients attending the Leicestershire Cancer Centre returned questionnaires of whom 14 were interviewed in three separate focus groups. Patients from a cancer patient self help group were also interviewed as a fourth focus group. The qualitative data enabled a deeper analysis and evaluation of the quantitative data to be made. The discussion of the data places the main questions asked by the study into a wider context, including the Calman Hine Report and patient-centred care. The conclusions are that although a significant minority of patients [13%] were using CM at the time of the survey a significant majority of respondents [73%] identified a role for CM alongside conventional cancer treatment and 78% responded that staff at the Cancer Centre should be trained to advise them on the use of CM. The respondents acknowledged the resource and educational implications for Cancer Centres but stated that equal status should be given to care and cure in managing malignant disease. This in line with the Calman–Hine Report. Far greater numbers of patients may use CM if appropriate levels of resources and information were available. The findings indicate that integration of CM could assist in promoting future improvements in quality of survival and patient-centred care as identified by Calman–Hine and other recent health policy initiatives.