Patients receiving tangential breast irradiation represent a significant proportion of the workload in a radiotherapy department. This paper describes the optimisation of an existing technique for tangential breast irradiation. Simulator sessions have been made more efficient by adopting a systematic approach to the simulation process, and set up times on treatment have been reduced and accuracy increased by improving the reliability of the patient set-up. There has been an overall reduction in both the problems and the time taken to both simulate and treat patients.

Patient position variation has been minimised by the use of vac-fix bags and the choice of reference tattoo placement on the patient's skin. The single simulation session for planning treatment has been organised into three parts: definition of target volume, calculation of treatment and field parameters and simulation of treatment fields. The improvement in patient set-up on treatment has been confirmed by a reduction in the variability of FSDs measured during treatment.

Background and purpose. The objective of this study was to assess set-up reproducibility of pelvic treatments for obese patients in the prone position, with and without the use of an immobilisation shell.

Method and materials. The patients were treated using a posterior open field and opposed lateral wedged fields for 20 fractions over four weeks. Ten fractions were set-up using a pelvic shell and ten fractions without. The patients were randomised into two groups, whose initial set-up was either with or without a shell. Portal images were obtained on 14 treatment fractions (7 for each set-up) and compared against initial simulator images to assess movement. For each fraction when portal imaging was scheduled the treatment radiographers also assessed the ease at which the patient could be positioned. The aim was to determine the correlation between good visual positioning to surface marks and accurate location of bony landmarks in portal imaging.

Results. Early results from this study highlighted large random positioning errors in the superior/inferior plane when patients were positioned in the pelvic shell. The study was therefore abandoned at patient number four.

Conclusion. The use of the pelvic shell was found to increase positioning errors in the longitudinal (superior-inferior) direction. Reasons for this observation are discussed and modifications to the shell design suggested. The study also highlighted that ease of patient positioning using surface marks is not a good guide to positional accuracy and emphasises the importance of regular on-set verification.

Small bowel toxicity due to radiotherapy treatment of rectal cancer is common. The potential use of intensity modulated radiation therapy (IMRT) to reduce the volume of small bowel irradiated during radiation therapy (RT) for cancer has previously been reported. However, IMRT treatment implementation is relatively difficult for these patients. The PTV is large and has a concave shape, with the small bowel in very close proximity. Therefore, the intensity profile calculated by an inverse planning engine could be highly modulated and complicated to deliver.

In this study, two methods were used to optimise IMRT plans for rectal cancer patients. Scatter contribution when backprojecting dose values to fluence values and a smoothing function were only implemented in the optimisation searching of one method. A common arrangement of five beams, each separated by equal gantry angle, was adopted. With both methods used, the dose coverage of the PTV was satisfactory. Small bowel irradiated to a dose of 95 % was reduced by about 70% as compared to a 3D conformal 3-field treatment technique. However, incorporation of scatter contribution and a smoothing function in the iteration of optimisation searching greatly reduced the degree of modulation in the two-dimensional intensity profiles. Instead of 120–160 step-and-shoot MLC segments only 30–60 segments were necessary to deliver the five intensity profiles. The number of monitor units per fraction was reduced accordingly to about one half. Therefore, by controlling the smoothness of the intensity profiles during optimisation, the produced IMRT plans could be delivered more efficiently. Moreover, the possibility to account for overlap of organs was found to be very valuable to avoid hot spots in these regions and to get the full DVHs of all organs at the same time.

Aims: To investigate the impact on localisation of utilising contrast enhanced computed tomography (CT) scans and the formal input of a radiologist in the radiotherapy planning process.

Method: Ten head and neck / brain patients had pre- and post-contrast CT scans in the treatment position. Over several months, their unenhanced and enhanced scans were re-contoured by the original oncologist, and a radiologist. These new contours were compared to the original unenhanced contours and differences in contour volume, geographical position and tolerance doses on the associated PTVs were evaluated.

Results: The use of contrast lead to significant differences in the size of GTVs. Mean differences in GTVs of 32.8 % were significant at p=0.01. No significant impact on the position of the contour centre was noted. The impact of the radiologist lead to large differences in GTV (mean 20.5 %), but large SDs meant this result was not statistically significant. The contouring precision of the oncologist showed no significant difference for GTVs and PTVs.

Conclusions: The use of contrast when planning the radiotherapy treatment for head and neck / brain patients was found to lead to significant differences in GTV size, a lesser effect on PTV definition and little impact on the position of the contour centre. It may have important implications for multi-phase treatments where the GTV (rather than the PTV) is targeted for boost doses. Differences due to the input of a radiologist appear to be considerable and require further investigation when additional patient numbers have been acquired to improve precision.

Purpose. To evaluate the effect of positioning errors from setup and from prostate motion during escalated dose conformal prostate irradiation for localised prostate cancer. Methods. Thirteen patients with localised prostate cancer had lateral portal films taken three times weekly during escalated dose conformal prostate radiotherapy. Field placement errors were measured by matching corresponding bony landmarks to the simulator film. Prostate motion at the base, mid-gland and apex was measured by imaging the displacement of 3 gold fiducial markers implanted into the prostate before therapy. From these measurements a planning target volume (PTV) was derived that allowed for both the prostate motion and field placement errors.

Results. The random isocentre positioning error was 2.2 mm (range 0.2–7.3 mm), and the mean systematic isocentre positioning error was 1.4 mm (range 0.2–3.3 mm).

Mean prostatic motion at the base was anterior 1.5 mm (SD 2.9 mm, range posterior 11.8 mm to anterior 16.8 mm), and superior 0.2 mm (SD 2.1 mm, range inferior 6.8 mm to superior 10.8 mm). At mid-gland it was anterior 0.6 mm (SD 2.4 mm, range posterior 7.2 mm to anterior 9.2 mm). At the apex it was posterior 0.3 mm (SD 2.1 mm, range posterior 7.9 mm to anterior 9.4 mm), and superior 0.5 mm (SD 2.1 mm, range inferior 6.7 mm to superior 10.2 mm).

The margin of PTV about the prostate needed to give a 99% probability of the GTV remaining within the 95% isodose line during the course of therapy for these patients is superior 5.8 mm, and inferior 5.6 mm. In the anterior and posterior direction, this margin is 7.2 mm at the base, 6.5 mm at the mid-gland and 6.0 mm at the apex.

Conclusions. Systematic setup errors were minimised by patient immobilisation and real-time corrections of setup errors. Prostate motion contributes the largest source of error, and this motion is greatest at the base of the gland compared to the apex. A non-uniform planning margin will improve target coverage while limiting normal tissue exposure. Fiducial markers implanted in the prostate improved quality assurance for radiation delivery by allowing confirmation of organ position within the treatment field over the course of therapy.

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.

Background: Radiotherapy is well established in the treatment of non-Hodgkin's lymphoma (NHL) but there is considerable variation in the radiotherapy regimens prescribed, even within one cancer centre. This paper compares the varying radiation schedules prescribed in the Beatson Oncology Centre, Glasgow, in a sample of patients treated in 1996 with a second sample treated in 1999 following the creation of a lymphoma team with defined treatment protocols.

Method: In 1997 a retrospective study within the Beatson Oncology Centre recorded the treatment details of 35 patients treated with radiotherapy for NHL in 1996. The various radiotherapy dose and fractionation regimens prescribed were analysed to identify the rationale behind the variations by correlating them to the grade of disease, the age of the patient, the prescribing consultant and use of cytotoxic chemotherapy. A further audit of 36 patients treated over a three-month period in 1999 re-examined the radiotherapy prescribed and was able to include intent of treatment and stage of disease in the analysis.

Results: The demographics of the 1996 and 1999 patients were similar. In the latter group all patients had grade of disease recorded and 83% had stage recorded compared to 91% had grade and only 31% had stage recorded in 1996. The range of doses prescribed was 20–45 Gy (Gray) (median 36) for LGNHL (low grade non-Hodgkin's lymphoma) in 1996 with a range of 5–50 Gy (median 30) for HGNHL (high grade NHL). In 1999 the LGNHL range was 20–45 Gy (median 30) with HGNHL 20–50 (median 40). The 1999 audit showed better recording of data and this allowed further analysis of radiotherapy regimens. The patients could be grouped into three categories of treatment intent: primary radical treatment with radiotherapy alone (36%), consolidation following chemotherapy (25%) and palliation (39%). The radical and consolidation groups received similarly high doses (median 40 Gy) which were significantly greater than the palliation group (median 20 Gy).

Conclusions: The creation of a lymphoma team has improved the recording of treatment data and reduced the variations in clinical practice. We would advocate that patients with NHL should be irradiated according to evidence based protocols and suitable patients should be considered for the current BNLI trial of radiation dose in NHL.

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.

Electronic portal imaging (EPI) has been used in the assessment of the accuracy of radiotherapy treatments in the pelvis. The daily reproducibility of any treatment is primarily dependent on the effectiveness of the set-up method. Treatments of radical planned volumes within the pelvis are subject to field placement errors (FPE) which could potentially compromise the successful outcome of radiotherapy treatment. Increasing use of shaped treatment fields to limit the dose delivered to surrounding normal tissues has prompted a more detailed examination of set-up methods.

Within the radiotherapy department at the Leicester Royal Infirmary it was noted that tattooed marks on the anterior or posterior and the lateral skin surface, marked at simulation, could not always be aligned for daily radiotherapy treatment.

An assessment of the relative merit of the anterior/posterior or the lateral tattoos in determining the isocentre position in the superior-inferior (cranio-caudal) plane is presented. This study showed that changes in the use of tattoo marks during set-up would have reduced the incidence of FPE >5 mm for a small sample group of patients. Implementation of changes in clinical practice, or research using a larger sample group is now needed to verify any improvement in accuracy using a modified treatment set-up technique.

The aim of this retrospective study is to develop an evidence-based approach to managing radiation induced skin reactions. A Clinical Guideline Development Group was established to undertake a systematic review of literature and a survey of cancer centres with the objectives of highlighting and recommending best practice. Thirty-one papers were reviewed using the United States Health Care Policy and Research and Scottish Intercollegiate Guidelines Network criteria and 42 United Kingdom Cancer Centres responded with a mix of guidelines and information about skin care assessment and advice. The evidence base for the findings is mainly levels II, III and IV.

Although perceived as common, the incidence of skin reactions has not been quantified. There is little evidence of consistent assessment of acute reactions and the survey data shows that the use of a scoring tool such as the Radiation Oncology Group criteria (RTOG/EORTC 1985) is rare. It also demonstrates that advice to patients is variable and sometimes contradictory. Appropriate and timely information is essential to relieve anxiety and reduce problems.

There appears to be a place for the use of creams in the management of early (RTOG/EORTC 0,1, 2a) skin reactions and in delaying the onset of subsequent skin breakdown, however this evidence is not clear and several of the studies identified some allergic reactions to creams. The intervention used varies between departments and individual patients and is ad hoc rather than based on firm evidence.

For reactions graded RTOG/EORTC 2b and 3, evidence from wound care literature suggests the use of hydrocolloids or hydrogels which are founded on moist wound healing principles. No evidence could be found to support the management of RTOG 4.

The study recommends the development of a clinical guideline encompassing factors affecting the onset of reactions, assessment and management principles, and patient information and makes suggestions for much needed further research.

Nasopharyngeal carcinoma (NPC) patients with parapharyngeal space (PPS) involvement are routinely given boost irradiation in Hong Kong. The current technique that employs a single field has many limitations in terms of dose distribution. This study is aimed to compare the dose distribution between the newly designed 3-dimensional conformal radiotherapy (3DCRT) and conventional techniques for the boost treatment of PPS so as to determine the more optimal treatment.

Fifteen NPC patients with unilateral PPS involvement were recruited. Their CT images were loaded into the FOCUS planning system for treatment planning. The planning target volume (PTV) and seven organs at risk (OARs) including the spinal cord, brain stem, optic chiasm, mandible, temporal lobe, temporo-mandibular (TM) joint and lens were outlined for dose assessment. The conventional and 3DCRT plans were then generated for each patient and the dose distributions were compared using dose parameters derived from the dose volume histograms (DVHs).

The 3DCRT technique provides better target coverage and significantly better dose to the planning target volume than the conventional technique. The 3DCRT treatment plans gives better sparing of the ipsilateral TM joints, mandible and lens, but it is less effective to spare spinal cord, brain stem, optic chiasm and temporal lobe. Nevertheless, the total doses to these OARs remain within the clinically defined thresholds and are clinically acceptable.

Palliative radiotherapy represents a substantial workload of a radiotherapy department. This paper provides an overview of a unique service designed to minimise the time between consent and delivery of radiotherapy for palliative patients. In common with other patient-focused care initiatives, this has been achieved by innovative and radically redesigned work practices. Through role development therapeutic radiographers can perform simple palliative treatments. Utilising dedicated equipment they cover all stages of the treatment process, from patient booking through to the end of treatment, providing seamless care for the patient and significant benefits for the department. Auditing the accuracy of simulator radiographs performed by radiographers alone tested the validity of providing simulation of palliative treatment without medical support. The results show 90% required no change with only 1% rejected due to radiographer misinterpretation. The remaining 9% required further information to be supplied by the medical staff. Evaluation of this service included patient and medical staff satisfaction surveys. The results of both were very positive with 100% of medical staff satisfied with the service and all patients rating the service from good to excellent. This project has more than achieved its targets.

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.

Patients undergoing cancer treatments, including radiotherapy, frequently report fatigue during their treatment. Recent research indicates that structured exercise programmes can alleviate fatigue and, in light of this research, many centres are now advocating activity as part of the strategy with which to combat fatigue. The aim of this investigation was to see how well this strategy would be received by patients and what effect it would have on fatigue levels. Of the 147 patients who agreed to take part in the study 123 completed all the questionnaires. Fiftyfour of the patients received the standard advice whilst 69 received the modified advice. Fatigue was measured at four time points using the MFI scale. Fatigue scores at the end of treatment were significantly higher than at the start of treatment but there was no difference in fatigue scores between the two groups of patients receiving the different advice. Activity levels between the two groups were comparable, as was their change in activity level compared to normal, indicating a reluctance to use this strategy.