bluuebunny/crossref_metadata_2025_split huggingface dataset:
An evaluation of three tangential breast irradiation techniques in Hong Kong
Authors: Law Maria Y.Y. , Cheung Fion W.K. , Wu Vincent W.C. , Tsang Venus W.C. , Kwan Rainnie W.Y. , Cheng Johnny Y.T. , Wong Fatson K.F. 
Published: August 2006

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.
Dose volume histogram analysis for organs at risk when using 6 external beam techniques for radical prostatic irradiation
Authors: Haycocks T. , Mui J. , Alasti H. , Catton C. 
Published: August 2006

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.
Dose analysis of three 3-D conformal radiotherapy techniques used in booster treatment of nasopharyngeal carcinoma
Authors: Wu Vincent W. C. , Chan Zeromon H. F. , Kung Shiris W. S. , Chau Celia K. F. , Fu Kenneth C. K. , Yip Kitty K. Y. 
Published: August 2006

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.
Randomized study comparing the impact of a simulator with CT option to diagnostic CT on workload and patients comfort
Authors: Bijdekerke P. , Vinh-Hung V. , Nys F. , Vandepoele E. , Van de Steene J. , D'Haese S. , Verellen D. , Storme G. 
Published: August 2006

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.
Errors from field placement and organ motion during conformal radiotherapy for prostate cancer
Authors: Wu J. , Haycocks T. , Alasti H. , Ottewell G. , Middlemiss N. , Abdolell M. , Warde P. , Toi A. , Catton C. 
Published: August 2006

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.
Intervention for acute radiotherapy induced skin reactions in cancer patients: the development of a clinical guideline recommended for use by the college of radiographers
Authors: Glean E. , Edwards S. , Faithfull S. , Meredith C. , Richards C , Smith M. , Colyer H. 
Published: August 2006

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.
Improving the accuracy of localisation in the radiotherapy treatment of head and neck, and brain cancer: some initial findings
Authors: McJury M. J. , Nakielny R. , Levy D. , Lilley J. , Conway J. , Robinson M. H. 
Published: August 2006

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.
Dose analysis of boost treatment to parapharyngeal space of nasopharyngeal carcinoma using three-dimensional conformal radiotherapy
Authors: Wu Vincent W C , Tsang Candy S C , Mak Freddy H K , Chan Joe C H , Leung Kenneth M W , Leung H W 
Published: August 2006

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.
A comparison between two types of beam direction shell for the treatment of age related macular degeneration
Authors: Harris R. , Elder P. , Brock K. , Blackler N. , Glanfield J. 
Published: August 2006

Background and Purpose: The aim of this study was to determine set-up accuracy when comparing an Orfit® thermoplastic shell to a traditional acetate shell for the treatment of patients with age related macular degeneration.Method and Materials: 20 patients with age related macular degeneration were sequentially allocated to be positioned in either an Orfit® shell or a traditional acetate shell (ten patients in each group). On each day of treatment, radiographic portal imaging was used to ascertain accuracy by comparison with the CT image and verification radiograph.Results: 140 portal images were assessed by three independent readers. Pearson Correlation and ANOVA statistics were performed on the data to assess differences between the two types of shell. Inter- and intraobserver variations were also analysed. Results, for both Orfit® and Acetate, revealed that over 95% of error movements were 2 mm or less.Conclusions: The study indicates that both devices are of comparable accuracy and that the Orfit® shell is an acceptable method of immobilisation for the treatment of age related macular degeneration.
A pelvic positioning study comparing the set-up reproducibility of prone pelvic treatments for obese patients, with and without the use of a thermoplastic immobilisation shell
Authors: Harris R. , Daniel F. , Elder P. , Luffman C. , Bowen C. , Casebow M. 
Published: August 2006

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.
Intensity modulated radiation therapy (IMRT) in the radiotherapy treatment of colo-rectal cancer: the influence of profile smoothing on the efficiency of delivery
Authors: Laub W. , Yan D. , Robertson J. , Martinez A. 
Published: August 2006

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.
“Living with radiotherapy”: the experiences of women with breast cancer
Authors: Johnson Jan 
Published: August 2006

The research attempts to gain a greater understanding of the experience of radiotherapy from the viewpoint of the female patient with breast cancer. A qualitative, phenomenological approach was employed using semistructured interviews undertaken in the patient's home approximately two weeks after completion of their treatment course. Data analysis resulted in the description of five important categories of experience for the women. Discussion concludes that it is paramount for all health care professionals and therapy radiographers in particular to undertake and promote this type of research in order for them to establish and maintain a true sense of empathy and understanding with their patients. It also helps health care professionals maintain a sense of the importance of the ‘whole experience’ for those in their care. This type of enquiry provides a valuable and yet all too rare insight into aspects of attending for radiotherapy which would otherwise remain buried beneath the bustle of a busy radiotherapy department.This article is an edited version of a Master's dissertation and as such can only convey the essence of the original work.
A survey of in vivo diode dosimetry in the UK
Authors: Appleyard Robert 
Published: August 2006

A clear rationale exists for routine in vivo dosimetry as part of an overall quality assurance (QA) programme within a radiotherapy department. A survey was undertaken in order to identify the extent of diode dosimetry practice within the UK.Questionnaires were distributed to 57 radiotherapy physics departments in the UK in order to determine the extent of central axis diode dosimetry and the protocols implemented, the range of other in vivo measurements performed using diodes and the type of equipment used. Fifty-four responses were received. Eighteen departments undertook some form of central axis entrance dosimetry. Fifteen departments could be considered to be doing this routinely. Seven departments indicated planned future use. Six centres routinely undertook exit dosimetry with a further 3 indicating planned future use. Varied protocols for use were reported by those centres undertaking central axis dosimetry. Thirty-two respondents used a diode system for other forms of in vivo measurements with critical organ and TBI dosimetry being the most common. The vast majority used Scanditronix equipment.Despite the distinct benefits of central axis diode dosimetry, this continues to be infrequently adopted as part of a departmental QA programme. However, an indication of a number of departments planning to implement such an approach is reassuring.
Spatial ability assessment: an aid to student selection for therapy radiography training
Authors: Waywell L. , Bogg J. 
Published: August 2006

Therapy radiographers require the ability to perceive three-dimensional relationships, in order to position patients correctly for treatment. A test predicting this would therefore be useful during undergraduate selection. This study examines whether therapy radiographers have a greater spatial ability than the general population, and secondly the relationship between spatial and clinical ability.A correlation design utilised 54 therapy radiographers. Each subject undertook 3 tests: 2 spatial ability tests; WAIS block test (WBT) and Lego block test (LBT), and a clinical set-up (CS). Results indicate that therapy radiographers have a significant higher level of spatial ability, p <0.001, than the general population in the 25–34 year age group. Pearsons correlation of WBT with LBT (r = 0.56, p < 0.0005) demonstrated concurrent validity of the new LBT.The results suggest therapy radiographers have a higher degree of spatial ability than the general population. A test of spatial ability would therefore be of use to determine potential clinical competency during undergraduate selection. Whilst a potential useful instrument has been identified further research needs to be undertaken in this area as spatial ability is just one factor needed for clinical competence.