We partner with a secure submission system to handle manuscript submissions.
Please note:
You will need an account for the submission system, which is separate to your Cambridge Core account. For login and submission support, please visit the
submission and support pages.
Please review this journal's author instructions, particularly the
preparing your materials
page, before submitting your manuscript.
Click Proceed to submission system to continue to our partner's website.
To save this undefined to your undefined account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your undefined account.
Find out more about saving content to .
To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Radiotherapy departments are having to work more efficiently to cope with increasing demand for radiotherapy resources. Radiotherapy treatment room efficiency may be increased by the introduction of hospital clothing as this negates the need for patient changing in the treatment room. However, studies have shown that hospital clothing can have a negative effect on patient dignity. It is therefore important to balance potential time saving with any detriment to patients.
Purpose
This study examined the effect that hospital clothing had on the time patients spend in the treatment room and aimed to identify patients’ opinions of the clothing.
Materials and methods
Potential time saving was determined by covertly timing patients currently undergoing radiotherapy treatment as they entered and exited the treatment room. A total of 348 patients were timed in their own clothing and 341 were timed when they wore hospital clothing. The timings of these two groups were compared to determine whether hospital clothing saved treatment unit time. Patient opinions of the clothing were examined by issuing a short questionnaire, designed to gather ordinal data, at the end of their course of treatment. Questionnaires were issued only to patients who had worn hospital clothing in the radiotherapy department.
Results
Introducing hospital clothing saved a significant amount of treatment room time and patients were generally positive about wearing the clothing.
Conclusion
It is suggested that hospital clothing is a welcome addition to the radiotherapy department to increase efficiency without detriment to patients.
To assess the reliability of post-implant CT (PICT) dosimetry for I-125 prostate seed brachytherapy by investigating the variation between centres in performing PICT through a multi-centre audit.
Materials and methods
Computerised tomography data sets from four I-125 prostate brachytherapy patients were circulated to nine participating centres. Centres followed local protocol for PICT outlining and seed identification, dosimetry for D90, V100 and V150 for the prostate was reported. Outlines were compared to determine the variation in: quality parameters (D90, V100 and V150), dose-volume histograms and approach to PICT dosimetry between the centres.
Results
There was significant variation in the prostate outlines drawn by the nine centres; for a prostate with mean volume 43 cm3, the range was 39–57 cm3 which led to variations of D90 of 119–154 Gy (mean 140 Gy) and V100 of 80–93% (mean of 88%). Using automatic seedfinder software reduced discrepancies between centres identifying seeds; overall consistency in seed location was good.
Conclusions
There was a significant uncertainty in the outlining of the prostate volume for PICT dosimetry with an uncertainty value of around ± 20 Gy on D90. PICT is a valuable technique but its accuracy and consistency limitations must be appreciated.
This study was designed to study the variations in different geometrical and dosimetric parameters.
Materials and methods
In this study, two groups comprises 21 and 28 patients, who were treated with 9·5 Gy × 2 Fx and 7·5 Gy × 3 Fx, respectively, using microselectron high-dose rate (HDR) remote control unit. All patients were analysed using orthogonal radiographs to evaluate variations in different parameters.
Results
Variations in different parameters are more in Group II patients than in Group I patients, which show that the variation in geometrical and dosimetrical parameters increases with increasing HDR number of fractions.
Conclusion
In the reporting of an outcome of multiple fractionation of HDR treatments resultant dosimetric parameters must be evaluated and must be used for clinical interpretation.
To investigate whether inadequate dose to Point-A necessitates treatment plan changes in a time of computed tomography (CT)-image-guided brachytherapy treatment planning for cervix cancer.
Materials and methods
A total of 125 tandem and ovoid insertions from 25 cervix patients treated were reviewed. CT-image-based treatment planning was carried out for each insertion. Point-A is identified and the dose documented; however, dose optimisation in each plan was based on covering target while limiting critical organ doses (PlanTarget). No attempts were made to equate prescription and Point-A dose. For each insertion, a second hypothetical treatment plan was generated by prescribing dose to Point-A (PlanPoint-A). Plans were inter-compared using dose–volume histogram analyses.
Results
A total of 250 treatment plans were analysed. For the study population, the median cumulative dose at Point-A was 80 Gy (range 70–95) for PlanTarget compared with 84·25 Gy for PlanPoint-A. Bladder and rectal doses were higher for PlanPoint-A compared with PlanTarget (p < 0·0001). Target D90 did not correlate with Point-A dose (p = 0·60).
Conclusions
Depending on applicator geometry, tumour size and patient anatomy, Point-A dose may vary in magnitude compared with prescription dose. Treatment plan modifications purely based on inadequate Point-A dose are unnecessary, as these may result in higher organ-at-risk doses and not necessarily improve target coverage.
To report outcomes and late toxicity for a hypofractionated dose-escalated radiotherapy schedule in patients treated using intensity-modulated radiotherapy (IMRT) for localised prostate cancer.
Materials and methods
Eighty-eight men with localised prostate cancer were treated with 57 Gy in 19 daily fractions over 4 weeks. A total of 70 out of 88 had high-risk disease. Overall survival, cause-specific survival and biochemical progression-free survival (bPFS, Phoenix definition) were reported. Toxicity was measured retrospectively using Radiation Therapy Oncology Group (RTOG) criteria and assessed prospectively with a validated Late Effects in Normal Tissues Subjective, Objective, Management and Analytic (LENT/SOMA) patient questionnaire.
Results
At 5 years, overall survival was 84%, cause-specific survival 88% and bPFS 65%. In patients with high-risk disease, 5-year bPFS was 62%. There was no RTOG toxicity above grade III. LENT/SOMA questionnaires were returned by 74% patients. Median scores for bowel and urinary function were <1. Maximum bowel and urinary toxicity scores ≥2 were reported by 64% and 59% of patients, respectively. The median score for sexual function was 1·5, but nearly all (96%) patients recorded a toxicity score ≥2 for at least one question.
Conclusions
Dose-escalated hypofractionated radiotherapy delivered using IMRT has promising outcomes and acceptable late toxicity. This fractionation schedule is being compared with conventional treatment within an on-going multicentre phase III clinical trial.
To analyse interfraction setup using two different image guidance modalities for prostate and head-and-neck (H&N) cancer treatment.
Materials and methods
Seventy-two prostate and 60 H&N cancer patients, imaged with kilovoltage cone beam computed tomography (KVCBCT) or megavoltage fan beam computed tomography (MVFBCT), were studied retrospectively. The daily displacements in mediolateral (ML), craniocaudal (CC) and anteroposterior (AP) dimensions were investigated. The setup errors were calculated to determine the clinical target volume to planning target volume (CTV-to-PTV) margins.
Results
Based on 1,606 KVCBCT and 2,054 MVFBCT scans, average interfraction shifts in ML, CC and AP direction for H&N cases were 0·5 ± 1·5, −0·3 ± 2·0, 0·3 ± 1·7 mm using KVCBCT, 0·2 ± 1·9, −0·2 ± 2·4 and 0·0 ± 1·7 mm using MVFBCT. For prostate cases, average interfraction displacements were −0·3 ± 3·9, 0·2 ± 2·4, 0·4 ± 3·8 mm for MVFBCT and −0·2 ± 2·7, −0·6 ± 2·9, −0·5 ± 3·4 mm for KVCBCT. The calculated CTV-to-PTV margins, if determined by image-guided radiotherapy (IGRT) data, were 5·6 mm (H&N) and 7·8 mm (prostate) for MVFBCT, compared with 4·8 mm and 7·2 mm for KVCBCT. We observed no statistically significant difference in daily repositioning using KVCBCT and MVFBCT in early, middle and late stages of the treatment course.
Conclusion
In the absence of IGRT, the CTV-to-PTV margin determined using IGRT data, may be varied for different imaging modalities for prostate and H&N irradiation.
Accurate delineation of the target volume and organs at risk (OARs) are vital to ensure systematic errors are small. The use of contrast agents (CAs) in the bladder and rectum may aid contouring and reduce inter and intra-observer variability. The aim of this study was to evaluate the dosimetric effect of the presence of such contrast on the monitor units (MUs), planning target volume (PTV), rectum and bladder.
Materials and methods
The prostate, seminal vesicles, rectum and bladder were contoured by a single observer on ten patients with bladder and rectal contrast. To evaluate the dosimetric effect of the presence of contrast, the density of the ten patients with contrast in the bladder and rectum was virtually changed to 1 g/cm3. A four-field 15 MV conformal radiation therapy technique was applied in which dose volume histograms and MUs were compared using computed tomographic (CT) density and the 1 g/cm3 density.
Results
The presence of contrast resulted in a 0·09% (<1 MU) increase in anterior MUs and decrease of 1% (<1 MU) in the posterior beam MUs. Lateral beams were not affected. The PTV and bladder dose increased slightly without contrast. The rectum showed a maximum change of 0·62% dose among the measured dose values. A maximum dose of 0·3 Gy at the 30% volume was also seen.
Conclusions
The dosimetric effect of bladder and rectal CAs on MUs, dose to the PTV and OARs in using this technique was very small. This would not be clinically significant, but only if the extreme limits of dose volume constraints were being reached.
Electron mode is used for treatment of superficial tumours in linac-based radiotherapy.
Purpose
The aim of present study is simulation of 8, 12 and 14 MeV electrons from a Siemens Primus linac using MCNPX Monte Carlo (MC) code and verification of the results based on comparison of the results with the measured data.
Materials and methods
Electron mode for 8, 12 and 14 MeV electron energies of a Siemens Primus linac was simulated using MCNPX MC code. Percent depth dose (PDD) data for 10 × 10, 15 × 15 and 25 × 25 cm2 applicators obtained from MC simulations were compared with the corresponding measured data.
Results
Gamma index values were less than unity in most of points for all the above-mentioned energies and applicators. However, for 25 × 25 cm2 applicator in 8 MeV energy, 10 × 10 cm2 applicator and 15 × 15 cm2 applicator in 14 MeV energy, there were four data points with gamma indices higher than unity. However among these data points, there are a number of cases with relatively large value of gamma index, these cases are positioned on the bremsstrahlung tail of the PDD curve which is not normally used in treatment planning.
Conclusion
There was good agreement between the results of MC simulations developed in this study and the measured values. The obtained simulation programmes can be used in dosimetry of electron mode of Siemens Primus linac in the cases in which it is not easily feasible to perform experimental in-phantom measurements.