How groups view themselves and each other is very important in order to promote effective work practices. These views can be tribal in nature and lead to stereotyping which may affect how we communicate and act with other groups. This study primarily aims to identify how student radiographers view their own and other radiographic profession.

A survey was undertaken using the Student Stereotypes Rating Questionnaire with all radiographic training sites in England. The questionnaire was given to radiography students training as either diagnostic radiographers or therapeutic radiographers. It asked students to rate four professions: doctors, diagnostic radiographers, therapeutic radiographers and nurses on nine characteristics.

The online survey was open between February and July 2019 and elicited 233 responses. Overall, the radiography students’ perceptions of their own profession and the other non-radiography professions were generally positive; however, each radiographic profession’s view on the other radiographic professions was less favourable, the scores being significantly lower than for other professions. The professions each identified unique attributes (interpersonal skills, being a team player and independent working) that separated the professions from each other. Differences and similarities in stereotypes appeared not to change with time, although gender differences for certain attributes did exist.

Students appear to have preconceived positive stereotype of their own profession and a more negative stereotype of the other radiography profession that appears relatively stable during their training period and was unaffected by interprofessional education.

To investigate the impact of intra-fractional motion on dose distribution in patients treated with intensity-modulated radiotherapy (IMRT) for lung cancer.

Twenty patients who had undergone IMRT for non-small cell lung cancer were selected for this retrospective study. For each patient, a four-dimensional computed tomography (CT) image set was acquired and clinical treatment plans were developed using the average CT. Dose distributions were then recalculated for each of the 10 phases of respiratory cycle and combined using deformable image registration to produce cumulative dose distributions that were compared with the clinical treatment plans.

Intra-fractional motion reduced planning target volume (PTV) coverage in all patients. The median reduction of PTV covered by the prescription isodose was 3·4%; D98 was reduced by 3·1 Gy. Changes in the mean lung dose were within ±0·7 Gy. V20 for the lung increased in most patients; the median increase was 1·6%. The dose to the spinal cord was unaffected by intra-fractional motion. The dose to the heart was slightly reduced in most patients. The median reduction in the mean heart dose was 0·22 Gy, and V30 was reduced by 2·5%. The maximum dose to the oesophagus was also reduced in most patients, by 0·74 Gy, whereas V50 did not change significantly. The median number of points in which dose differences exceeded 3%/3 mm was 6·2%.

Intra-fractional anatomical changes reduce PTV coverage compared to the coverage predicted by clinical treatment planning systems that use the average CT for dose calculation. Doses to organs at risk were mostly over-predicted.

Lung tumours, especially those in the lower lobes, can move a lot during respiration; this motion needs to be accounted for during radiotherapy. In cases where 4D CT simulation scans are not performed, the current protocol at our centre is to apply a generic (internal motion + setup) margin of 0·70 cm in the axial plane and 1·20 cm in the longitudinal plane to all lung tumours, regardless of location. We analyse the tumour motions of a cohort of our local patients and categorise them into different locations in the lung. We seek to assess the adequacy of the current margins and to derive a more accurate set of standard margins which are specific for lung tumour locations.

All cases of lung tumours treated with stereotactic ablative radiotherapy between 2012 and 2016 were identified retrospectively and 4D CT scan data analysed. These tumours were grouped into the following locations: upper zone (UZ), middle zone (MZ) and lower zone (LZ). The treatment planning system was used to generate the displacements of the centre of mass of the tumours in the right–left, anterior–posterior and superior–inferior axes; these were compared with the current generic margins. Median displacements were calculated for each axis in each location. New planning target volume (PTV) margins were derived by summing the median displacement, median absolute deviation (MAD) and 0·5 cm (for setup error).

Sixty-three cases were eligible for analyses. Motion in the superior–inferior direction was the greatest for all tumour locations, ranging from a median of 0·17 cm (MAD 0·12 cm) in UZ to 0·77 cm (MAD 0·27 cm) in LZ. Median tumour displacements in the anterior–posterior and right–left axes were similar for all locations, <0·30 and 0·20 cm, respectively. The current generic margins were adequate for only one-third of the cases in this study. A new PTV margin of 2·10 cm in the superior–inferior axis may be required for LZ tumours, while an additional 1–2 mm should be added to the current radial margins.

The current generic margins are inadequate for the majority of cases. Tumour motion is the greatest in LZ in the superior–inferior axis. Motion mitigation strategies are essential for large LZ tumours.

The purpose of this study is to evaluate the effectiveness and sensitivity of the Varian portal dosimetry (PD) system as a quality assurance (QA) tool for breast intensity-modulated radiation therapy (IMRT) treatment plans.

Four hundred portal dose images from 200 breast cancer patient IMRT treatment plans were analysed. The images were obtained using Varian PortalVision electronic portal imaging devices (EPIDs) on Varian TrueBeam Linacs. Three patient plans were selected, and the multi-leaf collimator (MLC) positions were randomly altered by a mean of 0·5, 1, 1·5 and 2 mm with a standard deviation of 0·1 mm on 50, 75 and 100% of control points. Using the improved/global gamma calculation algorithm with a low-dose threshold of 10% in the EPID, the change in gamma passing rates for 3%/3 mm, 2%/2 mm and 1%/1 mm criterion was analysed as a function of the introduced error. The changes in the dose distributions of clinical target volume and organ at risk due to MLC positioning errors were also analysed.

Symmetric and asymmetric breast or chest wall plan fields are different in delivery as well as in the QA. An average gamma passing rate of 99·8 ± 0·5 is presented for 3%/3 mm symmetric plans and 96·9 ± 4·5 is presented for 3%/3 mm asymmetric plans. An average gamma passing rate of 98·4 ± 4·3 is presented for 2%/2 mm symmetric plans and 89·7 ± 9·5 is presented for 2%/2 mm asymmetric plans. A large-induced error in MLC positioning (2·0 mm, 100% of control points) results in an insignificant change in dose that would be delivered to the patient. However, EPID portal dosimetry is sensitive enough to detect even the slightest change in MLC positioning error (0·5 mm, 50% of control points).

Stricter pre-treatment QA action levels can be established for breast IMRT plans utilising EPID. For improved sensitivity, a multigamma criteria approach is recommended. The PD tool is sensitive enough to detect MLC positioning errors that contribute to even insignificant dose changes.

Although hypofractionated radiotherapy has been standardised in early breast cancer, even in post-mastectomy no such consensus has been developed for locally advanced breast cancer (LABC), probably due to complex planning and field matching. This study is directed towards dosimetric evaluation and comparison of toxicity, response and disease-free survival (DFS) comparison between hypofractionation and conventional radiotherapy in post-mastectomy LABC.

In total, 222 female breast cancer patients were randomly assigned to be treated with either hypofractionated radiotherapy (n = 120) delivering 40 Gy in 15 fractions over 3 weeks or conventional radiotherapy (n = 102) with 50 Gy in 25 fractions over 5 weeks after modified radical mastectomy (MRM) along with neoadjuvant and/or adjuvant chemotherapy. All patients were planned with treatment planning software and assessed regularly during and after treatment.

Median follow-up period was 178 weeks in conventional arm (CRA) and 182 weeks in hypofractionation arm (HFA). There exists a dosimetric difference between the two arms of treatment, in spite of similar dose coverage [planning treatment volume (PTV) D90 92·04% in CRA versus 92·5% in HFA; p = 0·49], average dose in HFA is less than that of CRA (p < 0·001); so is the maximum clinical target volume (CTV) dose (p < 0·001). Similarly, average lung dose in HFA arm is significantly lower than CRA (9·9 versus 10·84; p = 0·06), but the V20Gy of lung and V30Gy of heart had no difference. The toxicity of radiation was comparable with similar mean time to produce toxicity [CRA: 7 W, HFA: 10 W; hazard ratio 0·64, 95% confidence interval (CI) = 0·28–1·45]. Three-year recurrence event was alike in two arms (CRA: 4·9%, HFA: 5·8%; p = 0·76). Mean DFS in CRA is 230 weeks and that of HFA is 235 weeks with hazard ratio 1·01 (95% CI = 0·32–3·19; p = 0·987).

Though biologically effective dose (BED) in hypofractionation is lesser than that of conventional fractionation, there are indistinguishable toxicity, locoregional recurrence, distant failure rate and DFS between the two modalities.

Sexual dysfunction is a common side effect of external beam radiotherapy (EBRT) and androgen deprivation therapy (ADT) to treat prostate cancer. Men are likely to experience erectile dysfunction, low libido, ejaculatory problems and penile shortening. This qualitative study explored men’s perceptions of sexual dysfunction, including factors such as self-perception, relationships and information and support needs.

Semi-structured interviews were carried out with n = 8 men living 18–30 months after EBRT ± ADT. The interviews were transcribed and thematic analysis was carried out.

All men experienced sexual dysfunction following treatment. The main themes arising were: (i) priorities—sexual issues were not a priority when making treatment decisions, (ii) information and support—men described a lack of information and support about sexual dysfunction and (iii) impact—sexual dysfunction impacted on their self-perception and relationships.

Men undergoing EBRT/ADT for prostate cancer may be affected by post-treatment changes in sexual function in a range of ways. This study suggests that they would benefit from early and wide-ranging information and support on sexual dysfunction, even if they do not consider it as a priority. Candid discussions about self-perception and relationships, as well as physical changes, may equip them to cope with post-treatment changes.

The aim of this work was to study the acceptability of plans prepared for prostate patients treated by volumetric modulated arc therapy (VMAT) with the vision to evaluate the quality of plans and test pre-treatment quality assurance (QA).

VMAT plans of 35 patients, planned on the Eclipse Treatment Planning System (Aria 15), were included in the study. Plan acceptability was checked using statistical analysis, which includes homogeneity index, radical and median homogeneity index, coverage and uniformity index. Dose–volume histograms (DVH) of the plans were also studied to check prescribed dose (PD), Dmax, Dmin, D5 and D95. Portal dosimetry was also done by gamma analysis using 3%/3 mm criterion. SD and mean SD error were also calculated and analysed.

Statistical analysis showed a mean HI of 1·054, coverage 0·959, UI 1·055, mDHI 0·962 and rDHI 0·866. SD of HI, coverage, UI, mDHI and rDHI was 0·019, 0·019, 0·014, 0·013 and 0·030, respectively. From the DVHs, mean of D5, D95, Dmin and Dmax was calculated at 6,252·9, 5,757·4, 6,413·3 and 5,657·7 cGy, respectively, with a prescribed dose of 6,000 cGy. According to gamma analysis, area gamma < 1 was 99·12% with a tolerance limit of 95%, maximum gamma was 1·466 with a tolerance limit of 3·5, average gamma was 0·388 with a tolerance limit of 0·5, area gamma > 1·2 was 0·242% with a tolerance limit of 0·5%, maximum dose difference was 0·6 with a tolerance limit of 1·0 and average dose difference was 0·029 with a tolerance limit of 0·2.

All three computations showed the results to be within acceptable limits. VMAT possesses a unique feature of delivering the whole treatment with only two rotations of the gantry. VMAT has an improved efficiency of delivery for equivalent dosimetric quality.

This study aims to evaluate the application of the exit skin dose (ESD) in verifying the accuracy of intra-cavitary brachytherapy treatments performed by the BEBIG 60Co machine using thermoluminescent dosimeters (TLDs).

Eleven patients who were treated for gynaecological (GYN) malignancy by high-dose-rate (HDR) brachytherapy machine have been considered in this study. A combination of tandem, cylinder and interstitial needles was applied for eight patients while tandem ovoid (TO) applicators were used for the rest (three patients). In order to measure ESD, thermoluminescent dosimetry was performed for each patient. TLDs were placed precisely on the patient’s skin along her symphysis pubis bone (anterior) and left (L)/right (R) sides of her pelvic. Positioning of the dosimeter was accurately determined using fiducial markers in computed tomography (CT) scan imaging, prior to the treatment. Finally, a comparison was made between the calculated dose from the treatment planning system (TPS) and the dose measured by TLDs.

About 90% of all cases showed a good agreement (while considering TLD uncertainty ∼5·5%) between TPS dose calculations and TLD measurements. The measured mean values of ESD received to anterior, left and right positions were 56·72, 12·18 and 12·82 cGy, respectively. For three patients, differences up to 11·9% were detected.

To conclude, ESD measurement method can be a suitable practical approach for verifying the accuracy of GYN HDR treatment delivery.

The updated World Health Organization 2016 classification of central nervous system tumours recommends the addition of molecular parameters to histological diagnosis. In a resource-constrained setting, molecular testing such as gene sequencing and fluorescence in situ hybridisation is not feasible for all the patients. We assessed the utility of immunohistochemistry (IHC) for isocitrate dehydrogenase (IDH1/R132H) gene and alpha thalassemia/mental retardation syndrome X linked gene (ATRX) to stratify adult diffuse gliomas into subgroups and analysed the outcomes.

Fifty-eight patients with grades III/IV astrocytic gliomas were tested by IHC for IDH1/R132H and ATRX mutation as per the standard protocol and were later stratified into three subgroups based on IHC. IDH1/R132H positive/ATRX retained gliomas were stratified as group 1 (G1), IDH1/R132H positive/ATRX lost were grouped as G2 and IDH1/R132H negative (with or without ATRX loss) as G3. All patients underwent adjuvant therapy as per the Stupp regimen. Outcomes and survival were analysed by Kaplan–Meier analysis using SPSS 21.v.

Median age of the cohort of 58 patients (male: 39, female: 19) was 40 years. Histologically, glioblastoma multiforme (GBM), anaplastic astrocytoma (AA) and anaplastic oligodendroglioma (AOD) were seen in 23:17:18 patients. Forty-eight percent were tested positive for IDH1/R132H, 62% had retained ATRX protein stratifying patients into three subgroups (G1:14, G2:14, G3:30). The G3 group contained both AA and GBM cases. At median follow-up of 18 months, overall survival (OS) of the entire cohort was 76%, higher in G1, compared to G2 and G3 (log-rank p = 0·01). In comparison to various factors such as age, gender, location of the lesion and presenting symptom on survival among various groups, we found that gender of the patient in group I (men vs. women, p = 0·02), laterality of the tumour in group II (right vs. left, p = 0·07) and age of the patient in group III (<45 vs. >45, p = 0·01) demonstrated significant impact on OS.

Subgroup stratification of adult diffuse gliomas based on IHC for IDH/R132H and ATRX demonstrates that group 1 was the most favourable prognostic factor. In a resource-constrained environment, IHC alone may guide appropriate management decision for the majority of adult diffuse gliomas, gene sequencing reserved for IDH1/R132H negative GBM in patients less than 45 years of age.

The objective of this article is to evaluate the dosimetric efficacy of volumetric modulated arc therapy (VMAT) in comparison to dynamic conformal arc therapy (DCAT) and 3D conformal radiotherapy (3DCRT) for very small volume (≤1 cc) and small volume (≤3 cc) tumours for flattened (FF) and unflattened (FFF) 6 MV beams.

A total of 21 patients who were treated with single-fraction stereotactic radiosurgery, using either VMAT, DCAT or 3DCRT, were included in this study. The volume categorisation was seven patients each in <1, 1–2 and 2–3 cc volume. The treatment was planned with 6 MV FF and FFF beams using three different techniques: VMAT/Rapid Arc (RA) (RA_FF and RA_FFF), dynamic conformal arc therapy (DCA_FF and DCA_FFF) and 3DCRT (Static_FF and Static_FFF). Plans were evaluated for target coverage (V100%), conformity index, homogeneity index, dose gradient for 50% dose fall-off, total MU and MU/dose ratio [intensity-modulated radiotherapy (IMRT) factor], normal brain receiving >12 Gy dose, dose to the organ at risk (OAR), beam ON time and dose received by 12 cc of the brain.

The average target coverage for all plans, all tumour volumes (TVs) and delivery techniques is 96·4 ± 4·5 (range 95·7 ± 6·1–97·5 ± 2·9%). The conformity index averaged over all volume ranges <1, 2, 3 cc> varies between 0·55 ± 0·08 and 0·68 ± 0·04 with minimum and maximum being exhibited by DCA_FFF for 1 cc and Static_FFF/RA_FFF for 3 cc tumours, respectively. Mean IMRT factor averaged over all volume ranges for RA_FF, DCA_FF and Static_FF are 3·5 ± 0·8, 2·0 ± 0·2 and 2·0 ± 0·2, respectively; 50% dose fall-off gradient varies in the range of 0·33–0·42, 0·35–0·40 and 0·38–0·45 for 1, 2 and 3 cc tumours, respectively.

This study establishes the equivalence between the FF and FFF beam models and different delivery techniques for stereotactic radiosurgery in small TVs in the range of ≤1 to ≤3 cc. Dose conformity, heterogeneity, dose fall-off characteristics and OAR doses show no or very little variation. FFF could offer only limited time advantage due to excess dose rate over an FF beam.

Total body irradiation (TBI) is an external beam radiation therapy in which large field size and extended source skin distances (SSDs) are applied to deliver a therapeutic dose to the whole body. As measurements in such situations are not common and have more uncertainties in comparison to standard dosimetry situations, it is more precise if calculated beam data can be used instead of measurements taken under TBI situations. The purpose of this study is to compare calculated beam data [percentage depth dose (PDD) and dose rate] with those obtained from simulated treatment measurements.

PDD and dose rates were measured for the 6- and 18-MV photon beams under TBI and standard conditions using 9,000 cm3 water phantom and ion chambers (Markus and Farmer). The results were then compared with the calculated PDD and dose rate data. The beam flatness was also measured under TBI and standard conditions for both 6- and 18-MV photon beams, and the results were then compared.

A comparison of the measurement and calculated beam data shows that the difference between calculated and measured PDD values is −6·97 and −4·14% for the 6- and 18-MV photon beams, respectively. The ratio of calculated to measured dose rate was 1·09 and 1·02 for the 6- and 18-MV photon beams, respectively. The beam flatness under TBI conditions was 4·59% for 6-MV and 5·37% for 18-MV photon beam, whereas under standard conditions, these values were 1·50 and 1·98% for 6- and 18-MV radiation beams, respectively.

According to the results, due to a high error level in dose rate and PDD calculations, these parameters must be directly measured under TBI conditions; however, regarding the obtained results, direct measurement is not necessary for the 18-MV photon beam.

For patients with locally advanced laryngeal cancer, two main treatment options are either up-front surgery [total laryngectomy (TL)] followed by postoperative adjuvant radiation therapy (RT) or definitive concurrent chemoradiation (CCRT) with surgery retained as salvage. The objectives were to study the feasibility of CCRT using intensity-modulated radiation therapy (IMRT) in locally advanced laryngeal cancer with respect to response, toxicities, and quality of life (QoL) and comparison with other modality—TL with post-operative RT.

The records of 48 patients with locally advanced laryngeal cancer (T3/T4aN0-2), registered between years 2014 and 2017, treated with IMRT (definitive or adjuvant postoperative IMRT) were analysed from the hospital database. The patients received RT either as definitive CCRT or as adjuvant treatment after TL. RT in all patients was delivered with IMRT-SIB(simultaneous integrated boost) technique and concurrent chemotherapy with weekly cisplatin. The response was assessed at 12 weeks. Toxicities and QoL were assessed and compared between patients receiving definitive CCRT and adjuvant RT.

92·3% patients who received definitive CCRT achieved complete response. Toxicities were of low grade in patients receiving both definitive and adjuvant treatments. All the patients (except two partial responders of CCRT) remained disease-free at the last follow-up. At 2 years of follow-up of each patient—Global QoL, emotional and social functioning were better in definitive CCRT patients. Laryngectomy patients had more dyspnoea, insomnia and financial difficulties. Although the problems of dry mouth, sticky saliva and swallowing were comparable, laryngectomy patients faced more problems with speech, senses, social eating, social contact and cough.

Definitive CCRT using IMRT-SIB with weekly cisplatin is a feasible option for patients of locally advanced laryngeal cancer with acceptable response rate. IMRT yields better toxicity outcomes with sparing of organs at risk. CCRT patients have better QoL than laryngectomy patients in several parameters.

The study aimed to evaluate the shear bond strength (SBS) of metal brackets and adhesive properties of bonded irradiated and non-irradiated teeth.

Sixty-six extracted premolar samples were randomly divided into three groups—(a) Control group consisting of 22 non-irradiated, non-aged teeth (Group 1), (b) 22 non-irradiated, aged samples (Group 2) and (c) 22 irradiated, aged samples (Group 3). Irradiation was done using gamma irradiation with a fractionated dose of 60 Gy for 5 consecutive days per week over 6 weeks. Metal brackets were bonded on all samples with light cure adhesive and subjected to SBS test using universal testing machine. The samples were assessed under the scanning electron microscope to check for the adhesive remnant index (ARI) and tag depth.

There was a statistically significant decrease in the mean SBS of the irradiated samples compared to the non-irradiated teeth. The non-irradiated, aged samples showed a majority of ARI scoring 1 and 2. Whereas, the irradiated samples showed ARI scoring 2 and 3. Approximately, 77·3% of the non-irradiated samples showed no adhesive present on the tooth surface, and 27·2% of the irradiated samples had more than 50% adhesive present on the enamel surface.

There is a statistically significant decrease in SBS of irradiated enamel compared to that of non-irradiated teeth. However, the SBS observed in the three groups was well above the ideal SBS for orthodontic bonding, that is, 5·6–6·8 MPa. The adhesive remnant was found on all samples of the irradiated group. Deeper adhesive resin tags were found in the irradiated group in the resin–enamel interface.

Brain tumours are relatively rare disease but present a large medical challenge as there is currently no method for early detection of the tumour and are typically not diagnosed until patients have progressed to symptomatic stage which significantly decreases chances of survival and also minimises treatment efficacy. However, if brain cancers can be diagnosed at early stages and also if clinicians have the potential to prospectively identify patients likely to respond to specific treatments, then there is a very high potential to increase patients’ treatment efficacy and survival. In recent years, there have been several investigations to identify biomarkers for brain cancer risk assessment, early detection and diagnosis, the likelihood of identifying which group of patients will benefit from a particular treatment and monitoring patient response to treatment.

This paper reports on a review of 21 current clinical and emerging biomarkers used in risk assessment, screening for early detection and diagnosis, and monitoring the response of treatment of brain cancers.

Understanding biomarkers, molecular mechanisms and signalling pathways can potentially lead to personalised and targeted treatment via therapeutic targeting of specific genetic aberrant pathways which play key roles in malignant brain tumour formation. The future holds promising for the use of biomarker analysis as a major factor for personalised and targeted brain cancer treatment, since biomarkers have the potential to measure early disease detection and diagnosis, the risk of disease development and progression, improved patient stratification for various treatment paradigms, provide accurate information of patient response to a specific treatment and inform clinicians about the likely outcome of a brain cancer diagnosis independent of the treatment received.

The management of breast cancer patients from diagnosis to treatment and beyond can be variable depending on factors including tumour extent and location, histology, genetics, health and wellbeing of the patient as well as personal patient preferences. The therapeutic radiographer’s role is not only vital to ensure safe and accurate radiotherapy delivery but also crucially, as the regular patient interface, they must be fully empowered to engage effectively with all aspects of the patient care pathway. They must be knowledgeable and up to date with evidence-based practices relating to the patient experience including surgery, chemotherapy, endocrine therapy and radiotherapy.

The aim of this paper is to outline the breast cancer management pathway, highlighting the potential side effects that occur as a result of breast radiotherapy treatment and concomitant treatment in order to inform therapeutic radiographers and best practice.

The treatment pathway for breast cancer patients varies greatly depending on a wide range of factors and is very much individualised for each patient. Each treatment modality has its advantages and disadvantages, and all come with a number of side effects that can affect a patient’s daily living. Toxicities can arise during radiotherapy treatment or months after treatment, and education regarding the management of these is essential for effective patient care. Many technological advances in radiotherapy treatment techniques and regimes have the potential to decrease radiation-induced side effects. Despite attempts to standardise clinical guidelines on the use of topical agents and dressings, historical opinions and ideas are still evident in clinical practice. The use of grading systems in radiotherapy tends to only record patients’ physical symptoms and not their holistic wellbeing and emotional needs.

Therapeutic radiographers must ensure that they remain equipped with the skills and knowledge to correctly manage and/or signpost services effectively. This overall outline of the management of patients with breast cancer is designed to help therapeutic radiographers reflect on the current practices and to inspire them, where evidence dictates, to seize opportunities, to explore improvement and to enhance best practice.

An image-guided radiotherapy capable linear accelerator was installed at our hospital which is equipped with an X-ray volumetric imaging (XVI) system. The aim of this study was to describe the results of acceptance tests which were carried out on the XVI facility to verify the manufacturer’s specification.

The commissioning test had six elements: system safety, geometric accuracy, image quality, registration and correction accuracy, X-ray tube and generator performance, and quality assurance (QA) procedures.

We had satisfactory results for all the tests. The system passed the safety testes, and the agreement of isocentres was found to be within the tolerance limit. Imaging quality was acceptable. Registration and correction accuracy was tasted with indigenously developed phantom and positioned accurately at isocentre. X-ray tube and generator test results showed that the tube was performing properly.

The described tests represent that the performance of the system is maintained at acceptable levels.

The aim of this study was to evaluate planning target volume (PTV) margins for two different locations using an electronic portal imaging device (EPID) to ensure that the correct radiation dose is delivered to the tumour when using intensity-modulated radiation therapy (IMRT).

Setup data were collected from 40 patients treated with IMRT for head and neck cancer (HN) (20 patients) and prostate cancer (20 patients). Setup errors from 720 registration images were analysed to evaluate systematic and random errors. Thereafter, optimal PTV margins were calculated based on International Commission on Radiation Units and Measurements 62 (ICRU), Stroom and Parker formulas compared with the Van Herk’s recipe.

To calculate the margins around the PTV, several different formulas have been used. Setup margins ranged between 2–4·3, 2·2–4·6 and 2·1–4·7 mm in X, Y and Z directions, respectively, for HN cases. Similarly, for the prostate site, setup margins ranged between 3·7–8·3, 3·2–6·8 and 3·3–8·2 mm in X, Y and Z directions.

To ensure better coverage of target volume, we adopted a PTV margin of 5 mm for HN PTVs and 10 mm for prostate PTVs in our department.

Optic nerve glioma (OPG) is a rare tumour of children and adolescents. The treatment is challenging as it may jeopardise the visual outcome. We are reporting a case of bilateral OPG, treated with intensity-modulated radiotherapy in our department.

An 18-year-old female presented with a gradually deteriorating vision in both eyes. A detailed clinical and ophthalmological examination was carried out. Her MRI of orbit and brain were suggestive of bilateral optic nerve glioma. She was treated with intensity-modulated radiotherapy to a total dose of 54Gy in 30 fractions over 6 weeks.

She well tolerated the treatment. Post radiotherapy at 8 weeks, she had stabilization of vision on clinical assessment.

Radiotherapy using IMRT can be successfully used to treat OPG, and it checks tumour growth and prevents further deterioration.