To analyse the impact of multileaf collimator (MLC) leaf width in multiple metastases radiosurgery (SRS) considering the target distance to isocenter and rotational displacements.

Ten plans were optimised. The plans were created with Elements Multiple Mets SRS v2·0 (Brainlab AG, Munchen, Germany). The mean number of metastases per plan was 5 ± 2 [min 3, max 9], and the mean volume of gross tumour volume (GTV) was 1·1 ± 1·3 cc [min 0·02, max 5·1]. Planning target volume margin criterion was based on GTV-isocenter distance and target dimensions. Plans were performed using 6 MV with high-definition MLC (HDMLC) and reoptimised using 5-mm MLC (MLC-5). Plans were compared using Paddick conformity index (PCI), gradient index, monitor units , volume receiving half of prescription isodose (PIV50), maximum dose to brainstem, optic chiasm and optic nerves, and V12Gy, V10Gy and V5Gy for healthy brain were analysed. The maximum displacement due to rotational combinations was optimised by a genetic algorithm for both plans. Plans were reoptimised and compared using optimised margin.

HDMLC plans had better conformity and higher dose falloff than MLC-5 plans. Dosimetric differences were statistically significant (p < 0·05). The smaller the lesion volume, the higher the dosimetric differences between both plans. The effect of rotational displacements produced for each target in SRS was not dependent on the MLC (p > 0·05).

The finer HDMLC offers dosimetric advantages compared with the MLC-5 in terms of target conformity and dose to the surrounding organs at risk. However, only dose falloff differences due to rotations depend on MLC.

Safety is a mandatory issue during the operation of a nuclear power plant. A nuclear reactor can have some atmospheric dispersion due to any errors in the safety system.

The aim of this study is to estimate the cancer risk incidence for different body organs due to accidentally released radionuclides from Bushehr Nuclear Power Plant (BNPP).

The assumed hypothesis was atmospheric dispersion of radionuclide into the environment due to the safety failure of BNPP. Total effective dose equivalent (TEDE) from radionuclide diffusion in the medium was calculated using HOTSPOT code at two different wind speeds. Finally, the risk of cancer incidence for different organs of male and female sex has been estimated by Biologic Effects of Ionizing Radiation (BEIR) VII model.

The results showed that with increasing the exposure age and attained age, the risk of cancer incidence for different organs is decreased. The value of TEDE was increased at lower wind speed. The most probable organ for cancer incidence at different levels of TEDE in male and female sex was colon and bladder, respectively. On the other hand, prostate and uterus had the lowest radiation sensitivity and cancer risk incidence in male and female sex, respectively. Increasing the wind speed reduces the risk of cancer incidence for all of organs understudy.

Based on the obtained results, it can be concluded that the younger persons are more subject to the cancer risk incidence because of both the intrinsically greater radio-sensitivity of their organs and their longer remaining life expectancy during which a cancer may develop. The overall risk of cancer incidence as well as the site specific solid cancer incidence were highly dependent to the sex of exposed person, so that the female sex was more exposed to the cancer risk incidence at all of the irradiation levels understudy.

This is a phantom study to evaluate the dosimetry effects of using virtual bolus (VB) in TomoTherapy Treatment Planning System (TPS) optimisation for superficial planning target volume (PTV) that extends to the body surface. Without VB, the inverse-planning TPS will continuously boost the photon fluence at the surface of the superficial PTV due to lack of build-up region. VB is used during TPS optimisation only and will not be present in actual treatment delivery.

In this study, a dummy planning target was contoured on a cylindrical phantom which extends to the phantom surface, and VB of various combinations of thickness and density was used in treatment planning optimisation with TomoTherapy TPS. The plans were then delivered with the treatment modality TomoTherapy. Radiochromic films (Gafchromic EBT3) were calibrated and used for dose profiles measurements. TomoTherapy Planned-Adaptive software was used to analyse the delivered Dose-Volume Histograms (DVHs).

The use of 2 mm VB was not providing adequate build-up area and was unable to reduce the hot spots during treatment planning and actual delivery. The use of 4 mm VB was able to negate the photon fluence boosting effect by the TPS, and the actual delivery showed relatively small deviations from the treatment plan. The use of 6 mm VB caused significant dose overestimation by the TPS in the superficial regions resulting in insufficient dose coverage delivered.

VB with the combination of 4 mm thickness and 1·0 g/cc density provides the most robust solution for the TomoTherapy TPS optimisation of superficial PTV.

The use of metallic containing creams to prevent and treat radiodermatitis is controversial and lacking evidence base. We compare the dose effect of two metallic-based skin creams, which could be used for treating radiodermatitis, to a control.

Universal containers of silver sulfadiazine cream, zinc oxide cream and aqueous cream were examined using a computed tomography scanner to assess their electron densities relative to water. Second, each cream was exposed to 100 kV and 6 MV photons. The relative doses were measured using an X-ray chamber.

The relative electron density measured was similar for the silver sulfadiazine and aqueous creams. Zinc oxide was 40% higher. The relative dose measurements showed that silver sulfadiazine behaved in a similar way to aqueous cream; however, zinc oxide cream exhibited a dose difference of 11·0% in kV photons and −4·1% in MV photons.

Application of silver sulfadiazine appears unlikely to bring about significant changes in the dose distribution when compared with aqueous during MV or kV radiotherapy. While zinc oxide cream brought about more significant dose changes.

To determine the feasibility of an anthropomorphic breast polyurethane-based three-dimensional (3D) dosimeter with cavity to measure dose distributions and skin dose for a commercial strut-based applicator strut-adjusted volume implant (SAVI™) 6–1.

An anthropomorphic breast 3D dosimeter was created with a cavity to accommodate the SAVI™ strut-based device. 2 Gy was prescribed to the breast dosimeter having D95 to planning target volume evaluation (PTV_EVAL) while limiting 125% of the prescribed dose to the skin. Independent dose distribution verification was performed with GAFCHROMIC® EBT2 film. The dose distribution from the 3D dosimeter was compared to the distributions from commercial brachytherapy treatment planning system (TPS) and film. Point skin doses, line profiles and dose–volume histogram (DVHs) for the skin and PTV_EVAL were compared.

The maximum difference in skin dose for TPS and the 3D dosimeter was 4% whereas 41% between the TPS and EBT2 film. The maximum dose difference for line profiles between TPS, 3D dosimeter, and film was 4·1%. DVHs of skin and PTV_EVAL for TPS and 3D dosimeter differed by a maximum of 4% at 5 mm depth and skin differed by a maximum 1·5% between TPS and 3D dosimeter. The criterion for gamma analysis comparison was 92·5% at ±5%±3 mm criterion. The TPS demonstrated at least ±5% comparability in predicting dose to the skin, PTV_EVAL and normal breast tissue.

3D anthropomorphic polyurethane dosimeter with cavity gives comparable results to the TPS dose predictions and GAFCHROMIC® EBT2 film results in the context of HDR brachytherapy.

Craniospinal irradiation is a technique indicated when a patient has a malignancy that has either disseminated, or is at risk of disseminating, throughout the subarachnoid space. While the craniospinal axis is treatable with conventional radiotherapy, the high doses to organs at risk carry an increased risk of acute and late side effects. Proton craniospinal irradiation is an expensive technique that shows great theoretical promise arising from reduced exit doses. The purpose of this systematic review is to determine the potential role of proton therapy as a standard modality for craniospinal irradiation.

A literature review was performed to determine the efficacy and cost of proton craniospinal irradiation. The Cochrane Library and the Inspec, Medline (via Pubmed) and Scopus databases were searched. After exclusion criteria were applied, the remaining papers were systematically appraised utilising the Scottish Intercollegiate Guidelines Network critical appraisal checklists.

A total of 14 articles remained following the application of the screening and critical appraisal processes. In total, five of the articles concluded that the risk of secondary malignancy was lower with proton therapy, while ten of the articles included data showing that toxicity rates and organs at risk doses were lower with proton therapy. Doses to most thoracic and abdominal organs at risk analysed in the literature were reduced when proton therapy was used, with the sole exception of the oesophagus, the dose to which depended on whether or not the entire vertebral body was treated. Proton therapy also delivered optimal doses to organs at risk in the head and neck compared with conformal radiation therapy. However, in one study that compared tomotherapy to proton therapy, tomotherapy outperformed proton therapy by delivering lower doses to organs at risk in the head and neck, as well as the kidneys. The two cost-effectiveness studies did not indicate proton therapy as an optimal modality for all treatment sites; however, one of the studies found that for medulloblastoma, protons were more cost effective than conventional radiation therapy.

Proton therapy is a superior treatment option for craniospinal irradiation. The reduction in risk of toxicity and radiocarcinogenesis offered by proton craniospinal irradiation appear to outweigh the increased costs.

We compare the accuracy of the off-axis Winston–Lutz (WL) test in two versions of ExacTracTM: version 6.0 (ETv6) and Dynamic (ETD) in the same linac (TrueBeam STx®).

An upgraded of the ExacTracTM system was done in our institution. It was designed as an off-axis WL test before the update for comparison purposes. A head 3D-printed phantom based on a patient’s computed tomography images was used. Nine metallic fiducials were inserted and distributed on the phantom. Each target (fiducial) was designed an off-axis WL test with eight different gantry/collimator/table combinations. The phantom was placed using two different ETv6 and ETD in the same linac, and cone-beam computed tomography and electronic portal imaging device (EPID) images were acquired. The 2D deviation between the centre of the fiducial and the radiation field was found and compared with the original digital reconstructed radiography (DRR) by the profiles.

The phantom allows the definition of a procedure to determine off-axis deviations in radiosurgery treatments. The displacements calculated from the WL test showed acceptable values for both versions taking into account 3D displacement tolerances of 1 mm. These values were reached with rigorous quality assurance (QA) linac tests performed routinely that include mechanical, MV/kV and image-guided radiotherapy (IGRT) tests. However, ETD indicated more accurate values for all the targets no matter the distance to the isocentre (3D displacements < 0·5 mm).

In terms of the IGRT correction without set-up displacements, ETD is up to twice as accurate as the ETv6, showing 3D displacements up to 0·5 mm in all targets.

The aim was to evaluate the feasibility of an intraoral stent (10 and 20 mm thickness) in radiotherapy of tongue cancer, and to measure the reduction in acute mucositis in the palate.

There were six patients in the intervention group, and seven patients in the control group. Target coverage was measured by the minimum dose covering 98% of the clinical target volume (CTV). Data were collected from the planning CT and daily cone-beam computer tomography (CBCT).

The 10 and 20 mm stent yielded a mean distance of 26 and 36 mm, respectively, between the tongue and the hard palate. We found comparable dose coverage of the CTV in the treatment plan, and on the CBCT. The stent reduced mean dose to the hard palate by 61.0% (p = 0.002). Dose to the soft palate was not reduced (p = 0.18). Average Common Terminology Criteria for Adverse Events (CTCAE) mucositis scores of the hard palate were 0 and 0.8 in the intervention and control group, respectively. The mucositis scores of the soft palate were 1.2 and 1.8.

Use of an intraoral stent substantially reduced the dose to the hard palate. CTV coverage was maintained. We did not find any significant reduction in visually scored radiation-induced mucositis.

Nasopharyngeal carcinoma (NPC) is a prevalent disease in Southern China. Radiation therapy remains the primary treatment modality for NPC due to its high radiation sensitivity. Conventional volumetric-modulated arc therapy (VMAT) can achieve excellent target volume coverage and superior conformal dose distributions while sparing organs at risk (OARs). However, VMAT may also produce substantial volume of low-dose region in the surrounding normal tissue. Our oncology centre has incorporated the concept of anterior cervical field with VMAT in clinical practice of NPC treatment planning. The purpose of this treatment-comparison case study is to demonstrate the lower neck OARs sparing ability of hybrid volumetric-modulated arc therapy (hybrid-VMAT) over conventional VMAT for NPC.

Four patients diagnosed with NPC of different clinical lymph node staging (N staging) were enrolled for this treatment-comparison case study. Planning target volumes and OARs were delineated with reference to Radiation Therapy Oncology Group (RTOG) 0225/0615. Additional OARs from lower neck region, including thyroid, trachea, cervical spine and pharyngeal constrictor muscles (PCMs), were also delineated. Two treatment techniques, hybrid-VMAT and VMAT, were created for each patient’s dataset.

Both treatment techniques produced adequate target coverage and reduced radiation dose to the OARs as suggested in RTOG 0225/0615. Hybrid-VMAT plans achieved superior dose reduction in larynx, oesophagus, middle PCM, inferior PCM, cervical spine and trachea comparing with VMAT plans. Hence, the clinical usability and functional outcome of hybrid-VMAT should be further investigated for NPC radiation therapy.

In developing countries like Pakistan the cost effectiveness and patient convenience in any treatment modality is a question of major concern. The purpose of this study was two-fold; first to report our experience with a high-dose rate Iridium-192 surface mould brachytherapy of keloid scars after surgical excision, using different radiation treatment regimen and second to establish the most convenient and cost effective treatment protocol having no compromise on the treatment outcomes.

From January 2012 to April 2015 a total 51 patients with 65 keloid lesions underwent postoperative Iridium-192 high-dose rate surface mould brachytherapy. The dose regimen used was: 8 Gy in a single fraction, 10 Gy in a single fraction, 15 Gy in three fractions and 18 Gy in three fractions. The median follow-up period was 33 months (range 15–53 months).

The success rates were 57·2, 89·5, 85 and 89·5% for the treatment regimen of 8 Gy/F×1, 10 Gy/F×1, 5 Gy/F×3 and 6 Gy/F×3, respectively. Grade 2 or above radiation induced toxicity was not observed.

The results of this study show that a dose regimen of 10 Gy (biological effective dose=20 Gy) in a single fraction have comparable results with a dose regimen of 15 Gy in three fractions or 18 Gy in three fractions. 10 Gy in a single fraction is therefore the most convenient and cost effective dose regimen for the management of keloid scars in developing countries like Pakistan, while 8 Gy in a single fraction is considered suboptimal and discouraged in practice.

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.

In the United Kingdom, 7·1% of people aged over 65 live with dementia. The National Dementia Strategy emphasises the need for a skilled workforce competent in dementia care. In all, 50% of cancer patients are in the 70 plus age group, suggesting that education of therapeutic radiographers in the care of the patient with dementia is key. The aim of the study was to review the literature regarding training of therapeutic radiographers on dementia and use the findings to make recommendations for training in the future in order to provide the best care.

A literature search of electronic databases holding peer-reviewed journals was conducted. Search terms were generated using the Population Intervention Comparison Outcome (PICO) method and retrieved articles were evaluated using the Critical Appraisal Skills Programme (CASP) tool. Additional evidence was accessed through snowballing and from grey literature.

The search failed to find any studies on dementia care education within a radiotherapy setting and only a limited number were found in the acute care setting. There appeared to be a large variation in the education provision for healthcare professionals on the subject of dementia care, both at the pre-registration and post-registration stages.

There is no evidence of a standardised education programme for healthcare professionals in dementia care. In the future, therapeutic radiographers are likely to see more patients with dementia but currently some may not have had the education and training to provide effective holistic care.

The study aimed to compare the dosimetric performance of Acuros® XB (AXB) and anisotropic analytical algorithm (AAA) for lung SBRT plans using Monte Carlo (MC) simulations.

We compared the dose calculation algorithms AAA and either of the dose reporting modes of AXB (dose to medium (AXB-Dm) or dose to water (AXB-Dw)) algorithms implemented in Eclipse® (Varian Medical Systems, Palo Alto, CA) Treatment planning system (TPS) with MC. PRIMO code was used for the MC simulations. The TPS-calculated dose profiles obtained with a multi-slab heterogeneity phantom were compared to MC. A lung phantom with a tumour was used to validate TPS algorithms using different beam delivery techniques. 2D gamma values obtained from Gafchromic film measurements in the tumour isocentre plane were compared with TPS algorithms and MC. Ten VMAT SBRT plans generated in TPS with each algorithm were recalculated with a PRIMO MC system for identical beam parameters for the clinical plan validation. A dose–volume histogram (DVH) based plan comparison and a 3D global gamma analysis were performed.

AXB demonstrated better agreement with MC and film measurements in the lung phantom validation, with good agreement in PDD, profiles and gamma analysis. AAA showed an overestimated PDD, a significant difference in dose profiles and a lower gamma pass rate near the field borders. With AAA, there was a dose overestimation at the periphery of the tumour. For clinical plan validation, AXB demonstrated higher agreement with MC than AAA.

AXB provided better agreement with MC than AAA in the phantom and clinical plan evaluations.

Dysphagia is common in patients presenting with oesophageal malignancy. This study aimed to determine the clinical effectiveness of biodegradable stents to help with malignant dysphagia due to radiotherapy for oesophageal cancer and furthermore to establish the complication and re-intervention rates associated with their use.

This was a retrospective, observational study of 22 patients between 2008 and 2013. Complications within 2 weeks and episodes of re-intervention required within 4 months of stent insertion prior to radiotherapy were recorded.

Pre-stent insertion, the mean O’Rourke dysphagia score was 3·5 (median 3, range 2–5). This improved to a mean score of 2·8 (median 3, range 1–4) 1–3 weeks following stent insertion. Complications occurred in seven patients (32%) in an immediate 2-week period, including: pain (2), dysphagia requiring dilatation (1), food obstruction not requiring intervention (1), food obstruction requiring intervention (2) and upper gastrointestinal bleed not requiring intervention (1). Re-intervention was required in 18% within a 4-month period.

We propose that biodegradable oesophageal stents are safe and may have benefit over self-expanding metal stents. We recommend they are placed alongside a radiologically inserted gastrostomy in a combined procedure prior to radiotherapy planning.