Contrast media are frequently used during radiation therapy simulation. However, there are concerns about dosimetric variations when dose calculation is done on contrast-enhanced computed tomography (CT). This study evaluates the dosimetric effect of oral contrast during three-dimensional conformal radiotherapy (3D-CRT) and volumetric modulated arc radiotherapy (VMAT) planning.

Rectal cancer patients were consecutively enrolled. For each patient, one unenhanced CT and one contrast-enhanced CT were taken using oral and intravenous contrast. Then, a 3D-CRT plan and an Intensity-modulated radiation therapy (IMRT)/VMAT plan were generated in the enhanced CT, and the dose distribution was recalculated in the respective unenhanced CT. The beam intensities were kept the same as for the enhanced CT plans. Finally, the unenhanced and enhanced plans were compared by calculating the gamma index.

For 3D-CRT plans, there were statistically significant differences in second phase planning target volume (PTV) D2% (Mean difference (MD) between unenhanced and enhanced CT 0·01 Gy, 95% CI [0·003 to 0·02 Gy]) and in maximum doses to the bladder (MD 0·26 Gy, 95% CI [0·05 to 0·47 Gy]). For IMRT/VMAT plans, there were statistically significant differences in small intestine V45 Gy (MD 3·1 cc, 95% CI [0·81 to 5·4 cc]), bladder V45 Gy (MD 2·9%, 95% CI [1·4 to 4·3%]) and maximum dose to the bladder (MD 0·65 Gy, 95% CI [0·46 Gy to 0·85 Gy]). In addition, for PTV D98% the MD between unenhanced and enhanced CT was 0·22 Gy 95% CI [0·05 to 0·39].

For most of the dose metrics, the differences were not clinically meaningful. The greatest differences were found in VMAT plans, especially in V45 Gy of the small intestine. This difference could lead to an underestimation of dose–volume metrics when the plan is based on an enhanced CT. The use of small bowel oral contrast does not significantly influence dose calculations and may not affect the acceptability of plans when adhering to constraints.

The control points (CP) play a significant role in the delivery of segmented based Intensity-Modulated Radiation Therapy (IMRT) delivery, particularly in dynamic mode. The number of segments is determined by control points and these segments will transfer from one to the other either during beam ON called dynamic delivery or during beam OFF called static delivery or step and shoot. This study was aimed at indirect estimation of the total monitor units (MU) to be delivered per field by exploiting the control points and also to find the MUs at any nth segment.

This study was performed in the Eclipse treatment planning software version 13.8.0. The details of control points, metre set weight per segment, leaf positions for each segment, field size, etc. were taken into consideration.

TPS calculated MU value and analytically estimated MU value were compared and the percentage of difference was estimated. The overall mean percentage of deviation was 1·03% between the TPS calculated method and the analytical method. The paired sample t-test was performed and, p-value <0·05, no significant difference was found. The analytical relationship determined to estimate the total number of MU delivered for any nth control point was also evaluated.

The control points are a potential parameter in the conventional IMRT delivery. Through this study, we have addressed the indirect method to estimate the monitor units delivered per segment.

Paratesticular sarcoma are extremely rare malignant tumours. Unlike other sites, they tend to be lower grade and have higher propensity of lymphatic spread. They tend to fail locally and occasionally in the regional lymph nodes. In the absence of target volume delineation guidelines and technical illustration of conformal planning, we have made an attempt to illustrate conformal planning methodology and define target volume based on current evidence in a case of paratesticular sarcoma.

We are presenting a case of 62-year-old male who presented with 15-cm scrotal swelling and underwent high inguinal orchidectomy with ligation of spermatic cord. Histopathology presented a well-differentiated leiomyosarcoma of epididymis. Post-operative radiotherapy target volume included the tumour bed, ipsilateral inguinal nodes and lower pelvic nodes as the clinical target volume.

Adjuvant radiotherapy using advanced delivery technique such as volumetric arc technique can provide good dose distribution with good sparing of organs at risk. The downside of conformal radiation delivery is that it is a resource-intensive and has no established target volume delineation guidelines.

To evaluate the extent to which intensity-modulated arc therapy (IMAT) for high-grade gliomas is comparable with three-dimensional conformal radiotherapy (3DCRT) in relation to the dose delivered to normal brain tissue (NBT), planning target volume (PTV) conformity and the dose delivered to brainstem and optic chiasma.

A total of 16 randomly selected 3DCRT treatment plans of grade 3 gliomas were re-planned using an IMAT planning technique and dose–volume histograms were compared. Primary outcomes were maximum, mean, 1/3 and 2/3 doses to NBT outside the PTV. Also the maximum, mean, D50 and D20 doses to PTV. Secondary outcomes were maximum and mean doses to the brainstem and optic chiasm. Wilcoxon signed rank test was used to compare data.

IMAT led to a statistically significant increase in mean dose to NBT (34·4 versus 33·3 Gy, (p=0·047) but a statistically significant reduction in maximum dose to NBT (62·7 versus 63·8 Gy, p=0·004) compared with 3DCRT. IMAT led to statistically significant reductions in maximum, D50 and D20 doses to the PTV (63·3 versus 64·7 Gy, p=0·001; 60·0 versus 60·7 Gy, p=0·001 and 60·5 versus 61·8 Gy, p=0·002, respectively). No statistically significant differences were seen in doses to brainstem and optic chiasm.

IMAT is at least comparable with 3DCRT in relation to minimising dose to NBT and ensuring good PTV conformity. Doses delivered to organs at risk using IMAT were also comparable with 3DCRT. This study supports the continued use of IMAT for the treatment of high-grade gliomas.

In radiotherapy (RT) bolus material is used to increase skin dose and eliminate the ‘skin-sparing’ effect. Bolus fabrication is limited to the expertise of the practitioner and is time and resource intensive for both patients and staff to construct bolus. In addition, prefabricated bolus does not always conform to irregular surfaces resulting in variations to dose distribution at the skin surface. The purpose of this paper is to ascertain whether it is feasible to improve bolus conformity within radiation therapy by using a 3D printer to fabricate bolus.

A literature review was conducted that utilised Boolean terminology and included keywords; (‘3d’ OR ‘3-dimensional’ OR ‘three dimensional’) ‘bolus’ OR ‘boli’ conform*, (‘Radiation therapy’ OR ‘radiotherapy’) Printing.

Several key papers were identified and critically evaluated based of the title of the feasibility of improving bolus conformity with the used of 3D printing. Several fabrication material devices were explored.

The literature advocates that fused deposition modelling fabrication device clear polylactic acid material to be an adequate product to construct 3D printed bolus and conform to irregular surfaces. 3D bolus would prove advantageous for volumetric arc therapy/intensity modulated radiation therapy techniques as literature has shown the presence of air gaps, small field sizes and large beam obliquity can result in a >10% dose reduction at skin surface.

Pre-registration teaching of radiotherapy planning in a non-clinical setting should allow students the opportunity to develop clinical decision-making skills. Students frequently struggle with their ability to prioritise and optimise multiple objectives when producing a clinically acceptable plan. Emerging software applications providing quantitative assessment of plan quality are designed for clinical use but may have value for teaching these skills. This project aimed to evaluate the potential value of automated feedback to second year BSc (Hons) Radiotherapy students.

All 26 students studying a pre-registration radiotherapy planning module were provided with automated prediction of relative feasibility for left lung tumour planning targets by planning metrics software. Students were also provided with interim quantitative reports during the development of their plan. Student perceptions of the software were gathered using an anonymous questionnaire. Independent blinded marking of plans was performed after module completion and analysed for correlation with software-assigned marks.

In total, 25 plans were utilised for marking comparison and 16 students submitted feedback relating to the software. Overall, student feedback was positive regarding the software. A ‘strong’ Spearman’s rank-order correlation (rs=0·7165) was evident between human and computer marks (p=0·000055).

Automated software is capable of providing useful feedback to students as a teaching aid, in particular with regard to relative feasibility of goals. The strong correlation between human and computer marks suggests a role in benchmarking or moderation; however, the narrow scope of assessment parameters suggests value as an adjunct and not a replacement to human marking.

The novel three-dimensional (3D) radiotherapy interactive outlining tool allows volumes to be created from a handful of points within axial, sagittal and coronal planes. 3D volumetric visualisation allows users to directly manipulate the resulting volume using innovative-sculpting tools. This paper discusses the development and initial evaluation of the software ahead of formal clinical testing.

User feedback was collated as part of the software development phase to ensure clinical suitability, define user training strategies and identify best practice. A loosely structured format was adopted with leading descriptive questions aiming to generate suggestions for improvements and initiate further discussion.

The four participants reported great satisfaction and value in being able to use all three planes for outlining, although orientation in 3D was evidently a problem. All participants felt that the software was capable of producing acceptable outlines rapidly and that the multi-planar capability allowed for improved outlining of the prostate apex.

Mesh generation from a small number of points placed on a range of planes is a rapid and effective means of target delineation. Multi-slice volume sculpting and 3D orientation is challenging and may indicate a need for a paradigm shift in anatomy and computed tomography training.

This single-case feasibility study presents an undergraduate radiotherapy student’s experiences of remote access to University treatment planning software in place of on-site practical learning. With clinical sites increasingly utilising telemedicine there is interest in educational applications of this technology.

This was an unplanned study with the student initiating remote access; additional tutor support was provided as requested. Subsequent discussion between the tutor and student formed the basis for the presented findings.

A second-year student planned five assessment cases from home, supported by regular on-campus tutorials. The student saved a 2-hour journey per practical and gained additional planning practice time. Unit performance was 10% less than a previous Unit, but student satisfaction with the format was high.

Educational remote access to treatment planning software is logistically feasible, although strict guidelines and formal tutor support is vital. Remote access can alleviate pressure on facilities and improve student time efficiency. Controlled and supported provision of remote access to planning software could enhance on-site practical teaching sessions for more mature independent learners. Further cohort-wide studies could clarify advantages, disadvantages and possible role of remote access for radiotherapy planning education.

This study aimed to determine the potential role and guidelines for implementation of skill-based peer mentoring for radiotherapy planning education.

After four weekly mentoring sessions, both Year 3 mentors (n=9) and Year 2 mentees (n=9) were invited to complete a short online questionnaire relating to the impact of the initiative. The tool contained a mixture of Likert-style questions concerning student enjoyment and perceived usefulness of the initiative as well as more qualitative open questions that gathered perceptions of the peer mentoring process, implementation methods and potential future scope.

Several key discussion themes related to benefits to each stakeholder group, challenges arising, improvements and potential future directions. There were high levels of enjoyment and perceived value of the mentoring from both sides with 100% of the 18 respondents enjoying the experience. The informal format encouraged further learning, while mentors reported acquisition of valuable skills and gains in knowledge.

Peer mentoring has a valuable and enjoyable role to play in radiotherapy planning training and helps consolidate theoretical understanding for experienced students. An informal approach allows for students to adopt the most appropriate mentoring model for their needs while providing them with a free space to engender additional discussion.

To establish whether the use of a passive or active technique of planning target volume (PTV) definition and treatment methods for non-small cell lung cancer (NSCLC) deliver the most effective results. This literature review assesses the advantages and disadvantages in recent studies of each, while assessing the validity of the two approaches for planning and treatment.

A systematic review of literature focusing on the planning and treatment of radiation therapy to NSCLC tumours. Different approaches which have been published in recent articles are subjected to critical appraisal in order to determine their relative efficacy.

Free-breathing (FB) is the optimal method to perform planning scans for patients and departments, as it involves no significant increase in cost, workload or education. Maximum intensity projection (MIP) is the fastest form of delineation, however it is noted to be less accurate than the ten-phase overlap approach for computed tomography (CT). Although gating has proven to reduce margins and facilitate sparing of organs at risk, treatment times can be longer and planning time can be as much as 15 times higher for intensity modulated radiation therapy (IMRT). This raises issues with patient comfort and stabilisation, impacting on the chance of geometric miss. Stereotactic treatments can take up to 3 hours to treat, along with increases in planning and treatment, as well as the additional hardware, software and training required.

Four-dimensional computed tomography (4DCT) is superior to 3DCT, with the passive FB approach for PTV delineation and treatment optimal. Departments should use a combination of MIP with visual confirmation ensuring coverage for stage 1 disease. Stages 2–3 should be delineated using ten-phases overlaid. Stereotactic and gated treatments for early stage disease should be used accordingly; FB-IMRT is optimal for latter stage disease.