Variation in delineation of target volumes/organs at risk (OARs) is well recognised in radiotherapy and may be reduced by several methods including teaching. We evaluated the impact of teaching on contouring variation for thoracic/pelvic stereotactic ablative radiotherapy (SABR) during a virtual contouring workshop.

Target volume/OAR contours produced by workshop participants for three cases were evaluated against reference contours using DICE similarity coefficient (DSC) and line domain error (LDE) metrics. Pre- and post-workshop DSC results were compared using Wilcoxon signed ranks test to determine the impact of teaching during the workshop.

Of 50 workshop participants, paired pre- and post-workshop contours were available for 21 (42%), 20 (40%) and 22 (44%) participants for primary lung cancer, pelvic bone metastasis and pelvic node metastasis cases, respectively. Statistically significant improvements post-workshop in median DSC and LDE results were observed for 6 (50%) and 7 (58%) of 12 structures, respectively, although the magnitude of DSC/LDE improvement was modest in most cases. An increase in median DSC post-workshop ≥0·05 was only observed for GTVbone, IGTVlung and SacralPlex, and reduction in median LDE > 1 mm was only observed for GTVbone, CTVbone and SacralPlex. Post-workshop, median DSC values were >0·7 for 75% of structures. For 92% of the structures, post-workshop contours were considered to be acceptable or within acceptable variation following review by the workshop faculty.

This study has demonstrated that virtual SABR contouring training is feasible and was associated with some improvements in contouring variation for multiple target volumes/OARs.

To compare the dosimetric results regarding the sparing effect on normal tissue between RapidArc (RA) and helical tomotherapy (HT) plans for nasopharyngeal carcinoma (NPC) patients in cases of the equal target dose controls utilising two techniques.

Thirteen NPC patients treated with HT were replanned using the Varian Eclipse treatment planning system (TPS) for the RA plan. The target dose of the RA plan was optimised equally to the HT plan in terms of target coverage, dose conformity (CI) and dose homogeneity (HI) for assessing the normal tissue sparing between two techniques. All dose–volume parameters monitor units (MUs) and delivery time were also investigated.

All dosimetric parameter comparisons of organs-at-risk (OARs) between the RA and HT plans were not significantly different for brain stem, spinal cord and cochlea. However, the RA plan showed a significantly lower dose to the left parotid gland. The mean and median dose were significantly lower in the RA plan versus the HT plan by p-value 0·005 and 0·039, respectively. The MUs and delivery time were also significantly lower in the RA plan with a p-value of 0·00.

With the same planning target volume coverage, homogeneity and conformity, almost all of RA and HT treatment planning met the planning goal for normal tissue sparing. There were no significant differences between the two techniques except in the left parotid gland. The RA plans were superior to HT plans by effectively reducing the MUs and treatment time.

This study reported the justification and selection of acceptable γ criteria with respect to low (6 MV) and high (15 MV) photon beams for intensity-modulated radiation therapy quality assurance (IMRT QA) using the Gafchromic external beam therapy 3 (EBT3) film.

Five-field step-and-shoot IMRT was used to treat 16 brain IMRT patients using the dual-energy DHX-S linear accelerator (Varian Medical System, Palo Alto, CA, USA). Dose comparisons between computed values of the treatment planning system (TPS) and Gafchromic EBT3 film were evaluated based on γ analysis using the Film QA Pro software. The dose distribution was analysed with gamma area histograms (GAHs) generated using different γ criteria (3%/2 mm, 3%/3 mm and 5%/3 mm) for the 6 and 15 MV photon beams, to optimise the best distance-to-agreement (DTA) criteria with respect to the beam energy.

From the comparison between the dose distributions acquired from the TPS and EBT3 film, a DTA criterion of 3%/2 mm showed less dose differences (DDs) with passing rates up to 93% for the 6 MV photon beams, while for the 15 MV a relaxed DTA criterion of 5%/3 mm was consistent with the DD acceptability criteria with a 95% passing rate.

Our results suggested that high-energy photon beams required relaxed DTA criteria for the brain IMRT QA, while low-energy photon beams showed better results even with tight DTA criteria.

Bone-seeking radiopharmaceuticals are potential therapeutic tools for bone marrow ablation in patients with multiple myeloma. In this procedure, estimation of radiation absorbed dose received by the target and non-target organs is one of the most important parameters that should be undertaken. This research revolves around the absorbed dose to human organs after 90Y-BPAMD injection.

90Y-(4-{[(bis(phosphonomethyl))carbamoyl]methyl}-7,10-bis(carboxymethyl)-1,4,7,10-tetraazacyclododec-1-yl) acetic acid (90Y-BPAMD) complex was successfully prepared under optimised conditions. The human absorbed dose of the complex was estimated based on the biodistribution data on rats using the radiation-absorbed dose-assessment resource method. The target to non-target absorbed dose ratios for the complex was compared with the ratios for 166Ho-DOTMP, as the main radiopharmaceutical for bone marrow ablation.

As expected, the highest amounts of absorbed dose were observed in the bone surface and the bone marrow with 2·52 and 2·29 mGy/MBq, respectively. The red marrow to the most organ absorbed dose ratios for 90Y-BPAMD are much higher than the ratios for 166Ho-DOTMP.

90Y-BPAMD has interesting characteristics compared with 166Ho-DOTMP and can be considered as a high potential agent for bone marrow ablative therapy of the patient with multiple myeloma.

This study aims to experimentally determine field output factors using the methodologies suggested by the IAEA-AAPM TRS-483 for small field dosimetry and compare with the calculation from Monte Carlo (MC) simulation.

The IBA-CC01, Sun Nuclear EDGE and IBA-SFD detectors were employed to determine the uncorrected and the corrected field output factors for 6 MV photon beams. Measurements were performed at 100 cm source to axis distance, 10 cm depth in water, and the field sizes ranged from 1 × 1 to 10 × 10 cm2. The use of field output correction factors proposed by the TRS-483 was utilised to determine field output factors. The measured field output factors were compared to that calculated using the egs_chamber user code.

The decrease in the percentage standard deviation of the measured three detectors was observed after applying the field output correction factors. Measured field output factors using CC01 and EDGE detectors agreed with MC values within 3% for field sizes down to 1 × 1 cm2, except the SFD detector.

The corrected field output factors agree with the calculation from MC, except the SFD detector. CC01 and EDGE are suitable for determining field output factors, while the SFD may need more implementation of the intermediate field method.

Mycetoma is a chronic infection of the skin and the subcutaneous tissue caused by both bacteria and fungi. Eumycetoma, caused by fungus, requires prolonged use of antifungals and/or surgery.

In this scenario it has been attempted to treat a case of eumycetoma with an aim to improve the symptoms and to give an antifungal drug free period. Radiotherapy was delivered in two sittings. In the first sitting, 20 Gy in five fractions was given. Because of the excellent response to the radiotherapy, after 9 months, another 15 Gy was delivered in five fractions.

The symptom-free period extended for another 11 months, making a cumulative effect of 21 months.

The use of radiotherapy in the salvage of refractory eumycetoma cases should be further explored.

Direct observation in the radiotherapy clinic remains the primary method for the assessment of procedural skills. But with increasing automation and reductions in clinical placement time during the recent pandemic, the role of summative, simulation-based assessment is being revisited. The aim of this article is to share early experiences of using Virtual Environment for Radiotherapy Training (VERT) in the assessment of a palliative, parallel pair, external beam treatment delivery technique in a new pre-registration undergraduate programme.

Eight first-year students completed a campus-based individual virtual assessment using virtual patient plans representing metastatic disease in the brain and pelvis and late-stage primary lung tumours. Performance was logged on a 25-item checklist for pre and post-procedure checks and treatment delivery tasks.

All eight students participated in the assessment with seven students (87·5%) achieving a pass grade at first attempt. The course team observed that participants demonstrated a range of skills and abilities and were able to compare and contrast individual approaches to patient positioning. Specific feed-forward action points were also highlighted as areas for students’ to focus on during their second placement. The project also identified logistical benefits for assessment teams.

While these experiences are a single snapshot, a VERT simulation-based summative assessment is feasible and identified benefits included controlled observation and structured feedback on individual performance and scheduling pressure reductions for clinical teams. However, more work is needed to determine the psychometric qualities and predictability of performance in more complex techniques.

To create practical lookup tables containing percent depth dose (PDD) and profile parameters of electron beams and to demonstrate clinical application of the lookup tables to skin cancer treatment to ensure target coverage in a clinical setup.

For 6 and 9 MeV electron energies, PDDs and profiles at clinically relevant depths [i.e., R95 (distal depth of 95% maximum dose), R90, R85 and R80] were measured in water at 100 cm source-to-surface distance for an 10×10 cm2 open field and circular cutouts with diameters of 4, 5, 6, 7 and 8 cm. Then PDD parameters along with profile parameters such as width of isodose lines and penumbra at the clinically relevant depths were determined. Output factors for the cutouts were measured at dmax in water and solid water.

With PDD and profile parameters, dosimetry lookup tables were generated. Based upon the lookup tables, target coverage at prescribed depths was retrospectively reviewed for three skin cancer cases. The lookup tables suggested larger cutouts for adequate target coverage.

Dosimetry lookup tables for electron beam therapy should include profile parameters at clinically relevant depths and be provided to clinicians to ensure target coverage in a clinical setup.

The aim of this paper is to compare neural induced changes in three-dimensional conformal radiotherapy (3D-CRT) versus intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) for nasopharyngeal cancers.

Radiotherapy plans for 10 patients with nasopharyngeal cancer stages III and IV were prospectively developed for 3D-CRT, IMRT and VMAT using Varian Eclipse planning system. The same radiation therapist carried out all planning and the same clinical dosimetric constraints were used. Normal tissue complication probabilities were calculated.

The mean planning target volume’s (PTVs) conformity index (CI) for 3D-CRT was 1·424, for IMRT 1·1, and for VMAT 1·081. The PTV homogeneity (HI) index was 0·204 for 3D-CRT, 0·124 for IMRT and 0·153 for VMAT. Normal tissue complication probabilities gave complex results for 3D-CRT, IMRT and VMAT and are analysed in detail in this paper. The mean monitor units were 95 (range 9–180) for 3D-CRT; 165 (range 52–277) for IMRT; and 331 (range 167–494) for VMAT (p<0·05).

VMAT is associated with similar dosimetric advantages as IMRT over 3D-CRT for nasopharyngeal cancer. VMAT is associated with faster delivery times and greater number of mean monitor units than IMRT. Brain radionecrosis severity and risk, in the past, have been underestimated. By improving the life expectancy of patients with nasopharyngeal cancer to ensure maintenance of the neural structures, recommended dose limits should be considered as a first degree priority (as the spinal cord, brainstem, etc.) when IMRT and VMAT plans are implemented.

Although manual adjustment of automatic cone beam computed tomography (CBCT) matching may improve the target coverage in certain points of interest, concerns exist that this may lead to dosimetric uncertainties which would negate the theoretical benefit of this approach. The objective of this study is to evaluate the dosimetric impact of manual adjustments made after automatic bony registration on CBCT in prostate patients.

A total of 50 CBCT datasets of ten high-risk prostate cancer patients were randomly chosen. Each CBCT dataset was registered three times. Method (A): Automatic registration, Method (M1): Manual adjustment carried out by two experienced radiation therapists, Method (M2): Manual adjustment carried out by different radiation therapists with varying levels of experience. The clinical target volume (CTV), planning target volume (PTV), the bladder and the rectum were subsequently contoured on each CBCT dataset by a radiation oncologist blinded to the registration methods. The absolute difference of various dosimetric parameters were then analysed and compared with the original planning doses. A comparison of the three matching methods employed was also carried out.

There was a statistically significant difference in the magnitude of move taken in the inferior superior direction between M1 and M2 method. There were no significant differences observed in any of the dosimetric parameters examined in relation to the rectum, bladder or CTV. The only significant difference observed was the volume of PTV covered by the prescription isodose (95%) which was statistically significant lower in method A compared with both M1 and M2. There was no difference observed between M1 and M2 methods. The mean duration of the automated registration and subsequent analysis was 64 seconds compared with 91 seconds for automated registrations which included the additional manual adjustment.

CBCT-based manual adjustments of automated bony-based registrations during the image-guided radiotherapy verification of prostate cancer patients can improve PTV coverage without impacting negatively on the doses received by the organs at risk. This strategy is associated with a small increase in overall treatment time.

This review evaluates whether brachytherapy can be considered as an alternative to whole breast irradiation (WBI) using criteria such as local recurrence rates, overall survival rates and quality of life (QoL) factors. This is an important issue because of a decline in local recurrence rates, suggesting that some women at very low risk of recurrence may be incurring the negative long-term side effects of WBI without benefitting from a reduction in local recurrence and greater overall survival. As such, the purpose of this literature review is to evaluate whether brachytherapy is a credible alternative to external beam radiation with a particular focus on the impact it has on patient QoL.

The search terms used were devised by using the Population Intervention Comparison Outcome framework, and a literature search was carried out using Boolean connectors and Medical Subject Headings in the PubMed database. The resultant articles were manually assessed for relevance and appraised using the Scottish Intercollegiate Guidelines Network tool. Additional papers were sourced from the citations of articles found using the search strategy. Government guidelines and regulations were also used following a manual search on the National Institute for Health and Care Excellence website. This process resulted in a total of 30 sources being included as part of the review.

Three types of brachytherapy were the foundation for the majority of the papers found: interstitial multi-catheter brachytherapy, intra-cavity brachytherapy and permanent seed implantation. The key themes that arose from the literature were that brachytherapy is equivalent to WBI both in terms of 5-year local recurrence rates and overall survival rates at 10–12 years. The findings showed that brachytherapy was superior to WBI for some QoL factors such as being less time-consuming and equal in terms of others such as breast cosmesis. The results did also show that brachytherapy does come with its own local toxicities that could impact upon QoL such as the poor breast cosmesis associated with some brachytherapy techniques.

In conclusion, brachytherapy was deemed a safe or acceptable alternative to WBI, but there is a need for further research on the long-term local recurrence rates, survival rates and quality of life issues as the volume of evidence is still significantly smaller for brachytherapy than for WBI. Specifically, there needs to be further investigation as to which patients will benefit from being offered brachytherapy and the influence that factors such as co-morbidities, performance status and patient choice play in these decisions.

Deep inspiratory breath hold (DIBH) during left-breast irradiation helps to minimise cardiac irradiation by physically separating the heart from the left breast. The dose to organs-at-risk in intensity-modulated radiotherapy (IMRT) and opposed tangent three-dimensional conformal radiotherapy (3DCRT) during DIBH in patients with left-sided breast cancer was compared.

A total of 20 consecutive patients with left-sided breast cancer had a computed tomography scan utilising DIBH. Mean volumes of the heart, left anterior descending coronary artery, total lung and right breast receiving 5–95% of the prescription dose were calculated.

Target volume homogeneity was improved with IMRT and average mean dose to target was higher for 3DCRT (51·03 Gy) compared with IMRT (50·47 Gy, p<0·01). The average mean dose to the heart was lower with 3DCRT (87 versus 77 cGy, p<0·01). The average mean dose to the contralateral breast was also lower with 3DCRT (19 versus 17 cGy, p<0·01). Less monitor units (MUs) were required with 3DCRT with an average difference of 225 MU/fraction (p<0·01).

Under DIBH, absolute differences between 3DCRT and IMRT were minimal. 3DCRT under DIBH provided excellent dosimetric results in most patients with left-sided breast cancer without the need for IMRT.

Patients having a course of radiotherapy (RT) must be appropriately immobilised for stability and accuracy. Having opened a new cancer service in June 2009 and commenced treating lower gastrointestinal cancers in 2010, a prone belly board device (BBD) was introduced as the standard radiotherapy immobilisation. A training package was created to aid clinical skills retention of therapeutic radiographers and manage setup quality. Setup reproducibility using the BBD was retrospectively assessed with electronic portal image (EPI) verified geometric displacements as the main outcome measure both before and after the introduction of training.

Twenty retrospective Pinnacle computed tomography-planned patients and their geometric displacements on treatment were evaluated between 2010 and 2011—ten prior to (Patient Group A) and ten following training (Patient Group B). The only inclusion criterion was that patients were immobilised for RT on the Medtec ContouraTM carbon fibre BBD. Patients were prone and were treated to 45–50·4 Gy in 25–28 fractions on a 6–10 MV LinAc equipped with EPI. Reproducibility was assessed by comparing geometric measurement of the bony pelvis on the Pinnacle digitally reconstructed radiograph (DRR) with an EPI captured at day 0, 1, 2 and weekly during treatment for each patient. Systematic and random errors were analysed with respect to the average geometric displacement with standard deviation per patient between the Pinnacle DRR and the EPI.

The age range was 41–77 years and there were 15 male and five female patients with diagnosed rectal cancers (T3–T4, N0–N2, M0). Three hundred and seventy one images were analysed. An improvement in population systematic and random error was most notable in the superior–inferior direction (Patient Group A Σpop = 3·1 mm, σpop = 3·6 mm to Patient Group B Σpop = 2·0 mm, σpop = 2·3 mm, respectively).

There is evidence that the use of the BBD is more reproducible when accompanied by a task-specific training package. Based on the results of this study, further work will be carried out on training standardisation for patient positioning with a BBD for reducing systematic and random geometric displacements.