Locally advanced head and neck cancer can be a distressing disease due to a variety of reasons. This retrospective study looks at the tolerability and outcomes for palliative split-course hypofractionated radiotherapy for this group of patients treated in our centre.

A total of 59 patients were treated with hypofractionated split-course radiotherapy for incurable mucosal squamous cell carcinoma of the head and neck region in our centre over a 10-year period. In all, 71% had stage IV disease. Radiotherapy consisted of three phases of 14·4 Gy/phase, in four to eight fractions over 4 days giving one·8–3·6 Gy/fraction. The phases were separated by 2 weeks. A total of 40 patients (63%) completed all three phases. A total of 72% patients had no acute toxicities and the palliation rate was 83% (complete and partial). Only five patients had no meaningful palliation having completed all three phases. Median duration of local control was 6 months (range: 1–63 months) and median overall survival was 8 months (range: 1–68 months). In five patients, the control was durable with no recurrence at the time of analysis with survival ranging from 6 to 57 months.

We are the first UK centre to report with long-term data, the use of a palliative three phase regime that provides meaningful palliation with acceptable toxicities. In addition, for some patients, it has resulted in durable long-term control.

A retrospective study was undertaken to analyse set-up variations in patients being treated with post-operative radiation therapy for carcinoma of gall bladder by image-guided radiotherapy (IGRT) using cone-beam computed tomography (CBCT) scans and paired kilovoltage beam portals (kVps).

Three consecutive patients receiving post-operative radiation therapy for carcinoma of gall bladder were studied. A total of 32 imaging studies were performed. The immobilisation system was an all-in-one system along with a thermoplastic mask, with knees either resting on the knee rest or in a vacuum cushion. The CBCT scans and kVps were reviewed in an off-line mode. The surrogate markers used for matching during co-registration were 12th rib, coeliac trunk, vertebral bodies and canal. Individual readings were used to calculate mean shifts (m); the mean of these means (M) was calculated to arrive at the systematic error in each direction and its standard deviation (Σ) was calculated. The margins for set-up error (SM) were then calculated.

There were a total of 32 readings of which 21 were CBCTs and 11 were kVps. The mean shifts in each direction for each patient were 0·06, 0·25 and 0·15 cm in vertical, longitudinal and lateral directions, respectively. The resultant planning target volume margins calculated were 0·24, 0·9 and 0·47 cm in vertical, longitudinal and lateral directions.

IGRT for upper abdominal malignancies using CBCT and kVps is a useful method to keep the margins for set-up error low. The use of surrogates for matching should be relevant to the target volume. Good immobilisation system helps in keeping the margins low.

The purpose of this study was to dosimetrically compare TomoDirect, TomoHelical and linear accelerator-based 3D-conformal radiotherapy (Linac-3DCRT) for craniospinal irradiation (CSI) in the treatment of medulloblastoma.

Five CSI patients were replanned with Linac-3DCRT, TomoHelical, TomoDirect-3DCRT and TomoDirect-intensity-modulated radiotherapy (IMRT). Dose of 36 Gy in 20 fractions was prescribed to the planning target volume (PTV). Homogeneity index (HI), non-target integral dose (NTID), dose–volume histograms, organs-at-risk (OARs) Dmax, Dmean and treatment times were compared.

TomoHelical achieved the best PTV homogeneity compared with Linac-3DCRT, TomoDirect-3DCRT and TomoDirect-IMRT (HI of 3·6 versus 20·9, 8·7 and 9·4%, respectively). TomoDirect-IMRT achieved the lowest NTID compared with TomoDirect-3DCRT, TomoHelical and Linac-3DCRT (141 J versus 151 J, 181 J and 250 J), indicating least biological damage to normal tissues. TomoHelical plans achieved the lowest Dmax in all organs except the breasts, and lowest Dmean for most OARs, except in laterally situated OARs, where TomoDirect triumphed. Beam-on time was longest for TomoHelical, followed by TomoDirect and Linac-3DCRT.

TomoDirect has the potential to lower NTID and shorten treatment times compared with TomoHelical. It reduces PTV inhomogeneity and better spares OARs compared with Linac-3DCRT. Therefore, TomoDirect may be a CSI treatment alternative to TomoHelical and in place of Linac-3DCRT.

Patients with cancer undergoing radiotherapy often develop diarrhoea, causing distress and hindering treatment. As probiotics have favourable effects on the gut flora, they are potentially good candidates in the prevention of radiotherapy-induced diarrhoea (RID).

The outcome of interest of this systematic review was the efficacy of probiotics in preventing RID.

Medline and Embase databases were systematically searched. Four randomised controlled trials (RCTs) were finally selected.

Three RCTs showed beneficial results, which were statistically significant. One RCT showed non-beneficial results, which were not statistically significant. The quality of the studies was mixed, and serious limitations were found.

While the indications are towards a benefit of the use of probiotics in preventing RID, more robust evidence is required in the form of well-designed RCTs.

Monte Carlo (MC) simulations have been used extensively for benchmarking photon dose calculations in modern radiotherapy using linear accelerators (linacs). Moreover, a major barrier to widespread clinical implementation of MC dose calculation is the difficulty in characterising the radiation source using data reported from manufacturers.

This work aims to develop a generalised full MC histogram source model of an Elekta Precise SL-25 linac (electron exit window, target, flattening filter, monitor chambers and collimators) for 6 MV photon beams used in standard therapies. The inclusion of many different probability processes such as scatter, nuclear reactions, decay, capture cross-sections and more led to more realistic dose calculations in treatment planning and quality assurance.

Two different codes, MCNPX 2·6 and EGSr-BEAM, were used for the calculation of particle transport, first in the geometry of the internal/external accelerator source, and then followed by tracking the transport and energy deposition in phantom-equivalent tissues. A full phase space file was scored directly above the upper multilayer collimator’s jaws to derive the beam characteristics such as planar fluence, angular distribution and energy spectrum. To check the quality of the generated photon beam, its depth dose curves and cross-beam profiles were calculated and compared with measured data.

In-field dose distributions calculated using the accelerator models were tuned to match measurement data with preliminary calculations performed using the accelerator information provided by the manufacturer. Field sizes of 3×3, 5×5, 10×10, 15×15 and 20×20 cm2 were analysed. Local differences between calculated and measured curve doses beneath 2% were obtained for all the studied field sizes. Higher discrepancies were obtained in the air–water interface, where measurements of dose distributions with the ionisation chamber need to be shifted for the effective point of measurement.

The agreements between MC-calculated and measured dose distributions were excellent for both codes, showing the strength and stability of the proposed model. Beam reconstruction methods as direct input to dose-calculation codes using the recorded histograms can be implemented for more accurate patient dose estimation.

Deep inspiration breath hold (DIBH) is a method of motion management used in stereotactic ablative body radiotherapy (SABR) for lung tumours. An external gating block marker can be used as a tumour motion surrogate, however, inter-fraction gross target volume (GTV) displacement within DIBH occurs. This study measured this displacement during a reproducible breath hold regime. In addition, factors such as position of the gating block marker were analysed.

A total of 121 cone beam computed tomography scans (CBCTs) from 22 patients who received DIBH SABR were retrospectively evaluated and the magnitude of inter-fraction GTV displacement was calculated for each fraction. This data was analysed to assess if any correlation existed between tumour displacement and variation in the gating block marker position on the patient, the amplitude of breath hold (BH) at computed tomography (CT), the amplitude of BH at treatment and the tumour location.

The measured tumour displacement was applied to the original planning CT to evaluate the dosimetric effect on surrounding organs at risk (OARs) using cumulative dose volume histograms (DVHs).

BH amplitude was reproducible within 0·13±0·1 cm (mean±standard deviation). The magnitude of tumour displacement within BH ranged from 0 to 1·52 cm (0·41±0·28 cm). Displacement in the superior-inferior, anterior-posterior and left-right planes were 0·31±0·26 cm, 0·16±0·18 cm and 0·07±0·12 cm, respectively. No statistically significant correlation was detected between tumour displacement within DIBH and the factors investigated. The range of variation in OAR dose was −7·0 to +3·6 Gy with one statistically significant increase in OAR dose observed (oesophagus mean dose increasing by 0·16 Gy).

Reproducible BH was achievable across a range of patients. Inter-fraction GTV displacement measured 0·41±0·28 cm. Due to this low level of motion, the correction of soft tissue moves did not adversely affect OAR dose.

The impact of COVID-19 social restrictions on mental wellbeing of health professional students during placement is largely unknown. Conventional survey methods do not capture emotional fluctuations. Increasing use of smartphones suggests short message service (SMS) functionality could provide easy, rapid data. This project tested the feasibility and validity of gathering data on Therapeutic Radiography student mental wellbeing during clinical placement via emoji and SMS.

Participants provided anonymous daily emoji responses via WhatsApp to a dedicated mobile phone. Additional weekly prompts sought textual responses indicating factors impacting on wellbeing. A short anonymous online survey validated responses and provided feedback on the method.

Participants (n = 15) provided 254 daily responses using 108 different emoji; these triangulated with weekly textual responses. Feedback concerning the method was positive. ‘Happy’ emoji were used most frequently; social interaction and fatigue were important wellbeing factors. Anonymity and opportunity to feedback via SMS were received positively; ease and rapidity of response engendered engagement throughout the 3-week study.

The use of emoji for rapid assessment of cohort mental wellbeing is valid and potentially useful alongside more formal evaluation and support strategies. Capturing simple wellbeing responses from a cohort may facilitate the organisation of timely support interventions.

Comparison of the integral dose (ID) delivered to organs at risk (OAR), non-target body and target body by using different techniques of craniospinal irradiation (CSI).

Ten CSI patients (medulloblastoma) already planned and treated either with linear accelerator three-dimensional conformal radiation therapy (Linac-3DCRT) technique or with linear accelerator RapidArc (Linac-RapidArc) technique by Novalis-Tx Linac machine have been analysed. Retrospectively, these patients are again planned on Radixact-X9 Linac with Helical, Direct-3DCRT and Direct-intensity-modulated radiation therapy (Direct-IMRT) techniques. The dose prescription to planning target volume brain (PTV-Brain) and PTV-Spine is 36 Gy in 20 fractions and is kept the same for all techniques. The target body, non-target body, OARs and total body dose are compared.

ID is lowest in the RapidArc plan for every patient in comparison to Helical and Direct-IMRT. The ID for Body-PTV was found slightly higher in the RapidArc plan in comparison to 3DCRT plans. But there is better normal tissue sparing for most of the OARs in RapidArc plans if it compares with 3DCRT plans.

RapidArc is a better alternative for the treatment of CSI. It provides better target coverage and better OARs sparing from any other treatment techniques.

This is the second of two papers giving an overview of the use of Monte-Carlo techniques for radiotherapy applications.

The first paper gave an introduction and introduced some of the codes that are available to the user wishing to model the different aspects of radiotherapy treatment. It also aims to serve as a useful companion to a curated collection of papers on Monte-Carlo that have been published in this journal.

This paper focuses on the application of Monte-Carlo to specific problems in radiotherapy. These include radiotherapy and imaging beam production, brachytherapy, phantom and patient dosimetry, detector modelling and track structure calculations for micro-dosimetry, nano-dosimetry and radiobiology.

This study aims to evaluate dosimetric parameters like percentage depth dose, dosimetric field size, depth of maximum dose surface dose, penumbra and output factors measured using IBA CC01 pinpoint chamber, IBA stereotactic field diode (SFD), PTW microDiamond against Monte Carlo (MC) simulation for 6 MV flattening filter-free small fields.

The linear accelerator used in the study was a Varian TrueBeam® STx. All field sizes were defined by jaws. The required shift to effective point of measurement was given for CC01, SFD and microdiamond for depth dose measurements. The output factor of a given field size was taken as the ratio of meter readings normalised to 10 × 10 cm2 reference field size without applying any correction to account for changes in detector response. MC simulation was performed using PRIMO (PENELOPE-based program). The phase space files for MC simulation were adopted from the MyVarian Website.

Variations were seen between the detectors and MC, especially for fields smaller than 2 × 2 cm2 where the lateral charge particle equilibrium was not satisfied. Diamond detector was seen as most suitable for all measurements above 1 × 1 cm2. SFD was seen very close to MC results except for under-response in output factor measurements. CC01 was observed to be suitable for field sizes above 2 × 2 cm2. Volume averaging effect for penumbra measurements in CC01 was observed. No detector was found suitable for surface dose measurement as surface ionisation was different from surface dose due to the effect of perturbation of fluence. Some discrepancies in measurements and MC values were observed which may suggest effects of source occlusion, shift in focal point or mismatch between real accelerator geometry and simulation geometry.

For output factor measurement, TRS483 suggested correction factor needs to be applied to account for the difference in detector response. CC01 can be used for field sizes above 2 × 2 cm2 and microdiamond detector is suitable for above 1 × 1 cm2. Below these field sizes, perturbation corrections and volume averaging corrections need to be applied.

To evaluate the efficacy of a Belly Board immobilisation device for rectal cancer patients.

A randomised trial in patients receiving neo-adjuvant chemoradiation for rectal carcinoma was established. Patients were treated, prone with control arm, according to standard departmental protocol and experimental arm with the use of a Belly Board. All treatments were planned using a three-field technique. The primary endpoints were reproducibility and irradiated small bowel volume. Questionnaires were used to assess secondary endpoints of patient comfort, ease of set-up and acute toxicities.

Pre-planned interim analysis was performed after recruiting 30 patients. In all, 348 portal images were analysed retrospectively. Around 8 out of 12 parameters measuring set-up reproducibility were in favour of the Belly Board arm. Random error in the anterior–posterior direction was improved and statistically significant in the experimental arm (95% CI; p≤0·05). Small bowel V15 was significantly lower in the Belly Board position (mean V15=14·5%) compared with the standard position (mean V15=21·4%), paired t-test 95% CI; p=0·035. Also, patients’ comfort satisfaction was greater in the Belly Board arm.

Set-up reproducibility, small bowel V15, patient comfort and satisfaction were all significantly improved by the use of the Belly Board.

To compare tumour dose distribution, conformality, homogeneity, normal tissue avoidance, tumour control probability (TCP) and normal tissue complication probability (NTCP) using 3D conformal radiation therapy (3DCRT), 3- and 4-field intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) in patients with locally advanced rectal cancer.

Twenty-four patients staged T1–3N+M0 with locally advanced rectal cancer underwent neoadjuvant chemoradiation therapy. Four different radiotherapy plans were prepared for each patient: 3DCRT, 3- and 4-field IMRT and VMAT are evaluated for target distribution using CI and homogeneity index (HI), normal tissue avoidance using Dmax, V45, V40, V50 and TCP and NTCP using the Lyman–Kutcher–Burman model.

VMAT has better HI (HI = 1·32) and 3DCRT exhibited better conformality (CI = 1·05) than the other radiotherapy techniques. With regard to normal tissue avoidance, all radiotherapy plans met the constraints. Dmax in the 3DCRT plans was statistically significant (p = 0·04) for bladder and no significant differences in V40 and V50. In the bowel bag, no significant differences in Dmax for any radiotherapy plan and V40 was lower in 3DCRT than VMAT (p = 0·024). In the case of femoral heads, 3DCRT has a statistically significant lower dose on Dmax than 4-field IMRT (p = 0·00 « 0·05). VMAT has the biggest TCP (80·76%) than the other three radiotherapy plans. With regard to normal tissue complications, probabilities were shown to be very low, of the order of 10-14 and 10-41 for bowel bag and femoral heads respectively.

It can be concluded that 3DCRT plan improves conformity and decreases radiation sparing in the organ at risks, but the VMAT plan exhibits better homogeneity and greater TCP.

Pancreatic cancer is the 12th most commonly diagnosed cancer and the 3rd leading cause of cancer mortality and accounts for approximately 2·7% of all newly diagnosed cancer cases and 6·4% of all cancer mortalities in Canada. It has a very poor survival rate mainly due to the difficulty of detecting the disease at an early stage. Consequently, in the advancement of disease management towards the concept of precision medicine that takes individual patient variabilities into account, several investigators have focused on the identification of effective clinical biomarkers with high specificity and sensitivity, capable of early diagnosis of symptomatic patients and early detection of the disease in asymptomatic individuals at high risk for developing pancreatic cancer.

We searched several databases from August to December 2020 for relevant studies published in English between 2000 and 2020 and reporting on biomarkers for the management of pancreatic cancer. In this narrative review paper, we describe 13 clinical and emerging biomarkers for pancreatic cancers used in screening for early detection and diagnosis, to identify patients’ risk for metastatic disease and subsequent relapse, to monitor patient response to specific treatment and to provide clinicians the possibility of prospectively identifying groups of patients who will benefit from a particular treatment.

Current and emerging biomarkers for pancreatic cancer with high specificity and sensitivity has the potential to account for individual patient variabilities, for early detection of disease before the onset of metastasis to improve treatment outcome and patients’ survival, help screen high-risk populations, predict prognosis, provide accurate information of patient response to specific treatment and improve patients monitoring during treatment. Thus, the future holds promise for the use of effective clinical biomarkers or a panel of biomarkers for personalised patient-specific targeted medicine for pancreatic cancer.