This study compares three different hybrid plans, for left-sided chest wall (CW) and nodal stations irradiation using a hypofractionated dose regimen.

Planning target volumes (PTVs) of 25 breast cancer patients that included CW, supraclavicular (SCL) and internal mammary node (IMN) were planned with 3 different hybrid techniques: 3DCRT+IMRT, 3DCRT+VMAT and IMRT+VMAT. All hybrid plans were generated with a hypofractionated dose prescription of 40·5 Gy in 15 fractions. Seventy per cent of the dose was planned with the base-dose component and remaining 30% of the dose was planned with the hybrid component. All plans were evaluated based on the PTVs and organs at risk (OARs) dosimetric parameters.

The results for PTVs parameters have shown that the 3DCRT+IMRT and 3DCRT+VMAT plans were superior in uniformity index to the IMRT+VMAT plan. The OARs dose parameters were comparable between hybrid plans. The IMRT+VMAT plan provided a larger low dose volume spread to the heart and ipsilateral lung (p < 0·001). The 3DCRT+VMAT plan required less monitor units and treatment time (p = 0·005) than other plans.

The 3DCRT+VMAT hybrid plan showed superior results with efficient treatment delivery and provide clinical benefit by reducing both low and high dose levels.

The COVID-19 pandemic has led to the introduction of alternative on-treatment and post-treatment radiographer-led review clinics in an attempt to protect patients, staff and the public. Pre-COVID, patient reviews were routinely undertaken face-to-face, led by therapeutic review radiographers with advanced practice qualifications and skills in radiotherapy symptom management, triage, referral and support services. During the COVID-19 pandemic, an alternative option has been to follow-up in the form of telephone reviews to reduce face-to-face exposure whilst continuing to manage patient radiotherapy treatment-related toxicities. The aim of the narrative review is to explore the subject of telephone reviews and how therapeutic review radiographers might need to adapt communication skills so that they can continue to effectively assess and manage radiotherapy patient treatment reactions remotely.

A narrative review was conducted using the SCOPUS database and 28 publications were included from 2013 to 2021. The review highlights a paucity of literature exploring specific telephone training for radiographers and other allied healthcare professionals. Experiences within medical and nursing programmes demonstrate that development and integration of training in this area is critical in preparing for patient interaction via telephone.

Multiple teaching modalities including simulation are ideal for teaching telephone-specific skills and content, demonstrating improvement in student knowledge, competence and confidence. Less is known regarding whether this knowledge translates to an improved patient experience. Enhancements in education and training, guided by the Health and Care Professions Council, may be warranted to ensure that patients continue to receive the optimal quality of care in a world where remote reviews are likely to become commonplace. Patient-reported outcome measures might be utilized for future training evaluations to ensure that effective patient care is being maintained.

To evaluate efficacy of helical tomotherapy (HT) for treatment of breast cancer with internal mammary lymph node involvement.

This is a retrospective clinical audit of planning, dosimetry, toxicity and short-term survival of a cohort of 65 patients. Patients were treated between November 2014 and May 2019. The primary and nodal region was prescribed a dose of 50 Gray (Gy) in 25 fractions, while all cases of breast conserving surgery received a simultaneous integrated boost to a dose of 61 Gy in 25 fractions.

The 95% coverage for the primary, supraclavicular, internal mammary node and tumour bed was 93·4%, 96·8%, 90·7% and 98·3%, respectively. Mean dose to total lung, heart and contra-lateral breast was 10·6 Gy, 6·92 Gy and 4·32 Gy, respectively. None developed grade III skin or oesophageal toxicity. Twenty-one patients had progression; of which eighteen developed only distant failure while three also had loco-regional recurrence. At a median follow-up of 36 months, the 3-year loco-regional control, disease-free survival and overall survival were 93·5, 73·9 and 85·9%, respectively.

We report encouraging clinical outcome for patients treated uniformly with HT. The predominant pattern of failure was distant metastases which suggests the need for systemic control intensification.

Identifying the patients at higher risk for poor outcomes after radiotherapy (RT) during coronavirus disease 19 (COVID-19) era is an unmet clinical need.

The Ovid MEDLINE, Ovid Embase, Clarivate Analytics Web of Science, PubMed and Wiley-Blackwell Cochrane Library databases were searched. Eligible studies were required to address the outcomes of cancer patients who underwent RT during the COVID-19 era. The primary outcome was early mortality, while secondary outcomes included length of hospital stay, hospital admission, intensive care unit (ICU) admission and use of mechanical ventilation. Pooled event rates were calculated, and meta-regression and ‘leave-one-out’ sensitivity analyses were performed.

Twelve eligible studies were included out of 928. The prevalence of early mortality after COVID-19 infection was 21·0%. The prevalence of hospital admission, ICU admission and mechanical ventilation was 78·1, 15·4 and 20·0%, respectively. Meta-regression showed that older age was significantly and positively associated with early mortality (β = 0·0765 ± 0·0349, p = 0·0284), while breast cancer was negatively associated with early mortality (β = −1·2754 ± 0·6373, p = 0·0454).

Older age adversely impacts the early mortality rate in cancer patients during COVID-19 era. The risks of interruption/delay of cancer treatment should be weighed against the risk of increased morbidity and mortality from the infection. A global registry is needed to establish international oncologic guidelines during the COVID-19 era.

High-risk prostate cancer is the most common presentation at our institute among patients with non-metastatic prostate cancer. Traditionally, pelvic lymph nodes were given a prophylactic dose of radiotherapy while the prostate was given a curative dose of radiation. This study aims to evaluate patterns of failure in patients who had prostate-only radiation at our centre.

All high-risk prostate cancer patients who underwent radical radiotherapy to prostate only since 2014 were retrospectively analysed. Local T stage, baseline prostate-specific antigen (PSA) and Gleason score were recorded. Bone scan and staging CT scan data were collected. Various dose levels prescribed to prostate were analysed. The follow-up records of these patients were assessed. Patients who failed in pelvic lymph nodes were recorded separately. Overall survival and failure-free survival were calculated using Kaplan–Meier curve.

One-hundred five patients fulfilling the inclusion criteria were analysed. Only three patients developed recurrence in pelvic lymph node following prostate-only radiotherapy (PORT). Five year overall survival was 77% while failure-free survival was 64%. Forty patients had a PSA failure after a median follow-up of 62 months.

Most high-risk prostate cancer patients who progress following hormone therapy and PORT have metastases outside pelvis. Till further conclusive evidence is available PORT can be considered as a safe option.

During the SARS-CoV-2 virus pandemic, University Hospital Birmingham NHS Trust Oncology Department incorporated the ultrahypofractionated regime of 26Gy/5 fractions alongside the moderate hypofractionated regime of 40Gy/15 fractions as part of local adjuvant breast radiotherapy treatment (RT) for eligible patients. We conducted a local study to assess the real-life experience of patients undergoing ultrahypofractionated schedule to compare feasibility and toxicity to the fast-forward trial during the COVID − 19 pandemic.

A single institution, retrospective, qualitative study. Patients included had early-stage breast cancer and received adjuvant radiotherapy between 23 March 2020 and 31 May 2020, a total of 211 patients. Inclusion was irrespective of any other neoadjuvant/adjuvant treatments. Data were collected retrospectively for treatment dose, boost dose and toxicity.

Of the total 211 patients, 85 were treated with 26Gy in 5# and 19 patients received a boost as per the fast-forward protocol. Of these 85 patients, 15·9% did not report any skin toxicity post-treatment. 63·5% of patients reported RTOG Grade 1, 15·9% had RTOG Grade 2, and 1·6% reported RTOG Grade 3 skin toxicity. 3·2% of the patients could not be contacted for follow-up. Of the 19 patients who received a breast boost, 10·53% reported no skin changes. 78·9% reported Grade 1 skin toxicity. Both Grades 2a and 2b skin toxicity were reported by 5·26% each. The patient demographics and tumour characteristics in our study cohort were comparable to those within the fast-forward trial. In terms of post-RT skin toxicity, fewer patients reported any toxicity in the UHB patient cohort versus those in the trial, and the number of Grade 2/3 toxicities reported was also low. A delay in toxicity reporting from 2 weeks for 40Gy/15 to 3 weeks for 26Gy/5 was observed.

Our study concluded that offering ultrahypofractionation was convenient for patients; reducing the number of hospital visits during the SARS-CoV-2 virus pandemic appeared safe in terms of acute post-RT-related skin toxicity. The reduced hospital visits limited exposure of patients and staff to the SARS-CoV-2 virus while also ensuring efficient use of Radiotherapy Department resources. Local follow-up protocols have been amended to ensure review at 3 weeks for the 26Gy/5 schedule to acknowledge the delay in acute toxicity development. To date, there is only 5-year toxicity and relapse data available from the fast-forward trial; therefore, hypofractionation schedules should be offered to patients as long as they fulfil the criteria and understand the limitations of the study as well as accelerated peer review processes in the face of the pandemic.

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.

In thoracic radiotherapy (RT), heart sparing is very essential, as the high cardiac dose is associated with poor survival in patients with locally advanced non-small-cell lung cancer (NSCLC). The study aims to determine the doses exposed to heart substructures and coronary arteries by different RT techniques in central tumor irradiation in lung cancer.

Twenty patients with NSCLC, irradiated between January 2018 and December 2020 in our department, were included in this study. Patients whose primary tumor was centrally located in the left lung were selected. The heart substructures [left atrium, right atrium (RA), left ventricle, and right ventricle] and coronary arteries (left main, left anterior descending, circumflex, and right coronary arteries) were delineated by the same physician. The doses of 60 Gy external RT were prescribed in 30 fractions using three-dimensional conformal radiotherapy (3D-CRT), static intensity-modulated radiotherapy (s-IMRT), and dynamic intensity-modulated radiotherapy (d-IMRT) techniques in all patients. The obtaining plans using three different techniques were compared.

The d-IMRT plans were statistically the best optimal plan for planning target volume (PTV) [Dmean (p = 0 04), Dmax (p < 0 0001), V95 (p < 0 0001), V107 (p < 0 0001), CI (p < 0 0001) and HI (p < 0 0001)]. The s-IMRT plans were significantly superior to 3D-CRT plans for PTV. RA Dmax and V45 were not different between the three techniques [Dmax (p = 0 148) and V45 (p = 0 12)]. The d-IMRT technique was significantly better in other heart substructures and coronary arteries.

Compared to 3D-CRT and s-IMRT techniques, the d-IMRT technique provided the best protection in all heart substructures except for a few parameters (RA Dmax and V45 doses).

Primary non-Hodgkin’s lymphoma (NHL) of the orbit is rare. Orbital NHLs show good response to both radiotherapy (RT) and chemotherapy, and hence, the emphasis should be to ensure maximum cure rate with minimum morbidity. In this study, we present the clinical profile and treatment outcomes of patients with NHL who had initial presentation in the orbit.

In this retrospective analysis, case records of patients with a diagnosis of NHL of the orbit were analysed from January 2005 to January 2015. Patients were worked up and staged according to the Ann Arbor system. Patients with large tumours were initially given chemotherapy with CHOP regimen (cyclophosphamide, vincristine, adriamycin and prednisolone) three weekly for 4–6 cycles. Patients with residual disease were given RT 20–30 Gy at 2 Gy per fraction. RT when given as a primary treatment consisted of 36–45 Gy at 1·8–2 Gy per fraction on either Cobalt 60 machine or linear accelerator.

A total of 52 patients with diagnosis of orbital NHL were included in this study. Median age at presentation was 57 years (range 13–71). Left, right and bilateral orbit was involved in 21 (40%), 28(54%) and 3(6%) patients, respectively. Low- and high-grade pathology was seen in 39(75%) and 13(25%) patients, respectively. On immunohistochemistry, 23(44%) tumors were CD 20 positive. After staging, 33 (63%) patients had stage I disease. Median tumour size was 4·0 × 3·2 × 1·5 cm (1·7 × 1·7 × 1·4 cm to 5·8 × 4·0 × 4·7 cm). Primary RT was given to 7(13%) patients. Upfront chemotherapy was given in 45(86·5%) patients, out of which 24 had stage I disease. RT consolidation was done in 26 (50%) patients for residual disease after chemotherapy. Median follow-up was 88 months (range 29–183 months). Relapse occurred in 6(9·6%) patients; 2 local; 2 local + distant and in 2 distant alone. These patients were successfully salvaged with systemic chemotherapy and local RT. One patient died due to neutropenia. Overall survival in this series was 96%.

Excellent local control was achieved with initial chemotherapy followed by RT for primary orbital NHL with minimal toxicity. We recommend a dose of 36–40 Gy for definitive RT and 30 Gy for lymphoma following chemotherapy using 2 Gy/fraction for Indian patients who present with bulky tumours. RT should be incorporated in treatment of orbital NHL whenever possible as it is safe, effective and is associated with minimal complications.

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.

To evaluate the dosimetric effect of modelling a non-homogeneous couch on patients’ quality assurance (QA) gamma pass rates for intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) techniques.

A non-homogeneous treatment couch (TxT 550 TTM, CIVCO, USA) was imaged using the LINAC mounted cone-beam computer tomography (CBCT) system. Modelling this couch in different situations, including incomplete (homogeneous model), correct model and not defined situations in the treatment planning system (TPS), was performed based on the geometrical and material densities data extracted from the CBCT images. Calculated gamma pass rates between TPS dose calculations and the measurements in a phantom for different couch models were obtained and compared at two gamma criteria (2%-2 mm and 3%-3 mm).

Comparing TPS calculations for the correct modelled couch and the measurements showed high gamma pass rates for both the IMRT and VMAT techniques (96·5 ±  0·9%, 99·2 ±  0·5% for IMRT in 2%-2 mm and 3%-3 mm criteria; 97·5 ±  0·8%, 99·4 ±  0·5% for VMAT). The overall gamma pass rate of the IMRT plan QAs was reduced by about 2% and 3% on average for incomplete and no couch modelling, respectively. These reductions for VMAT techniques were 2·5% and 4·3%, respectively.

Non-homogeneous couches have different parts with different attenuations, which can be correctly defined using LINAC CBCT. Modelling of treatment couch has a significant effect on patient QA results for VMAT and IMRT plans, especially in radiation fields/subfield transmitting from the couch. We suggest using LINAC CBCTs as an appropriate device for couch modelling in modulated radiotherapy techniques.

Patients presenting for radiation therapy (RT) at a single institution were analysed regarding treatment delays and disparities during the coronavirus disease 2019 (COVID-19) pandemic.

The study was conducted at an urban multidisciplinary cancer centre. In April 2020, the institution’s radiation oncology department implemented universal COVID-19 screening protocols prior to RT initiation. COVID-19 testing information on cancer patients planned for RT from 04/2020 to 01/2021 was reviewed. Trends of other lifetime COVID-19 testing and overall care delays were also studied.

Two hundred and fifty-four consecutive cancer patients received RT. Median age was 63 years (range 24–94) and 57·9% (n = 147) were Black. Most (n = 107, 42·1%) patients were insured through Medicare. 42·9% (n = 109) presented with stage IV disease. One (0·4%) asymptomatic patient tested positive for COVID-19 pre-RT. The cohort received 975 lifetime COVID-19 tests (median 3 per patient, range 1–18) resulting in 29 positive test results across 21 patients. Sixteen patients had RT delays. Identifying as Hispanic/Latino was associated with testing positive for COVID-19 (p = 0·015) and RT delay (p = 0·029).

Most patients with cancer planned for RT tested negative for COVID-19 and proceeded to RT without delay. However, increased testing burden, delays in diagnostic workup and testing positive for COVID-19 may intensify disparities affecting this urban patient population.

This work reports on the normal tissue complication probabilities (NTCP) from a UK cohort of previously treated peripheral lung SABR patients (n = 198) supplementing our previous publication on tumour control probabilities (TCP). Each patient was recalculated for alternative schedules.

NTCP for 3 (54 Gy), 5 (55 and 60 Gy) and 8 (50 Gy) fraction (#) schemes were calculated with the Lyman Kutcher Burman (LKB) model in the software platform ‘Biosuite’ (Version 12·01) for lung and chest wall. Patients treated with 5 # or 8 # were then recomputed for alternative fractionations and doses (3 # and 5 #, for both 55 Gy and 60 Gy).

The mean lung NTCP (NTCPLUNG, for the outcome of radiation pneumonitis) was 2·8% (range 0·6 – 10·6). The mean chest wall NTCP (NTCPCW, for the outcome of rib fracture) was 1·4% (range 0·0–55·9). There were no statistically significant differences observed between male and female, tumour status or fractionation groups except for the NTCPLUNG between 5 # and 3 #. When recalculating NTCP and TCP individually, for 8 # patients, no differences were observed between mean TCP, NTCPLUNG or NTCPCW compared with 3 # or 5 # indicating that fractionation reduction is possible. Parity was observed between the 60 Gy group when recalculated for 55 Gy. For the 60 Gy in 5 # group, the NTCPCW increased significantly when recalculated for 3 #.

NTCPs achievable with current UK planning techniques have been presented indicating SABR Consortium compliant centres are likely to have low complication population risks (< 3 %). 5 # schedules could be justified for 8 # patients, thereby reducing the number of treatment visits. Where there is a large overlap of PTV and chest wall, this indicates an NTCP/TCP calculation is required to investigate if fractionation reduction is individually appropriate.

Therapeutic radiographers are an essential part of a cancer patient’s journey and play a vital and changing role in the delivery of radiotherapy services. This retrospective audit highlights the number of incidental abnormalities found by a Breast Advanced Practitioner on radiotherapy computed tomography (CT) planning scans and their subsequent management.

This retrospective audit investigated the incidental abnormalities found by the Breast Advanced Practitioner on routine CT planning scans for breast cancer patients 2016–2021. Any breast cancer patient found to have an abnormality had their planning scan uploaded to the national picture archiving and communication systems (PACS) system for radiology review. Further formal CT imaging was requested or direct referral to an appropriate multi-disciplinary team meeting.

Sixty-three significant abnormalities were found over the five-year period, of these thirty seven were malignant and the majority of these were lung lesions. Seven patients went on to have surgery alone, surgery plus chemoradiation or stereotactic ablative radiotherapy for their newly diagnosed lung primaries. Five patients were found to have liver metastases that unfortunately changed their treatment plan to palliative.

This retrospective audit has demonstrated that CT planning for radiotherapy offers an opportunity to identify malignant abnormalities at a potentially early stage, thereby improving prognosis and survival. Radiographers have a duty of care to appraise these CT scans to ensure any abnormalities can be addressed in a timely manner.

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.

The researcher’s centre was in a unique position of merging with another established radiotherapy centre to create a Satellite Site. It was noted that the Satellite Site delivered more fractions per linac within the same working day profile as the Main Site. Subtle differences in the workflows allowed for an appraisal of the processes within a fraction of radiotherapy and how this can be refined to improve efficiency.

Retrospective fraction timings were collected using the Oncology Information System for 98 breast and prostate treatments at both sites. A literature review was also conducted to further explore factors that impact fraction timings in other departments internationally.

Breast and prostate treatments took 2·1 and 2·93 minutes, respectively, longer to deliver at the Main Site. Set-up to the isocentre and verification image assessment took significantly longer in all cases at the Main Site. Literature surrounding efficiency is scarce but suggests methods used for online management of verification imaging significantly impacts appointment times.

Implementation of a paperless workflow and process improvements for image assessment such as introducing a traffic light protocol may reduce the time to deliver a fraction of radiotherapy and maximise service efficiency.

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.

In radiotherapy, the dose delivered outside the field is known as peripheral dose (PD). In this study, we have attempted to develop a dataset using the PD values measured with a two-dimensional array, IMatrixx.

The IMatrixx was used to measure the PD up to a distance of 45 cm from the field edge, in a Varian Clinac 2100-C machine. Solid water slabs and water phantom were used to get the required geometry for the PD measurements. The measurements were done for different field sizes, collimator angles, source to surface distance (SSD) and depths. The influence of gantry angles and photon energies on the PD was studied. The surface dose measurements were carried out using thermoluminescent detectors (TLD).

The dataset shows that the PD increased significantly with field size and depth and its increase was insignificant for collimator rotation and SSD. The influence of gantry angle was less pronounced at dmax than at the surface. The TLD measurements at the surface of patients were in agreement with the IMatrixx measurements.

The IMatrixx can be used for the generation of PD values and it is less time-consuming, accurate, and commonly available in all radiotherapy departments.

To report the planning parameters, efficacy and toxicity of total body irradiation using volumetric modulated arc therapy (VMAT).

From July 2019 till May 2021, nine patients treated with VMAT-based total body irradiation as a part of the myeloablative regimen for homologous stem cell transplant were evaluated. The CT acquisition, planning parameters, doses to target volume and critical structures were evaluated retrospectively.

Median age was 24 with median height 172 cm. Average Mean Lung dose was 9·5 Gy, mean dose to kidney was kidney dose 8·4 Gy, planning target volume (PTV) 95% was 98 % and mean heterogeneity index of PTV was 1·2 all patients. Total fraction delivery time including setup was 3·1 h while beam on time was 23 min. Main toxicity observed was mucositis and fatigue, while no Grade 3 or more acute radiation toxicity was observed.

At our institution, high dose TBI performed with multi-isocentric VMAT is now a standard procedure. Though it is cumbersome and time-consuming process but VMAT offers an advantage of increased dose homogeneity in the target volume with reduction in doses to critical organs especially lungs and kidneys in comparison to standard source to skin distance technique, longer follow-up time is necessary to evaluate our method and long-term toxicity.