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The Varian Trilogy linear accelerator’s multi-leaf collimator moves on a carriage with a maximum leaf span of 15 cm. The traditional open and limited X-jaw technique of volumetric-modulated arc radiotherapy (VMAT) yields a relatively compromised dose distribution within the planning target volume (PTV) region. This study aimed to determine whether the split X-jaw planning technique for VMAT improves plan quality regarding target dose coverage and organs at risk (OAR) sparing for PTVs that require a field size of more than 15 cm in the X-jaw direction in prostate cancer patients.
Method:
Computed tomography data sets from 15 patients with prostate cancer were enrolled in the study. Only the PTVs requiring a field size larger than 18 cm in the X-jaw position were considered, and a dose of 4500 cGy in 25 fractions was prescribed. For each case, three separate treatment plans were generated: open, limited and split X-jaw planning techniques with similar planning objectives
Results:
The split X-jaw technique resulted in statistically significant superior coverage of PTV when compared with the open (P < 0·0001) and limited methods (P < 0·001). The split technique delivered a lower dose to the OARs, although statistical significance could not be achieved. D2% (cGy) was lowest for the PTV in the split technique (4684·8 ± 18·16) and highest for the open technique (4710 ± 18·75), P < 0·001.
Conclusion:
The x-split jaw technique can replace the traditional open X-jaw practice of VMAT for PTVs requiring an X-jaw width of more than 15 cm in the Varian linear accelerator.
Following radiotherapy for head and neck cancer, a proportion of patients present with mandibular osteoradionecrosis (ORN). Reported incidence and presentation of ORN vary widely, although often initiated by trauma with radiotherapy being the biggest risk factor. Evolved disease requires surgery, mandibular resection and reconstruction. As ORN is a progressive disease, it can manifest beyond resected volumes, compromising surgery. To minimise surgical failures, we present incorporating radiotherapy dose into the surgical design and decision processes—dose guided surgery (DGS).
Method:
Five mandibular ORN patients, referred for resection and reconstruction, underwent DGS—mandible visualised on diagnostic CT, propagated to radiotherapy planning CT, radiotherapy dose displayed on the mandible, high-risk mandible converted to stl files and incorporated in the surgical design.
Results:
DGS ensures high-dose, high-risk ORN mandible is resected, and fixation devices are located in low-dose, low-risk areas.
Conclusions:
DGS represents a potential new standard of care for patients presenting with mandibular ORN post-radiotherapy. Formal follow-up of this small cohort is ongoing although DSG is anticipated to increase the success rate of this high cost, high burden procedure compared to surgery designed on clinical and radiological assessments alone.
This study aims to look at the trends in our head and neck cancer patient population over the past 5 years with an emphasis on the past 2 years to evaluate how the coronavirus disease 2019 (COVID-19) pandemic has impacted our disparities and availability of care for patients, especially those living in rural areas. An additional aim is to identify existing disparities at our institution in the treatment of head and neck patients and determine solutions to improve patient care.
Materials and Methods:
A retrospective chart review was performed to identify patients who were consulted and subsequently treated with at least one fraction of radiation therapy at our institution with palliative or curative intent. Patient demographic information was collected including hometown, distance from the cancer centre based on zip-codes and insurance information and type of appointment (in-person or telehealth). Rural–urban continuum codes were used to determine rurality.
Results:
A total of 490 head and neck cancer patients (n = 490) were treated from 2017 to 2021. When broken down by year, there were no significant trends in patient population regarding travel distance or rurality. Roughly 20–30% of our patients live in rural areas and about 30% have a commute > 50 miles for radiation treatment. A majority of our patients rely on public insurance (68%) with a small percentage of those uninsured (4%). Telehealth visits were rare prior to 2019 and rose to 5 and 2 visits in 2020 and 2021, respectively.
Conclusions:
Head and neck cancer patients, despite rurality or distance from a cancer centre, may present with alarmingly enough symptoms despite limitations and difficulties with seeking medical attention even during the COVID-19 pandemic in 2020. However, providers must be aware of these potential disparities that exist in the rural population and seek to address these.
This paper aims to discuss the psychosocial concomitants with involvement in oncology clinical trials, focusing on barriers that can impact upon participation. It will conclude with some recommendations for strategies to address potential psychosocial barriers with the aim of increasing trial participation rates.
Materials and methods:
A literature search was carried out using CINAHL, PubMed and EMCare databases with the following keywords for filtering: psychological distress, clinical trials, participation and oncology. The final selection of papers that met the inclusion criteria for this review was manually subjected to Critical Appraisal Skills Programme tool for relevance.
Results:
Thirteen papers were included in the review. The dominant theme within the literature is psychosocial obstacles to oncology clinical trial participation. Five key barriers were identified: anxiety and fear; ethnicity and social background; tensions between scientific objectives and personal motivations to participation; tensions between personal benefits versus altruism; carer perspectives.
Conclusions:
The key barriers discussed led to the identification of a set of strategies to help mediate conflicting tensions and motivations of trial enrolment with a view to increasing participation rates. Further prospective research garnering primary data investigating both the psychological and psychosocial factors influencing cancer clinical trial participation for patients needs to be undertaken.
Intensity-modulated radiation therapy (IMRT) has revolutionised the way head and neck cancers can be treated. It allows for a more conformal treatment plan when compared to 3D conformal radiation therapy. In paediatric patients, however, IMRT continues to deliver higher doses than desirable. Proton beam therapy on the other hand has the potential to further spare organs-at-risk.
Methods:
A 16-year-old boy with a left-sided paraganglioma of the left base of skull manifested by headaches, neck pain and tongue cramping was simulated, planned and treated with proton therapy with significant contralateral organ-at-risk sparing.
Results:
For this patient, dosimetric plan comparison between photon and proton plans clearly showed better sparing of contralateral organs-at-risk with protons. The contralateral parotid gland received a mean dose of 386·3 cGy with photons, whereas it received 1·3 cGy (CGE) in the proton plan.
Conclusions:
The dosimetric advantage of proton beam over photon beam therapy has successfully been demonstrated in this case study for a paediatric patient with a head and neck tumour. Sparing of contralateral structures is especially important in paediatric patients who are at a greater risk of secondary malignancies due to possible long life expectancy.
Peer review is an essential quality assurance component of radiation therapy planning. A growing body of literature has demonstrated substantial rates of suggested plan changes resulting from peer review. There remains a paucity of data on the impact of peer review rounds for stereotactic body radiation therapy (SBRT). We therefore aim to evaluate the outcomes of peer review in this specific patient cohort.
Methods and materials:
We conducted a retrospective review of all SBRT cases that underwent peer review from July 2015 to June 2018 at a single institution. Weekly peer review rounds are grouped according to cancer subsite and attended by radiation oncologists, medical physicists and medical radiation technologists. We prospectively compiled ‘learning moments’, defined as cases with suggested changes or where an educational discussion occurred beyond routine management, and critical errors, defined as errors which could alter clinical outcomes, recorded prospectively during peer review. Plan changes implemented after peer review were documented.
Results:
Nine hundred thirty-four SBRT cases were included. The most common treatment sites were lung (518, 55%), liver (196, 21%) and spine (119, 13%). Learning moments were identified in 161 cases (17%) and translated into plan changes in 28 cases (3%). Two critical errors (0.2%) were identified: an inadequate planning target volume margin and an incorrect image set used for contouring. There was a statistically significantly higher rate of learning moments for lower-volume SBRT sites (defined as ≤30 cases/year) versus higher-volume SBRT sites (29% vs 16%, respectively; p = 0.001).
Conclusions:
Peer review for SBRT cases revealed a low rate of critical errors, but did result in implemented plan changes in 3% of cases, and either educational discussion or suggestions of plan changes in 17% of cases. All SBRT sites appear to benefit from peer review, though lower-volume sites may require particular attention.
The management of extracranial arterio-venous malformations (AVMs) is complex and often requires a multidisciplinary approach. Currently, treatment includes surgical resection and embolotherapy.
Methods:
We present the case of a foot AVM that was managed with adjuvant radiotherapy after previous surgery and embolotherapy had been attempted, and we discuss the role of radiotherapy in the management of extracranial AVMs.
Results:
The malformation was successfully eradicated with complete obliteration of the nidus and no recurrence.
Conclusions:
The addition of radiotherapy in the management of extracranial arterio-venous malformations offers promising results using similar doses to those used in brain AVMs.
The aim of this study is to compare patient geometrical uncertainties in the treatment of breast boost three-dimensional conformal radiation therapy (3D-CRT) considering both manual alignment and automatic different registration methods in cone-beam computed tomography (CBCT).
Methods:
A total of 85 patients were chosen for this study. A total of 254 registrations of CBCT vs planning computed tomography (CT) were retrospectively performed using automatic registration algorithms from Elekta XVI system (Clipbox and Mask) to detect patient setup uncertainties. All CBCTs were also matched manually by three health professionals. Mean shift values obtained with manual registration performed by health professionals were used as reference. Absolute value of difference between automatic algorithm shifts and reference values shifts was collected for each enrolled patient considering the three different spatial directions (x,y,z), and the magnitude was calculated (δm for Mask and δc for Clipbox).
Results:
Data analysis showed a significant difference in δm and δc. t-Test statistics showed a high difference between Mask and Clipbox, in particular mean δm = (1.3 ± 0.1) mm and δc = (3.3 ± 1.2) mm (p-value <0.0001). Mask algorithm was performed in a very similar way with respect to the reference alignment, and the differences between these two procedures were of the order of 1 mm. Clipbox algorithm showed larger differences with manual registration.
Conclusions:
These results suggest that the Mask algorithm may be the optimal choice for patient setup verification in clinical practice for breast boost treatment in 3D-CRT.
Intensity-modulated radiation therapy (IMRT) treatment delivery requires pre-treatment patient-specific quality assurance (QA) for the dosimetry verification due to its complex multileaf-collimator movement. The prostate target close position between the bladder and rectum requires a tight margin during planning, and mistreatment would have a huge impact on the patient. A commercially available QA tool consists of a homogeneous medium and does not represent an exact photon interaction on the tumour and also on the nearby healthy organ.
Objective:
A heterogeneous male pelvis phantom was developed and investigated the efficiency of the treatment planning system (TPS) calculation on the off-axis region.
Methods:
Polymethyl methacrylate was used for the phantom housing, and the material closed to the bladder, rectum and prostate density was chosen to construct the organ models. The phantom was scanned and validated by the computed tomography number and density. An IMRT treatment was planned in the Monaco TPS, and a thermoluminescent dosimeter (TLD-100) was used to validate the point dosimetry. In addition, an EGSnrc Monte Carlo simulation was carried out to validate the phantom dosimetry.
Results & Discussion:
The dose measurement between TLD-100, TPS, and EGSnrc was compared and validated in the pelvis phantom. In the prostate region, the dose difference was within ± 5%, and the maximum dose difference outside-the-irradiated field was up to 20·07 % and 47·31 % in TPS and TLD-100, respectively. Meanwhile, the measured dose was lower than the calculated dose, and it was apparent for the dose outside-the-irradiated field.
Conclusion:
The developed heterogeneity male pelvis phantom was validated and verified to be an important QA device for validating radiation dosimetry in the pelvis region. The dose outside-the-irradiated field was underestimated by both TPS and TLD, respectively.
The magnetic resonance linear accelerator system (MR Linac) is a novel piece of radiotherapy (RT) equipment allowing the routine application of daily MR-guided treatment adaptation. The hardware design required for such technical capabilities and the increased complexity of the treatment workflow entails a notable departure from cone beam computed tomography (CBCT)-based RT. Patient tolerability of treatment is paramount to RT practice where high compliance is required. Presented is a comparative analysis of how such modality specific characteristics may ultimately impact the patient experience of treatment.
Materials and Methods:
Forty patients undergoing RT for prostate cancer (PCa) on either the MR Linac (n = 20) or a CBCT-based linac (n = 20) were provided with a validated patient reported outcomes measures (PROM’s) questionnaire at fraction 1 and fraction 20. The 18-item questionnaire provided patient responses recorded using a 4-point Likert scale, 0 denoting a response of ‘Not at all’, 1 ‘Slightly’, 2 ‘Moderately’ and 3 signifying ‘Very’. The analysis provided insight into both comparisons between modalities at singular time points (fractions 1 and 20), as well as a temporal analysis within a single modality, denoting changing patient experience.
Results:
Patients generally found the MR Linac treatment couch more comfortable, however, found the increase in treatment duration harder to tolerate. Responses for all items remained stable between first and last fraction across both cohorts, indicating minimal temporal variation within a single modality. None of the responses were statistically significant at the 0·01 level.
Conclusion:
Whether radiotherapy for PCa is delivered on a CBCT linac or the MR Linac, there is little difference in patient experience with minimal experiential variation within a single modality.
Prostate cancer is a common malignancy with rising incidence in Western countries such as the United Kingdom. In localised disease there are a variety of curative treatment modalities. Patients can be referred for surgery, or for a combination of hormonal therapies and radiotherapy (external beam radiotherapy or brachytherapy). Each treatment option comes with side effects and in the case of radiotherapy one potential complication is bowel toxicity from radiation exposure. New technologies are being developed to try and mitigate the side effects and long term morbidity of this treatment, and to expand access to radiotherapy for patients who may previously have been excluded (i.e those with inflammatory bowel disease). Rectal Spacers are absorbable polyethylene glycol hydrogels injected into the perirectal space. These position the anterior rectal wall away from the prostate, subsequently minimising radiation dose to the rectum. Rectal Spacers have been introduced to National Healthcare Service (NHS) practice as part of the Innovation and Technology Payment (ITP) programme, however, their use is now under review.
Methodology and Results:
In this editorial we conduct a narrative review of some of the available evidence for Rectal Spacers, discuss their utilization within the NHS and the barriers to their wider use. We also explore preliminary dosimetry and quality of life data for use of Rectal Spacers in our centre where we have been part of the NHS ITP programme. Dosimetry data and Quality of life questionnaires were gathered from 22 treated patients and 11 matched controls. This indicated lower radiation doses to the prostate in those treated with Rectal Spacers.
Conclusion:
Rectal Spacers are an effective method to reduce radiation dose to the prostate in men treated for localised prostate cancer, however, their use remains under review in the NHS and there are a variety of barriers to upscaling their use.
Therapeutic radiographers are the first point of contact for cancer patients undergoing radiotherapy treatment and therefore have an important role in providing both physical and psychosocial support to these patients. This study aimed to evaluate therapeutic radiographers’ perception about their role in identifying and providing psychosocial support for patients receiving RT treatment.
Method:
The study used a cross-sectional, prospective research design. A self-designed questionnaire was distributed to all therapeutic radiographers (n = 26) working at a radiotherapy department in Malta.
Results:
A total of 21 therapeutic radiographers completed the questionnaire. All participants felt that the provision of psychological care was an important part of their role as therapeutic radiographers. The majority of the participants reported having the most confidence in giving treatment-related symptoms advice rather than psychological support. The most common barrier to providing psychological support was lack of training (95·2%), followed by the lack of an appropriate screening tool (85·7%), availability of private space to talk to patients (76·2%) and a lack of knowledge (61·9%).
Conclusion:
While most therapeutic radiographers believed that providing psychosocial support was an important aspect of their role, several barriers prevented them from fulfilling this role. Training, the introduction of a psychosocial screening tool and clear referral processes are recommended to improve radiotherapy service.
Radiation-induced malignancies are the most feared complications of radiotherapy. Depilatory radiotherapy for ringworm of the scalp in childhood was the cause of an increase in the incidence of skin tumours of the scalp in adults. The aim of our study was to describe the epidemiological, clinical and therapeutic characteristics of radiation-induced skin tumours of the scalp in order to highlight the characteristics of these tumours compared to non-radiation-induced tumours.
Methods:
This is a bi-centric retrospective study, extending over a period of 41 years, which collected 137 patients with 200 tumours of the scalp. These patients were selected after noting a history of depilatory radiotherapy for ringworm in childhood in the clinical records of all patients with scalp tumours.
We studied the epidemiological, clinical, therapeutic and evolving characteristics of this population.
Results:
The average age of consultation was 56·6 years. The sex ratio M/F was 3. Radiation dermatitis was found in 33% of cases. The average latency between depilatory radiotherapy and the appearance of radiation-induced tumours was 42·6 years. Multiple carcinomas (>2 tumours) were observed in 23·3% of cases. In 73% of cases, ulceration was the most frequent macroscopic aspect. The predominant histological type was basal cell carcinoma in 82% of cases. Radiation therapy has been the main treatment modality in 77·3% of cases, followed by surgery in 43% of cases. The appearance of new tumours on the scalp was observed in six patients.
Conclusion:
Radiation-induced tumours of the scalp are comparable in epidemiological and clinical characteristics to non-radiation-induced tumours. However, they may represent a challenge in therapeutic care and require regular monitoring.
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.
Methods:
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.
Results:
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].
Conclusions:
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.
In recent years, there has been a growing interest to enhance patients’ symptom management during routine cancer care using patient-reported outcome measures. The goal of this study is to analyse patients’ responses to the Edmonton Symptom Assessment System (ESAS) to determine whether patient-reported outcomes could help characterise those patients with the highest supportive care needs and symptom burden in order to help provide targeted support for patients.
Methods:
In this study, we analysed ESAS questionnaire responses completed by patients as part of their routine care and considered part of patients’ standard of care. Statistical analyses were performed using the IBM SPSS Statistics version 26.0. Descriptive statistics are used to summarise patient demographics, disease characteristics and patient-reported symptom severity and prevalence.
Results:
The overall mean age is 65.2 ± 12.8 years comprising 43.8% male and 56.2% female patients. The five common primary disease sites are breast (26.2%), haematology (21.1%), gastrointestinal (15.3%), genitourinary (12.7%) and lung (12.0%) cancers. The mean severity for each symptom is all mild (score: 1–3). The three most common reported symptoms causing distress are tiredness, poor overall wellbeing and anxiety, and the least reported symptom is nausea.
Conclusions:
Systematic self-reporting of patients’ symptoms is important to improve symptom management, timely facilitation of appropriate intervention, patient experience, and patient and family satisfaction. The awareness of disease site, gender and age-related symptom variations should help in the design and provision of appropriate symptom-directed, tumour-specific and patient-focused interventions to meet patients’ immediate needs.
The RapidPlan is a radiotherapy planning tool that uses a dataset of approved plans to predict the dose distribution and automatically generates the dose–volume constraints for optimisation of the new plan. This study compares three strategies of model building for the treatment of prostate cancer with the 10-MV photon beam.
Methods:
Three models for prostate treatment were compared: Model 6X, Model10X and Model6Xrefined. Model6X is already used in our department and was trained on treatment plans based on the 6-MV photon beam. Model10X was trained on treatment plans based on the 10-MV photon beam and manually optimised by an experienced medical physicist. Finally, Model6Xrefined was trained on plans automatically created by the Model6X, but using the 10-MV photon beam. The three models were used to generate 25 new plans with the 10-MV photon beam.
Results:
Model10X generated plans with 2 Gy lower mean dose to bladder-PTV and rectum-PTV volumes and 8% lower V15Gy at bladder and rectum volumes, although the number of monitor units increased by 170 on average.
Conclusions:
The model trained on manually optimised plans generated plans with higher normal tissue sparing. However, model building is a time-consuming process, so a cost–benefit balance should be performed.
This study aimed to determine the radiation dose to the spleen in adjuvant chemoradiotherapy for gastric cancer, resulting in haematological toxicities.
Methods:
This retrospective analysis of a prospectively maintained database was conducted at a tertiary referral cancer centre. All patients with biopsy-proven non-metastatic gastric adenocarcinoma planned for adjuvant chemoradiotherapy from January 2017 to December 2021 were included. The mean dose to the spleen (Dmean) was estimated and correlated with the development of haematological toxicities.
Results:
The mean spleen volume was 186·65 cc. The Dmean to the spleen was 35·35 Gy (20–42 Gy). Grade 3 leukopenia was observed in 67%, grade 4 in 15%, and grade 3 thrombocytopenia was noted in 41% of patients. Radiotherapy (RT) dose > 35·5 Gy to the spleen resulted in ≥ grade 3 leukopenia. RT dose ≥ 36·5 Gy resulted in grade 3 thrombocytopenia. The occurrence of leukopenia and thrombocytopenia was also affected by the location of the primary gastric cancer (higher incidence in distal than in proximal tumours).
Conclusion:
The spleen should be considered as an important organs at risk during adjuvant RT for gastric cancer. Dmean to the spleen should be < 35·5 Gy to prevent major haematological toxicities.
The study was aimed to evaluate the effect of tumour involvement on resin Yttrium-90 (Y90) activity determination for metastatic liver cancer treatment.
Methods:
One hundred and two cases of resin Y90 microsphere treatment were retrospectively studied. Body surface area (BSA) method was used in the calculation of resin Y90 activity. The total activity (TA) was calculated as a summation of activities obtained from BSA-based calculation and tumour involvement (TI). TI and TA of each case were evaluated. The contributions of TI to TA were calculated with the ratio of TI/TA.
Results:
The average contribution of TI to TA was 4·1%. The contributions were < 5·8% in 75% of the cases, < 2·2% in 50% of the cases and < 1·0% in 25% of the cases.
Conclusions:
Overall the effect of tumour involvement on the activity determination was small. The activity calculation could be simplified by neglecting TI in 25% of the cases where the activity contribution from TI was less than 1%. Contouring tumour and liver structures for TI calculation could be avoided in these cases, and the efficiency of the workflow for resin Y90 procedures could be improved.
The use of volumetric modulated arc therapy (VMAT) on the breast has several dosimetric advantages but its impact on skin dose should be evaluated and compared to well-established treatment techniques using tangential fields. The aim of this work is to contrast the skin dose for VMAT and field-in-field (FIF) and to estimate the magnitude of the skin dose involved.
Method:
The skin dose was measured, without build-up, using thermoluminescent dosimeter (TLD) and optically stimulated luminescence dosimeter (OSLD) in breast radiotherapy by an in-house anthropomorphic phantom. Two different treatment techniques were used: FIF and VMAT, based on the planning strategy proposed by Nicolini et al. The dose levels were 4300 cGy, 4600 cGy and 5600 cGy in 20 fractions. In vivo dosimetry with TLD for VMAT was performed for different breast sizes in the same locations as phantom measurements.
Results:
The ipsilateral phantom breast skin dose using both treatment techniques was equivalent. TLD measured doses by the VMAT technique were up to 5% higher than OSLD, although they agree if we consider the geometry uncertainty of the TLD. In accordance with in vivo dosimetry, the mean dose of the ipsilateral breast skin was 62 ± 6% (51%, 75%) relative to the prescribed dose, regardless of the breast size for the volumes considered with this small population (n = 9) as shown by Mann–Whitney U-test (Z = 1·9, 95% confidence). The uncertainty expected in this region due to geometry (volume) changes is up to 9% higher for volumes from 225·9 cc to 968·8 cc. According to the treatment techniques and in vivo dosimetry, the contralateral breast skin dose was 1·0% in FIF and 2·5% in VMAT concerning the prescribed dose.
Conclusion:
There is no difference in skin dosimetry between VMAT and FIF techniques on the ipsilateral breast. It provides useful support for the use of VMAT as a planning technique for breast irradiation. The work describes the importance of quantifying potential differences in skin dosimetry.
Head and neck (HN) radiotherapy (RT) is complex, involving multiple target and organ at risk (OAR) structures delineated by the radiation oncologist. Site-agnostic peer review after RT plan completion is often inadequate for thorough review of these structures. In-depth review of RT contours is critical to maintain high-quality RT and optimal patient outcomes.
Materials and Methods:
In August 2020, the HN RT Quality Assurance Conference, a weekly teleconference that included at least one radiation oncology HN specialist, was activated at our institution. Targets and OARs were reviewed in detail prior to RT plan creation. A parallel implementation study recorded patient factors and outcomes of these reviews. A major change was any modification to the high-dose planning target volume (PTV) or the prescription dose/fractionation; a minor change was modification to the intermediate-dose PTV, low-dose PTV, or any OAR. We analysed the results of consecutive RT contour review in the first 20 months since its initiation.
Results:
A total of 208 patients treated by 8 providers were reviewed: 86·5% from the primary tertiary care hospital and 13·5% from regional practices. A major change was recommended in 14·4% and implemented in 25 of 30 cases (83·3%). A minor change was recommended in 17·3% and implemented in 32 of 36 cases (88·9%). A survey of participants found that all (n = 11) strongly agreed or agreed that the conference was useful.
Conclusion:
Dedicated review of RT targets/OARs with a HN subspecialist is associated with substantial rates of suggested and implemented modifications to the contours.