Radiotherapy Patients Research Articles

Investigating DWI changes in white matter of meningioma patients treated with proton therapy.

To evaluate changes in diffusion and perfusion-related properties of white matter (WM) induced by proton therapy, which is capable of a greater dose sparing to organs at risk with respect to conventional X-ray radiotherapy, and to eventually expose early manifestations of delayed neuro-toxicities. Apparent diffusion coefficient (ADC) and IVIM parameters (D, D* and f) were estimated from diffusion-weighted MRI (DWI) in 46 patients affected by meningioma and treated with proton therapy. The impact on changes in diffusion and perfusion-related WM properties of dose and time, as well as the influence of demographic and pre-treatment clinical information, were investigated through linear mixed-effects models. Decreasing trends in ADC and D were found for WM regions hit by medium-high (30-40Gy(RBE)) and high (>40 Gy(RBE)) doses, which are compatible with diffusion restriction due to radiation-induced cellular injury. Significant influence of dose and time on median ADC changes were observed. Also, D* showed a significant dependency on dose, whereas f consistently showed no dependency on dose and time. Age, gender and surgery extent were also found to affect changes in ADC. These results overall agree with those from studies conducted on cohorts of mixed proton and X-ray radiotherapy patients. Future work should focus on relating our findings with clinical information of co-morbidities and thus exploiting such or more advanced imaging data to build normal tissue complication probability models to better integrate clinical and dose information.

The Multidimensional Assessment for Pediatric Patients in Radiotherapy (M.A.P.-RT) Tool for Customized Treatment Preparation: RADAR Project.

Aims: Pediatric patients may experience considerable distress during radiotherapy. Combining psychological interventions with standard therapies can reduce the need for sedation. The RADAR Project aims to use a systematic method of recording data that can reveal patients' difficulties and fragility during treatment.In this context, the aim of our study was to investigate the ability of a multidimensional assessment tool (M.A.P.-RT schedule) to predict the need for sedation during radiotherapy. The schedule, which is administered during the first evaluation, was created to collect information on patients and their families in a standardized way.Materials and Methods: The study enrolled pediatric patients (aged 0–18 years or 18–21 with cognitive impairment). Data were collected by means of the M.A.P.-RT module; this explores various thematic areas, and is completed by the radiation oncologist, psychologist and nurse during their first evaluation. Features were selected by means of the Boruta method (random forest classifier), and the totals of the significant partial scores on each subsection of the module were inserted into a logistic model in order to test for their correlation with the use of anesthesia and with the frequency of psychological support. The results of logistic regression (LR) were used to identify the best predictors. The AUC was used to identify the best threshold for the scores in the evaluation.Results: A total of 99 patients were considered for this analysis. The feature that best predicted both the need for anesthesia and the frequency of psychological support was the total score (TS), the AUC of the ROC being 0.9875 for anesthesia and 0.8866 for psychological support.Conclusion: During the first evaluation, the M.A.P.-RT form can predict the need for anesthesia in pediatric patients, and is a potential tool for personalizing therapeutic and management procedures.

Predictors of radiation-induced complications in radiation oncology based on cell survival tests after ex vivo exposure: literature review

Background. Among cancer patients receiving radiotherapy about 5–15 % may have adverse reactions in normal tissues and organs that limit their treatment in a full, originally scheduled regimen. The development of biomarkers and assays for radiation oncology allowing the prediction of patients’ normal tissue toxicity requires a lot of resourses, threfore its current status amd potential directions for future research have to be periodically analyzed and re-evaluated.
 Purpose – this review summarizes the methodological approaches and developments in the area of functional laboratory assays based on ex vivo cell survival for the prediction of the individual clinical radiosensitivity.
 Materials and methods. Data for the analysis and systematization were obtained from the full-text articles published in peer review international scientific journals (in English) in 1990–2020, which were selected by the extensive search in PubMed information database and cross references on the topic “Functional cellular tests for intrinsic radiosensitivity to predict adverse radiation effects and radiotherapy complications”.
 Results. In theory, it might be expected that clonogenic cell survival after ex vivo irradiation can surve as the best individual predictor of radiation toxicity, as it is an integral indicator of cell damage and decline of their regenerative potential. Tendentially, fibroblasts, as a test system for such studies, did not show significant advantages over lymphocytes either in detecting inter-individual variations in the intrinsic cellular radiosensitivity or in predicting clinical radiation toxicity, even for that in skin. It was found that clonogenic cell survival assay, being very time consuming and technically demanding, also suffers from the lack of sensitivity and specificity, essential uncertainty and low reproducibility of the results, and thus is not suitable for the sceening for the abnormal intrinsic radiosensitivity. However, this type of assays is applicable for the radiobiological expertise post factum in individual cases with unexpected, extreme radiation lesions. Radiation-induced lymphocyte apoptosis assay seems to be more promising however still requires further fundamental research for better understanding of its background and more validation studies in order to assess the optimum patient groups, radiotherapy regimens and adverse effects for its confident use in clinical practice. Changes in the regulation of cell cycle check-points (radiationinduced delay) ex vivo can have either positive or inverted association, or no correlation with clinical radiation responses in tissues, thus so far cannot be included in the toolbox of applied radiobiological tests.
 Conclusions. To date, in the practice of clinical radiobiology, there are no fully validated and standardized functional tests based on the cell survival after ex vivo irradiation, which would allow a sufficiently accurate prediction of adverse radiation effects in normal tissues of radiotherapy patients. In general, ex vivo tests based on the evaluation of only one form of cell death in one cell type are not fully reliable as a “stand alone” assay, because different pathways of cell death probably play different roles and show different dose response within the overal reaction of the irradiated tissue or critical organ. Such tests should become a part of the multiparametric predictive platforms.

The Prevalence and Risk Factors of Tracheostomal Stenosis Following Total Laryngectomy

Background: Tracheostomal stenosis (TS) following total laryngectomy is relatively common in patientsand a distressing complication with major effects on patient rehabilitation it affected 4-44% of patientsfollowing total laryngectomy worldwide. Various etiological factors and some risks have been indicated ascontributing to the onset of stenosis.Purpose: We aimed to investigate the prevalence and risk factors of tracheostomy stenosis following totallaryngectomyMethod: Tracheostomal stenosis was defined as respiratory insufficiency at rest or during exercise, difficultyin tracheal clearance due to non laminar flow, or both. Eighty data of patients were enrolled in this studyconsisting of 76 male (95.0%) and 4 females (5.0%). Baseline characteristics (BL) stage of cancer (SC), typeof surgery (TS), the onset of stenosis following surgery (OS) and risk factors (RF) from each patient wererecorded and analyzed using a pre-installed statistic software.Result: The overall prevalence of tracheostomal stenosis was 13.8% (11 of 80 patients). The prevalence andrisk factors of tracheostomal stenosis following total laryngectomy consisted of 7 hypertrophic scar patients(63.3%), 2 infection patients (18.12), and 1 radiotherapy and peristomal fat patient (9.01), respectively.Conclusion: Out of eighty patients, eleven patients indicates the characters of tracheostomal stenosisusing the bevel technique. The most common etiological factor is hypertrophic scar, followed by infection,radiotherapy and peristomal fat.

Reducing 4DCBCT scan time and dose through motion compensated acquisition and reconstruction

Conventional 4DCBCT captures 1320 projections across 4 min. Adaptive 4DCBCT has been developed to reduce imaging dose and scan time. This study investigated reconstruction algorithms that best complement adaptive 4DCBCT acquisition for reducing imaging dose and scan time whilst maintaining or improving image quality compared to conventional 4DCBCT acquisition using real patient data from the first 10 adaptive 4DCBCT patients. Adaptive 4DCBCT was implemented in the ADaptive CT Acquisition for Personalized Thoracic imaging clinical trial. Adaptive 4DCBCT modulates gantry rotation speed and kV acquisition rate in response to the patient’s real-time respiratory signal, ensuring even angular spacing between projections at each respiratory phase. We examined the first 10 lung cancer radiotherapy patients that received adaptive 4DCBCT. Fast, 200-projection scans over 60–80 s, and slower, 600-projection scans over ∼240 s, were obtained after routine patient treatment and compared against conventional 4DCBCT acquisition. Adaptive 4DCBCT acquisitions were reconstructed using Feldkamp−Davis−Kress (FDK), McKinnon–Bates (MKB), Motion Compensated FDK (MCFDK) and Motion Compensated MKB (MCMKB) algorithms. Reconstructions were assessed via, Structural SIMilarity (SSIM), Signal-to-Noise-Ratio (SNR), Contrast-to-Noise-Ratio (CNR), Tissue Interface Sharpness of Diaphragm (TIS-D) and Tumor (TIS-T). The 200- and 600-projection adaptive 4DCBCT acquisition corresponded to 85% and 55% reduction in imaging dose, shorter and similar scan times of approximately 90 s and 236 s respectively, compared to conventional 4DCBCT acquisition. 200- and 600-projection adaptive 4DCBCT reconstructions achieved more than 0.900 SSIM relative to conventional 4DCBCT acquisition. Compared to conventional 4DCBCT acquisition, 200-projection adaptive 4DCBCT reconstructions achieved higher SNR, CNR, TIS-T, TIS-D with motion compensated algorithms, MCFDK (208%, 159%, 174%, 247%) and MCMKB (214%, 173%, 266%, 245%) respectively. The 200-projection adaptive 4DCBCT MCFDK- and MCMKB-reconstruction results show image quality improvements are possible even with 85% fewer projections acquired. We established acquisition-reconstruction protocols that provide substantial reductions in imaging time and dose whilst improving image quality.

Sedation and anesthesia of pediatric patient for External beam radiotherapy (XRT)

BACKGROUND: External beam radiation delivers a beam of high-energy x-rays to a patient's tumor site, Ιn order to destroy the cancer cells. External beam radiation gets its name from the fact that the beams come from an external source (a machine called a linear accelerator) and are aimed at the site of the tumor.AIM: was to obtain the most recent guideline in sedation and anesthesia of pediatric patient for External beam radiotherapy (XRT). Providing sedation anesthesia techniques during the performance of diagnostic and therapeutic procedures οn children decreases anxiety, discomfort, and pain and may improve child wellbeing. Immobilization is a pre-requisite for accurate radiotherapy. SUBJECTS and METHODS: This is a review article, the search was performed in MEDLINE , Embase , Pubmed, and CINHAL. RESULTS: Anesthetic drugs can be used in sub-anesthetic doses to cause sedation but, because they are potent, the difference between sedative and anesthetic doses is too small and airway skills are required too often for non-anesthetists to use them.C0NCLUSION: Sedation and anesthesia of pediatric patients have serious associated risks, as hypoventilation, apnea airway obstruction and cardiopulmonary impairment or depression. These risks should be avoided, diagnosed rapidly and treated appropriately. Medical practitioners responsible for the sedation process should know the nature of the sedatives and their side-effects. They should be able to detect and manage complications.This study was approved by the institutional ethical committee.

A feasibility trial of acupuncture in cancer patients undergoing radiotherapy treatment

ObjectiveWe conducted a feasibility trial of acupuncture in cancer patients undergoing radiotherapy treatment. The trial included training radiographers to deliver acupuncture within patients’ routine NHS care. MethodsMixed methods pragmatic randomized parallel-group exploratory feasibility trial comparing standard care to standard care plus acupuncture. ResultsMost aspects of the research design and acupuncture intervention were acceptable to the 101 participants. Participants’ valued the opportunity to receive acupuncture within their NHS care, perceived the treatment as eliciting a number of beneficial effects, and had a positive impact on their NHS cancer treatment. However, quantitative analysis of outcome measure data revealed no consistent significant differences between those receiving standard care and those receiving standard care plus acupuncture. ConclusionIt is feasible to implement acupuncture in a busy radiotherapy unit provided by specially trained radiographers. The methodology employed appears acceptable for the evaluation of acupuncture for radiotherapy patients.

Abstract P18: Radical cancer treatment is safe during COVID-19: The experience of a large London-based Comprehensive Cancer Centre

Abstract Background: The provision of cancer services has been strongly impacted by the outbreak of SARS-CoV-2. Our Cancer Centre in South-East London treats about 8,800 patients annually (incl. 4,500 new diagnoses) and is one of the largest Comprehensive Cancer Centres in the UK. The first COVID-19 positive cancer patient was reported on 29 Feb 2020. Whilst we are dealing with the second wave of COVID-19, it is important to further evaluate safety of cancer treatments whilst balancing risks of COVID-19 infection and complications. Methods: Using descriptive statistics, we report on the patient/tumour characteristics as well as short-term clinical outcomes of those patients undergoing radical treatment (i.e. systemic anticancer treatment (SACT), surgery, or radiotherapy (RT)) for their cancer during the first wave as to help establish the clinical guidelines for the management of cancer patients in a SARS-CoV-2 epidemic. Results: Between March-July 2020, 1,553 patients underwent surgery, 1,125 received SACT, and 814 had RT. Compared to the same period in 2019, there was a decrease of 28% for surgery, 15% for SACT, and 10% for radiotherapy. Whilst surgery was performed on more male patients (58%), more women received SACT (75%) and RT (58%). The age distribution was similar between treatment arms, with the majority of patients aged 50 to 80 years. The most common tumour types were breast (21%), thoracic (20%), and urological (29%) for surgical treatment; breast (49%), gastrointestinal (18%), and gynaecological (10%) for SACT; and breast (40%), urology (25%), and head & neck (11%) for RT. Within SACT, 36% received combination therapy, 35% received systemic chemotherapy, 23% targeted therapy, 5% immunotherapy, and 2% biological therapy. In terms of oncological outcomes, outcomes were similar to pre-COVID-19 times; with 6 deaths at 30 days (<1%) for surgical patients and 36 readmissions (2%), 10 deaths (<1%) for SACT patients, and 52% of RT delivered with radical intent (which was the same in 2019). The COVID-19 infection rates for our patients were very low: 12 patients were positive pre-surgery (1%), 7 post-surgery (<1%), 17 SACT patients (2%) and 3 RT patients (<1%). No COVID-19 related deaths were registered for the surgical, SACT and RT patients. Conclusion: Whilst there was a decline in overall radical treatment, likely due to a delay in cancer diagnoses, those who did undergo their treatment were treated in a safe COVID-19 managed environment. Our findings highlight that cancer patients should have the confidence to attend hospitals and be reassured of the safety measurements taken. Citation Format: Beth Russell, Victoria Harris, Harvey Dickinson, Charlotte Moss, Graham Roberts, Kate Haire, Eirini Tsotra, Harris Gousis, Debra Josephs, Deborah Enting, Ailsa Sita-Lumsden, Jose Roca, Vasilliki Michalaera, Mary Lei, Angela Swampillai, Eleanor Sawyer, Daniel Smith, Irene De Francesco, Teresa Guerrero-Urbano, Mieke Van Hemelrijck, Saoirse Dolly, Guy's Cancer Real World Evidence. Radical cancer treatment is safe during COVID-19: The experience of a large London-based Comprehensive Cancer Centre [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2021 Feb 3-5. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(6_Suppl):Abstract nr P18.

Generalized approach for radiotherapy treatment planning by optimizing projected health outcome: preliminary results for prostate radiotherapy patients

Research in cancer care increasingly focuses on survivorship issues, e.g. managing disease- and treatment-related morbidity and mortality occurring during and after treatment. This necessitates innovative approaches that consider treatment side effects in addition to tumor cure. Current treatment-planning methods rely on constrained iterative optimization of dose distributions as a surrogate for health outcomes. The goal of this study was to develop a generally applicable method to directly optimize projected health outcomes. We developed an outcome-based objective function to guide selection of the number, angle, and relative fluence weight of photon and proton radiotherapy beams in a sample of ten prostate-cancer patients by optimizing the projected health outcome. We tested whether outcome-optimized radiotherapy (OORT) improved the projected longitudinal outcome compared to dose-optimized radiotherapy (DORT) first for a statistically significant majority of patients, then for each individual patient. We assessed whether the results were influenced by the selection of treatment modality, late-risk model, or host factors. The results of this study revealed that OORT was superior to DORT. Namely, OORT maintained or improved the projected health outcome of photon- and proton-therapy treatment plans for all ten patients compared to DORT. Furthermore, the results were qualitatively similar across three treatment modalities, six late-risk models, and 10 patients. The major finding of this work was that it is feasible to directly optimize the longitudinal (i.e. long- and short-term) health outcomes associated with the total (i.e. therapeutic and stray) absorbed dose in all of the tissues (i.e. healthy and diseased) in individual patients. This approach enables consideration of arbitrary treatment factors, host factors, health endpoints, and times of relevance to cancer survivorship. It also provides a simpler, more direct approach to realizing the full beneficial potential of cancer radiotherapy.

Evaluation of HIF-1α and VEGF-A expression in radiation-induced cystitis: A case-control study.

ABSTRACTThe standard treatment for locally advanced cervical cancer (CC) is chemoradiotherapy. Once the bladder receives part of the radiation, a typical inflammatory condition that configures radiation-induced cystitis may develop. Chronic radiation-induced cystitis is commonly characterized by the bladder new submucosal vascularization, which is typically fragile and favors hematuria. The current study aims to investigate if Hypoxia-Induced Factor (HIF-1α) and its transcriptional target Vascular Endothelial Growth Factor A (VEGF-A) could be a primary pathway leading to increased submucosal vascularization. HIF-1α and VEGF-A mRNA levels in bladder core biopsies from CC patients treated with radiotherapy versus untreated (non-irradiated) patients were analyzed using a droplet digital polymerase chain reaction technology. Gene expression results showed that HIF-1α and VEGF-A had no significant differences between bladder samples from patients previously irradiated and untreated patient samples. However, a direct relationship between the degree of late morbidity and the expression of HIF-1α and VEGF-A has been demonstrated. Despite the lack of statistical significance precludes a definitive conclusion, the data presented herein suggests that further studies investigating the role of HIF-1α in bladder neovascularization in radiation-induced cystitis are highly recommended.

Examining the diagnostic pathway for lung cancer patients in Wales using discrete event simulation.

BackgroundUK’s National Health Service (NHS) has one of the poorest lung cancer survival rates in Europe. To improve patient outcomes, a single cancer pathway was introduced in the NHS. In this study, a Discrete Event Simulation was developed to understand bottlenecks during lung cancer treatment.MethodsThis study focused on the lung cancer diagnostic pathways at two Welsh hospitals. Discrete Event Simulation is a computer-based method that has been effectively used in demand and capacity planning. In this study, simulation models were developed for the current and proposed single cancer pathways. The validated models were used to provide Key Performance Indicators. Several “what-if” scenarios were considered for the current and proposed pathways.ResultsUnder the current diagnostic pathway, the mean time to treatment for a surgery patient was 68 days at the Royal Glamorgan Hospital and 79 days at Prince Charles Hospital. For chemotherapy patients, the mean time to treatment was 52 days at the Royal Glamorgan Hospital and 57 days at Prince Charles Hospital. For radiotherapy patients, the mean time to treatment was 44 days at Royal Glamorgan Hospital and 54 days at Prince Charles Hospital. Ensuring that the patient attends their first outpatient appointment within 7 days and streamlining the diagnostic tests would have the potential to remove approximately 20 days from the current lung cancer pathway resulting in a 20–25% increase of patients receiving treatment within 62 days. Ensuring that patients begin their treatment within 21 days of diagnosis sees almost all patients comply with the 62-day target.ConclusionsDiscrete Event Simulation coupled with a detailed statistical analysis provides a useful decision support tool which can be used to examine the current and proposed lung cancer pathways in terms of time spent on the pathway.

P02.14 Radiotherapy-Associated CT Imaging as a Potential Screening Tool for COVID-19

COVID-19 is associated with characteristic lung CT findings, such as rounded ground-glass opacities in certain distributions. Diagnosing COVID-19 is a particular concern in oncology care, since cancer patients are a vulnerable population who receive treatment in close proximity to other patients and staff. Radiotherapy patients routinely undergo CT simulation before starting therapy. We hypothesized that simulation CT scans obtained on patients treated during the pandemic would reveal characteristic COVID-19 findings and represent a tool to identify patients with asymptomatic COVID-19.

IPEM topical report: guidance on the use of MRI for external beam radiotherapy treatment planning * *Note: this work is part of an IPEM working party and work was shared between the group equally. The working party was chaired by Richard Speight.

This document gives guidance for multidisciplinary teams within institutions setting up and using an MRI-guided radiotherapy (RT) treatment planning service. It has been written by a multidisciplinary working group from the Institute of Physics and Engineering in Medicine (IPEM). Guidance has come from the experience of the institutions represented in the IPEM working group, in consultation with other institutions, and where appropriate references are given for any relevant legislation, other guidance documentation and information in the literature. Guidance is only given for MRI acquired for external beam RT treatment planning in a CT-based workflow, i.e. when MRI is acquired and registered to CT with the purpose of aiding delineation of target or organ at risk volumes. MRI use for treatment response assessment, MRI-only RT and other RT treatment types such as brachytherapy and gamma radiosurgery are not considered within the scope of this document. The aim was to produce guidance that will be useful for institutions who are setting up and using a dedicated MR scanner for RT (referred to as an MR-sim) and those who will have limited time on an MR scanner potentially managed outside of the RT department, often by radiology. Although not specifically covered in this document, there is an increase in the use of hybrid MRI-linac systems worldwide and brief comments are included to highlight any crossover with the early implementation of this technology. In this document, advice is given on introducing a RT workload onto a non-RT-dedicated MR scanner, as well as planning for installation of an MR scanner dedicated for RT. Next, practical guidance is given on the following, in the context of RT planning: training and education for all staff working in and around an MR scanner; RT patient set-up on an MR scanner; MRI sequence optimisation for RT purposes; commissioning and quality assurance (QA) to be performed on an MR scanner; and MRI to CT registration, including commissioning and QA.

Comparative Survival Outcomes of High-risk Prostate Cancer Treated with Radical Prostatectomy or Definitive Radiotherapy Regimens

BackgroundObservational data has indicated improved survival after radical prostatectomy (RP) compared with definitive radiotherapy (RT) in men with high-risk prostate cancer (PCa). ObjectiveTo compare PCa-specific mortality (PCSM) and overall mortality (OM) in men with high-risk PCa treated with RP or RT, providing information on target doses and fractionations. Design, setting, and participantsThis is an observational study from the Cancer Registry of Norway. Patients were diagnosed with high-risk PCa during 2006–2015, treated with RP ≤12 mo or RT ≤15 mo after diagnosis, and stratified according to RP or RT modality; external beam radiotherapy (EBRT; 70–<74, 74–<78, or 78 Gy), hypofractionated RT or EBRT combined with brachytherapy (BT-RT). Outcome measurements and statistical analysisCompeting risk and Kaplan-Meier methods estimated PCSM and OM, respectively. Multivariable Cox regression models evaluated hazard ratios (HRs) for PCSM and OM. Results and limitationsIn total, 9254 patients were included (RP 47%, RT 53%). RT patients were older, had poorer performance status and more unfavorable disease characteristics. With a median follow-up time of seven and eight yrs, the overall 10-yr PCSM was 7.2% (95% confidence interval [CI] 6.4–8.0) and OM was 22.9% (95% CI 21.8–24.1). Compared with RP, EBRT 70–<74 Gy was associated with increased (HR 1.88, 95% CI 1.33–2.65, p < 0.001) and BT-RT with decreased (HR 0.49, 95% CI 0.24–0.96, p = 0.039) 10-yr PCSM. Patients treated with EBRT 70–78 Gy had higher adjusted 10-yr OM than those treated with RP. ConclusionsIn men with high-risk PCa, treatment with EBRT <74 Gy was associated with increased adjusted 10-yr PCSM and OM, and BT-RT with decreased 10-yr PCSM, compared with RP. Patient summaryIn this study, we compared mortality after radical prostatectomy (RP) and radiotherapy (RT) in men with high-risk prostate cancer (PCa); the results suggest that men receiving lower-dose RT have higher, and patients receiving brachytherapy may have lower, risk of death from PCa than patients treated with prostatectomy.

Assessment of an ultrasound bladder scanner in prostate radiotherapy: A validation study and analysis of bladder filling variability.

During prostate radiotherapy treatment, it is important to ensure the position of the bladder and prostate is consistent between treatments. The aim of this study was to provide a quantitative basis for incorporating ultrasound bladder volume estimates into local practice for prostate radiotherapy. Agreement between bladder volume estimates obtained using computed tomography (CT) and ultrasound was assessed. Analysis of bladder volumes between planning and treatment scans was used to quantify expected variations in bladder volume over the course of radiotherapy. Dose-volume statistics were estimated and compared to planned dose constraints to propose a target bladder volume and tolerance. Bladder volume measurements were obtained from 19 radiotherapy patients using ultrasound and CT. Ultrasound underestimated bladder volume compared to CT with a mean bias of -28 ± 30 ml. Pre-treatment (planning) bladder volumes varied from 71 to 383 ml with a mean of 200 ml. Treatment bladder volumes reduced by more than half in 9% of patients during the course of their treatment, potentially leading to a 30% increase in mean bladder dose. Patients with pre-treatment bladder volumes < 200 ml were most likely to exhibit differences in bladder volume, resulting in 'out of tolerance' increases in dose. A pragmatic individualised drinking protocol, aimed at achieving a minimum ultrasound bladder volume of 200 ml at planning CT, may be beneficial to reproducibility in radiotherapy treatment. Ultrasound measurements prior to treatment should ideally confirm that bladder volume is at least half the volume measured at planning.

Relapse pattern and quality of life in patients with localized basal ganglia germinoma receiving focal radiotherapy, whole-brain radiotherapy, or craniospinal irradiation

Background and purposeThe optimal target volume in localized basal ganglia (BG) germinoma is still undetermined. Thus, based on the relapse pattern and health-related quality of life (HRQOL), we evaluated three target volumes. Material and methodsThe clinical data of 161 patients with localized BG germinoma were included in this retrospective study. Relapse status and relapse sites after treatment were explored. HRQOL was evaluated using the Pediatric Quality of Life Inventory 4.0 (PedsQL 4.0) (≤15 years) and Short Form-36 (SF-36) (>15 years) questionnaires based on the patients’ age at last follow-up. ResultsAfter a median follow-up duration of 83 months (range, 20–214 months), 19 patients experienced relapse, including 15, 4, and 0 patients in the focal radiotherapy (FR) (n = 35), whole-brain radiotherapy (WBRT) plus boost (n = 109), and craniospinal irradiation (CSI) plus boost (n = 17) groups, respectively. The 5-year disease-free survival rates were 74.3%, 97.2%, and 100%, respectively (p < 0.001). Among the 15 patients who relapsed after FR, 14 had positive radiological findings, including seven (50.0%) with lesions in the periventricular area and seven (50.0%) with frontal lobe lesions. Relapse in both these areas were significantly reduced by WBRT or CSI. HRQOL data were available for 69 patients, who generally scored low. Among 38 patients evaluated by SF-36, those receiving CSI had significantly lower mental component scores than those receiving WBRT (p = 0.027) or FR (p = 0.011). ConclusionsConsidering both disease control and HRQOL, WBRT is the optimal target volume in our series. The relapse pattern identified in patients receiving FR is informative for further treatment volume optimization.

Preparation and Effect of Selenium Nanoparticles/Oligochitosan on the White Blood Cell Recovery of Mice Exposed to Gamma-Ray Radiation

Owing to their excellent bioavailability, high bioactivity, and low toxicity, selenium nanoparticles (SeNPs) are emerging nanomaterials. In this study, SeNPs with a size of ∼41.8 nm were synthesised by γ-irradiation using oligochitosan (OCS) as the stabiliser. As-synthesized SeNPs/OCS were characterised by UV-Vis spectroscopy, transmission electron microscopy, and energy-dispersive X-ray (EDX) analysis. Results revealed that the as-obtained SeNP/OCS powder exhibits high purity. The SeNP/OCS solution’s stability test results indicated that the SeNP/OCS solution stored at 4°C exhibits good stability for 60 days. The SeNP/OCS solution was unstable at ambient temperature, and SeNP/OCS exhibited agglomeration after about 15 days. SeNP/OCS products recovered the total white blood cells of γ-ray irradiated mice. The SeNP/OCS product, which was synthesised by a green approach, with high purity and efficient recuperation of white blood cells, can be used potentially as a functional supplement to assist cancer radiotherapy patients.

Abstract PD4-05: Axillary recurrence is a rare event in node-positive patients. treated with sentinel node biopsy alone after neoadjuvant chemotherapy: Results of a prospective study

Abstract Background: Four prospective multi-institutional trials have demonstrated that clinically node-positive patients (cN1) who receive neoadjuvant therapy (NAC) and convert to cN0 can be reliably staged with sentinel lymph node biopsy (SLNB) with false-negative rates (FNRs) of &amp;lt; 10%, when ≥ 3 SLNs are retrieved. Since study patients all had axillary lymph node dissection (ALND), the rate of axillary recurrence after SLNB alone is unknown. Of concern is the possibility that residual chemotherapy-resistant axillary disease could lead to higher recurrence rates than seen in the primary surgery setting for cN0 patients where SLN FNRs of 5-10% result in axillary recurrence in &amp;lt; 1% of cases. Here we report regional recurrence rates in a prospectively defined cohort of cN1 patients receiving NAC, followed by a negative SLNB using a standardized technique, and no further axillary surgery. Methods: From 06/2014 to 02/2019, patients with cT1-3 biopsy-proven cN1 breast cancer who received NAC and converted to cN0 by physical exam were prospectively managed with SLNB with dual tracer mapping and omission of ALND if ≥ 3 SLNs were pathologically negative. Nodes were not routinely clipped, and retrieval of clipped metastatic nodes was not required. Pathologically negative SLNs were defined as the absence of any metastases including isolated tumor cells. Results: Of 610 cN1 patients treated with NAC, 555 (91%) converted to cN0 and had SLNB; 234 (42%) had ≥ 3 negative SLNs and were treated with SLNB alone. Median patient age was 49 years and median tumor size at presentation was 3 cm; 61% were HER2+ and 18% triple negative. Most (91%) received doxorubicin-based NAC and 88% received adjuvant radiotherapy (RT), with 80% (n = 164) of RT patients receiving nodal RT (Table). At a median follow-up of 35 months, there was only 1 (0.4%) axillary recurrence for the entire cohort, synchronous with a breast recurrence, in a patient who refused RT. Among patients who received RT (n = 205), there were no axillary recurrences. The 4-year rate of distant recurrence for all patients was 6.1% (95% CI, 3.4-10.7%) and 4-year overall survival was 93.9% (95% CI, 87.6-97.1%). Conclusion: In cN1 patients treated with NAC, rates of axillary recurrence in patients with ≥ 3 pathologically negative SLNs treated with SLNB alone were low, without routine nodal clipping. Although further follow-up is needed, multiple studies have shown that nodal recurrence is an early event, particularly in HER2+ and triple negative patients, who comprised the majority of the population. Our findings support omitting ALND in cN1 patients after NAC when the SLNs are negative using an optimal SLNB technique. Table. Patient PopulationOverall cohort (n = 234)Age, years (median, IQR)49 (40, 58)Tumor size at presentation, cm (median, IQR)3.0 (2.2, 5.0)Number SLNs retrieved (median, IQR)4 (3, 5)Palpable nodes at presentation (n, %)179 (76%)HistologyDuctal211 (90%)Lobular and mixed7 (3%)Micropapillary and mixed10 (4%)Other3 (1%)Occult3 (1%)DifferentiationWell1 (0.5%)Moderate36 (15%)Poor196 (84%)Unknown1 (0.5%)Receptor StatusHR+/HER2-47 (20%)HR+/HER2+80 (34%)HR-/HER2+64 (27%)HR-/HER2-43 (18%)Breast SurgeryBCS118 (50%)Mastectomy116 (50%)Breast pCR¥Yes161 (70%)No70 (30%)NAC regimenAC-T197 (84%)AC-T + carbo15 (6.4%)TC8 (3.4%)Other14 (6%)Neoadjuvant anti-HER2 treatmentHP (dual-therapy)144 (100%)Adjuvant RTYes205 (88%)No*29 (12%)¥3 patients had occult primary breast cancer and were not included in breast pCR calculation; *6/29 patients who did not receive RT enrolled in NSABP B-51 Citation Format: Andrea V Barrio, Giacomo Montagna, Anita Mamtani, Varadan Sevilimedu, Hiram S Cody, III, Mahmoud El-Tamer, Mary L Gemignani, Alexandra S Heerdt, Tracy-Ann Moo, Melissa Pilewskie, George Plitas, Lisa Sclafani, Kimberly J Van Zee, Monica Morrow. Axillary recurrence is a rare event in node-positive patients. treated with sentinel node biopsy alone after neoadjuvant chemotherapy: Results of a prospective study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD4-05.

Incorporating parotid gland inhomogeneity into head-and-neck treatment optimization through the use of artificial base plans.

Despite a great improvement in target volume dose conformality made possible in recent years by modulated therapies, xerostomia remains a common and severe side effect for head‐and‐neck radiotherapy patients. It is known that parotid glands exhibit a spatially varying dose response; however, the relative importance of subregions throughout the entire gland has yet to be incorporated into treatment plan optimization, with the current standard being to minimize the mean dose to whole parotid glands. The relative importance of regions within contralateral parotid glands has been recently quantified, creating an opportunity for the development of a method for including this data in plan optimization. We present a universal and straightforward approach for imposing varying sub‐parotid gland dose constraints during inverse treatment planning by using patient‐specific artificial base plans to penalize dose deposited in sensitive regions. In this work, the proposed method of optimization is demonstrated to reduce dose to regions of high relative importance throughout contralateral parotids and improve predictions for stimulated saliva output at 1‐year post‐radiotherapy. This method may also be applied to impose varying dose constraints to other organs‐at‐risk for which regional importance data exists.

Positron emission tomography after response to rituximab-CHOP in primary mediastinal large B-cell lymphoma: impact on outcomes and radiotherapy strategies.

End-of-treatment (EoT) PET/CT is used as a guide to omit radiotherapy (RT) patients with primary mediastinal large B-cell lymphoma (PMBCL). We present the mature and extended results of a retrospective study evaluating the prognostic significance of EoT-PET/CT after adequate response to R-CHOP. Among 231 consecutive PMLBCL patients, 182 underwent EoT-PET/CT and were evaluated according to the Deauville 5-point scale (D5PS) criteria. Freedom from progression (FFP) was measured from the time of PET/CT examination. Among 182 patients, 72 (40%) had D5PS score 1 (D5PSS-1), 33 (18%) had 2, 28 (15%) had 3, 29 (16%) had 4, and 20 (11%) had 5. The 5-year FFP was 97, 94, 92, 82, and 44% for D5PSS-1, D5PSS-2, D5PSS-3, D5PSS-4, and D5PSS-5, respectively. Among 105 patients with unequivocally negative PET/CT (D5PSS-1/D5PSS-2), 49 (47%) received RT (median dose 3420 cGy) and 56 (53%) did not with relapses in 0/49 vs. 4/56 patients (2 mediastinum and 2 isolated CNS relapses).The 5-year FFP for those who received RT or not was 100% versus 96%, when isolated CNS relapses were censored (p = 0.159). Among D5PSS-3 patients (27/28 irradiated-median dose 3600 cGy), the 5-year FFP was 92%. The 5-year FFP for D5PSS-4 and D5PSS-5 was 82 and 44%; 44/49 patients received RT (median dose 4000 and 4400 cGy for D5PSS-4 and D5PSS-5). Our study supports the omission of RT in a sizeable fraction of PET/CT-negative patients and definitely discourages salvage chemotherapy and ASCT in patients with PMLBCL who conventionally respond to R-CHOP, solely based on PET/CT positivity in the absence of documented progressive or multifocal disease. The persistence of positive PET/CT with D5PSS < 5 after consolidative RT should not trigger the initiation of further salvage chemotherapy in the absence of conventionally defined PD.