Pediatric Radiation Research Articles

MRI-based inter- and intrafraction motion analysis of the pancreatic tail and spleen as preparation for adaptive MRI-guided radiotherapy in neuroblastoma

BackgroundIn pediatric radiotherapy treatment planning of abdominal tumors, dose constraints to the pancreatic tail/spleen are applied to reduce late toxicity. In this study, an analysis of inter- and intrafraction motion of the pancreatic tail/spleen is performed to estimate the potential benefits of online MRI-guided radiotherapy (MRgRT).Materials and methodsTen randomly selected neuroblastoma patients (median age: 3.4 years), irradiated with intensity-modulated arc therapy at our department (prescription dose: 21.6/1.8 Gy), were retrospectively evaluated for inter- and intrafraction motion of the pancreatic tail/spleen. Three follow-up MRIs (T2- and T1-weighted ± gadolinium) were rigidly registered to a planning CT (pCT), on the vertebrae around the target volume. The pancreatic tail/spleen were delineated on all MRIs and pCT. Interfraction motion was defined as a center of gravity change between pCT and T2-weighted images in left-right (LR), anterior-posterior (AP) and cranial-caudal (CC) direction. For intrafraction motion analysis, organ position on T1-weighted ± gadolinium was compared to T2-weighted. The clinical radiation plan was used to estimate the dose received by the pancreatic tail/spleen for each position.ResultsThe median (IQR) interfraction motion was minimal in LR/AP, and largest in CC direction; pancreatic tail 2.5 mm (8.9), and spleen 0.9 mm (3.9). Intrafraction motion was smaller, but showed a similar motion pattern (pancreatic tail, CC: 0.4 mm (1.6); spleen, CC: 0.9 mm (2.8)). The differences of Dmean associated with inter- and intrafraction motions ranged from − 3.5 to 5.8 Gy for the pancreatic tail and − 1.2 to 3.0 Gy for the spleen. In 6 out of 10 patients, movements of the pancreatic tail and spleen were highlighted as potentially clinically significant because of ≥ 1 Gy dose constraint violation.ConclusionInter- and intrafraction organ motion results into unexpected constrain violations in 60% of a randomly selected neuroblastoma cohort, supporting further prospective exploration of MRgRT.

Assessing Equity of Family Members’ Roles in Supporting Pediatric Patients Receiving Proton Radiation Therapy: A Retrospective Study of Parent/Guardian Attendance at Clinic Visits

The primary burden of receiving radiation therapy falls on the patient. However, families of pediatric patients receiving radiation therapy experience interruptions in their lives and make great sacrifices so their children can receive cancer care that spans weeks to months. There is a paucity of literature on relative burden of care on female versus male caregivers in pediatric cancer care in general, and no prior reports on the relative burden for each in pediatric radiation therapy. The purpose of our study was to determine on whom the burden of bringing pediatric patients to radiation therapy appointments falls. Our hypothesis was that it disproportionately falls on female parents/guardians. With Institutional Review Board approval, the charts of patients less than 18 years old at the time of treatment at a proton center were reviewed. Ninety-four patients treated between January 1, 2021, to July 12, 2022, were identified and their family structures were categorized. Notes from one consultation per patient and a total of 493 on treatment visits were reviewed to identify which caregivers attended these visits. Attendance was analyzed to assess differences between female and male parents/guardians. Mothers lived in the homes of 88 patients, and three other parent-age female guardians living in homes of pediatric patients were identified. Fathers lived in the homes of 76 patients, and two other parent-age male guardians were identified. Seventy-three patients lived with both their mother and father, and 20 lived with other combinations of parents/guardians. No children lived in homes where parents were both male or both female. The family structure of one patient's home could not be identified. Mothers and all female parents/guardians attended 78% and 81% of all clinic visits, respectively; fathers and all male parents/guardians attended 41% and 42% of all clinic visits. However, whereas 55% of consultations were attended by both the patient's mother and father, only 21% of on treatment visits were attended by both. While a majority of patients live with both male and female parents/guardians, female parents/guardians carry a higher burden of bringing pediatric patients to receive their radiation care. Consultations are more likely to be attended by both female and male caregivers, and subsequent visits are more likely to be attended by either. This greater burden of care by female caregivers should be recognized and supported by providers and cancer care organizations.

Pancreas: An Organ-at-Risk to Consider in Future Pediatric Abdominal Radiotherapy

Irradiation to the pancreas during pediatric radiotherapy is associated with secondary late effects, yet the pancreas is not typically considered an organ-at-risk (OAR) during radiotherapy planning. This audit investigated incidental pancreatic doses to estimate the relative risk (RR) of developing diabetes in later life. Incidental pancreas doses were audited from 92 patients aged 2 to 19 historically treated with photons for craniospinal irradiation (CSI, N = 73) and for abdominal neuroblastoma (N = 19). Prescription doses ranged 21-36 Gy and 21-39 Gy (with boost to spine up to 50 Gy) for neuroblastoma and CSI patients, respectively. The pancreas was segmented on all planning CT scans following RTOG guidelines. Furthermore, the pancreas was split into its sub-volumes (head, body and tail) for abdominal cases only, since these scans were acquired with contrast enhancement. The RR of developing subsequent diabetes was estimated as a function of dose (D): RR = 1+0.65 × D × exp(-0.3 × D). Dose to the pancreas tail was used for neuroblastoma cases, whereas dose to the whole pancreas was used for CSI patients given that the pancreas could not be split in non-contrast scans. The mean dose delivered to the whole pancreas was 15.4±7.5 Gy for all patients, 12.7±4.7 Gy for CSI patients and 25.9±7.4 Gy for abdominal patients. Pancreas V10Gy was 61.2% for all patients, 51.5% for CSI, and 98.6% for abdominal patients; V30Gy = 0% in all cases. These doses represented an estimated diabetes RR of 7.3±1.5, 6.6±1.3, and 8.7±0.6, respectively; RR>5 in 88%, 85% and 100% of all patients, CSI and abdominal patients audited, respectively. Current incidental doses were associated with a diabetes RR>5 in all patients treated for abdominal neuroblastoma and the majority who received CSI. These findings suggest the pancreas should be routinely delineated and considered as an OAR in radiotherapy planning. This may help to identify higher risk patients and inform late-effect monitoring during survivorship. Further work in underway to assess if proton therapy could reduce the RR of diabetes particularly in abdominal cases. Improved availability of high-quality imaging during radiotherapy planning, such as contrast administration or planning MRI, is becoming more necessary to accurately delineate subsegments of the pancreas for improved RR estimations.

Rural Pediatric Radiation Oncology in the Era of COVID-19: A Single Institution Analysis

Health inequities have recently gained prominence in public consciousness as a result of the COVID-19 pandemic. Rural access to care was particularly impacted regarding delays in cancer screening, diagnosis, and treatment. The fractionated nature of radiotherapy creates transportation burdens in this population. We reviewed our institutional experience with pediatric radiotherapy at a tertiary academic center serving a primarily rural population over a large geographic area. The financial burden of radiotherapy in pediatric patients in our database was modeled using cost-analysis. The cost of transportation using distance to our facility and the IRS-assessed tax value per mile was calculated. Correlative analyses were conducted to evaluate the association of radiotherapy delivered pre- vs. post-COVID with patient race, age at diagnosis, and distance from our institution. Analyses were conducted with two-tailed Pearson correlations for transportation cost vs. age at diagnosis. Mann-Whitney U testing was used to analyze transportation cost vs. patient race. Fisher's Exact Test was used to analyze the trends between tumor primary sites pre- and post-COVID. There was a statistically significant increase in brain tumors vs. all others from 9.1% to 66.7% post-COVID (p = 0.029). When comparing patients treated prior to the onset of the COVID-19 pandemic in 2020 to those treated during the peak years of the pandemic in 2020-2021, there was no difference in the average distance traveled for treatment. However, the mean cost of transportation for pediatric patients undergoing radiotherapy prior to COVID-19 was $266 USD (median = $331), vs. a mean of $535 (median = $378) for patients treated during 2020-2021. For patients treated in 2022, after the height of COVID-19, the mean cost of transportation was $501 (median = $432). No statistically significant differences were found between the cost of transportation and patient race or age at diagnosis before vs. after the onset of COVID-19. Our results highlight the importance of understanding barriers to care and what type of resources are most impactful to rural pediatric patients at our center. The rise of transportation costs for radiotherapy following the COVID-19 pandemic may indicate an additional barrier to care, potentially associated with increasing inflation, for rural pediatric patients that is underreported in the literature. The rise in the relative prevalence of brain tumors at our institution during this period warrants further investigation.

The need for consensus on delineation and dose constraints of dentofacial structures in paediatric radiotherapy: Outcomes of a SIOP Europe survey

Background and purposeChildren receiving radiotherapy for head-and-neck tumours often experience severe dentofacial side effects. Despite this, recommendations for contouring and dose constraints to dentofacial structures are lacking in clinical practice. We report on a survey aiming to understand current practice in contouring and dose assessment to dentofacial structures. MethodsA digital survey was distributed to European Society for Paediatric Oncology members of the Radiation Oncology Working Group, and member-affiliated centres in Europe, Australia, and New Zealand. The questions focused on clinical practice and aimed to establish areas for future development. ResultsResults from 52 paediatric radiotherapy centres across 27 countries are reported. Only 29/52 centres routinely delineated some dentofacial structures, with the most common being the mandible (25 centres), temporo-mandibular joint (22), dentition (13), orbit (10) and maxillary bone (eight). For most bones contoured, an ‘As Low As Reasonably Achievable’ dose objective was implemented. Only four centres reported age-adapted dose constraints.The largest barrier to clinical implementation of dose constraints was firstly, the lack of contouring guidance (49/52, 94%) and secondly, that delineation is time-consuming (33/52, 63%). Most respondents who routinely contour dentofacial structures (25/27, 90%) agreed a contouring atlas would aid delineation. ConclusionRoutine delineation of dentofacial structures is infrequent in paediatric radiotherapy. Based on survey findings, we aim to 1) define a consensus-contouring atlas for dentofacial structures, 2) develop auto-contouring solutions for dentofacial structures to aid clinical implementation, and 3) carry out treatment planning studies to investigate the importance of delineation of these structures for planning optimisation.

Validation of an automated contouring and treatment planning tool for pediatric craniospinal radiation therapy.

Treatment planning for craniospinal irradiation (CSI) is complex and time-consuming, especially for resource-constrained centers. To alleviate demanding workflows, we successfully automated the pediatric CSI planning pipeline in previous work. In this work, we validated our CSI autosegmentation and autoplanning tool on a large dataset from St. Jude Children's Research Hospital. Sixty-three CSI patient CT scans were involved in the study. Pre-planning scripts were used to automatically verify anatomical compatibility with the autoplanning tool. The autoplanning pipeline generated 15 contours and a composite CSI treatment plan for each of the compatible test patients (n=51). Plan quality was evaluated quantitatively with target coverage and dose to normal tissue metrics and qualitatively with physician review, using a 5-point Likert scale. Three pediatric radiation oncologists from 3 institutions reviewed and scored 15 contours and a corresponding composite CSI plan for the final 51 test patients. One patient was scored by 3 physicians, resulting in 53 plans scored total. The algorithm automatically detected 12 incompatible patients due to insufficient junction spacing or head tilt and removed them from the study. Of the 795 autosegmented contours reviewed, 97% were scored as clinically acceptable, with 92% requiring no edits. Of the 53 plans scored, all 51 brain dose distributions were scored as clinically acceptable. For the spine dose distributions, 92%, 100%, and 68% of single, extended, and multiple-field cases, respectively, were scored as clinically acceptable. In all cases (major or minor edits), the physicians noted that they would rather edit the autoplan than create a new plan. We successfully validated an autoplanning pipeline on 51 patients from another institution, indicating that our algorithm is robust in its adjustment to differing patient populations. We automatically generated 15 contours and a comprehensive CSI treatment plan for each patient without physician intervention, indicating the potential for increased treatment planning efficiency and global access to high-quality radiation therapy.

Diagnostic performance of artificial intelligence for pediatric pulmonary nodule detection on chest computed tomography: comparison of simulated lower radiation doses.

The Lung CAD shows low sensitivity at all simulated lower doses for the detection of pulmonary nodules in this pediatric population. However, radiation dose may be reduced from standard without further compromise to the Lung CAD performance. • High diagnostic performance of Lung CAD for detection of pulmonary nodules in adults. • Several imaging techniques are applied to reduce pediatric radiation dose. • Low sensitivity at all simulated lower doses for the detection of pulmonary nodules in our pediatric population. • Radiation dose may be reduced from standard without further compromise to the Lung CAD performance.

Pediatric Radiation Therapy at the Princess Margaret Cancer Centre

Pediatric Radiation Therapy at the Princess Margaret Cancer Centre

308 Safety Incidents and Near-Miss Events in Pediatric Radiotherapy

308 Safety Incidents and Near-Miss Events in Pediatric Radiotherapy

A pilot study to estimate the Pediatric radiation dose during thyroid, renal, and bone scan

Pediatric patients benefited from nuclear medicine (NM) results. NM provides information regarding the general and localized function of the body's organs, systems, and lesions. This includes applications in the bone, neuro, renal, cardiovascular, endocrine, and other organ systems, as well as in detecting and managing cancer. The administration of radiopharmaceuticals associated with exposure to ionizing radiation is a necessary component of NM practice. This study aims to estimate the Pediatric radiation dose during thyroid, renal, and bone scans. Methods The study involved 161 pediatric patients who underwent thyroid, renal, and bone scans using Tc-99m radionuclide. Effective dose has been estimated using web-based software depending on conductive activity.Effective dose has been estimated using computer software depending on conductive activity. The results show patient dose information from thyroid, renal, and bone scans. For a thyroid scan, the patient's age was 12.26 ± 3.65 years, the patient's height was 1.43 ± 0.20 cm, and the patient's weight was 41.87 ± 16.56 kg. The activity was 2.89 ± 1.12 mCi, and the effective dose for thyroid was 1.92 ± 0.81 mSv. For the renal scan, the patient's age was 6.55 ± 4.83 years, height was 1.09 ± 0.37 cm, and weight was 24.01 ± 18.19 kg. The activity was 2.41 ± 0.88 mCi, and the effective dose was 0.72 ± 0.19 mSv. for a bone scan patient's age was 11 ± 4.12 years, the patient's height was 1.4 ± 0.19 cm, the patient's 33.64 ± 14.3 kg. the activity 11.46 ± 3.64 mCi and the effective dose 3.1 ± 0.61 mSv.Implementing national guidelines must improve the practice and patient safety, and the relationship between administered activity and patient weight needs to be better understood.

RadioTransNet, Radiotherapy Translational and Preclinical Research Network: Results from the dedicated French cancer institute (INCa) call for projects

PurposeThe RadioTransNet project is a French initiative structuring preclinical and translational research in radiation therapy for cancer at national level. The network's activities are organized around four chosen priorities, which are: target definition, normal tissue, combined treatments and dose modelling. The subtargets linked to these four major priorities are unlimited. They include all aspects associated with fundamental radiobiology, preclinical studies, imaging, medical physics research and transversal components clearly related to these scientific areas, such as medical oncology, radio-diagnostics, nuclear medicine and cost-effectiveness considerations. MethodDuring its first phase of activity, four workshops following the consensus conference model and based on scientific and medical state of the art in radiotherapy and radiobiology were organized on the four above-mentioned objectives to identify key points. Then a road map has been defined and served as the basis for the opening in 2022 of a dedicated call, SEQ-RTH22, proposed by the French cancer national institute (INCa). ResultsFour research projects submitted by RadioTransNet partners have been selected to be supported by INCa: the first by Professor Anne Laprie from Oncopole Claudius-Regaud and Inserm ToNic in Toulouse on neurocognition and health after pediatric irradiation, the second submitted by Fabien Milliat from IRSN aims to study decryption and targeting of endothelial cell–immune cells interactions to limit radiation-induced intestinal toxicity, the third project, submitted by Yolanda Prezado from institut Curie–CNRS on proton minibeam radiotherapy as a new approach to reduce toxicity, and the latest project proposed by R. de Crevoisier from centre Eugène-Marquis in Rennes on predictive multiscale models of head and neck radiotoxicity induced for optimized personalized radiation therapy. Topics of each of these projects are presented here. ConclusionRadioTransNet project has been launched in 2018, supported by INCa, in order to structure and promote preclinical research in oncology radiotherapy and to favor collaboration between the actors of this research. INCa relied on RadioTransNet initiatives and activities, resulting in the opening of dedicated call for projects. Beyond its first main goals, RadioTransNet network is able to help to fund the human and technical resources necessary to conduct optimal translational and preclinical research in radiation oncology.

Management of the vertebrae as an organ at risk in paediatric radiotherapy clinical trials: Initial QUARTET experience

Irradiation of the vertebrae in prepubertal patients, if non-homogenous, can result in future growth deformities including kyphoscoliosis. Vertebral delineation and dosimetry were assessed for 101 paediatric cases reviewed within QUARTET-affiliated trials. Despite the availability of published consensus guidelines, a high variability in vertebral delineation was observed, with impact on dosimetry.

Techniques and Complications of Anesthesia in Pediatric Radiotherapy: A Retrospective Cohort Study.

Anesthesia during pediatric external beam radiation therapy poses a challenge, as radiotherapy rooms are not designed for the administration of anesthesia. We conducted a retrospective cohort study of children who underwent radiation therapy to describe the anesthetic approach and assess anesthetic-related complications. Data of all, who underwent radiation therapy under general anesthesia between November 2019 and January 2021, were recorded. Data were obtained from medical records, including demographic characteristics and information, regarding the anesthetic procedure and its associated complications. We describe our protocols for preoperative assessment, anesthetic procedures, and postanesthetic discharge evaluation. Over the reporting period, 739 sessions of general anesthesia were performed. The mean number of radiation therapy rounds per patient was 23.5 sessions. Anesthetic induction was accomplished by sevoflurane inhalation in 639 sessions (86.4%) and intravenous propofol in the remaining 13.6%. General anesthesia was maintained with sevoflurane in all cases. Anesthesia-related complications occurred in 118 sessions (15.7%). The most frequent was nausea in 48 (6.4%) cases, followed by hypotension in 38 (5.1%). Airway-related complications occurred at a low frequency (2.3%), and all were resolved successfully with positive pressure ventilation. No patient hospitalizations were required because of any anesthetic complications. Inhalation anesthesia is reliable and safe for pediatric patients undergoing radiation therapy.

An evaluation of the use and efficacy of behavioural therapy when treating paediatric patients with radiation therapy.

The paediatric radiation therapy group (PRTG) provided a multidisciplinary network to support patients accessing radiation therapy (RT). This study aims to evaluate the use and efficacy of behaviour therapy practices used by the PRTG. A retrospective cross-sectional review of general anaesthetic (GA) utilisation for paediatric patients was completed between 1 January 2010 and 30 June 2014. The PRTG incorporated behavioural therapy techniques into all appointments but offered additional play appointments to children unable to comply with the requirements of RT. This aimed to increase their compliance and minimise GA use. Two-hundred and seventy-four patients had 5402 occasions of service, of which 1361 were delivered under GA (25.2%). Two-hundred and fifty-seven patients met the eligibility criteria. Patients under 8 years who required GA for their entire treatment reduced for each year of increase in age (odds ratio 0.37, 95% confidence interval 0.27-0.51, P < 0.001). Participants 3 years and younger were shown not as likely to change their GA requirements with the use of play appointments. Seventy-eight per cent (83/106) of 3-8-year-olds used no GA or ceased GA during treatment. Most paediatric patients <3 years will gain minimal benefit to reduce GA use from additional play appointments. Children older than nine were not likely to require play appointments to be compliant with RT. Encouragingly, 53.3% of 3-8-year-olds who were categorised as full GA after CT planning did not continue to a full course of GA due to the behavioural therapy interventions of the PRTG.

Analysis of the Pediatric Radiotherapy Landscape in Mexico and a Subsequent Educational e-Contouring Intervention.

Mexico and Central America have the highest childhood cancer incidence in the West. Pediatric-specific oncology knowledge contributes to the disparity. We sought to (1) determine the self-identified treatment patterns and needs of Mexican pediatric radiation oncologists and (2) pilot a workshop to improve contouring accuracy. Partnering with local experts and the Sociedad Mexicana de Radioterapeutas (SOMERA), a 35-question survey was designed to ascertain pediatric radiotherapy capacity and distributed through the SOMERA listserv. The most challenging malignancies were selected for workshop. Participants received precontouring and postcontouring homework to assess improvement per the Dice metric. The Wilcoxon sign-rank test was used for comparative statistics. Ninety-four radiation oncologists attempted and 79 completed the survey. Forty-four (76%) felt comfortable treating a pediatric patient, and 36 (62%) were familiar with national protocols for pediatric treatment. Most had access to nutrition, rehabilitation, endocrinology, and anesthesia; 14% had access to fertility services and 27% to neurocognitive support; 11% noted no support, and only one respondent had child-life support. The postsurvey contouring workshop was conducted for high-grade glioma, medulloblastoma, and Hodgkin lymphoma. Significant improvements were seen in all target volumes. We present the first national survey of Mexico's pediatric radiotherapy capacity and Latin American e-contouring educational intervention with preworkshop and postworkshop Dice metrics, noting statistically significant improvement in all target volumes. Participation improved compared with prior experience through SOMERA partnership and Continuing Medical Education incentivization.

Impact of COVID-19 pandemic on delivery of pediatric radiotherapy: A critical review.

The COVID-19 pandemic has prevented the timely diagnosis and treatment of many diseases, including pediatric cancer. Its impact on pediatric oncologic treatments warrants investigation. As radiotherapy is an integral component of cancer care, we reviewed the published data regarding the impact of COVID-19 on the delivery of pediatric radiotherapy to inform actions for future global events. We found that disruptions in radiotherapy were reported amongst interruptions in other therapies. Disruptions were more common in low-income countries (78%) and low middle-income countries (68%) compared with upper middle-income countries (46%) and high-income countries (10%). Several papers included recommendations for mitigation strategies. Altered treatment regimens were common, including increasing the use of active surveillance and systemic therapy to delay local therapies, and accelerated/hypofractionated dose delivery. Our findings suggest that COVID-19 has impacted radiotherapy delivery in the pediatric population globally. Countries with limited resources may be more affected. Various mitigation strategies have been developed. The efficacy of mitigation measures warrants further investigation.

The Pediatric Proton and Photon Therapy Comparison Cohort: Study Design for a Multicenter Retrospective Cohort to Investigate Subsequent Cancers After Pediatric Radiation Therapy

The physical properties of protons lower doses to surrounding normal tissues compared with photons, potentially reducing acute and long-term adverse effects, including subsequent cancers. The magnitude of benefit is uncertain, however, and currently based largely on modeling studies. Despite the paucity of directly comparative data, the number of proton centers and patients are expanding exponentially. Direct studies of the potential risks and benefits are needed in children, who have the highest risk of radiation-related subsequent cancers. The Pediatric Proton and Photon Therapy Comparison Cohort aims to meet this need. We are developing a record-linkage cohort of 10,000 proton and 10,000 photon therapy patients treated from 2007 to 2022 in the United States and Canada for pediatric central nervous system tumors, sarcomas, Hodgkin lymphoma, or neuroblastoma, the pediatric tumors most frequently treated with protons. Exposure assessment will be based on state-of-the-art dosimetry facilitated by collection of electronic radiation records for all eligible patients. Subsequent cancers and mortality will be ascertained by linkage to state and provincial cancer registries in the United States and Canada, respectively. The primary analysis will examine subsequent cancer risk after proton therapy compared with photon therapy, adjusting for potential confounders and accounting for competing risks. For the primary aim comparing overall subsequent cancer rates between proton and photon therapy, we estimated that with 10,000 patients in each treatment group there would be 80% power to detect a relative risk of 0.8 assuming a cumulative incidence of subsequent cancers of 2.5% by 15 years after diagnosis. To date, 9 institutions have joined the cohort and initiated data collection; additional centers will be added in the coming year(s). Our findings will affect clinical practice for pediatric patients with cancer by providing the first large-scale systematic comparison of the risk of subsequent cancers from proton compared with photon therapy.

Re-irradiation in Paediatric Tumours of the Central Nervous System: National Guidelines from the Swedish Workgroup of Paediatric Radiotherapy

There is a lack of clinical protocols for re-irradiation in paediatric central nervous system (CNS) tumours. To fill this void, the Swedish Workgroup of Paediatric Radiotherapy (SBRTG) compiled national guidelines on re-irradiation in paediatric CNS tumours (diffuse intrinsic pontine glioma, ependymoma, germinoma and medulloblastoma). These have been in clinical practice since 2019 in all paediatric radiotherapy centres in Sweden. Since the implementation, the guidelines have been complemented with a yearly review on clinical outcome and toxicities in all paediatric patients treated according to the guidelines. This article presents the Swedish national guidelines on re-irradiation in paediatric CNS tumours.

The Effect of Health Insurance on Pediatric Cancer Survival: An Analysis of Children Evaluated for Radiation Therapy in Diverse Multicenter Health Systems.

Understanding the role of health insurance in cancer survival in a diverse population of pediatric radiation oncology patients could help to identify patients at risk of adverse outcomes. Data were collected from cancer patients evaluated for radiation therapy, age < 19, diagnosed from January 1990 to August 2019. Predictors of recurrence-free survival (RFS) and overall survival (OS) were analyzed by univariable and multivariable Cox regression. Variables included health insurance, diagnosis type, sex, race/ethnicity, and socioeconomic status deprivation index. The study included 459 patients with a median diagnosis age of 9 years. Demographic breakdown was 49.5% Hispanic, 27.2% non-Hispanic White, and 20.7% non-Hispanic Black. There were 203 recurrences and 86 deaths observed over a median follow-up of 2.4 years. Five-year RFS was 59.8% (95% CI, 51.6, 67.0) versus 36.5% (95% CI, 26.6, 46.6), and 5-year OS was 87.5% (95% CI, 80.9, 91.9) versus 71.0% (95% CI, 60.3, 79.3) in private pay insurance versus Medicaid/Medicare, respectively. Multivariable showed Medicaid/Medicare patients experienced a 54% higher risk of recurrence (hazard ratio: 1.54, 95% CI, 1.08, 2.20) and 79% higher risk of death (hazard ratio: 1.79, 95% CI, 1.02, 3.14) than privately insured patients. Significant disadvantages in RFS and OS were identified in radiation oncology patients with Medicaid/Medicare insurance, even after adjusting for clinical and demographic variables.

Image guidance and interfractional anatomical variation in paediatric abdominal radiotherapy.

To identify variables predicting interfractional anatomical variations measured with cone-beam CT (CBCT) throughout abdominal paediatric radiotherapy, and to assess the potential of surface-guided radiotherapy (SGRT) to monitor these changes. Metrics of variation in gastrointestinal (GI) gas volume and separation of the body contour and abdominal wall were calculated from 21 planning CTs and 77 weekly CBCTs for 21 abdominal neuroblastoma patients (median 4 years, range: 2 - 19 years). Age, sex, feeding tubes, and general anaesthesia (GA) were explored as predictive variables for anatomical variation. Furthermore, GI gas variation was correlated with changes in body and abdominal wall separation, as well as simulated SGRT metrics of translational and rotational corrections between CT/CBCT. GI gas volumes varied 74 ± 54 ml across all scans, while body and abdominal wall separation varied 2.0 ± 0.7 mm and 4.1 ± 1.5 mm from planning, respectively. Patients < 3.5 years (p = 0.04) and treated under GA (p < 0.01) experienced greater GI gas variation; GA was the strongest predictor in multivariate analysis (p < 0.01). Absence of feeding tubes was linked to greater body contour variation (p = 0.03). GI gas variation correlated with body (R = 0.53) and abdominal wall (R = 0.63) changes. The strongest correlations with SGRT metrics were found for anterior-posterior translation (R = 0.65) and rotation of the left-right axis (R = -0.36). Young age, GA, and absence of feeding tubes were linked to stronger interfractional anatomical variation and are likely indicative of patients benefiting from adaptive/robust planning pathways. Our data suggest a role for SGRT to inform the need for CBCT at each treatment fraction in this patient group. This is the first study to suggest the potential role of SGRT for the management of internal interfractional anatomical variation in paediatric abdominal radiotherapy.