Risk of hematologic malignant neoplasms from head CT radiation in children and adolescents presenting with minor head trauma: a nationwide population-based cohort study.

OBJECTIVES: The carcinogenic risks of CT radiation in children and adolescents remain debated. We aimed to assess the carcinogenic risk of CTs performed in children and adolescents with minor head trauma. METHODS: In this nationwide population-based cohort study, we included 2,411,715 patients of age 0-19 with minor head trauma from 2009 to 2017. We excluded patients with elevated cancer risks or substantial past medical radiation exposure. Patients were categorized into CT-exposed or CT-unexposed group according to claim codes for head CT. The primary outcome was development of hematologic malignant neoplasms. Secondary outcomes included development of malignant solid neoplasms and benign neoplasms in the brain. We measured the incidence rate ratio (IRR) and incidence rate difference (IRD) using G-computation with Poisson regression adjusting for age, sex, hospital setting, and the type of head trauma. RESULTS: Hematologic malignant neoplasms developed in 100 of 216,826 patients during 1,303,680 person-years in the CT-exposed group and in 808 of 2,194,889 patients during 13,501,227 person-years in the CT-unexposed group. For hematologic malignant neoplasms, the IRR was 1.29 (95% CI, 1.03-1.60) and the IRD was 1.71 (95% CI, 0.04-3.37) per 100,000 person-years at risk. The majority of excess hematologic malignant neoplasms were leukemia (IRR, 1.40 [98.3% CI, 1.05-1.87]; IRD, 1.59 [98.3% CI, 0.02-3.16] per 100,000 person-years at risk). There were no between-group differences for secondary outcomes. CONCLUSIONS: Radiation exposure from head CTs in children and adolescents with minor head trauma was associated with an increased incidence of hematologic malignant neoplasms. CLINICAL RELEVANCE STATEMENT: Our study provides a quantitative grasp of the risk conferred by CT examinations in children and adolescents, thereby providing the basis for cost-benefit analyses and evidence-driven guidelines for patient triaging in head trauma. KEY POINTS: • This nationwide population-based cohort study showed that radiation exposure from head CTs in children and adolescents was associated with a higher incidence of hematologic malignant neoplasms. • The incidence rate of hematologic malignant neoplasms in the CT-exposed group was 29% higher than that in the CT-unexposed group (IRR, 1.29 [95% CI, 1.03-1.60]), and there were approximately 1.7 excess neoplasms per 100,000 person-years at risk in the CT-exposed group (IRD, 1.71 [0.04-3.37]). • Our study provides a quantified grasp of the risk conferred by CT examinations in children and adolescents, while controlling for biases observed in previous studies via specifying CT indication and excluding patients with predisposing conditions for cancer development.

Incidence of radiation-associated sarcoma after breast-conserving surgery plus radiation.

BACKGROUND: Radiation-associated sarcoma (RAS) is a rare sequela of radiotherapy. Radiotherapy modalities for breast conservation and radiation treatment (BCT) have changed over time. We sought to determine if the incidence of RAS after BCT has changed over time. METHODS: We identified breast cancer survivors (diagnosed 1988-2012) treated with BCT within the SEER database. We excluded patients with prior cancer, <1-year follow-up/survival, and nonexternal beam radiation (n = 276 301). We identified patients with a subsequent chest sarcoma diagnosis. The primary predictor variable was a 5-year period of breast cancer diagnosis year (1988-1992, 1993-1997, etc.). The incidence of sarcoma was estimated by the Kaplan-Meier method, censoring at sarcoma diagnosis, death, or last follow-up (available through December 2017). Given the known latency of RAS, we used Joinpoint analysis to identify the time point at which RAS incidence significantly increased (start of the analytic window). A log-rank test assessed differences in RAS incidence by diagnosis year. RESULTS: The incidence of RAS was 0.03% at 5 years (95% confidence interval [CI]: 0.03-0.04) and 0.16% at 10 years (95% CI: 0.14-0.18). No statistical difference in RAS incidence by diagnosis year was observed (p = 0.2). CONCLUSIONS: RAS remains a rare but persistent sequela after BCT. As new radiation modalities become more common, ongoing surveillance is necessary to track these rare events.

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

The standard treatment for locally advanced cervical cancer (CC) is chemo-radiotherapy. 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.

Iodine-125 brachytherapy as upfront and salvage treatment for brain metastases : A comparative analysis.

BACKGROUND: Outcome and toxicity profiles of salvage stereotactic ablative radiation strategies for recurrent pre-irradiated brain metastases are poorly defined. This study compared risk-benefit profiles of upfront and salvage iodine-125 brachytherapy (SBT) for small brain metastases. As the applied SBT treatment algorithm required histologic proof of metastatic brain disease in all patients, we additionally aimed to elucidate the value of biopsy before SBT. PATIENTS AND METHODS: Patients with small untreated (n = 20) or pre-irradiated (n =28) suspected metastases intended for upfront or salvage SBT, respectively, were consecutively included. Temporary iodine-125 implants were used (median reference dose: 50 Gy, median dose rate: 15 cGy/h). Cumulative biologically effective doses (BED) were calculated and used for risk assessment. Treatment toxicity was classified according to Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC) criteria. RESULTS: Upfront SBT was initiated in 20 patients and salvage SBT in 23. In 5 patients, salvage SBT was withheld because of proven radiation-induced lesions. Treatment groups exhibited similar epidemiologic data except for tumor size (which was slightly smaller in the salvage group). One-year local/distant tumor control rates after upfront and salvage SBT were similar (94 %/65 % vs. 87 %/57 %, p = 0.45, respectively). Grade I/II toxicity was suffered by 2 patients after salvage SBT (cumulative BED: 192.1 Gy3 and 249.6 Gy3). No toxicity-related risk factors were identified. CONCLUSION: SBT combines diagnostic yield with effective treatment in selected patients. The low toxicity rate in the salvage group points to protective radiobiologic characteristics of continuous low-dose rate irradiation. Upfront and salvage SBT are similarly effective and safe. Histologic reevaluation should be reconsidered after previous radiotherapy to avoid under- or overtreatment.

Evaluating the Necessity and Radiation Risk of Brain CT Scans Requested by the Trauma Emergency Department.

Background: Numerous Computed Tomography (CT) scan requests for trauma patients have raised serious concern about the impacts of radiation such as radiation-induced cancers. Objective: This study aimed to evaluate the necessity rate of requested head CT scans for traumatic patients and to ultimately estimate the risk of radiation-induced brain cancer. Material and Methods: In this retrospective analytical study, traumatic patients, who had undergone a head CT scan in a two-month period from August 23 to October 22, 2018, were considered as the study population. Two radiologists reviewed each patient individually to evaluate the rate of normal and abnormal cases. Dose length product in milligrays (mGy) was utilized to calculate the effective dose (ED) in millisieverts (mSv), resulting in an assessment of the risk of radiation-induced brain cancer using ICRP 103. Results: Among 523 scans, 460 patients (88%) received normal reviews, while only 47 patients (9%) had findings related to their current trauma. The mean effective dose value was 1.05±0.36 mSv. Risk of the radiation induced brain cancer was calculated to be 0.037 and 0.030 new cancer cases in 10000 males and females per Gy, respectively. Conclusion: Final results demonstrated that a significant number of traumatic patients undergoing a CT scan are in fact, healthy. Such reckless usage of CT and consequently the excess exposure could result in a dramatic rise in cancer rates. The need to limit unnecessary CT scan usage and keeping the radiation given to patients as low as reasonably achievable (ALARA) when collecting essential diagnostic data is more critical than ever.

A Huge Radiation-Induced Cavernous Hemangioma Following Stereotactic Radiosurgery for Meningioma: A Case Report.

Radiation-induced cavernous hemangiomas (RICHs) have been increasingly reported as a late complication after conventional radiotherapy. RICH after stereotactic radiosurgery (SRS) is extremely rare and the few cases have been reported to demonstrate their properties. A 72-year-old female patient presented with progressive neurologic deficits. She underwent tumor surgery for meningioma 13 years ago and two times of SRS for treating a residual tumor. Newly-developed mass was 4.3 cm-sized heterogeneously enhancing mass with severe cerebral edema. She underwent surgical resection and the histologic examinations revealed organized hematoma. Finally, it was diagnosed as a RICH following SRS based on radiological and histological findings and a history of multiple radiosurgeries. Clinical, radiological, and histological features of a RICH following SRS were discussed in this report.

Analysis of Intraoperative Exposure to X-rays and Surgical Time in Different Techniques for Fixation of Transtrochanteric Fractures of the Femur.

Objective The present study aimed to evaluate and compare the total surgical procedure time and intraoperative X-ray exposure during different techniques for fixation of transtrochanteric fractures of the femur in elderly patients, using extramedullary and intramedullary methods based on cephalic traction screws. Methods The Orthopedics and Traumatology Service from our hospital evaluated 107 patients with transtrochanteric fractures, including 34 males and 73 females, with age ranging from 61 to 101 years old. Fracture fixation was performed with a dynamic hip system (DHS) in 21 patients, a standard proximal femoral nail (PFN) in 55 subjects, and a standard gamma nail in 31 patients. All procedures were performed by the same surgeon and his team of nursing assistants, along with the same radiology technician using the same image intensifier. Total surgery time (in minutes) and X-ray emission (in centigrays [cGy]) were evaluated. Results Transtrochanteric fracture fixation with PFN provides a significantly shorter surgical time ( p = 0.013) in comparison to the 2 other techniques. Intraoperative exposure to X-rays was significantly lower when using DHS ( p = 0.015) as a fixation method when compared with gamma nail and PFN. Conclusion Although PFN resulted in the shortest surgical time, DHS was associated with the lowest X-ray exposure levels within the studied sample.

Proton Radiotherapy to Reduce Late Complications in Childhood Head and Neck Cancers.

In most childhood head and neck cancers, radiotherapy is an essential component of treatment; however, it can be associated with problematic long-term complications. Proton beam therapy is accepted as a preferred radiation modality in pediatric cancers to minimize the late radiation side effects. Given that childhood cancers are a rare and heterogeneous disease, the support for proton therapy comes from risk modeling and a limited number of cohort series. Here, we discuss the role of proton radiotherapy in pediatric head and neck cancers with a focus on reducing radiation toxicities. First, we compare the efficacy and expected toxicities in proton and photon radiotherapy for childhood cancers. Second, we review the benefit of proton radiotherapy in reducing acute and late radiation toxicities, including risks for secondary cancers, craniofacial development, vision, and cognition. Finally, we review the cost effectiveness for proton radiotherapy in pediatric head and neck cancers. This review highlights the benefits of particle radiotherapy for pediatric head and neck cancers to improve the quality of life in cancer survivors, to reduce radiation morbidities, and to maximize efficient health care use.

Volume effects of radiotherapy on the risk of second primary cancers: A systematic review of clinical and epidemiological studies.

As modern radiotherapy, including intensity-modulated techniques, is associated with high dose gradients to normal tissues and large low-to-moderate dose volumes, the assessment of second primary cancer (SPC) risks requires quantification of dose-volume effects. We conducted a systematic review of clinical and epidemiological studies investigating the effect of the irradiated volume or dose-volume distribution to the remaining volume at risk (RVR) on SPC incidence. We identified eighteen studies comparing SPC risks according to the irradiated volume (i.e., in most studies, the size or number of fields used), and four studies reporting risk estimates according to the dose distribution to the RVR (after whole-body dose reconstruction). An increased risk of SPCs (mainly breast and lung cancers) with extended radiotherapy was observed among patients treated for Hodgkin lymphoma or childhood cancers. However, normal tissue dose distribution was not estimated, limiting the interpretation of those results in terms of volume effects on organs at risk. Studies considering whole-body exposures quantified dose-response relationships for point dose estimates, without accounting for dose-volume distributions. Therefore, they disregarded possible tissue effects (e.g. bystander and abscopal effects, stem cell repopulation) which may play a role in the induction of SPCs. Currently, there is no clinical or epidemiological information about a possible role of high dose gradients in surrounding organs, or increasing volumes of distant tissues exposed to low doses, in the risk of SPCs. Opportunities for future research nevertheless now exist, since methods and tools for estimating individual whole-body dose-volume distributions in large patient populations have been developed.

Radiation-induced angiosarcoma of the breast: a retrospective analysis of 15 years' experience at an oncology center.

OBJECTIVE: To characterize a population of patients with radiation-induced angiosarcoma (RIAS) of the breast treated at an oncology center, focusing mainly on the imaging features, although also on the clinical presentation, diagnosis, and management. MATERIALS AND METHODS: We performed a retrospective review of patients with histologically proven angiosarcoma of the breast or chest wall, all of whom received radiotherapy, after conservative or radical breast surgery, between 2000 and 2015. RESULTS: Eleven patients met the inclusion criteria. The median age at the time of diagnosis of RIAS of the breast was 71.5 years (range, 58-87 years), and the median latency period was 8.9 years (range, 4-27 years). The rate of local recurrence was 54.4%, RIAS recurring after a median period of 10 months (range, 3-18 months), and distant metastases occurred in three patients (27.3%). All of the tumors were accompanied by skin changes, and a palpable mass was seen in four. Most of the imaging findings were nonspecific. Six patients underwent magnetic resonance imaging, which revealed pronounced skin enhancement in all six. Ultrasound-guided core needle biopsies were negative in three of the eight patients. CONCLUSION: RIAS of the breast is a rare but recognized complication of radiotherapy for breast carcinoma, with a poor prognosis and high recurrence rate, which requires a high index of suspicion for a prompt diagnosis.

OBJETIVO: Caracterizar uma população de pacientes com angiossarcoma da mama induzido por radioterapia em um instituto de oncologia, com foco principalmente nas características de imagem, mas também na apresentação clínica, diagnóstico e gerenciamento. MATERIAIS E MÉTODOS: Efetuamos análise retrospectiva, entre 2000 e 2015, de pacientes com angiossarcoma da mama ou parede torácica histologicamente comprovado que foram previamente irradiadas após cirurgia mamária, conservadora ou radical. RESULTADOS: Onze pacientes preencheram os critérios de inclusão. A mediana da idade na ocasião do diagnóstico de angiossarcoma da mama induzido por radioterapia foi 71,5 anos (variação: 58-87 anos) e o período médio de latência foi 8,9 anos (variação: 4-27 anos). A taxa de recorrência local foi 54,4%, após mediana de 10 meses (variação: 3-18 meses), e metástases a distância ocorreram em três pacientes (27,3%). Todos os tumores apresentaram alterações na pele, e massa palpável observou-se em quatro. Os achados de imagens foram globalmente inespecíficos. Os seis paciente que realizaram ressonância magnética revelaram aumento de captação de contraste cutâneo. As biópsias ecoguiadas foram negativas em três de oito pacientes. CONCLUSÃO: Angiossarcoma da mama induzido por radioterapia é complicação rara, mas conhecida, da radioterapia para câncer da mama, com mau prognóstico e alta taxa de recorrência, sendo necessário elevado índice de suspeição para seu diagnóstico imediato.