Imaging in pediatric patients: time to think again about surveillance

International consensus statement on the diagnosis and management of phaeochromocytoma and paraganglioma in children and adolescents

Phaeochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumours that arise not only in adulthood but also in childhood and adolescence. Up to 70-80% of childhood PPGL are hereditary, accounting for a higher incidence of metastatic and/or multifocal PPGL in paediatric patients than in adult patients. Key differences in the tumour biology and management, together with rare disease incidence and therapeutic challenges in paediatric compared with adult patients, mandate close expert cross-disciplinary teamwork. Teams should ideally include adult and paediatric endocrinologists, oncologists, cardiologists, surgeons, geneticists, pathologists, radiologists, clinical psychologists and nuclear medicine physicians. Provision of an international Consensus Statement should improve care and outcomes for children and adolescents with these tumours.

Integration of Certified Child Life Specialists to Decrease in Periprocedural Benzodiazepine Use: A Pilot Study

INTRODUCTION

Periprocedural anxiety is common in pediatric patients and is characterized by tension, anxiety, irritability, and autonomic activation. Periprocedural anxiety increases during certain events including admission to the preoperative area, separation from caregivers, induction of anesthesia, and IV placement. A study of children aged 2-12 showed that perioperative anxiety in children may be influenced by high parental anxiety and low sociability of the child. While these are nonmodifiable variables in the perioperative setting, there are numerous ways to ameliorate both parental and patient anxiety including the use of certified child life specialists (CCLSs) to aid in child comfort. In this study, our objective was to evaluate the integration of CCLS in our perioperative setting on the rate of benzodiazepine use.

METHODS

We used a prospectively maintained database to identify patients undergoing outpatient elective surgical and radiologic procedures from July 2022 to September 2023 and January 2023 to September 2023 respectively. CCLSs were used to work with appropriately aged children in order to decrease the use of benzodiazepines and reduce possible adverse events associated with their use.

RESULTS

A total of 2175 pediatric patients were seen by CCLS in same day surgery from July 2022 to September 2023. During this period, midazolam use decreased by an average of 11.4% (range 6.2%-19.3%). An even greater effect was seen in the radiologic group with 73% reduction. No adverse events were reported during this period.

CONCLUSIONS

CCLSs working with age-appropriate patients in the periprocedural setting is a useful adjunct in easing anxiety in pediatric patients, reducing the need for periprocedural benzodiazepine administration and the risk of exposure to unintended side effects.

Relapse after non-metastatic rhabdomyosarcoma: The impact of routine surveillance imaging on early detection and post-relapse survival

BACKGROUND

Patients with rhabdomyosarcoma (RMS) whose disease relapses have little chance of being cured, so front-line treatments are usually followed up with surveillance imaging in an effort to detect any recurrences as early as possible, and thereby improve post-relapse outcomes. The real benefit of such routine surveillance imaging in RMS remains to be demonstrated, however. This retrospective, single-center study examines how well surveillance imaging identifies recurrent tumors and its impact on post-relapse survival.

METHODS

The analysis concerned 79 patients <21 years old treated between 1985 and 2020 whose initially localized RMS relapsed. Clinical findings, treatment modalities, and survival were analyzed, comparing patients whose relapse was first suspected from symptoms they developed (clinical symptoms group) with those whose relapse was identified by radiological surveillance (routine imaging group).

RESULTS

Tumor relapses came to light because of clinical symptoms in 42 cases, and on routine imaging in 37. The time to relapse was much the same in the two groups. The median overall survival (OS) and 5-year OS rate were, respectively, 10 months and 12.6% in the clinical symptoms group, and 11 months and 27.5% in the routine imaging group (p-value .327). Among patients with favorable prognostic scores, survival was better for those in the routine imaging group (5-year OS 75.0% vs. 33.0%, p-value .047).

CONCLUSION

It remains doubtful whether surveillance imaging has any real impact on RMS relapse detection and patients' post-relapse survival. Further studies are needed to establish the most appropriate follow-up recommendations, taking the potentially negative effects of regular radiological exams into account.

Relapsing pediatric non-rhabdomyosarcoma soft tissue sarcomas: The impact of routine imaging surveillance on early detection and post-relapse survival

PURPOSE

The chances of patients with relapsing pediatric non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) being cured are limited. This retrospective single-institutional study examines the potential role of routine surveillance imaging for detecting recurrent tumor, and its impact on post-relapse survival.

METHODS

The analysis concerned 86 patients < 21 years old with relapsing NRSTS treated from 1985 to 2020. Clinical findings, treatment modalities and survival were analyzed, comparing patients whose relapse was first suspected from symptoms (symptomatic group) with those whose relapse was detected by radiological surveillance (imaging group).

RESULTS

Tumor relapses were identified from clinical symptoms in 49 cases and on routine imaging in 37. Time to relapse was similar in the two groups. Routine imaging detected 6/32 local relapses and 31/48 distant relapses (and 79% of the cases of lung metastases). Overall survival (OS) at 5 years was 34.3% for the symptomatic group, and 24.0% for the imaging group (p-value 0.270). In patients with lung metastases at relapse, the 5-year OS was statistically better for the imaging group, that is, 25.8% versus 0% for the symptomatic group (p-value 0.044).

CONCLUSION

This is the first study to explore the role of surveillance imaging in pediatric NRSTS. Judging from our findings, the value of routine scanning of primary sites seems limited, while radiological surveillance may help to detect lung metastases, improving survival for this patient category. The potentially negative effects of periodic radiological exams should be considered in deciding the optimal follow-up for patients off therapy.

Feasibility of ultrasound-assisted lumbar punctures performed by pediatric oncologists at the point of care

BACKGROUND

Ultrasound assistance improves success rates and reduces adverse outcomes of lumbar punctures (LPs) among adult patients in the emergency room and the operating room, but has not been evaluated in pediatric patients with cancer. Our objectives were (1) to determine whether pediatric oncologists could perform ultrasound-assisted LPs following a structured teaching curriculum, and (2) to determine the feasibility of recruiting pediatric cancer patients to a clinical trial of this procedure.

METHODS

Three pediatric oncologists completed a curriculum composed of didactic teaching followed by hands-on workshops. Each learner was evaluated during 20 attempts at three ultrasound tasks using the cumulative sum method. The three pediatric oncologists then performed ultrasound assessments prior to routinely scheduled LPs. Feasibility was defined as ability to perform at least 30 ultrasound-assisted LPs within 6 months. Secondary outcomes were the proportion of successful, bloody, or traumatic LPs, time required, and perceived helpfulness of ultrasound.

RESULTS

All three pediatric oncologists achieved competence in the three tasks of ultrasound scanning within 20 evaluated attempts. We recruited 62 patients within 1 month, and 58 underwent an ultrasound-assisted LP. All LPs were successful. Two LPs (4%) had ≥500 red blood cells (RBCs)/μl, and nine (16%) had ≥10 RBCs/μl. Median time to conduct the scan was 1.9 minutes (range 0.8-4.0 minutes). In 37 (64%) of the LPs, ultrasound assistance was considered helpful or very helpful.

CONCLUSIONS

Pediatric oncologists readily achieved competence in ultrasound-assisted LPs, and ultrasound was commonly perceived as helpful. It is feasible to proceed to a randomized trial of this procedure in pediatric cancer.

Radiation protection perspective to recurrent medical imaging: what is known and what more is needed?

This review summarises the current knowledge about recurrent radiological imaging and associated cumulative doses to patients. The recent conservative estimates are for around 0.9 million patients globally who cumulate radiation doses above 100 mSv, where evidence exists for cancer risk elevation. Around one in five is estimated to be under the age of 50. Recurrent imaging is used for managing various health conditions and chronic diseases such as malignancies, trauma, end-stage kidney disease, cardiovascular diseases, Crohn's disease, urolithiasis, cystic pulmonary disease. More studies are needed from different parts of the world to understand the magnitude and appropriateness. The analysis identified areas of future work to improve radiation protection of individuals who are submitted to frequent imaging. These include access to dose saving imaging technologies; improved imaging strategies and appropriateness process; specific optimisation tailored to the clinical condition and patient habitus; wider utilisation of the automatic exposure monitoring systems with an integrated option for individual exposure tracking in standardised patient-specific risk metrics; improved training and communication. The integration of the clinical and exposure history data will support improved knowledge about radiation risks from low doses and individual radiosensitivity. The radiation protection framework will need to respond to the challenge of recurrent imaging and high individual doses. The radiation protection perspective complements the clinical perspective, and the risk to benefit analysis must account holistically for all incidental and long-term benefits and risks for patients, their clinical history and specific needs. This is a step toward the patient-centric health care.

Impact of a statewide computed tomography scan educational campaign on radiation dose and repeat CT scan rates for transferred injured children

Purpose

Research demonstrates that children receive twice as much medical radiation from Computed Tomography (CT) scans performed at non-pediatric facilities as equivalent CTs performed at pediatric trauma centers (PTCs). In 2014, AFMC outreach staff educated Emergency Department (ED) staff on appropriate CT imaging utilization to reduce unnecessary medical radiation exposure. We set out to determine the educational campaign's impact on injured children received radiation dose.

Methods

All injured children who underwent CT imaging and were transferred to a Level I PTC during 2010 to 2013 (pre-campaign) and 2015 (post-campaign) were reviewed. Patient demographics, mode of transportation, ED length of stay, scanned body region, injury severity score, and trauma center level were analyzed. Median effective radiation dose (ERD) controlled for each variable, pre-campaign and post-campaign, was compared using Wilcoxon rank sum test.

Results

Three hundred eighty-five children under 17 years were transferred from 45 and 48 hospitals, pre- and post-campaign. Most (43%) transferring hospitals were urban or critical access hospitals (30%). Pre- and post-campaign patient demographics were similar. We analyzed 482 and 398 CT scans pre- and post-campaign. Overall, median ERD significantly decreased from 3.80 to 2.80. Abdominal CT scan ERD declined significantly from 7.2 to 4.13 (P-value 0.03). Head CT scan ERD declined from 3.27 to 2.45 (P-value < 0.0001).

Conclusion

A statewide, CT scan educational campaign contributed to ERD decline (lower dose scans and fewer repeat scans) among transferred injured children seen at PTCs. State-level interventions are feasible and can be effective in changing radiology provider practices.

Role of surveillance screening in detecting tumor recurrence after treatment of childhood cancers

Objective

As the survival rates in children with cancer reach up to 80%, this improvement in survival increases the number of patients under follow-up. After cancer treatment is completed, patients are taken to follow-up surveillance to ensure the early detection of recurrence and the late effects of treatments. The frequency and necessity of surveillance screening tests are controversial. This study aimed to assess the efficacy of surveillance screening in the detection of recurrence.

Material and methods

The files of 533 children who were diagnosed as having cancer at our pediatric oncology clinic between 2004 and 2013 were retrospectively evaluated. We looked at outcomes after recurrence, the timing and pattern of recurrence, the presence of symptoms during recurrence, physical examination findings, tumor marker levels, laboratory findings, and radiologic tests.

Results

Of the 63 patients with recurrence, 23 were symptomatic and 40 were asymptomatic at the time of the recurrence. Tumor location and time of the recurrence did not affect the post recurrence survival. The median post-recurrence survival for patients was 13 (range, 1-98) months. The median post-relapse survival was 10 (range, 1-73) months in patients with symptomatic recurrence, and 16 (range, 1-98) months in patients with asymptomatic recurrence. It was determined that patients in whom recurrence was identified with surveillance tests had longer post-relapse survival time. The 5-year survival rate of 23 patients with symptomatic recurrence was 12.2%; this rate was 49.5% in asymptomatic patients (p<0.05).

Conclusions

It should be considered that surveillance testing offers the benefit of prolonging post recurrence survival.

Evaluation of whole-body MRI with diffusion-weighted sequences in the staging of pediatric cancer patients

BACKGROUND

The purpose of this study was to determine whether whole-body MRI (WBMRI) with diffusion-weighted sequences, which is free of ionizing radiation, can perform as well as traditional methods when used alone for staging or follow-up of pediatric cancer patients.

METHODS

After obtaining approval from our institutional research ethics committee and appropriate informed consent, we performed 34 examinations in 32 pediatric patients. The examinations were anonymized and analyzed by two radiologists with at least 10 years' experience.

RESULTS

The sensitivity and specificity findings, respectively, were as follows: 100% and 100% for primary tumor; 100% and 86% for bone metastasis; 33% and 100% for lung metastasis; 85% and 100% for lymph node metastasis; and 100% and 62% for global investigation of primary or secondary neoplasias. We observed excellent interobserver agreement for WBMRI and excellent agreement with standard staging examination results.

CONCLUSIONS

Our results suggest that pediatric patients can be safely imaged with WBMRI, although not as the only tool but in association with low-dose chest CT (for subcentimeter pulmonary nodules). However, additional exams with ionizing radiation may be necessary for patients who tested positive to correctly quantify and locate the lesions.

Routine Surveillance Imaging Is Associated with Improved Postrelapse Survival in Patients with Ewing Sarcoma

Purpose: Children with Ewing sarcoma (ES) routinely undergo surveillance imaging after completion of therapy; however, the medical benefit of this imaging remains unclear. We aimed to determine whether there is a difference in survival between patients whose relapse was detected based on development of new symptoms or by routine imaging. Methods: We retrospectively reviewed all patients consecutively diagnosed with ES at Children's Healthcare of Atlanta from 2000 to 2011. Patient characteristics and outcomes were compared based on whether their relapse was diagnosed based on symptoms or by routine surveillance imaging alone. Results: Thirty-three percent (28/85) of patients relapsed. Median age at time of relapse was 15.5 years (interquartile range: 12.5-18.0). Among the relapsed patients, 57% (16/28) were symptomatic and 43% (12/28) were asymptomatic, having relapse detected on surveillance imaging alone. The most common presenting symptom was bone pain occurring in 69% (11/16) of patients. The 5-year postrelapse overall survival for patients with symptomatic relapse was 0% (95% confidence interval [CI]: not estimated) compared with 15% (95% CI: 1-48) for patients with an asymptomatic relapse (p < 0.01). After adjusting for extent of disease and time to relapse, having a symptomatic relapse was still strongly associated with a worse outcome (hazard ratio: 9.68; 95% CI: 3.09-30.34). Conclusion: Patients with ES whose relapse is detected on imaging before the development of symptoms have significantly better outcomes, suggesting a potentially beneficial role of routine surveillance imaging in this population of patients. Further prospective analyses are needed to confirm these findings, and determine the optimal evidence-based imaging modality and schedule.

Surveillance imaging in pediatric lymphoma

Current therapies used in treating children with Hodgkin lymphoma and many histological subtypes of non-Hodgkin lymphoma have resulted in overall survival rates exceeding 90% in many instances. With increasing concerns related to the cost of radiologic imaging, exposure to ionizing radiation, and potential false-positive results, the role of routine off-therapy surveillance imaging has been called into question. Although radiologic imaging plays an important role in diagnosing and assessing treatment response, in these children - the majority of whom have an excellent outcome following completion of therapy - there is an opportunity to dramatically reduce the number of off-therapy imaging evaluations. This review summarizes several recent studies in both Hodgkin and non-Hodgkin lymphoma providing evidence to support these efforts. In addition, we propose a surveillance imaging strategy that uses a novel risk-adapted and response-based approach to determine which children would most benefit from off-therapy imaging surveillance.

Pediatric Cancer Predisposition Imaging: Focus on Whole-Body MRI

The American Association for Cancer Research convened a meeting of international pediatric oncologists, geneticists, genetic counselors, and radiologists expert in childhood cancer predisposition syndromes (CPS) in October 2016 to propose consensus surveillance guidelines. Imaging plays a central role in surveillance for most, though not all, syndromes discussed. While encompassing the full gamut of modalities, there is increasing emphasis on use of nonionizing radiation imaging options such as magnetic resonance imaging (MRI) in children and adolescents, especially in the pediatric CPS population. In view of rapid evolution and widespread adoption of whole-body MRI (WBMRI), the purpose of our review is to address WBMRI in detail. We discuss its place in the surveillance of a range of pediatric CPS, the technical and logistical aspects of acquiring and interpreting these studies, and the inherent limitations of WBMRI. We also address issues associated with sedation and use of gadolinium-based contrast agents in MRI in children. Clin Cancer Res; 23(11); e6-e13. ©2017 AACRSee all articles in the online-only CCR Pediatric Oncology Series.

Pediatric imaging in DICER1 syndrome

BACKGROUND

DICER1 syndrome, arising from a mutation in the DICER1 gene mapped to chromosome 14q32, is associated with an increased risk of a range of benign and malignant neoplasms.

OBJECTIVE

To determine the spectrum of abnormalities and imaging characteristics in patients with DICER1 syndrome at a tertiary pediatric hospital.

MATERIALS AND METHODS

This retrospective analysis evaluated imaging in patients ≤18 years with DICER1 germline variants between January 2004 and July 2016. An imaging database search including keywords pleuropulmonary blastoma, cystic nephroma, pineoblastoma, embryonal rhabdomyosarcoma, ovarian sex cord-stromal tumor, ovarian Sertoli-Leydig cell tumor and DICER1 syndrome, was cross-referenced against the institutional Cancer Genetics Program database, excluding patients with negative/unknown DICER1 gene testing.

RESULTS

Sixteen patients were included (12 females; mean age at presentation: 4.2 years, range: 14 days to 17 years), with surveillance imaging encompassing the following modalities: chest X-ray and CT; abdominal, pelvic and neck US; and brain and whole-body MRI. Malignant lesions (68.8% of patients) included pleuropulmonary blastoma (5), pineoblastoma (3), ovarian Sertoli-Leydig cell tumor (1), embryonal rhabdomyosarcoma (1) and renal sarcoma (1); benign lesions (37.5% of patients) included thyroid cysts (2), thyroid nodules (2), cystic nephroma (2), renal cysts (1) and pineal cyst (1). A common lesional appearance observed across modalities and organs was defined as the "cracked windshield" sign.

CONCLUSION

The spectrum of DICER1-related tumors and the young age at presentation suggest early surveillance of at-risk patients is critical, while minimizing exposure to ionizing radiation.

Total estimated effective doses from radiologic imaging modalities of children with cancer: a single center experience

BACKGROUND

Recently, awareness of the cumulative radiation exposure for pediatric oncology patients has been increasing, together with increased survival rates and longer life expectancy. The aim of our study was to quantify the amount of ionising radiation from imaging modalities of pediatric oncology patients.

METHODS

Eighty-eight patients who were diagnosed with childhood cancer and followed up for 5 years between 2004-2014 in our center were included in the study. Patients' medical files were reviewed retrospectively for imaging history in the first 5 years after diagnosis. Total estimated effective doses from radiologic imaging modalities were determined. Also, the basic demographic data, histologic type, stage, and outcomes of disease were collected for all patients.

RESULTS

The individual total estimated effective doses ranged from 8.73 to 167 mSv, with a median of 62.92 mSv. Computed tomography was the greatest contributor of total effective doses. The doses ranged 21.45-113.20 mSv (median: 62.92 mSv) in Hodgkin lymphoma, 12.53-167.10 mSv (median: 52 mSv) in non-Hodgkin lymphoma, 4.13-172.98 mSv (median: 52 mSv) in neuroblastoma, 31-149.89 mSv (median: 63.10 mSv) in Wilms' tumor, 11.50-73.72 mSv (median: 36.90 mSv) in germ cell tumor, 26.46-125.86 mSv (median: 80.90 mSv) in other solid tumor and 0.02-13.31 mSv (5.25 mSv) in brain tumor subgroup. Twenty-two children (25%) died with progressive disease during the 5-year follow-up period.

CONCLUSIONS

Similar to previous studies, the total estimated effective doses in children with cancer have been found various according to diagnosis, stage and clinical course. To clarify the harmfull effects of radiation burden, prospective studies should be conducted in children with cancer.

Does clinical indication play a role in CT radiation dose in pediatric patients?

PURPOSE

The purpose of this study was to identify the main pathologies for which CT is applied on pediatric patients and the related radiation doses as reported in the literature in order to facilitate justification and CT optimization.

METHODS

A critical analysis of a literature review was performed. Different search engines were used such as PubMed, Google Scholar and Science Direct. Various terms and keywords were used to locate pertinent articles such as Pediatric, Computed tomography, Radiation Dose, Organ dose, Effective dose.

RESULTS

The results showed that the main pathologies for which CT is applied are: Crohn's disease, hydrocephalus, cystic fibrosis and pediatric malignancies-mainly lymphoma. The related radiation dose data are extremely scarce and are in the range of 3.48-17.56, 0.2-15.3mSv, 0.14-6.20mSv, and 2.8-518.0mSv, respectively. The radiation doses reported are high especially in pediatric oncology.

CONCLUSIONS

Pediatric patients with malignancies are those exposed to the higher levels of radiation during CT imaging. Literature is lacking reporting of dose in Pediatric CT imaging. More studies need to be realized for the determination of radiation dose in those patients. Special protocols need to be recommended in order to reduce the exposure of children in radiation.

Surveillance imaging and radiation exposure in the detection of relapsed neuroblastoma

BACKGROUND

More than half of children with high-risk neuroblastoma (NB) will experience recurrence. Radiologic imaging is used for initial staging and during therapy to assess response. However, the role of surveillance imaging in the detection of relapse has not been well studied. Surveillance potentially results in high cumulative exposure to ionizing radiation, which may be associated with an increased risk of developing second malignancies.

PROCEDURE

We reviewed NB cases at our institution between 2000 and 2011. We calculated radiation exposure due to imaging (during diagnosis, treatment, and posttherapy surveillance) using cumulative effective dose (CED) estimates and determined whether cross-sectional imaging identified recurrences.

RESULTS

Fifty of 183 patients with NB experienced a recurrence. The median time from diagnosis to relapse was 1.20 years (range: 0.18-6.66 years). Most patients had evidence of metastases and only 4 of 50 patients presented with isolated primary tumor site recurrences. The mean CED prior to relapse was 125.2 mSv (range: 24.5-259.7), 64% of which was from computed tomography (CT) scans. Thirty-seven of 50 patients had clinically evident or measurable disease detected by X-ray (XR), ultrasound (US), or urinary catecholamines (UCats), and the addition of metaiodobenzylguanidine (MIBG) scans identified eight additional recurrences. Thus, cross-sectional imaging (CT/MRI, where MRI is magnetic resonance imaging) was only required to identify 10% (5/50) of cases.

CONCLUSION

Relapsed disease was detected in most patients by symptoms/exam, MIBG scan, UCats, and/or XR/US, supporting reduced use of CT imaging in posttherapy surveillance, thereby decreasing cumulative radiation dose. Refinement of surveillance imaging may be further guided by risk stratification, disease sites, and potentially biomolecular markers.

Relapse surveillance in AFP-positive hepatoblastoma: re-evaluating the role of imaging

BACKGROUND

Children with hepatoblastoma routinely undergo repetitive surveillance imaging, with CT scans for several years after therapy, increasing the risk of radiation-induced cancer.

OBJECTIVE

The purpose of this study was to determine the utility of surveillance CT scans compared to serum alpha-fetoprotein (AFP) levels for the detection of hepatoblastoma relapse.

MATERIALS AND METHODS

This was a retrospective study of all children diagnosed with AFP-positive hepatoblastoma from 2001 to 2011 at a single institution.

RESULTS

Twenty-six children with hepatoblastoma were identified, with a mean age at diagnosis of 2 years 4 months (range 3 months to 11 years). Mean AFP level at diagnosis was 132,732 ng/ml (range 172.8-572,613 ng/ml). Five of the 26 children had hepatoblastoma relapse. A total of 105 imaging exams were performed following completion of therapy; 88 (84%) CT, 8 (8%) MRI, 5 (5%) US and 4 (4%) FDG PET/CT exams. A total of 288 alpha-fetoprotein levels were drawn, with a mean of 11 per child. The AFP level was elevated in all recurrences and no relapses were detected by imaging before AFP elevation. Two false-positive AFP levels and 15 false-positive imaging exams were detected. AFP elevation was found to be significantly more specific than PET/CT and CT imaging at detecting relapse.

CONCLUSION

We recommend using serial serum AFP levels as the preferred method of surveillance in children with AFP-positive hepatoblastoma, reserving imaging for the early postoperative period, for children at high risk of relapse, and for determination of the anatomical site of clinically suspected recurrence. Given the small size of this preliminary study, validation in a larger patient population is warranted.

Pediatric oncology surveillance imaging: two recommendations. Abandon CT scanning, and randomize to imaging or solely clinical follow-up

Radiologic assessments in children with cancer provide information crucial to patient management at diagnosis and during follow-up. Many studies have now been published, however, questioning the usefulness of off-therapy surveillance imaging. There is growing concern regarding the hazards from diagnostic irradiation to young patients, most notably from CT scanning. In this paper we advocate abandoning repeated CT surveillance in young patients with a previously treated solid malignancy not arising in the central nervous system. In addition, randomized studies of imaging surveillance versus no imaging surveillance strategies are needed to determine whether earlier detection of recurrence results in improved survival.

Current opinions on medical radiation: a survey of oncologists regarding radiation exposure and dose reduction in oncology patients

PURPOSE

The aim of this study was to evaluate oncologists' opinions about the use of ionizing radiation in medical imaging of oncology patients.

METHODS

An electronic survey was e-mailed to 2,725 oncologists at the top 50 National Cancer Institute-funded cancer centers. The survey focused on opinions on CT dose reduction in oncology patients and current philosophies behind long-term imaging in these patients.

RESULTS

The response rate was 15% (415 of 2,725). Eighty-two percent of respondents stated that their patients or families have expressed anxiety regarding radiation dose from medical imaging. Although fewer than half of oncologists (48%) did not know whether CT dose reduction techniques were used at their institutions, only 25% were concerned that small lesions may be missed with low-dose CT techniques. The majority of oncologists (63%) follow National Comprehensive Cancer Network guidelines for imaging follow-up, while the remainder follow other national guidelines such as those of the Children's Oncology Group, the American Society of Clinical Oncology, or clinical trials. Ninety percent of respondents believe that long-term surveillance in oncology patients is warranted, particularly in patients with breast cancer, melanoma, sarcoma, and pediatric malignancies. The majority of oncologists would consider the use of low-dose CT imaging in specific patient populations: (1) children and young women, (2) those with malignancies that do not routinely metastasize to the liver, and (3) patients undergoing surveillance imaging.

CONCLUSIONS

Cumulative radiation exposure is a concern for patients and oncologists. Among oncologists, there is support for long-term imaging surveillance despite lack of national guidelines.

Imaging in childhood cancer: a Society for Pediatric Radiology and Children's Oncology Group Joint Task Force report

Contemporary medical imaging is a cornerstone of care for children with cancer. As 5-year survival rates for children with cancer exceed 80%, imaging technologies have evolved in parallel to include a wide array of modalities. Here, we overview the risks and benefits associated with commonly used imaging modalities and survey the current landscape of medical imaging for children with cancer. We find evidence-based imaging guidelines to assist in protocol development and to guide decision-making for optimal patient care are often lacking. The substantial variation in protocol-based recommendations for imaging both during and following therapy may hinder optimal clinical research and clinical care for children with cancer.

Neuroblastoma: the impact of biology and cooperation leading to personalized treatments

Neuroblastoma is the most common extra-cranial solid tumor in children. It is a heterogeneous disease, consisting of neural crest-derived tumors with remarkably different clinical behaviors. It can present in a wide variety of ways, including lesions which have the potential to spontaneously regress, or as an extremely aggressive form of metastatic cancer which is resistant to all forms of modern therapy. They can arise anywhere along the sympathetic nervous system. The median age of presentation is approximately 18 months of age. Urinary catecholamines (HVA and VMA) are extremely sensitive and specific tumor markers and are used in diagnosis, treatment response assessment and post-treatment surveillance. The largest national treatment groups from North America, Europe and Japan have formed the International Neuroblastoma Risk Group Task Force (INRG) to identify prognostic factors, to understand the mechanisms of tumorigenesis in this rare disease and to develop multi-modality therapies to improve outcomes and decrease treatment-related toxicities. This international cooperation has resulted in a significant leap in our understanding of the molecular pathogenesis of neuroblastoma. Lower staged disease can be cured if the lesion is resectable. Treatment of unresectable disease (loco-regional and metastatic) is stratified depending on clinical features (age at presentation, staging investigations) and specific tumor biological markers that include histopathological analyses, chromosomal abnormalities and the quantification of expression of an oncogene (MYCN). Modern treatment of high-risk neuroblastoma is the paradigm for the evolution of therapy in pediatric oncology. Outcomes have improved substantially with multi-modality therapy, including chemotherapy, surgery, radiation therapy, myeloablative therapy with stem cell transplant, immunotherapy and differentiation therapy; these comprise the standard of care worldwide. In addition, newer targeted therapies are being tested in phase I/II trials. If successful these agents will be incorporated into mainstream treatment programs.

Pediatric Hodgkin lymphoma: are we over-scanning our patients?

Despite the favorable outcome of most pediatric patients with Hodgkin lymphoma (HL), there is rising concern about risks of carcinogenesis from both diagnostic and therapeutic radiation exposure for patients treated on study protocols. Although previous studies have investigated radiation exposure during treatment, radiation from post-treatment surveillance imaging may also increase the likelihood of secondary malignancies. All diagnostic imaging examinations involving ionizing radiation exposure performed for surveillance following completion of therapy were recorded for 99 consecutive pediatric patients diagnosed with HL from 2000 to 2010. Cumulative radiation dosage from these examinations and the frequency of relapse detection by these examinations were recorded. In the first 2 years following completion of therapy, patients in remission received a median of 11 examinations (range 0-26). Only 13 of 99 patients relapsed, 11 within 5 months of treatment completion. No relapse was detected by 1- or 2-view chest radiographs (n = 38 and 296, respectively), abdomen/pelvis computed tomography (CT) scans (n = 211), or positron emission tomography (PET) scans alone (n = 11). However, 10/391 (2.6%) of chest CT scans, 4/364 (1.1%) of neck CT scans, and 3/47 (6.4%) of PET/CT scans detected relapsed disease. Thus, only 17 scans (1.3%) detected relapse in a total of 1358 scans. Mean radiation dosages were 31.97 mSv for Stage 1, 37.76 mSv for Stage 2, 48.08 mSv for Stage 3, and 51.35 mSv for Stage 4 HL. Approximately 1% of surveillance imaging examinations identified relapsed disease. Given the very low rate of relapse detection by surveillance imaging stipulated by current protocols for pediatric HL patients, the financial burden of the tests themselves, the high cure rate, and risks of second malignancy from ionizing radiation exposure, modification of the surveillance strategy is recommended.

Surveillance computed tomography imaging and detection of relapse in intermediate- and advanced-stage pediatric Hodgkin's lymphoma: a report from the Children's Oncology Group

PURPOSE Children with Hodgkin's lymphoma (HL) routinely undergo surveillance computed tomography (CT) imaging for up to 5 years after therapy, resulting in cost and radiation exposure, without clear benefit. The objective of this study was to determine the contribution of surveillance CT, as compared with clinical findings, to detection of disease recurrence. PATIENTS AND METHODS Two hundred sixteen patients, age ≤ 21 years old, were treated on the multicenter Pediatric Oncology Group 9425 trial. Data for patients who experienced relapse were retrospectively reviewed to determine whether imaging or clinical events prompted suspicion of disease recurrence. Correlation was made to disease stage, time to recurrence, relapse site, and overall survival (OS). Results With a median follow-up time of 7.4 years, 25 (11.6%) of 216 patients had experienced a relapse, of whom 23 experienced local relapse. Median time to relapse was 7.6 months (range, 0.2 to 48.9 months). Nineteen relapses (76%) were detected based on symptoms, laboratory or physical examination findings, and two relapses (8%) were detected by imaging within the first year after therapy. Only four patients (16%) had their recurrence detected exclusively by surveillance imaging after the first year. Six deaths occurred, all in patients who experienced relapse within the first year after therapy. No patient with a recurrence after 1 year off treatment has died, regardless of how the recurrence was detected. CONCLUSION The majority of pediatric HL relapses occurred within the first year after therapy or were detected based on change in clinical status. Detecting late relapse, whether by imaging or clinical change, did not affect OS. These findings indicate that CT is overused for routine surveillance of patients with HL.

Synovial sarcoma in children and adolescents: a critical reappraisal of staging investigations in relation to the rate of metastatic involvement at diagnosis

BACKGROUND

European protocols for paediatric synovial sarcoma (SS) require that all children routinely undergo chest computed tomography (CT) scanning and bone scanning as initial staging procedures. This study aims to determine the rate of initial metastases in paediatric SS based on specific clinical characteristics, thereby investigating whether these diagnostic procedures are really necessary in all patients.

METHODS

Data on 258 previously-untreated SS patients <21 years old were pooled from the databases of different European paediatric groups (study period 1988-2005) for this analysis, and the associations between patients' characteristics and any presence of metastasis were estimated.

RESULTS

Fifteen cases (5.8%) had distant metastases at diagnosis (86% pulmonary). The presence of metastases was unassociated with patients' gender or age, tumour grade or site, but it was influenced by T-status, and especially primary tumour size: the risk of metastases was 32 times higher in cases of tumour >5 cm than for tumours ≤ 5 cm.

CONCLUSIONS

Our findings suggest that tumour diameter can be used as a variable for identifying patients at greater risk of metastases and warranting more accurate radiological investigations. Chest CT scanning may improve the accuracy of pulmonary staging over X-ray, but requires different ionising radiation exposures that might have carcinogenic potential: it can be omitted for patients with tumours ≤ 5 cm. Given the very low risk of bone metastases, bone scans may be recommended only in cases with evidence of lung metastases.

Oncological imaging: tumor surveillance in children

As the need for accurate diagnostic imaging often continues throughout a cancer survivor's life, imaging methods with the least toxicity must be used so as to provide needed information without contributing to long-term sequelae that might compound toxicities inherent with the primary disease and its treatment. In this regard, the costs, benefits and potential risks of post-therapy monitoring for disease recurrence warrant periodic review. Unfortunately, few analyses are available regarding the impact of surveillance imaging on the detection of disease recurrence, salvage rates of relapse disease and long-term survival outcomes for pediatric cancer survivors. This review will examine the role and limitations of surveillance imaging in pediatric oncology.

Leukemia and lymphoma

Leukemia and lymphoma are the most common and third most common pediatric malignancies, respectively, and share cell lineages, but the clinical and imaging manifestations of these malignancies vary substantially. Along with providing pertinent details on classification, epidemiology, and treatment, this article reviews the current roles of imaging in the management of childhood leukemia and lymphoma, with attention to diagnosis, staging, risk stratification, therapy response assessment, and surveillance for disease relapse and adverse effects of therapy. Advances in functional imaging are also discussed to provide insights into future applications of imaging in the management of pediatric patients with leukemia and lymphoma.

Regional and whole-body imaging in pediatric oncology

The goals of tumor imaging include tumor detection, tumor characterization and differential diagnosis, imaging-guided biopsy, evaluation of tumor extent and staging, assessment of treatment responses, and surveillance for residual tumor or tumor recurrence. In clinical practice, various combinations of imaging modalities are used to achieve these goals. Recently introduced tumor imaging methods, such as diffusion MRI, perfusion MRI, whole-body MRI, and positron emission tomography (PET-CT), have shown promising results. Depending on tumor type and management plan, imaging protocols for children should be individually optimized to achieve the shortest examination time, the highest image quality, the lowest risk, and maximum clinical benefits. In this article, the roles of regional and whole-body tumor imaging will be reviewed, and several important issues related to recent technical developments will be discussed.

Radiation doses originating from diagnostic procedures during the treatment and follow-up of children and adolescents with malignant lymphoma

Children with malignant lymphoma undergo many diagnostic procedures that involve exposure to ionising radiation. In addition, many, but by no means all, undergo further exposure to ionising radiation during radiotherapy. While therapeutic radiation exposures are prescribed, the extent of radiation exposure arising from diagnostic procedures utilised in such children is largely unknown. We completed an audit of the radiation doses arising from diagnostic imaging procedures performed in a cohort of children with malignant lymphoma. The cumulative effective radiation dose associated with radiographic and radioisotopic procedures was derived for 81 children and adolescents with malignant lymphoma during their diagnosis, treatment and follow-up. Thirty-eight of the 42 patients (90%) with Hodgkin lymphoma were alive at study termination, with follow-up periods ranging from 1.9 to 11.7 years (median 5.3). Thirty-three of the 39 patients (85%) with non-Hodgkin lymphoma were alive at study termination with follow-up periods ranging from 2.4 to 12.3 years (median 7.5). The median effective dose was 518 mSv for patients with Hodgkin lymphoma and 309 mSv for those with non-Hodgkin lymphoma. The maximum effective dose was 1.7 Sv. The principal contributors to the effective dose were computed tomography (CT) and nuclear medicine imaging procedures using (67)Ga. Protocols for the management of children and adolescents with malignant lymphoma should be reviewed in order to reduce the radiation detriment without loss of essential diagnostic information.

Cumulative effective doses from radiologic procedures for pediatric oncology patients

OBJECTIVE

Our aim was to estimate the cumulative effective doses (CEDs) from radiologic procedures for a cohort of pediatric oncology patients.

METHODS

A retrospective cohort study of the imaging histories of 150 pediatric oncology patients (30 each in 5 subgroups, that is, leukemia, lymphomas, brain tumors, neuroblastomas, and assorted solid tumors) for 5 years after diagnosis was performed. All procedures involving ionizing radiation were recorded, including radiography, computed tomography (CT), nuclear medicine (NM) studies, fluoroscopy, and interventional procedures. CED estimates were calculated.

RESULTS

Individual CED estimates ranged from <1 mSv to 642 mSv, with a median of 61 mSv. CT and NM were the greatest contributors; CT constituted 30% of procedures but 52% of the total CED, and NM constituted 20% and 46%, respectively. There was considerable variability between tumor subgroups. CED estimates were highest in the neuroblastoma (median: 213 mSv [range: 36-489 mSv]) and lymphoma (median: 191 mSv [range: 10-642 mSv]) groups and lowest in the leukemia group (median: 5 mSv [range: 0.2-57 mSv]).

CONCLUSIONS

CEDs from diagnostic and interventional imaging for pediatric oncology patients vary considerably according to diagnoses, individual clinical courses, and imaging modalities used. Increased awareness may promote strategies to reduce the radiation burden to this population.