3D-Printed Osteoinductive Polymeric Scaffolds with Optimized Architecture to Repair a Sheep Metatarsal Critical-Size Bone Defect.

The reconstruction of critical-size bone defects in long bones remains a challenge for clinicians. A new osteoinductive medical device is developed here for long bone repair by combining a 3D-printed architectured cylindrical scaffold made of clinical-grade polylactic acid (PLA) with a polyelectrolyte film coating delivering the osteogenic bone morphogenetic protein 2 (BMP-2). This film-coated scaffold is used to repair a sheep metatarsal 25-mm long critical-size bone defect. In vitro and in vivo biocompatibility of the film-coated PLA material is proved according to ISO standards. Scaffold geometry is found to influence BMP-2 incorporation. Bone regeneration is followed using X-ray scans, µCT scans, and histology. It is shown that scaffold internal geometry, notably pore shape, influenced bone regeneration, which is homogenous longitudinally. Scaffolds with cubic pores of ≈870 µm and a low BMP-2 dose of ≈120 µg cm-3 induce the best bone regeneration without any adverse effects. The visual score given by clinicians during animal follow-up is found to be an easy way to predict bone regeneration. This work opens perspectives for a clinical application in personalized bone regeneration.

Successful Elective Thoracoscopic Resection of Complicate Extralobar Bronchopulmonary Sequestration after Intrafoetal Vascular Laser Ablation: The Paediatric Surgeon's Point of View.

Few reports of laser coagulation for foetal bronchopulmonary sequestration (BPS), a rare congenital malformation characterised by the absence of tracheobronchial connection and the presence of a systemic feeding artery, have been published. Additionally, very few of them focus also on the postnatal management, with results limited and controversial. Postnatal treatment of residual malformation remains debated, hence the need to share our experience of a combined pre- and postnatal approach to complicated extra-lobar BPS. We report the case of a female foetus with the diagnosis of a pulmonary lesion. Due to mediastinal shift, unilateral compressive hydrothorax, ascites, and hydrops, a foetal treatment with ultrasound-guided laser coagulation of the anomalous vessel was performed. At birth, due to the persistence of the malformation, an elective delayed thoracoscopical surgery was performed. Prenatal laser ablation for complicated BPS is a life-saving procedure not always resulting in lesion disappearance. Thoracoscopical surgical exploration in case of persistent lesions at birth offers the possibility of a minimally invasive sequestrectomy feasible and safe.

The monthly incidence of abusive head trauma, inflicted skeletal trauma, and unexplained skin lesion in children in six French university hospitals during the COVID-19 pandemic.

INTRODUCTION: The COVID-19 pandemic was a stressful period. Lockdowns may have added to parental difficulty leading to an increase in violence. This study aimed to compare the monthly incidence of high suspicion of child physical abuse before and during the COVID-19 pandemic. MATERIAL: We have retrospectively reviewed imaging examinations of children having a skeletal X-ray examination in six university hospitals with high suspicion of abusive head traumatism (AHT), inflicted skeletal trauma (IST) and unexplained skin lesions (USL) between March 2020 and June 2021 and compared with the similar period from 2018 to 2019. The monthly incidence of the different physical maltreatment was analyzed using a QuasiPoisson regression model. RESULTS: We included 178 children (n = 127 boys, 71.3 %), 110 during the pandemic period, median age 5 months. AHT was diagnosed in 91 children, 55 had inflicted skeletal trauma (IST) and 46 had unexplained skin lesions (USL). Among the 91 patients with AHT, 86 had a subdural hematoma (95.6 %) and 40 had bridging veins thrombosis (44 %). The ophthalmological examination performed on 89 children (97.9 %) revealed retinal hemorrhages in 57 children (89.8 %). The incidence of AHT doubled during the months of COVID-19 lockdowns (rate ratio = 2; 95 % CI [1.1; 3.6], p = 0.03). No difference in monthly incidence was observed for IST and USL groups. CONCLUSION: A significant increase in AHT was observed during the months with lockdowns and curfews during the COVID-19 pandemic. This highlights the need for developing a national strategy to prevent physical abuse in children in this context.

Diffusion properties of asymptomatic lumbar intervertebral discs in a pediatric cohort: a preliminary study of apparent diffusion coefficient.

PURPOSE: To explore the apparent diffusion coefficients of intervertebral discs in an asymptomatic pediatric cohort. METHODS: We conducted a prospective MRI study of the lumbar spine from below the thoracolumbar junction to the lumbosacral junction on 12 subjects (mean age 13 y.o.) with no spinal pathology or spinal posture disorder. MRI was carried out using a 1.5 T machine with acquisitions realized both in sagittal and coronal planes. First, disc hydration was determined, and then, diffusion-weighted images were obtained using an SE single-shot echo-planar sequence. Apparent diffusion coefficients (ADC) of anterior annulus fibrosus (AAF), nucleus pulposus (NP) and posterior annulus fibrosus (PAF) were measured in the sagittal plane. RESULTS: Averaged hydration of 0.27 SD 0.03 confirmed the asymptomatic nature of discs. Average scaled values of ADC were 0.46 SD 0.01, 0.22 SD 0.09 and 0.18 SD 0.03 for NP, AAF and PAF, respectively. ADC of NP were almost constant along the spine; PAF values show a slight increase in the thorax-sacrum direction, while AAF values showed a pronounced decrease. Locally, ADC of AAF was higher compared to ADC PAF values below the thoracolumbar junction and it reversed for subjacent discs. CONCLUSIONS: In our knowledge, our study provided the first diffusive properties of asymptomatic intervertebral discs in an adolescent cohort. ADC of NP was slightly higher than adults'. ADC evolutions of AAF were correlated with lordosis concavity which pointed out the role of compressive strain on fluid transport properties. This study could furnish information about segment homeostasis for exploration of pediatric spinal pathologies.

Does harvesting of the semitendinosus tendon really spare the gracilis in pediatric anterior cruciate ligament reconstruction?

Purpose: The use of isolated semitendinosus tendon for Anterior Cruciate Ligament Reconstruction bears several advantages and is popular worldwide. It assumes that the gracilis tendon is spared. The aim of the study was to measure the surface area of the gracilis tendon in children who had undergone arthroscopic reconstruction of the anterior cruciate ligament using a semitendinosus tendon graft. Our hypothesis was that the gracilis tendon may be unintentionally and iatrogenically sectioned due to the anatomical proximity and the small size of the patients. Methods: Fifty patients who had undergone a magnetic resonance imaging preoperatively and postoperatively at 1 year from the surgery and who had been operated between January 2017 and March 2019 were included in this prospective series. The surface area of the gracilis tendon was measured on fat-saturated T2-weighted axial views at the widest point of the medial epicondyle of the femur. Age, sex, body weight, and height were documented. Results: One hundred magnetic resonance imaging of 50 knees were reviewed, from 34 boys (68%) and 16 girls (32%). The mean age was 14.5 years (10-18). The gracilis was visualized in all cases at 1 year postoperatively. The average tendinous surface area of the gracilis before the surgical procedure was 7.13 mm2 versus 8.73 mm2 at 1 year, representing an increase of 1.6 mm2 (p = 0.0003). Conclusions: This study demonstrated that harvesting of the semitendinosus for the purpose of Anterior Cruciate Ligament Reconstruction was a safe technique that preserves the gracilis. Level of evidence: III.

Imaging Follow-up of Pediatric Transphyseal Anterior Cruciate Ligament Reconstruction: A Case Report.

CASE: We are reporting on the x-ray and magnetic resonance imaging (MRI) follow-up of an 8-year-old boy who underwent transphyseal anterior cruciate ligament reconstruction with a 4-strand semitendinosus tendon graft. His graft was followed for 5 years by MRI, demonstrating a satisfactory but slow and gradual ligamentization process. CONCLUSION: The long-term MRI follow-up demonstrated the satisfactory outcome of the transphyseal reconstruction, although with a slower and more progressive ligamentization process than in adult patients.

Prenatal features and neonatal management of severe hyperparathyroidism caused by the heterozygous inactivating calcium-sensing receptor variant, Arg185Gln: A case report and review of the literature.

BACKGROUND: Loss-of-function variants in the calcium-sensing receptor (CASR) gene are known to be involved in a clinical spectrum ranging from asymptomatic familial hypocalciuric hypercalcemia (FHH) to neonatal severe hyperparathyroidism (NSHPT). Homozygous or compound heterozygous variants are usually responsible for severe neonatal forms, whereas heterozygous variants cause benign forms. One recurrent pathogenic variant, p.Arg185Gln, has been reported in both forms, in a heterozygous state. This variant can be a de novo occurrence or can be inherited from a father with FHH.NSHPT leads to global hypotonia, failure to thrive, typical X-ray anomalies (diffuse demineralization, fractures, metaphyseal irregularities), and acute respiratory distress which can be fatal. Phosphocalcic markers show severe hypercalcemia, abnormal urinary calcium resorption, and hyperparathyroidism as major signs.Classical treatment involves calcium restriction, hyperhydration, and bisphosphonates. Unfortunately, the disease often leads to parathyroidectomy. Recently, calcimimetics have been used with variable efficacy. Efficacy in NSHPT seems to be particularly dependent on CASR genotype. CASE PRESENTATION: We describe the antenatal presentation of a male with short ribs, initially suspected having skeletal ciliopathy. At birth, he presented with NSHPT linked to the pathogenic heterozygous CASR variant, Arg185Gln, inherited from his father who had FHH. Postnatal therapy with cinacalcet was successful. DISCUSSION: An exhaustive literature review permits a comparison with all reported cases of Arg185Gln and to hypothesize that cinacalcet efficacy depends on CASR genotype. This confirms the importance of pedigree and parental history in antenatal short rib presentation and questions the feasibility of phosphocalcic exploration during pregnancy or prenatal CASR gene sequencing in the presence of specific clinical signs. It could in fact enable early calcimimetic treatment which might be effective in the CASR variant Arg185Gln.

Prevalence and Detection of Meniscal Ramp Lesions in Pediatric Anterior Cruciate Ligament-Deficient Knees.

BACKGROUND: Anterior cruciate ligament (ACL) tears represent 13% of knee injuries in children. Medial meniscal tears are commonly associated with ACL ruptures. Ramp lesions correspond to posterior meniscocapsular tears of the medial meniscus. Depending on the study, the prevalence of ramp lesions is inconsistent. PURPOSE: To describe the prevalence of ramp lesions in children and adolescents and to investigate the sensitivity of magnetic resonance imaging (MRI) for diagnosing such lesions. STUDY DESIGN: Cohort study (Diagnosis); Level of evidence, 3. METHODS: We analyzed videos from arthroscopic ACL reconstruction (ACLR) in children. During these procedures, we systematically looked for potential ramp lesions. To do so, an arthroscope was passed through the intercondylar notch to visualize the posteromedial compartment. A needle was introduced at the site of a posteromedial portal to unfold the meniscocapsular junction to reveal any hidden meniscal tear. Surgical procedures were performed by 2 senior surgeons. Videos were blindly analyzed by a third surgeon. Preoperative MRIs were screened by 2 blinded, independent senior radiologists to look specifically for ramp lesions. RESULTS: Videos of 50 consecutive arthroscopic ACLRs concerning 32 boys and 18 girls were analyzed. Mean age at surgery was 14.2 years (range, 8.5-17.6 years). A total of 14 ramp lesions (28%) in 8 boys and 6 girls were identified. In addition, there were 22 tears of the meniscal body in 20 patients (40%). Arthroscopic and MRI findings did not correlate. Among 14 arthroscopically diagnosed ramp lesions, only 8 were detected on the MRI. Conversely, 12 patients had a ramp lesion detected on the MRI, which could not be confirmed intraoperatively. The sensitivity of MRI was 57% and the positive predictive value was 40%. CONCLUSION: A meniscal ramp lesion was present in 14 of 50 children (28%) undergoing ACLR. MRI has a low sensitivity for diagnosis of ramp lesions in children. Careful exploration of the posteromedial compartment is strongly recommended. Overlooking such lesions during ACLR may contribute to ongoing instability and higher re-rupture rates in these young patients.

Diffusion-weighted MRI for outcome prediction in early Legg-Calvé-Perthes disease: Medium-term radiographic correlations.

BACKGROUND: Outcome prediction at the early sclerotic stage of Legg-Calvé-Perthes disease (LCPD) is valuable to select patients likely to benefit from early surgery. The metaphyseal apparent diffusion coefficient (ADC) ratio correlated significantly with Herring's classification of LCPD in a preliminary study of 49 MRIs, in which values greater than 1.63 were associated with poor outcomes. The objective of this study was to determine whether the femoral neck ADC ratio, with the 1.63 cut-off, determined at the initial stage of LCPD correlated with medium-term radiographic outcomes. HYPOTHESIS: The metaphyseal ADC ratio correlates significantly with medium-term radiographic outcomes of LCPD. MATERIALS AND METHODS: A prospective study was performed in 27 children (mean age, 13 years; range, 9.5-16 years) who underwent 49 MRIs at the sclerosis or fragmentation stage of unilateral LCPD. ADCs measured bilaterally at the femoral head and neck were used to compute the corresponding ADC ratios between the affected and unaffected sides. The patients received regular follow-up for at least 5 years. The correlation between the ADC ratios and Stulberg grade at last follow-up was assessed. RESULTS: After a mean follow-up of 6.8 years (range, 5.2-8.4 years) from the date of the first MRI, 13 hips were Stulberg 1 or 2, 13 were Stulberg 3 or 4, and 1 was Stulberg 5. The metaphyseal ADC ratio increased significantly with the Stulberg grade (p<0.01). When only MRIs obtained at the early stage of sclerosis were considered, the correlation remained significant (p=0.03). It was also significant in the subgroup of surgically treated patients (p<0.0001) but was not significant in the subgroup without surgery (p=0.51). A metaphyseal ADC ratio greater than 1.63 was associated with a worse Stulberg grade (p=0.02). DISCUSSION/CONCLUSION: Diffusion-weighted MRI is a non-irradiating and non-invasive investigation that contributes to the management of LCPD when used in combination with morphological MRI sequences. Elevation of the femoral neck ADC is a finding of adverse prognostic significance that correlates with Herring's grade at the fragmentation stage and with Stulberg's grade at the healed stage. Early ADC elevation in the affected femoral neck can serve to select those patients most likely to benefit from early surgery before the fragmentation stage, i.e., before Herring's classification can be applied. LEVEL OF EVIDENCE: III, prospective uncontrolled study 3.

Planning for Bone Excision in Ewing Sarcoma: Post-Chemotherapy MRI More Accurate Than Pre-Chemotherapy MRI Assessment.

BACKGROUND: In determining the level of bone resection in Ewing sarcoma, the most suitable time at which to perform magnetic resonance imaging (MRI) remains controversial. Current guidelines recommend that surgical planning be based on MRI performed prior to neoadjuvant chemotherapy. The goal of this study was to determine whether pre-chemotherapy or post-chemotherapy MRI provides greater accuracy of tumor limits for planning bone excision in the management of Ewing sarcoma. METHODS: This was a single-center, retrospective study. MRI was performed using 3 sequences: T1-weighted, T1-weighted with contrast enhancement by gadolinium injection, and a fluid-sensitive sequence (STIR [short tau inversion recovery] or proton-density-weighted with fat saturation). The tumor extent as assessed on pre-chemotherapy and post-chemotherapy MRI was compared with histological measurement of the resected specimen. RESULTS: Twenty patients with Ewing sarcoma of a long bone were included. In 6 cases, the tumor was located on the femur, in 5, the tibia; in 5, the fibula; and in 4, the humerus. The median patient age at diagnosis was 9.7 years. We found greater accuracy of measurements from MRI scans acquired after chemotherapy than from those acquired before chemotherapy. For both pre-chemotherapy and post-chemotherapy MRI, the greatest accuracy was achieved with the nonenhanced T1 sequence. There was no benefit to gadolinium enhancement. The median difference between T1 MRI and histological measurements was 19.0 mm (interquartile range [IQR], 4.3 to 32.8 mm) before chemotherapy and 5.0 mm (IQR, 2.0 to 13.0 mm) after chemotherapy. Adding a minimum margin of 20 mm to the limit of the tumor on post-chemotherapy T1 MRI always led to safe histological margin. CONCLUSIONS: Post-chemotherapy MRI provided a more accurate assessment of the limits of Ewing sarcoma. Surgical planning can therefore be based on post-chemotherapy MRI. Surgical cuts can be, at minimum, 20 mm from the limits as seen on MRI.

Non-operative Management for Uncomplicated Appendicitis: An Option to Consider.

AIM: The main goal of our study was to assess a 7 days long course of antibiotics for acute uncomplicated appendicitis. MATERIALS AND METHODS: From March 2014 to November 2015, all patients diagnosed with acute appendicitis have been considered to be treated by only antibiotics. Inclusion criteria included clinical (tenderness), biological (C-reactive protein [CRP] < 50), and radiological features (diameter > 6 mm). All patients were treated with intravenous amoxicillin and clavulanic acid (100 mg/kg/day) for 2 days (six doses). At the end of the treatment, clinical and paraclinical examinations included blood samples at day 7 and ultrasound (US) scan at 3 months. RESULTS: A total of 166 patients were treated and followed up prospectively during the study period. Mean age at diagnosis was 10.8 ± 0.6 years. All children, but four were discharged with a clinical improvement after 48 hours and six intravenous antibiotics injection according to our protocol. Four children required surgery during the initial hospitalization period.Initial ultrasound scan showed a mean diameter of 7.85 ± 1.6 mm, with inflamed fat in 124 patients (74.7%). At Day 7, the diameter was 5.2 ± 1.6 mm (p < 0.0001).During a median follow-up of 18.8 months (3.5-18), 22 patients (13.25%) had to be managed for a novel episode of acute appendicitis after a median period of 138 days (13-270). None had to be managed for a complicated appendicitis. CONCLUSION: Non-operative treatment (NOT) is a safe alternative for the management of uncomplicated acute appendicitis in children. Further study should be conducted to determine relapse risk factors.

Relationship between tibial spine size and the occurrence of osteochondritis dissecans: an argument in favour of the impingement theory.

PURPOSE: Pathophysiology of osteochondritis dissecans (OCD) of the medial femoral condyle remains uncertain. Specifically, the relationship between the size of the anterior tibial spine (ATS) and the presence of OCD has not been explored. The purpose of this study was to evaluate the relationship between ATS size and the occurrence of OCD. METHODS: Seventy-nine children between 8 and 17 years of age were included in two groups: OCD (n = 37) and control (n = 42). The groups were matched in terms of age, gender, BMI and weight. Two independent observers performed an MRI analysis of the size of the tibial spine and intercondylar notch relative to the size of the respective epiphyses. For this study, the "S ratio" was calculated by dividing the height of the tibial spine by the height of the tibial epiphysis. The "N ratio" was calculated by dividing the height of the notch by the height of the femoral epiphysis. These two ratios for both groups were compared using Student's t test. RESULTS: The mean value of the S ratio in the OCD group was 0.39 ± 0.06; the mean value of the S ratio in the control group was 0.32 ± 0.03 (P = 0.004). The mean value of the N ratio in the OCD group was 0.70 ± 0.08; the mean value of the N ratio in the control group was 0.70 ± 0.07 (n.s.). CONCLUSION: This study's findings confirm our hypothesis that patients with OCD have a more prominent tibial spine than in patients without OCD. LEVEL OF EVIDENCE: IV.

Non-contrast-enhanced MR angiography using time-spin labelling inversion pulse technique for detecting crossing renal vessels in children with symptomatic ureteropelvic junction obstruction: comparison with surgical findings.

OBJECTIVES: Investigate the feasibility and evaluate the accuracy of non-contrast-enhanced MR angiography (NC-MRA) using time-spin labelling inversion pulse (time-SLIP)to identify crossing renal vessels (CRVs) in children requiring surgical treatment of ureteropelvic junction (UPJ) obstructionand compare to laparoscopic findings. MATERIALS AND METHODS: Nineteen children ranging from 6 to 16 years of age underwent NC-MRA using the time-SLIP technique before surgery. Two independent readers analysed the MRA images. Number of renal arteries and presence or absence of CRVs were identified and compared with surgicalfindings. Image quality was assessed, as well as the presence of CRVs and measurement of renal pelvis diameter. Intra and inter-reader agreement was calculated using Cohen's kappa coefficient and Bland-Altman plots. RESULTS: The overall image quality was fair or good in 88% of cases. NC-MRA demonstrated CRVs at the level of the obstruction in 10 children and no CRV in 9 children. All were confirmed intra-operatively except in one of the nine children. Sensitivity, specificity, NPV, PPV for predicting CRVs were 92%, 100%, 100% and 87.5%, respectively, for both readers. CONCLUSION: NC-MRA is a good alternative to contrast-enhanced MRA and CT scanning for identifying CRVs in children with symptomatic UPJ. KEY POINTS: • Time-SLIP technique offers acceptable imaging quality for identifying crossing renal vessel. • Time-SLIP technique is easy to apply to the renal MRA examination. • Time-SLIP technique is an alternative to contrast-enhanced MRA and CT scanning.

Low-dose biplanar radiography can be used in children and adolescents to accurately assess femoral and tibial torsion and greatly reduce irradiation.

PURPOSE: To evaluate in children the agreement between femoral and tibial torsion measurements obtained with low-dose biplanar radiography (LDBR) and CT, and to study dose reduction ratio between these two techniques both in vitro and in vivo. MATERIALS AND METHODS: Thirty children with lower limb torsion abnormalities were included in a prospective study. Biplanar radiographs and CTs were performed for measurements of lower limb torsion on each patient. Values were compared using Bland-Altman plots. Interreader and intrareader agreements were evaluated by intraclass correlation coefficients. Comparative dosimetric study was performed using an ionization chamber in a tissue-equivalent phantom, and with thermoluminescent dosimeters in 5 patients. RESULTS: Average differences between CT and LDBR measurements were -0.1° ±1.1 for femoral torsion and -0.7° ±1.4 for tibial torsion. Interreader agreement for LDBR measurements was very good for both femoral torsion (FT) (0.81) and tibial torsion (TT) (0.87). Intrareader agreement was excellent for FT (0.97) and TT (0.89). The ratio between CT scan dose and LDBR dose was 22 in vitro (absorbed dose) and 32 in vivo (skin dose). CONCLUSION: Lower limb torsion measurements obtained with LDBR are comparable to CT measurements in children and adolescents, with a considerably reduced radiation dose. KEY POINTS: • LDBR and CT lower-limb torsion measurements are comparable in children and adolescents. • LDBR considerably reduced radiation dose necessary for lower-limb torsion measurements. • LDBR can be used for evaluation of lower limb-torsion in orthopaediatric patients.

Complex communicating bronchopulmonary foregut malformation with pancreatic heterotopy depicted with fetal magnetic resonance imaging: a case report.

Bronchopulmonary foregut malformation (BPFM) is a group of rare congenital anomalies that affect the respiratory and upper gastrointestinal tracts. We report here the first case of prenatal depiction of communicating BPFM, including extrapulmonary sequestration and foregut cyst, both with pancreatic differentiation. Magnetic resonance imaging on the fetus confirmed a polymalformative syndrome with right-lung and gastric cysts and allowed the detection of respiratory and alimentary tracts communication and aberrant feeding vessels. Diagnosis was confirmed after birth by multidetector computed tomography and postnatal pathologic findings. The patient, a boy, underwent surgery for respiratory distress at 4 weeks of life. This singular case confirms the benefits of early surgery for communicating BPFM.

Severity scores in children with acute pancreatitis.

Severity scores are used to predict the outcome of acute pancreatitis (AP). Several scores are used in adult patients, but none has been thoroughly validated for specific use in paediatric patients. We retrospectively collected data from 48 children with AP (13 severe and 35 mild). The main causes were trauma (23%), idiopathic (23%), lithiasis (12.5%), and virus (10.5%). We evaluated 3 clinical scores (Ranson, Glasgow modified, and DeBanto) and Balthazar computed tomography severity index. The clinical scores had a good specificity (approximately 85%) but a low sensitivity (approximately 55%) in predicting the severity of paediatric AP. The radiological score is better (sensitivity 80%, specificity 86%). The area under the receiver operator characteristic curve was 0.699 (95% CI 0.508%-0.891%, P = 0.054) for the DeBanto score, 0.846 (95% CI 0.69%-1%, P = 0.001) for the Ranson score, and 0.774 (95% CI 0.584%-0.964%, P = 0.008) for the Glasgow and 0.898 (95% CI 0.73%-1%, P = 0.011) for the Balthazar computed tomography severity index score. In our paediatric cohort, the severity of AP was best predicted by Balthazar computed tomography-based scoring scale. Our results confirm previously reported low sensitivity of adult-based clinical scoring scales.

A rare cause of anaemia associated with hypertension in a 14-year-old girl.

We report a rare example of anaemia and hypertension due to an incomplete Carney triad in a 14-year-old girl with no previous medical history. This rare non-familial syndrome generally involves two disparate tumours: gastrointestinal stromal tumour, paraganglioma and/or pulmonary chondroma. The complete triad is a syndrome that involves at least five loci: stomach, oeophagus, lung, the paraganglionic system, adrenal (cortex or medulla). The pathogenesis is unclear as these tumours have different embryological origins. Surgical treatment is necessary, and long-term follow-up is advisable as patients with Carney triad may re-present with tumour(s), even several years after the first presentation.

Coregistration of prechemotherapy PET-CT for planning pediatric Hodgkin's disease radiotherapy significantly diminishes interobserver variability of clinical target volume definition.

PURPOSE: To assess the interobserver variability in clinical target volume (CTV) definitions when using registered (18)F-labeled deoxyglucose positron emission tomography (FDG-PET-CT) versus side-by-side image sets in pediatric Hodgkin's disease (HD). METHODS AND MATERIALS: Prechemotherapy FDG-PET-CT scans performed in the treatment position were acquired from 20 children (median age, 14 years old) with HD (stages 2A to 4B) and registered with postchemotherapy planning CT scans. The patients had a median age of 14 years and stages of disease ranging between 2A and 4B. Image sets were coregistered using a semiautomatic coregistration system. The biological target volume was defined on all the coregistered images as a guide to defining the initial site of involvement and to avoid false-positive or negative results. Five radiation oncologists independently defined the CTV for all 20 patients: once using separate FDG-PET-CT images as a guide (not registered) to define CTVa and once using the registered FDG-PET-CT data to define CTVb. The total volumes were compared, as well as their coefficients of variation (COV). To assess the interobserver variability, the percentages of intersection between contours drawn by all observers for each patient were calculated for CTVa and for CTVb. RESULTS: The registration of a prechemotherapy FDG-PET-CT scan caused a change in the CTV for all patients. Comparing CTVa with CTVb showed that the mean CTVb increased in 14 patients (range, 0.61%-101.96%) and decreased in 6 patients (range, 2.97%-37.26%). The COV for CTVb significantly decreased for each patient; the mean COVs for CTVa and CTVb were 45% (21%-65%) and 32% (13%-57%), respectively (p = 0.0004). The percentage of intersection among all CTVbs for the five observers increased significantly by 89.77% (1.99%-256.41%) compared to that of CTVa (p = 0.0001). CONCLUSIONS: High observer variability can occur during CT-based definition of CTVs for children diagnosed with HD. Registration of FDG-PET and planning CT images resulted in significantly greater consistency of tumor volume definition.