Search

An objective of the Children's Oncology Group AREN0534 Study was to improve the survival of patients with bilateral Wilms tumors (BWT) by using preoperative chemotherapy of limited duration and tailoring postoperative therapy based on histopathologic response. The authors report outcomes based on postoperative histopathologic responses.Patients with BWT received treatment with vincristine, dactinomycin, and doxorubicin for 6 or 12 weeks followed by surgery. Postoperative therapy was prescribed based on the highest risk tumor according to the International Society of Pediatric Oncology classification and the Children's Oncology Group staging system.Analyses were performed on data from 180 evaluable children. The 4-year event-free survival (EFS) and overall survival (OS) rates were 81% (95% CI, 74%-87%) and 95% (95% CI, 91%-99%), respectively. Seven patients who had completely necrotic tumors had a 4-year EFS rate of 100%. Of 118 patients who had tumors with intermediate-risk histopathology, the 4-year EFS and OS rates were 82% (95% CI, 74%-90%) and 97% (95% CI, 94%-100%), respectively. Fourteen patients who had blastemal-type tumors had 4-year EFS and OS rates of 79% (95% CI, 56%-100%) and 93% (95% CI, 79%-100%), respectively. Eighteen patients who had diffuse anaplasia had 4-year EFS and OS rates of 61% (95% CI, 35%-88%) and 72% (95% CI, 47%-97%), respectively; and the 4-year EFS and OS rates of 7 patients who had focal anaplasia were 71% (95% CI, 38%-100%) and 100%, respectively. There was no difference in the outcomes of patients who had different histopathologic subtypes within the intermediate-risk group (P = .54).A risk-adapted treatment approach for BWT results in excellent outcomes. This approach was not successful in improving the outcome of patients who had diffuse anaplasia.

Background A primary objective of Children's Oncology Group study AREN0534 (Treatment for Patients With Multicentric or Bilaterally Predisposed, Unilateral Wilms Tumor) was to facilitate partial nephrectomy in 25% of children with bilaterally predisposed unilateral tumors (Wilms tumor/aniridia/genitourinary anomalies/range of developmental delays [WAGR] syndrome; and multifocal and overgrowth syndromes). The purpose of this prospective study was to achieve excellent event-free survival (EFS) and overall survival (OS) while preserving renal tissue through preoperative chemotherapy, completing definitive surgery by 12 weeks from diagnosis, and modifying postoperative chemotherapy based on histologic response. Methods The treating institution identified whether a predisposition syndrome existed. Patients underwent a central review of imaging studies through the biology and classification study AREN03B2 and then were eligible to enroll on AREN0534. Patients were treated with induction chemotherapy determined by localized or metastatic disease on imaging (and histology if a biopsy had been undertaken). Surgery was based on radiographic response at 6 or 12 weeks. Further chemotherapy was determined by histology. Patients who had stage III or IV disease with favorable histology received radiotherapy as well as those who had stage I through IV anaplasia. Results In total, 34 patients were evaluable, including 13 males and 21 females with a mean age at diagnosis of 2.79 years (range, 0.49-8.78 years). The median follow-up was 4.49 years (range, 1.67-8.01 years). The underlying diagnosis included Beckwith-Wiedemann syndrome in 9 patients, hemihypertrophy in 9 patients, multicentric tumors in 10 patients, WAGR syndrome in 2 patients, a solitary kidney in 2 patients, Denys-Drash syndrome in 1 patient, and Simpson-Golabi-Behmel syndrome in 1 patient. The 4-year EFS and OS rates were 94% (95% CI, 85.2%-100%) and 100%, respectively. Two patients relapsed (1 tumor bed, 1 abdomen), and none had disease progression during induction. According to Response Evaluation Criteria in Solid Tumor 1.1 criteria, radiographic responses included a complete response in 2 patients, a partial response in 21 patients, stable disease in 11 patients, and progressive disease in 0 patients. Posttherapy histologic classification was low-risk in 13 patients (including the 2 complete responders), intermediate-risk in 15 patients, and high-risk in 6 patients (1 focal anaplasia and 5 blastemal subtype). Prenephrectomy chemotherapy facilitated renal preservation in 22 of 34 patients (65%). Conclusions A standardized approach of preoperative chemotherapy, surgical resection within 12 weeks, and histology-based postoperative chemotherapy results in excellent EFS, OS, and preservation of renal parenchyma.

PURPOSE AREN0321 evaluated the activity of vincristine and irinotecan (VI) in patients with newly diagnosed diffuse anaplastic Wilms tumor (DAWT) and whether a regimen containing carboplatin (regimen UH1) in addition to regimen I agents used in the National Wilms Tumor Study 5 (NWTS-5; vincristine, doxorubicin, cyclophosphamide, and etoposide plus radiotherapy) would improve patient outcomes. PATIENTS AND METHODS Patients with stage II to IV DAWT without measurable disease received regimen UH1. Patients with stage IV measurable disease were eligible to receive VI (vincristine, 1.5 mg/m2 per day intravenously on days 1 and 8; irinotecan, 20 mg/m2 per day intravenously on days 1-5 and 8-12 of a 21-day cycle) in an upfront window; those with complete (CR) or partial response (PR) had VI incorporated into regimen UH1 (regimen UH2). The study was designed to detect improvement in outcomes of patients with stage II to IV DAWT compared with historical controls treated with regimen I. RESULTS Sixty-six eligible patients were enrolled. Of 14 patients with stage IV measurable disease who received VI, 11 (79%) achieved CR (n = 1) or PR (n = 10) after 2 cycles. Doses of doxorubicin, cyclophosphamide, and etoposide were reduced midstudy because of nonhematologic toxicity. Four patients (6%) died as a result of toxicity. Four-year event-free survival, relapse-free survival, and overall survival rates were 67.7% (95% CI, 55.9% to 79.4%), 72.9% (95% CI, 61.5% to 84.4%), and 73.7% (95% CI, 62.7% to 84.8%), respectively, compared with 57.5% (95% CI, 47.6% to 67.4%; P = .26), 57.5% (95% CI, 47.6% to 67.4%; P = .048), and 59.2% (95% CI, 49.4% to 69.0%; P = .08), respectively, in NWTS-5. CONCLUSION VI produced a high response rate in patients with metastatic DAWT. AREN0321 treatment seemed to improve outcomes for patients with stage II to IV DAWT compared with NWTS-5, but with increased toxicity. The UH2 regimen warrants further investigation with modifications to reduce toxicity.

OBJECTIVE. Distinguishing nephrogenic rests from small Wilms tumors can be challenging. This retrospective study was performed to determine if imaging characteristics can be used to distinguish nephrogenic rests from Wilms tumors. MATERIALS AND METHODS. All cases of pathologically confirmed nephrogenic rests and Wilms tumors smaller than 5 cm in maximum dimension on imaging in patients younger than 5 years old were identified from the Children’s Oncology Group AREN03B2 study (July 2006–August 2016). Exclusion criteria were chemotherapy before pathologic evaluation or more than 30 days between imaging and surgery; in addition, patients with nephrogenic rests occurring within or juxtaposed to a Wilms tumor and patients with diffuse hyperplastic perilobar nephroblastomatosis were excluded. Two radiologists who were blinded to pathology results assessed all lesions. The two-sample t test was used for continuous variables, and the Fisher exact test was used for categoric variables. ROC analysis was performed to determine the optimal size cutoff for distinguishing between nephrogenic rests and Wilms tumors. RESULTS. Thirty-one pathologically confirmed rests (20 perilobar, 11 intralobar) and 26 Wilms tumors smaller than 5 cm met the eligibility criteria for study inclusion. The median diameter of the nephrogenic rests was 1.3 cm (range, 0.7–3.4 cm) and the median diameter of the Wilms tumor was 3.2 cm (range, 1.8–4.9 cm) (p < 0.001). Imaging findings supportive of Wilms tumors were spherical (p < 0.001) and exophytic (p < 0.001) lesions. Perilobar rests (17/20) were more likely to be homogeneous than intralobar rests (3/11) or Wilms tumor (3/26) (p < 0.001). ROC analysis showed that the optimal size cutoff for distinguishing between nephrogenic rests and Wilms tumors was 1.75 cm. CONCLUSION. In children younger than 5 years old, the diagnosis of a Wilms tumor should be favored over a nephrogenic rest when a renal mass is spherical, exophytic, or larger than 1.75 cm. Homogeneity favors the diagnosis of perilobar nephrogenic rests, whereas intralobar rests and Wilms tumors are more likely to be inhomogeneous.

Diffuse hyperplastic perilobar nephroblastomatosis (DHPLN) represents a unique category of nephroblastomatosis. Treatment has ranged from observation to multiple regimens of chemotherapy. Wilms tumors (WTs) develop in 100% of untreated patients and between 32 and 52% of treated patients. Renal preservation rates have not been previously reported. An aim of the Children's Oncology Group (COG) study AREN0534 was to prospectively evaluate the efficacy of chemotherapy in preserving renal units and preventing WT development in children with DHPLN.Patients were enrolled through the COG protocol AREN03B2 with central radiological review. DHPLN was defined as the cortical surface of the kidney being composed of hyperplastic rests, with the entire nephrogenic zone involved, and with a thick rind capping all of one or both kidneys. Treatment was with vincristine and dactinomycin (regimen EE4A), with cross-sectional imaging at weeks 6 and 12. If the patient's disease was stable or decreasing, treatment was continued for 19 weeks. Renal preservation, WT development rates at 1 year, and overall survival (OS) are reported.Nine patients were enrolled (five females and four males), with a median age at enrollment of 10.22 months (range 2.92-29.11). One patient who was enrolled was deemed unevaluable because they did not meet the radiological criteria for DHPLN, resulting in eight evaluable patients. These eight patients had DHPLN confirmed via radiological criteria (all bilateral). Initial chemotherapy was EE4A for all eight patients, with seven of eight patients starting chemotherapy without tissue diagnosis.One patient who had an upfront partial nephrectomy was found to have DHPLN in the specimen and was subsequently treated with EE4A. All patients remained alive, with a median follow-up of 6.6 years (range 4.5-9.1). No patients were anephric; 14 of 16 kidneys were functioning (87.5%). Six of eight patients (75%) did not have WT on therapy, but two of these patients relapsed within 6 months of stopping therapy; both had favorable histology WT. One patient who was diagnosed with WT on therapy relapsed at 12 months (one of eight [12.5%]) and developed anaplastic histology.Chemotherapy for patients with DHPLN was effective in preserving kidney function. Five-year OS is excellent, however the ideal type and duration of chemotherapy to prevent WT development remains elusive.

Wilms tumor is the most common pediatric renal tumor, accounting for approximately 7% of all childhood cancers. Imaging plays an important role in the detection, staging, post-therapy evaluation and surveillance of Wilms tumor. Wilms tumor can be detected during surveillance of a known cancer predisposition or after a child presents with symptoms. In this manuscript we describe an evidence-based approach to the initial evaluation of Wilms tumor using current guidelines from the Children's Oncology Group (COG). We illustrate the COG staging system for pediatric renal tumors and highlight key imaging findings that are critical for surgical management. We also discuss the controversies regarding detection and significance of

Background The National Wilms Tumor Study (NWTS) approach to treating stage III favorable-histology Wilms tumor (FHWT) is Regimen DD4A (vincristine, dactinomycin, and doxorubicin) and radiation therapy. Further risk stratification is required to improve outcomes and reduce late effects. We evaluated clinical and biologic variables for patients with stage III FHWT without combined loss of heterozygosity (LOH) at chromosomes 1p and 16q treated in the Children’s Oncology Group protocol AREN0532. Methods From October 2006 to August 2013, 588 prospectively treated, centrally reviewed patients with stage III FHWT were treated with Regimen DD4A and radiation therapy. Tumor LOH at 1p and 16q was determined by microsatellite analysis. Ineligible patients (n = 5) and those with combined LOH 1p/16q (n = 40) were excluded. Results A total of 535 patients with stage III disease were studied. Median follow-up was 5.2 years (range, 0.2 to 9.5). Four-year event-free survival (EFS) and overall survival estimates were 88% (95% CI, 85% to 91%) and 97% (95% CI, 95% to 99%), respectively. A total of 58 of 66 relapses occurred in the first 2 years, predominantly pulmonary (n = 36). Eighteen patients died, 14 secondary to disease. A better EFS was associated with negative lymph node status ( P < .01) and absence of LOH 1p or 16q ( P < .01), but not with gross residual disease or peritoneal implants. In contrast, the 4-year EFS was only 74% in patients with combined positive lymph node status and LOH 1p or 16q. A total of 123 patients (23%) had delayed nephrectomy. Submitted delayed nephrectomy histology showed anaplasia (n = 8; excluded from survival analysis); low risk/completely necrotic (n = 7; zero relapses), intermediate risk (n = 63; six relapses), and high-risk/blastemal type (n=7; five relapses). Conclusion Most patients with stage III FHWT had good EFS/overall survival with DD4A and radiation therapy. Combined lymph node and LOH status was highly predictive of EFS and should be considered as a potential prognostic marker for future trials.

To retrospectively determine the diagnostic performance of computed tomography (CT) in identifying the presence or absence of preoperative Wilms tumor rupture.The cohort was derived from the AREN03B2 study of the Children's Oncology Group. The study was approved by the institutional review board and was compliant with HIPAA. Written informed consent was obtained before enrollment. The diagnosis of Wilms tumor rupture was established by central review of notes from surgery and/or pathologic examination. Seventy Wilms tumor cases with rupture were matched to 70 Wilms tumor controls without rupture according to age and tumor weight (within 6 months and 50 g, respectively). CT scans were independently reviewed by two radiologists, and the following CT findings were assessed: poorly circumscribed mass, perinephric fat stranding, peritumoral fat planes obscured, retroperitoneal fluid (subcapsular vs extracapsular), ascites beyond the cul-de-sac, peritoneal implants, ipsilateral pleural effusion, and intratumoral hemorrhage. All fluids were classified as hemorrhagic or nonhemorrhagic by using a cutoff of 30 HU. The relationship between CT findings and rupture was assessed with logistic regression models.The sensitivity and specificity for detecting Wilms tumor rupture were 54% (36 of 67 cases) and 88% (61 of 69 cases), respectively, for reviewer 1 and 70% (47 of 67 cases) and 88% (61 of 69 cases), respectively, for reviewer 2. Interobserver agreement was substantial (ĸ = 0.76). All imaging signs tested, except peritoneal implants, intratumoral hemorrhage, and subcapsular fluid, showed a significant association with rupture (P ≤ .02). The attenuation of ascitic fluid did not have a significant correlation with rupture (P = .9990). Ascites beyond the cul-de-sac was the single best indicator of rupture for both reviewers, followed by perinephric fat stranding and retroperitoneal fluid for reviewers 1 and 2, respectively (P.01).CT has moderate specificity but relatively low sensitivity in the detection of preoperative Wilms tumor rupture. Ascites beyond the cul-de-sac, irrespective of attenuation, is most predictive of rupture.

Little information exists regarding pediatric contrast-enhanced US. To assess the safety and feasibility of contrast-enhanced US of pediatric abdominal and pelvic tumors. This prospective study included eight boys and five girls (mean age, 10.8 years) with abdominal or pelvic tumors. Cohorts of three subjects underwent US with perflutren contrast agent at escalating dose levels. Neurological and funduscopic examination, electrocardiography and continuous pulse oximetry were performed before and after contrast administration. Three radiologists independently scored six imaging parameters on pre- and postcontrast sonography. Inter-reviewer agreement was measured by the Kappa statistic. No neurological, retinal, electrocardiographical or pulse oximetry changes were attributable to the contrast agent. Two subjects reported minor, transient symptoms. Postcontrast US parameter scores improved slightly in 8 of 12 subjects. Postcontrast ultrasound inter-reviewer agreement improved slightly for detection of tumor margins (precontrast = 0.20, postcontrast = 0.26), local tumor invasion (precontrast = -0.01, postcontrast = 0.10) and adenopathy (precontrast = 0.35, postcontrast = 0.44). Although our sample size is small, perflutren contrast agents appear to be safe and well tolerated in children. Contrast-enhanced sonography of pediatric abdominal and pelvic tumors is feasible, but larger studies are needed to define their safety and efficacy in children.

BACKGROUND: The objective of this study was to prospectively evaluate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) as an early imaging indicator of tumor histologic response to preoperative chemotherapy and as a possible prognostic factor for event-free survival (EFS) and overall survival in pediatric patients with newly diagnosed, nonmetastatic osteosarcoma who were treated on a single, multi-institutional phase 2 trial. METHODS: Three serial DCE-MRI examinations at week 0 (before treatment), week 9, and week 12 (tumor resection) were performed in 69 patients with nonmetastatic osteosarcoma to monitor the response to preoperative chemotherapy. Four DCE-MRI kinetic parameters (the influx volume transfer constant [Ktrans], the efflux rate constant [kep], the relative extravascular extracellular space [ve], and the relative vascular plasma space [vp]) and the corresponding differences (ΔKtrans, Δkep, Δve, and Δvp) of averaged kinetic parameters between the outer and inner halves of tumors were calculated to assess their associations with tumor histologic response, EFS, and overall survival. RESULTS: The parameters Ktrans, ve, vp, and kep decreased significantly from week 0 to week 9 and week 12. The parameters Ktrans, vp, and Δkep at week 9 were significantly different between responders and nonresponders (P = .046, P = .021, and P = .008, respectively). These 3 parameters were indicative of histologic response. The parameter Δve at week 0 was a significant prognostic factor for both EFS (P = .02) and overall survival (P = .03). CONCLUSIONS: DCE-MRI was identified as a prognostic factor for EFS and overall survival before treatment on this trial and was indicative of a histologic response to neoadjuvant therapy. Further studies are needed to verify these findings with other treatment regimens and establish the potential role of DCE-MRI in the development of risk-adapted therapy for osteosarcoma. Cancer 2012. © 2011 American Cancer Society.

Objective Summarize current knowledge of lymphatic malformation development, biology, and clinical outcome measures. Methods Panel presentation of lymphatic malformation biology and measurement of head and neck malformation treatment outcomes. Results Characterization of lymphatic malformation endothelial and stromal cells may lead to biologically based treatment. Traditionally, lymphatic malformation treatment outcomes have been measured according to reduction of malformation size. Currently, methods to measure functional outcomes following lymphatic malformation treatment are lacking. This is particularly apparent when the malformation directly involves the upper aerodigestive tract. Conclusions The etiology and pathogenesis of head and neck lymphatic malformations are poorly understood, but understanding is improving through ongoing investigation. Reduction of lymphatic malformation size is generally possible, but further work is necessary to optimize methods for measuring therapeutic outcomes in problematic areas.

Objective To describe a method of airway infantile hemangioma staging using standardized assessment of airway narrowing, and hemangioma location and volume, as determined with endoscopy and CT angiography. Study design Case series with chart review. Setting Tertiary pediatric hospital, 2003-2008. Subjects and methods Subjects included airway hemangioma patients evaluated at a tertiary pediatric hospital. Data collected were age at first symptoms, diagnostic evaluation, percent airway compromise, and estimated hemangioma volume. Data were analyzed with descriptive and Fisher exact statistics. Results Twelve patients were identified and seven had complete data sets. Mean age at first symptoms was 1.9 months (SD 1.09 months, range 0.5-4 months). Evaluation consisted of nasopharyngoscopy, microlaryngoscopy, CT angiography, and/or MRI. Mean laryngeal airway narrowing was estimated at 63.75 percent (SD 19.0%, range 40%-90%). Total hemangioma volume was less in patients with isolated (focal) endolaryngeal hemangiomas compared with airway hemangiomas associated with extralaryngeal (segmental) hemangiomas. Airway hemangioma stages were stage one (5 of 12; 41.6%), stage two (6 of 12; 50.0%), and stage three (1 of 12; 8.3%). Conclusion This method of airway hemangioma staging may be applicable to treatment planning and used to measure treatment outcomes.

BACKGROUND: This prospective study was designed to be the first to evaluate the toxicity of radiofrequency ablation (RFA) in patients with recurrent pediatric solid tumors. METHODS: From 2003 through 2008, a phase 1/pilot study of RFA for recurrent pediatric solid tumors was conducted. A multidisciplinary cancer management team selected appropriate candidates for the study. Imaging-guided RFA was performed percutaneously. Repeat RFA was performed for recurrences when appropriate. Toxicity and imaging response was assessed at 1 month and 3 months prospectively. Accrual stopped in 2006, and data collection stopped in 2008. RESULTS: Sixteen patients (ages 4 years-33 years; median age, 15 years) and 56 tumor sites were treated in 37 RFA sessions including 38 pulmonary, 11 musculoskeletal, and 7 hepatic lesions (82 lesion-treatments). Postprocedural pain was moderate (median 5 on a scale from 1 to 10) and lasted a median of 9 days. Prolonged hospitalization (beyond 1 day) occurred 17 times (range, 2 days-25 days; median, 3 days). Hypoxia supported by supplemental oxygen occurred in 8 of 16 patients and resolved within 1 month after each RFA. No patient had tumor lysis syndrome but myoglobinuria/hemoglobinuria occurred in 6 of 16 patients, all without renal damage. Serious complications from pulmonary RFA included 2 diaphragmatic hernias. Of 82 lesions imaged, 24 (29%) remained ablated at the end of the study. CONCLUSIONS: The toxicity from RFA of recurrent pediatric solid tumors was real but limited, and RFA may offer a local tumor control alternative in carefully selected cases. Cancer 2009. © 2009 American Cancer Society.

BACKGROUND. Approximately 5% of children with Wilms tumor present with bilateral disease. The treatment challenge is to achieve a high cure rate while maintaining adequate long-term renal function. The authors of this report assessed the feasibility and outcome of nephron-sparing surgery in patients with bilateral Wilms tumor who were treated at a single institution. METHODS. A retrospective review was performed of all children who were treated at St. Jude Children's Research Hospital for synchronous, bilateral Wilms tumors from 1999 through 2006. Imaging studies, surgical techniques, and pathology reports were reviewed. The outcomes evaluated included surgical complications, tumor recurrence, renal function, and patient survival. RESULTS. Twelve patients with synchronous, bilateral Wilms tumors were identified, including 10 patients who underwent successful bilateral nephron-sparing procedures. One patient who presented with renal failure and anaplastic histology underwent bilateral nephrectomies, and 1 patient with intra-atrial tumor extension underwent an ipsilateral nephrectomy/thrombectomy and subsequent contralateral partial nephrectomy. Postoperative complications included persistent urine leak in 3 patients, macroscopic residual tumor in 2 patients, and pyelonephritis in 1 patient. Long-term complications included local tumor recurrence in 2 patients, intestinal obstruction in 2 patients, ureteropelvic junction obstruction in 1 patient, and renal failure in 1 patient. The overall survival rate was 83% (mean follow-up, 3.9 years); both patients who died had bilateral, diffuse, anaplastic histology. CONCLUSIONS. All patients who had bilateral Wilms tumors with favorable histology, except for 1 patient who had extensive tumor thrombus, underwent successful bilateral partial nephrectomies. Complications were minimal, and long-term renal function and survival were excellent. From this experience, the authors concluded that bilateral nephron-sparing surgery should be considered for all patients who have bilateral Wilms tumor with favorable histology, even if preoperative imaging studies suggest that the lesions are unresectable.Cancer 2008. © 2008 American Cancer Society.

The outcome of desmoid tumor in children cannot be reliably predicted on the basis of histologic findings. We sought to determine whether the postoperative presence of residual or recurrent tumor can be predicted on the basis of demographic variables and baseline MRI features of the tumor. We also aimed to determine how imaging features change during adjuvant treatment and how the imaging features relate to the histologic features.Two radiologists retrospectively reviewed images from 281 MRI examinations performed at baseline and during postoperative therapy for desmoid tumor. The examinations had been performed on 17 children treated between September 1991 and March 2003. Tumor volume; distinctness of margins; involvement of bone and neurovascular bundle; and T1-weighted, T2-weighted, and STIR signal intensity and contrast enhancement pattern were recorded. Baseline imaging and demographic features were correlated with the postoperative presence of residual or recurrent tumor. Imaging changes during follow-up were compared with treatment response and outcome. The imaging features of eight tumors were compared with percentage cellularity and collagen deposition in biopsy samples obtained within 30 days of imaging.Baseline involvement of the neurovascular bundle approached significance as a predictor of the presence of residual or recurrent tumor (p = 0.08). Other baseline imaging and demographic features were not predictive (por = 0.4). Changes in imaging features were variable during follow-up. T2-weighted and STIR signal intensity may be correlated with percentage cellularity and collagen deposition.MRI has limited value in prediction of the postoperative presence of residual or recurrent desmoid tumor in children. It is useful, however, for detecting disease and monitoring postoperative adjuvant therapy.

Core body temperature elevation (hyperthermia) can occur during radiofrequency ablation of large centrally located tumors in small children. Hyperthermia can be predicted on the basis of long burn times, high wattage delivered by the RF system and low body weight. If hyperthermia is anticipated, cooling blankets using refrigerated air or water are recommended. The advantage of these systems is that the cooling can help maintain normal core body temperature.

Pleurodesis for end-of-life care has been used in adults for decades, but little is known about the usefulness of this technique in improving the quality of care for pediatric patients.To assess whether intractable pleural effusions in pediatric oncology patients at end of life could be sufficiently relieved by pleurodesis.Eleven pleurodeses were performed with doxycycline in seven pediatric cancer patients (age 3-21 years) with intractable pleural effusions at the end of life. Five patients had unilateral pleurodeses and two had a unilateral followed by bilateral pleurodeses.Respiratory rates decreased in all seven patients (P = 0.016) and aeration improved significantly after chest tube placement (P = 0.033). The chest tubes were placed a median of 1 day before pleurodesis. Eight of nine chest tubes (89%) were removed before discharge at a median of 3 days after pleurodesis. Pain secondary to the pleurodesis lasted 1 day or less. Improvement in the respiratory rate remained after pleurodesis and chest tube removal (P = 0.031). Five of seven patients (70%) were able to leave the hospital to return home. The five patients discharged lived 10 to 49 days (median 19 days) after discharge.Pediatric oncology patients with intractable effusions at end of life can have respiratory benefit from pleurodeses and, as a result, are more likely to return home for terminal care.

Purpose To estimate the response rate and toxicity associated with intravenous topotecan when it is administered on a protracted schedule according to a pharmacokinetically guided dosing approach to treat childhood high-risk neuroblastoma. Patients and Methods In this prospective phase II trial, topotecan was administered intravenously daily for 5 days for each of 2 consecutive weeks for two cycles. On the basis of topotecan systemic clearance, doses were individualized to attain a single-day topotecan lactone area under the plasma concentration-time curve (AUC) of 80 to 120 ng/mL · h. Patients subsequently received standard treatment. Results Both cycles were administered to 28 (93%) of the 30 enrolled patients (median age, 3.1 years). Target topotecan AUCs were achieved in 92 (72%) of the 127 measurements conducted after pharmacokinetically guided adjustment; the median dosage required to achieve target AUCs was 2.7 mg/m2 (range, 0.95 to 3.8 mg/m2). The response rate was 60% (95% CI, 41% to 77%); there were one complete and 17 partial responses. No patient experienced disease progression during initial topotecan therapy. Primary tumor volumes decreased (median decrease, −58.2%; range, −95.1% to −4.9%) in the 26 patients with available size data. Homovanillic acid levels in 16 (89%) of 18 patients and vanillylmandelic acid levels in 14 (78%) of 18 patients were lower (P = .002 and P = .018, respectively) after topotecan therapy. Reversible grade 4 myelosuppression occurred in all patients, but no deaths occurred as a result of infection or toxicity. Conclusion Topotecan is active against neuroblastoma when it is administered on a protracted schedule and targeted systemic exposure is achieved.

Background: MRI is an effective tool in evaluating bone marrow metastases. However, no study has defined which MRI sequences or image characteristics best correlate with bone-marrow metastases in neuroblastoma. Objective: To identify and refine MRI criteria and sequence selection for the diagnosis of bone-marrow metastases in children with neuroblastoma. Materials and methods: Ninety-one children (mean age: 3.2 years; standard deviation: 2.8 years) enrolled in the RDOG IV study participated in our study. Forty-five children had bone metastases determined by bone-marrow aspiration or biopsy (n=4), radionuclide imaging (n=2), or both (n=39). Spine lesions were characterized using coronal T1-weighted (T1W) sagittal short tau inversion recovery (STIR) and coronal gadolinium-enhanced T1-weighted (GAD) MR sequences. Contingency table analysis was performed to determine which MRI sequences and characteristics were associated with metastases. The MRI criteria for metastatic disease were then developed for each imaging sequence. The sensitivity, specificity, predictive values, and accuracy of these criteria were determined for the whole group, children younger than 12 months old, and children 12 months and older. Results: The MR characteristics that had significant (P ≤ 0.05) associations with metastases were homogeneous low T1-signal intensity, homogeneous high STIR-signal intensity, and heterogeneous pattern on T1, STIR, or GAD. Homogeneous low T1-signal had the highest sensitivity (88%), but a specificity of 62% for detecting metastases. A heterogeneous pattern on GAD was highly specific (97%), but relatively insensitive (65%) for detecting metastases. These MR characteristics were most accurate in children 12 months and older. Conclusion: The combination of non-contrast-enhanced T1W and GAD sequences can be used to determine the presence of spinal metastases in children with neuroblastoma, particularly those children who are 1 year and older.

Background The optimal timing for attempting removal of the primary tumor and regional disease in patients with high-risk neuroblastoma is uncertain. The purpose of this study was to evaluate resectability of the primary tumor and regional disease, as determined radiographically, in children with high-risk neuroblastoma during neoadjuvant chemotherapy. Procedure Patients enrolled in our institutional high-risk neuroblastoma protocol were evaluated prospectively by CT scan and/or MRI to determine the resectability of their primary tumor and regional disease at diagnosis, after two cycles of experimental therapy and after standard induction therapy. Tumors were considered to be unresectable if there was significant involvement with major vascular structures or contiguous organs, or would likely require nephrectomy to remove the entire tumor. Results Twenty-four patients were referred prior to surgery for treatment of high-risk neuroblastoma. Seven of 24 (29%) patients were felt to be resectable at diagnosis, with an additional 9 patients becoming resectable after the initial experimental therapy. Thus, overall, 16 of 24 (67%) patients were felt to be resectable by the completion of the initial therapy. Only four additional patients of the remaining eight were considered resectable after the completion of standard induction therapy. Conclusions Based on these data, we conclude that complete resection of the primary tumor and regional disease in children with high-risk neuroblastoma can be performed after an initial phase therapy in the majority of patients. Since earlier tumor removal may decrease the chance for the subsequent development of chemotherapy-resistant disease, we are recommending surgical resection as soon as the locoregional disease appears to be resectable. © 2004 Wiley-Liss, Inc.

Background This study provides insight into the clinical behavior, diagnostic complexities, and long-term management of patients with hyperplastic perilobar nephroblastomatosis (HPLN). Procedure Fifty-two patients with HPLN with available long-term follow-up were retrospectively analyzed for pathologic, radiologic, and clinical features. Results The mean age at diagnosis was 16 months; the lesions were bilateral in 49 patients. Of 33 patients who initially underwent diagnostic biopsy and adjuvant chemotherapy, 18 (55%) developed Wilms tumor (WT) at a mean of 35 months from diagnosis. Of 16 patients whose initial therapy included nephrectomy and adjuvant therapy, three (19%) developed WT at a mean of 36 months from diagnosis. All three patients who underwent initial diagnostic biopsy and received no adjuvant therapy during their initial course developed WT 4, 4, and 10 months following diagnosis. 24/52 patients developed either a single (13 patients) or multiple (11 patients) WT throughout their course; 8/24 (33%) of WT were anaplastic. The time from initial diagnosis to the development of the last WT ranged from 13 to 116 months (mean 42 months). Three children with HPLN died of WT at 3, 5, and 6 years of age; 2/3 were anaplastic. Conclusions HPLN is a self-limited, pre-neoplastic proliferative process associated with a high risk of developing WT. The accurate diagnosis and the choices of therapy during the often-complex course of HPLN depend on the availability and accurate interpretation of a combination of pathologic, radiologic, and clinical information. When such information is appropriately obtained, the long-term survival of patients with HPLN is excellent. © 2005 Wiley-Liss, Inc.

BACKGROUND The objective of the current study was to determine the diagnostic accuracy of percutaneous biopsy of pediatric solid tumors, a procedure that is less invasive than open biopsy. METHODS The authors conducted a retrospective analysis of clinical data related to 202 percutaneous core-needle biopsies of solid tumors at St. Jude Children's Research Hospital over 5.5 years (from 1997 to 2003). In 103 patients, the procedure was performed to establish an initial diagnosis of a suspected malignancy; and, in 99 patients, disease recurrence was suspected. Biopsies were guided by ultrasound, computed tomography, or fluoroscopic imaging. From each tumor, 1–17 core biopsy samples (median, 6 samples) were obtained; the median needle size was 15 gauge (range, 13–20 gauge). The specimens were submitted for histopathologic analysis and other ancillary procedures (molecular pathology and/or cytogenetic analyses). The accuracy of the diagnoses from the biopsies was determined by subsequent surgery with or without pathologic assessment or by outcome. RESULTS When the biopsy samples were assessed for the presence of malignancy, there were 121 true-positive results (90% sensitivity), 67 true-negative results (100% specificity), and 14 false-negative results (93% accuracy). In 103 tumors, when the procedure was performed for initial diagnosis, percutaneous needle biopsy showed a sensitivity of 97%, a specificity of 100%, and an accuracy of 98%. The 99 procedures for suspected recurrence were less reliable (sensitivity, 83%; specificity, 100%; accuracy, 88%). CONCLUSIONS Image-guided percutaneous biopsy was highly accurate and safe in the diagnosis of pediatric malignant solid tumors. This technique may be able to supplant diagnostic open biopsy. Cancer 2005. © 2005 American Cancer Society.

The feasibility, safety, and efficacy of liver-directed gene transfer was evaluated in 5 male macaques (aged 2.5 to 6.5 years) by using a recombinant adeno-associated viral (rAAV) vector (rAAV-2 CAGG-hFIX) that had previously mediated persistent therapeutic expression of human factor IX (hFIX; 6%-10% of physiologic levels) in murine models. A dose of 4 × 1012 vector genomes (vgs)/kg of body weight was administered through the hepatic artery or portal vein. Persistence of the rAAV vgs as circular monomers and dimers and high-molecular-weight concatamers was documented in liver tissue by Southern blot analysis for periods of up to 1 year. Vector particles were present in plasma, urine, or saliva for several days after infusion (as shown by polymerase chain reaction analysis), and the vgs were detected in spleen tissue at low copy numbers. An enzyme-linked immunosorption assay capable of detecting between 1% and 25% of normal levels of hFIX in rhesus plasma was developed by using hyperimmune serum from a rhesus monkey that had received an adenoviral vector encoding hFIX. Two macaques having 3 and 40 rAAV genome equivalents/cell, respectively, in liver tissue had 4% and 8% of normal physiologic plasma levels of hFIX, respectively. A level of hFIX that was 3% of normal levels was transiently detected in one other macaque, which had a genome copy number of 25 before abrogation by a neutralizing antibody (inhibitor) to hFIX. This nonhuman-primate model will be useful in further evaluation and development of rAAV vectors for gene therapy of hemophilia B.

Fluid aspiration, percutaneous biopsy, and catheter drainage are standard minimally invasive methods of diagnosing lymphoma or leukemia in adults.To determine the effectiveness of interventional radiologic techniques in diagnosing specific hematologic malignancies in children.During a 4-year period, 22 patients (16 male, 6 female; median age, 13 years) underwent 25 percutaneous biopsies, 6 fluid aspirations, 3 catheter drainages, and 1 needle localization for diagnosing suspected hematologic malignancy.For Hodgkin's disease, the procedures yielded 6 true-positive (TP) results, 2 true-negative (TN) results, and 2 false-negative (FN) results; for non-Hodgkin lymphoma (NHL), 14 TP results, 1 TN result, and 3 FN results; and for leukemia, 4 TP results and 3 FN results. Percutaneous biopsies yielded 16 TP results, 3 TN results, and 6 FN results. Aspirations and drainages yielded 8 TP results and 1 FN result. The one needle localization yielded a FN result. Overall sensitivity was 75%+/-7.3%; specificity, 100%; and accuracy, 77%+/-7.1%.Percutaneous biopsy of lymphoma is usually diagnostic. Drainage or aspiration of a fluid collection associated with NHL or leukemia is often diagnostic and is less invasive than biopsy. These procedures are minimally invasive and effective for diagnosing pediatric hematologic malignancies.

Primary malignant liver cancers in children have an overall incidence of two cases per million. Hepatoblastoma (HB) is the most common, and the majority will present in infants and toddlers within the first 2 years of life. On the other hand, hepatocellular carcinoma (HCC) which is the second most frequent malignant liver tumor will present later, typically in school-aged children or adolescents. The fundamental principle for treatment is complete surgical resection of the tumor. Unfortunately 50 % of children with HB and 70 % of those with HCC present initially as inoperable due to the extent of tumor involvement, vascular invasion, or distant metastasis. The prognosis for children that cannot ultimately achieve a complete tumor resection or transplant is dismal. HB is generally chemosensitive, particularly to platinum-based agents such as cisplatin. Following systemic chemotherapy up to 85 % are appropriate candidates for surgical resection. However, HCC remains relatively chemoresistant, and the fibrolamellar type of HCC most often attributable to children (13–22 % of HCC in children) does not respond any differently than the typical HCC with current therapeutic regimens, having an overall survival rate below 25 % at 3 years.

BACKGROUND Approximately 5–10% of patients with rhabdomyosarcomas (RMS) are diagnosed during the first year of life, and their clinical characteristics have been well documented. However, because RMS rarely occurs during the neonatal period, little is known about neonatal RMS. METHODS Four patients with neonatal RMS were treated at St. Jude Children's Research Hospital between 1962 and 1999. The authors report the results of a review of these patients and of cases described in the literature. Clinical, radiologic, and pathologic features of these patients and their outcomes were evaluated. RESULTS One patient with embryonal RMS was treated successfully with a combination of systemic chemotherapy and local control measures. The other three patients had alveolar RMS. Two of them had multiple skin and subcutaneous metastatic nodules at the time of diagnosis and developed brain metastases early in their course. In one of these patients, the PAX3-FKHR fusion transcript was detected. Three other similar cases of neonatal alveolar RMS with metastases to the skin and brain have been reported in the literature. CONCLUSIONS A distinct syndrome of neonatal RMS is described. This syndrome is characterized by alveolar histology, multiple skin and subcutaneous metastases, and fatal outcome as the result of early brain metastasis. Cancer 2001;92:1613–20. © 2001 American Cancer Society.

Background. The identification of risk factors that predict poor clinical outcome at the time of diagnosis could lead to intensified early therapy and improved outcome for pediatric patients with Ewing sarcoma family of tumors (ESFT). Objective. To compare the effectiveness of static magnetic resonance (MR) imaging measurements of tumor volume with variables obtained by dynamic contrast-enhanced MR imaging (DEMRI) in predicting ESFT outcome. Methods. MR examinations that included DEMRI were retrospectively reviewed. The analyses included 45 examinations of 21 patients with ESFT (performed from 1992 to 1996). Tumor volumes were measured on the static MR images, and the regions of interest were selected for DEMRI analysis. The relationships of static MR imaging and DEMRI variables with the probability of progression-free survival (PFS) and disease-free survival (DFS) were determined. Results. Larger tumor volume at the time of diagnosis predicted poorer PFS and DFS estimates. No DEMRI variable predicted outcome. Conclusion. Determination of tumor volume by static MR imaging at the time of diagnosis is a simple and reliable method of predicting the clinical outcome of patients with ESFT. DEMRI is not as reliable a technique as static MR imaging for predicting the outcome of these patients.

Background. Reports of the usefulness of ultrasonography in the diagnosis of hepatic veno-occlusive disease (HVOD) have presented conflicting results.¶Objective. To determine the usefulness of gray-scale or Doppler ultrasonographic measurements in the diagnosis of HVOD in pediatric patients undergoing BMT.¶Materials and methods. We prospectively obtained 202 serial sonograms on 48 patients and examined the association between the clinical diagnosis of HVOD (McDonald criteria) and eight ultrasound parameters, including the hepatic artery resistive index (HARI), direction and velocity of portal venous flow, and thickness of the gall bladder wall.¶Results. HVOD developed in 29 of the 48 patients. The portal venous velocity increased after BMT in the group without HVOD and decreased in the group with HVOD; this difference was significant (P = 0.01). However, there was a great deal of variability in velocity measurements for individual patients. The mean HARI was 0.64 in the group with HVOD and 0.63 in the group without HVOD, and there was no difference between the two groups in the pattern of change in HARI relative to the day of BMT (P = 0.4). There was also no significant difference in thickness of the gallbladder wall between the two groups (P = 0.6).¶Conclusion. No ultrasound parameter studied was as useful as the McDonald criteria for diagnosing HVOD.

Malignant mesothelioma is a rare tumor in childhood. We present two cases of malignant peritoneal mesothelioma in which contrast-enhanced, fat-saturated magnetic resonance (MR) imaging was used advantageously to detect peritoneal tumor involvement.

In pediatric oncology patients, hemorrhagic cystitis may be a life-threatening complication of bone-marrow transplantation, chemotherapy, and/or radiation therapy. The inciting agent in urine can affect the entire urothelium from the renal collecting system to the bladder, and the severity of disease can vary. The radiologist often plays a key role in the diagnosis, follow-up, and occasionally the treatment of hemorrhagic cystitis and its complications. This review discusses the imaging findings in the kidneys and bladder in patients with hemorrhagic cystitis both before and after treatment for this disease. Findings on two-dimensional sonography, color Doppler and power Doppler sonography, computed tomography, magnetic resonance imaging, antegrade pyleography, and cystography are presented.

We used contrast-enhanced three-dimensional magnetic resonance angiography (3D MRA) modified for pediatric use to evaluate the hepatic vasculature prior to partial hepatectomy in five consecutive children with hepatoblastoma. Modifications included non-breath-hold technique in four of the five children who were sedated. The single breath-hold technique was performed in only one awake child. Scan delay times were based on contrast infusion time rather than total infusion time. The hepatic artery, portal vein, and inferior vena cava were identified in all patients. MRA findings were confirmed by conventional angiography in one patient and by surgery in all. Contrast-enhanced 3D MRA is a useful and rapid technique prior to partial hepatectomy in patients with hepatoblastoma.

PURPOSE We report the treatment of 10 children for progressive desmoid tumor not amenable to standard surgical or radiation therapy with the use of vinblastine (VBL) and methotrexate (MTX). PATIENTS AND METHODS Ten patients aged 6.4 to 18 years with primary (two patients) or recurrent (eight patients) desmoid tumor were treated with VBL and MTX for 2 to 35 months. Patients with recurrent tumors had been previously treated with surgical resection with (two patients) or without (five patients) radiation therapy or with radiation therapy alone (one patient). No patient had previously received cytotoxic chemotherapy. The tumor response was assessed at routine intervals by physical examination and magnetic resonance imaging (MRI). RESULTS Five patients had clinical evidence of response to therapy with complete resolution (three patients) or partial resolution (two patients) of physical examination and radiographic abnormalities. Three patients had stable disease during 10 to 35 months of treatment. Two of these patients had progressive disease 9 and 37 months after treatment stopped; one patient had no progression 16 months after therapy. Two additional patients with stable disease had chemotherapy discontinued after 2 and 3 months. Common side effects included mild alopecia and myelosuppression and moderate nausea and vomiting. In patients with responding tumors, MRI showed decreased tumor size and, in two patients, changes consistent with fibrosis and decreased cellularity of the tumor. CONCLUSION Combination chemotherapy with VBL and MTX appears to control desmoid tumor without significant acute or long-term morbidity in most children. This may allow for further growth and development in these patients, which may decrease the morbidity of subsequent definitive therapy.

This paper reviews the techniques that we employ to perform musculoskeletal magnetic resonance imaging in the pediatric patient. We examine the procedures for preparation and screening of the patient and the protocols for sedation. The selection of imaging coils and sequences for the evaluation of the pediatric musculoskeletal system is also addressed, followed by a summary of scanning protocols.

Localization of skeletal tracer in a neuroblastoma primary is common but localization in extraskeletal metastatic sites has not received recognition. Tc-99m MDP concentration in hepatic or pulmonary metastases was noted in three of ten patients with such metastases. Lesion size appears to be important for demonstrating these metastases with Tc-99m MDP. This was particularly true for hepatic metastases, which were identified only when they were 5 cm or greater in diameter.

PURPOSE: To determine whether percutaneous biopsy can provide the diagnostic and prognostic information necessary to treat children with advanced neuroblastoma. MATERIALS AND METHODS: From 1991 through 1995, 21 percutaneous biopsies were performed in 20 children with advanced neuroblastoma by using 15- or 16-gauge core biopsy needles. An average of six samples were obtained. Since September 1994, fresh tissue was sent to the reference laboratory, where touch preparations were prepared for N-myc evaluation. RESULTS: Histologic confirmation and prognostic information (Shimada classification) were obtained in all cases. Genetic prognostic information was obtained in 19 patients (95%), DNA index (ploidy) in 18 (90%), N-myc gene expression in 14 (70%), and cytogenetic analysis in 10 (50%). N-myc and ploidy determinations were successful in all five biopsy specimens obtained since September 1994. CONCLUSION: Percutaneous biopsy of advanced neuroblastoma is a feasible alternative to open biopsy.

Desmoid fibromatosis (desmoid tumor, DT) is a soft tissue neoplasm prone to recurrence despite complete surgical resection. Numerous small retrospective reports suggest that non-cytotoxic chemotherapy using tamoxifen and sulindac may be effective for DT. We evaluated the safety and efficacy of tamoxifen and sulindac in a prospective phase II study within the Children's Oncology Group.Eligible patients were19 years of age who had measurable DT that was recurrent or not amenable to surgery or radiation. The primary objective was to estimate progression-free survival (PFS). Patients received tamoxifen and sulindac daily for 12 months or until disease progression or intolerable toxicity occurred. Response was assessed by magnetic resonance imaging.Fifty-nine eligible patients were enrolled from 2004 to 2009; 78% were 10-18 years old. Twenty-two (38%) were previously untreated; 15 (41%) of the remaining 37 enrolling with recurrent DT had prior systemic chemotherapy and six (16%) had prior radiation. No life-threatening toxicity was reported. Twelve (40%) of 30 females developed ovarian cysts, which were asymptomatic in 11 cases. Ten patients completed therapy without disease progression or discontinuing treatment. Responses included four partial and one complete (5/59, 8%). The estimated 2-year PFS and survival rates were 36% (95% confidence interval: 0.23-0.48) and 96%, respectively. All three deaths were due to progressive DT.Tamoxifen and sulindac caused few serious side effects in children with DT, although ovarian cysts were common. However, the combination showed relatively little activity as measured by response and PFS rates.

The objective of this study was to prospectively evaluate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) as an early imaging indicator of tumor histologic response to preoperative chemotherapy and as a possible prognostic factor for event-free survival (EFS) and overall survival in pediatric patients with newly diagnosed, nonmetastatic osteosarcoma who were treated on a single, multi-institutional phase 2 trial.Three serial DCE-MRI examinations at week 0 (before treatment), week 9, and week 12 (tumor resection) were performed in 69 patients with nonmetastatic osteosarcoma to monitor the response to preoperative chemotherapy. Four DCE-MRI kinetic parameters (the influx volume transfer constant [K(trans) ], the efflux rate constant [k(ep) ], the relative extravascular extracellular space [v(e) ], and the relative vascular plasma space [v(p) ]) and the corresponding differences (ΔK(trans) , Δk(ep) , Δv(e) , and Δv(p) ) of averaged kinetic parameters between the outer and inner halves of tumors were calculated to assess their associations with tumor histologic response, EFS, and overall survival.The parameters K(trans) , v(e) , v(p) , and k(ep) decreased significantly from week 0 to week 9 and week 12. The parameters K(trans) , v(p) , and Δk(ep) at week 9 were significantly different between responders and nonresponders (P = .046, P = .021, and P = .008, respectively). These 3 parameters were indicative of histologic response. The parameter Δv(e) at week 0 was a significant prognostic factor for both EFS (P = .02) and overall survival (P = .03).DCE-MRI was identified as a prognostic factor for EFS and overall survival before treatment on this trial and was indicative of a histologic response to neoadjuvant therapy. Further studies are needed to verify these findings with other treatment regimens and establish the potential role of DCE-MRI in the development of risk-adapted therapy for osteosarcoma.

Interventional radiology techniques to treat oncological disease have already shown value in adults. The adoption and development of interventional oncology (IO) in children have been more limited and challenging. This relates to the approval process for new devices and agents, oncology group protocol limitations and the inherent hesitation of trying new treatments in children. This paper will discuss how new procedures are developed and approved, and the new therapies that will become available to better treat pediatric malignancies. Bringing the benefits of IO to children will require initiative on the part of pediatric diagnostic and interventional radiologists as well as the cooperation of our clinical colleagues.

Interventional radiologists (IRs) with expertise in image guidance have an inherent skill set for the safe and reliable placement of central venous access catheters (CVACs) in children. Above and beyond the technical requirements, IRs have an integral role as consultants in evaluating children for the most appropriate catheter to meet their short- and long-term needs. This article is meant to serve as a reference for decision making along with tips and pearls on how we approach placing CVACs in pediatric patients at our Children's Hospital.

Image-guided procedures involving the musculoskeletal (MSK) system of children can be challenging because of the variability posed by the child's age, skeletal maturity, and the stage of development. The imaging findings of the maturing MSK system and the underlying diseases affecting children, particularly those that are skeletally immature, can differ significantly from typical adults. The breadth of possible MSK procedures performed by an interventional radiology service depends on the availability of local expertise/experience as well as the referral patterns. In our practice, the majority of nonvascular MSK procedures involve children with a sequela of pain and in need of a therapeutic intervention. We describe our techniques for our more commonly performed MSK procedures, including corticosteroid injections, treating osteoid osteomas, and performance of image-guided bone biopsies and foreign body removal.