Fit of biokinetic data in molecular radiotherapy: a machine learning approach.

BACKGROUND: In literature are reported different analytical methods (AM) to choose the proper fit model and to fit data of the time-activity curve (TAC). On the other hand, Machine Learning algorithms (ML) are increasingly used for both classification and regression tasks. The aim of this work was to investigate the possibility of employing ML both to classify the most appropriate fit model and to predict the area under the curve (τ). METHODS: Two different ML systems have been developed for classifying the fit model and to predict the biokinetic parameters. The two systems were trained and tested with synthetic TACs simulating a whole-body Fraction Injected Activity for patients affected by metastatic Differentiated Thyroid Carcinoma, administered with [131I]I-NaI. Test performances, defined as classification accuracy (CA) and percentage difference between the actual and the estimated area under the curve (Δτ), were compared with those obtained using AM varying the number of points (N) of the TACs. A comparison between AM and ML were performed using data of 20 real patients. RESULTS: As N varies, CA remains constant for ML (about 98%), while it improves for F-test (from 62 to 92%) and AICc (from 50 to 92%), as N increases. With AM, [Formula: see text] can reach down to - 67%, while using ML [Formula: see text] ranges within ± 25%. Using real TACs, there is a good agreement between τ obtained with ML system and AM. CONCLUSIONS: The employing of ML systems may be feasible, having both a better classification and a better estimation of biokinetic parameters.

Venetoclax plus cyclophosphamide and topotecan in heavily pre-treated relapsed metastatic neuroblastoma: a single center case series.

The prognosis of relapsed/refractory (R/R) neuroblastoma (NB) is dismal, calling for new therapeutic strategies. Venetoclax (VEN) is a highly selective, potent, orally bioavailable, BCL-2 inhibitor small-molecule that showed a synergistic effect with cyclophosphamide and topotecan (Cy-Topo) in murine NB models. Our aim was to evaluate the feasibility of VEN plus Cy-Topo in children with R/R NB. Four patients, who had previously failed > 3 lines of treatment, were treated with VEN plus Cy-Topo based on a 28-day schedule in an outpatient setting. BCL-2 expression in immunochemistry on tumor samples at relapse and the BCL2 gene status was evaluated in all patients. The main toxicity was hematological, with grade 4 neutropenia and thrombocytopenia occurring in all courses and leading to transient VEN discontinuation. Grade 3 oral mucositis was observed in 1/8 courses. No other grade 2-4 toxicities were observed. BCL-2 was expressed in all tumors, while no molecular abnormalities in the BCL-2 genes were detected. A stable disease was observed in all patients, without any progression during the study period. VEN plus Cy-Topo is well tolerated, with encouraging results that may be improved by testing the schedule in less advanced patients.

Myocardial Functional Imaging in Pediatric Nuclear Cardiology.

The role of nuclear medicine in pediatric cardiology has grown rapidly over the years, providing useful functional and prognostic information and playing a complementary role to morphological imaging in the evaluation of myocardial perfusion, cardiovascular inflammation and infections, and cardiac sympathetic innervation. The aim of this narrative review is to summarize and highlight the most important evidence on pediatric nuclear cardiology, describing clinical applications and the possibilities, advantages, and limitations of nuclear medicine techniques. Moreover, a special focus will be given to the minimization of radiation exposure in pediatric nuclear cardiology imaging, a critical topic in children.

Diagnostic and Dosimetry Features of [64Cu]CuCl2 in High-Grade Paediatric Infiltrative Gliomas.

PURPOSE OF THE REPORT: Paediatric diffuse high-grade gliomas (PDHGG) are rare central nervous system neoplasms lacking effective therapeutic options. Molecular imaging of tumour metabolism might identify novel diagnostic/therapeutic targets. In this study, we evaluated the distribution and the dosimetry aspects of [64Cu]CuCl2 in PDHGG subjects, as copper is a key element in cellular metabolism whose turnover may be increased in tumour cells. MATERIAL AND METHODS: Paediatric patients with PDHGG were prospectively recruited. [64Cu]CuCl2 PET/CT was performed 1 h after tracer injection; if the scan was positive, it was repeated 24 and 72 h later. Lesion standardised uptake value (SUV) and target-to-background ratio (TBR) were calculated. Tumour and organ dosimetry were computed using the MIRD algorithm. Each patient underwent an MRI scan, including FLAIR, T2-weighted and post-contrast T1-weighted imaging. RESULTS: Ten patients were enrolled (median age 9, range 6-16 years, 6 females). Diagnoses were diffuse midline gliomas (n = 8, 5 of which with H3K27 alterations) and diffuse hemispheric gliomas (n = 2). Six patients had visible tracer uptake (SUV: 1.0 ± 0.6 TBR: 5 ± 3.1). [64Cu]CuCl2 accumulation was always concordant with MRI contrast enhancement and was higher in the presence of radiological signs of necrosis. SUV and TBR progressively increased on the 24- and 72-h acquisitions (p < 0.05 and p < 0.01, respectively). The liver and the abdominal organs received the highest non-target dose. CONCLUSIONS: [64Cu]CuCl2 is a well-tolerated radiotracer with reasonably favourable dosimetric properties, showing selective uptake in tumour areas with visible contrast enhancement and necrosis, thus suggesting that blood-brain barrier damage is a pre-requisite for its distribution to the intracranial structures. Moreover, tracer uptake showed an accumulating trend over time. These characteristics could deserve further analysis, to determine whether this radiopharmaceutical might have a possible therapeutic role as well.

The Pitfall of Ganglioneuroblastoma-Nodular Diagnosis: Clinical and Imaging Considerations over a Rare Bifocal Sporadic Case.

Neuroblastic tumors (NTs) represent the most common extracranial neoplasm occurring in childhood. Although ganglioneuroblastoma intermixed (GNBI) and ganglioneuroma (GN) are classified as very low-risk tumors, neuroblastoma (NB) and ganglioneuroblastoma-nodular (GNBN) may represent a serious risk to survival. Unfortunately, areas of GNBI and GNBN can coexist in the same mass, leading to incorrect risk staging when only biopsy is performed. Herein, we describe a case of multifocal NT (thoracic and abdominal localization) occurring in a 4-year-old male. Different histological subtypes, namely GNBI and GNBN, were revealed in the two lesions. We focus on the difficulties of proper diagnosis and risk stratification, underlining the usefulness of several diagnostic tools for appropriate management and therapeutic choices.

Central Nervous System Metastasis in Neuroblastoma: From Three Decades Clinical Experience to New Considerations in the Immunotherapy Era.

Central nervous system (CNS) metastatic spread in neuroblastoma (NB) is rare and occurs more often at relapse/progression. We report on CNS involvement in high risk (HR) NB over 25 years. For this retrospective study, we reviewed the CNS imaging of all the patients treated at Bambino Gesù Children Hospital from 1 July 1996 to 30 June 2022. A total of 128 patients with HR NB were diagnosed over 26 years. Out of 128 patients, CNS metastatic spread occurred in 6 patients: 3 patients presented a metastatic spread at diagnosis, while in 3 patients, CNS was involved at relapse. Overall, the rate of occurrence of CNS spread is 4.7% with the same distribution at diagnosis and at relapse, namely 2.3%. Interestingly, CNS spread at diagnosis was observed only before 2012, whereas CNS was observed at relapse only after 2012, in the immunotherapy era. CNS metastases presented similar imaging features at diagnosis and at relapse, with a peculiar hemorrhagic aspect and mainly hemispheric localization in patients with bone skull involvement at the time of diagnosis. The outcome is dismal, and 3 out of 6 patients died for progressive disease.

PET/CT in congenital hyperinsulinism: transforming patient's lives by molecular hybrid imaging.

Congenital hyperinsulinism (HI) is a life-threatening condition characterized by severe and recurrent episodes of hypoglycaemia due to defects in key genes involved in regulating insulin secretion. The delay in diagnosis and inappropriate management of HI lead to high risk of permanent hypoglycemic brain injury. The management of HI is challenging as each form of HI (focal, diffuse, and atypical) requires its own therapeutic strategy. In HI diagnostic work-up, integrated PET/CT scan is currently the first-line imaging technique allowing to differentiate between diffuse and focal form and, in the latter case, to localize the focus within the pancreas with high precision. Only in focal HI partial pancreatectomy is the treatment of choice and a curative surgical treatment means a real chance of transforming patient's lives and HI patient's future. The aim of this review is to discuss the role of PET/CT imaging in HI scenario, its technical advantages and limitations and how successful surgery is strongly dependent on accurate preoperative assessment (genetic analysis and PET/CT scan). A multidisciplinary approach in HI diagnosis and treatment inside a single team (involving different expertise) allows to manage children safely and properly, supporting their families in an organized care network.

Personalized dosimetry for a deeper understanding of metastatic response to high activity 131I-mIBG therapy in high risk relapsed refractory neuroblastoma.

BACKGROUND: Dosimetry in molecular radiotherapy for personalized treatment is assuming a central role in clinical management of aggressive/relapsed tumors. Relapsed/refractory metastatic high-risk neuroblastoma (rrmHR-NBL) has a poor prognosis and high-activity 131I-mIBG therapy could represent a promising strategy. The primary aim of this case series study was to report the absorbed doses to whole-body (DWB ), red marrow (DRM ) and lesions (DLesion ). A secondary aim was to correlate DLesion values to clinical outcome. METHODS: Fourteen patients affected by rrmHR-NBL were treated with high-activity 131I-mIBG therapy (two administrations separated by 15 days). The first administration was weight-based whereas the second one was dosimetry-based (achieving DWB equals to 4 Gy). In all patients DWB and DRM was assessed; 9/14 patients were selected for DLesion evaluation using planar dosimetric approach (13 lesions evaluated). Treatment response was classified as progressive and stable disease (PD and SD), partial and complete response (PR and CR) according to the International Neuroblastoma Response Criteria. Patients were divided into two groups: Responder (CR, PR, SD) and Non-Responder (PD), correlating treatment response to DLesion value. RESULTS: The cumulative DWB , DRM and DLesion ranged from (1.5; 4.5), (1.0; 2.6) and (44.2; 585.8) Gy. A linear correlation between DWB and DRM and a power law correlation between the absorbed dose to WB normalized for administered activity and the mass of the patient were observed. After treatment 3, 2, 4 and 5 patients showed CR, PR, SD and PD respectively, showing a correlation between DLesion and the two response group. CONCLUSIONS: Our experience demonstrated feasibility of high activity therapy of 131I-mIBG in rrmHR-NBL children as two administration intensive strategy. Dosimetric approach allowed a tailored high dose treatment maximizing the benefits of radionuclide therapy for pediatric patients while maintaining a safety profile. The assesment of DLesion contributed to have a deeper understaning of metabolic treatment effects.

Case report: Pylorus-preserving pancreatoduodenectomy for focal congenital hyperinsulinism in a 5-month-old baby.

Background: In focal congenital hyperinsulinism (CHI), surgery is the gold standard of treatment, even for lesions localized in the head of the pancreas. We report the video of the pylorus-preserving pancreatoduodenectomy performed in a five-month-old child with focal CHI. Operative technique: Baby was placed in the supine position with both arms outstretched to the up. After transverse supraumbilical incision and mobilization of ascending and transverse colon, exploration and multiple biopsies of the tail and the body of the pancreas ruled out multifocality. Pylorus-preserving pancreatoduodenectomy was performed according to the following steps: extended Kocher maneuver, followed by retrograde cholecystectomy and common bile duct isolation; division of the gastroduodenal artery and of the gastrocolic ligament; division of the duodenum, Treitz ligament and jejunum; transection of the pancreatic body. The reconstructive time was with: pancreato-jejunostomy; hepaticojejunostomy; pilorus-preserving antecolic duodeno-jejunostomy. The anastomoses were accomplished with synthetic absorbable monofilament sutures; two drains were placed close to the biliary and pancreatic anastomoses and to the intestinal anastomosis, respectively. Total operative time was 6 h, with no blood loss and/or intra-operative complications, immediate normalization of blood glucose levels and discharge from surgical ward 19 days after surgery. Conclusions: Surgical treatment of medical unresponsive focal forms of CHI is feasible in very small children: it is mandatory to refer the baby to a high-volume centre for a multidisciplinary management involving hepato-bilio-pancreatic surgeons and experts in metabolic disease.

Prognostic factors in children and adolescents with differentiated thyroid carcinoma treated with total thyroidectomy and RAI: a real-life multicentric study.

PURPOSE: This multicentric study aimed to investigate the main prognostic factors associated with treatment response at 1 year after radioactive iodine therapy (RAIT) and the last disease status in pediatric patients affected by differentiated thyroid carcinoma (DTC). MATERIALS AND METHODS: In the period 1990-2020, all consecutive patients ≤ 18 years from six different centers were retrospectively included. Patients were classified as low, intermediate, and high risk for persistence/recurrence. The response to RAIT was evaluated and scored 1 year later according to 2015 ATA guidelines. Moreover, at the last follow-up, the disease status was evaluated and dichotomized as no evidence of disease (NED) or persistent disease. RESULTS: Two hundred and eighty-five patients (197 female, 88 male; mean age 14.4 years) were recruited. All, except nine, underwent near-total thyroidectomy followed by RAIT. One-year after first RAIT, 146/276 (53%) patients had excellent response, 37/276 (14%) indeterminate response, and 91/276 (33%) incomplete response. One-year after RAIT, children with excellent response had significantly lower stimulated thyroglobulin (sTg) compared to not excellent group (median sTg 4.4 ng/ml vs 52.5 ng/ml, p < 0.001). ROC curve showed sTg higher than 27.2 ng/ml as the most accurate to predict 1-year treatment response. After a median follow-up of 133 months, NED was present in 241 cases (87%) while persistent disease in 35 (13%). At multivariate analysis, sTg and 1-year treatment response categories were both significantly associated with the last disease status (p value 0.023 and < 0.001). CONCLUSIONS: In pediatric DTC, sTg is significantly associated with 1-year treatment response and final outcome. However, 1-year response is the principal prognostic factor able to predict pediatric DTCs outcome.

Subtotal functional sialoadenectomy vs four-duct ligation for the treatment of drooling in neurologically impaired children: Long-term follow-up.

OBJECTIVES: The best surgical option to treat drooling in neurodisabilities is still under debate. The aim of this study was to describe the technique of subtotal functional sialoadenectomy (SFS) (ie four-duct ligation (4-DL) together with bilateral sublingual gland excision) and its long-term outcomes, in comparison with 4-DL. DESIGN: Retrospective observational cohort study. SETTING: Unit of Pediatric Surgery of Bambino Gesù Children's Hospital (Rome). PARTICIPANTS: Seventy-five patients surgically treated for drooling between 2002 and 2012, with at least five years of follow-up, divided into two groups: 4-DL group (19 patients) underwent four-duct ligation, and SFS group (56 patients) underwent subtotal functional sialoadenectomy. MAIN OUTCOME MEASURES: Primary end points were the evaluation of drooling improvement after surgery (parameters: Drooling Severity and Frequency Scale, DSFS; no of bibs/day; no of shirts/day; no of pneumonia/year; use of antidrooling drugs) and the comparison between two different surgical techniques. RESULTS: Median age at surgery was 10 years (1-35). Long-term outcomes showed significant improvement in DSFS and in no of shirts/day in both groups. Significantly better results were found in the SFS group than in the 4-DL group as far as DSFS (P value .045), no of bibs/day (P value .041), no of shirts/day (P value .032) are concerned. Reoperation rate for recurrence was 42% in the 4-DL group and 0% in the SFS group (P value < .0001). Six patients (8%; 2 in the 4-DL group and 4 in the SFS group) experienced perioperative complications, while 4 patients (5%; 2 in the 4-DL group and 2 in the SFS group) recorded long-term complications, with no difference between groups neither need for surgical treatment. No surgery-related mortality was recorded. CONCLUSIONS: In our experience, subtotal functional sialoadenectomy ensured significantly greater long-term effects than four-duct ligation for drooling treatment in neurologically impaired child, with equal complication rate.

Anakinra in a Cohort of Children with Chronic Nonbacterial Osteomyelitis.

OBJECTIVE: To report efficacy and safety in patients with chronic nonbacterial osteomyelitis (CNO) unresponsive to nonsteroidal antiinflammatory drugs (NSAID) and bisphosphonates and/or glucocorticoids treated with anakinra. METHODS: Nine patients (6 females) with refractory CNO were treated with anakinra for at least 6 months. We recorded, at baseline and after 6 months of treatment, clinical and laboratory features, and number and distribution of bone lesions detected by 99mTc-MDP bone scintigraphy. Disease activity was evaluated using a physician's global assessment (PGA). RESULTS: At baseline, 9/9 patients had mild to severe PGA. After 6 months of treatment, in 5 patients the PGA score was graded from none to minimal. At baseline, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were elevated in 8 out of 9 patients. After 6 months, 5/9 patients had normalized CRP and ESR and in all except 1, CRP and ESR decreased. Before starting anakinra, a total of 77 bone lesions were detected by bone scintigraphy. After 6 months of treatment of the 77 lesions, 42 had resolved and 35 were stable. In 7/9 patients, 20 new lesions appeared during treatment; 2 of these 7 patients were symptomatic. At the last followup visit (median 1.7 yrs, range 0.8-2.8), 6/9 patients maintained a PGA graded as none to minimal. CONCLUSION: Anakinra is a possible therapeutic alternative in patients with refractory CNO. The practical significance of clinically silent bone lesions detected by bone scintigraphy remains to be established.

A Pediatric Case of Well-Functioning Supernumerary Kidney: Relative Renal Function Assessment Using Radionuclide Imaging.

We present an interesting image of a well-functioning supernumerary kidney evaluated with DMSA (dimercaptosuccinic acid) renal scintigraphy in a 14-year-old girl. At 2 years of age, the patient had a diagnosis of supernumerary kidney. She remained asymptomatic up to childhood age, and then a DMSA study was required to guide the following adequate surveillance strategy. DMSA study provided a clear imaging of supernumerary kidney in the left side of the abdomen showing a regular uptake and a normal function in relation to its own size.

Unusual Presentation of Relapse in Neuroblastoma: Pancreatic Metastases Detected by 123I-MIBG Scintigraphy.

Neuroblastoma is the most common extracranial solid tumor in children and accounts for 8% to 10% of all childhood cancers. The spread of metastases is both lymphatic and hematogenous. Hematogenous route occurs most commonly in bone marrow and cortical bone; pancreatic metastases are very rare, and there are few reports about this topic in medical literature. We report the case of a 14-year-old boy who suffers a third relapse of neuroblastoma: in this patient I-MIBG confirms that lesions detected by CT were due to a relapse in pancreatic tissue and influenced subsequent therapeutic management.

Local control in metastatic neuroblastoma in children over 1 year of age.

BACKGROUND: Local control is always considered in metastatic neuroblastoma (NBL). The aim of this study is to evaluate the impact of radical surgery on survival in children over 1 year of age. METHODS: Fifty-eight patients older than 1 year of age with metastatic NBL were treated with conventional plus high-dose chemotherapy with or without addition of local radiotherapy (RT, 21Gy). Surgery was classified as radical surgery (complete resection and gross total resection) or non-radical surgery. The Kaplan-Meier method and the Cox proportional hazard model were used to calculate the probability of progression free and overall survival (PFS and OS) and for multivariate analysis. RESULTS: The 5-year PFS and OS for patients with radical surgery were 26% (95% CI 14-40%) and 38% (95% CI 23-53%) respectively, while the PFS and OS for patients without radical surgery were 33% (95% CI 10-59%) and 31% (95% CI 10-55%) (respectively, P 0.85 and P 0.42). The 5-year PFS and OS for patients who received RT were 36% (95% CI 19-53%) and 46% (95% CI 26-64%) respectively, while the 5-year PFS and OS for patients who did not receive RT were 22% (95% CI 9-38%) and 27% (95% CI 13-42%) respectively (P 0.02 for PFS). Multivariate analysis confirmed the role of well-known prognostic factors, such as the presence of MYCN amplification, age and response before high-dose chemotherapy. CONCLUSIONS: Our data suggest that the degree of resection does not influence survival in metastatic NBL patients treated with high-dose chemotherapy; local RT contributes to local disease control.

Cystic fibrosis: a surgical matter?

BACKGROUND: Gastroesophageal reflux disease (GERD) is very common in patients with chronic lung diseases. We evaluated the incidence of GERD in young patients with cystic fibrosis (CF) and defined the characteristics of gastroesophageal reflux episodes analyzed by pH-multichannel intraluminal impedance (pH-MII) and esophagogastric scintigraphy. PATIENTS AND METHODS: Since 2010, 31 patients with CF underwent pH-MII. Scintigraphy and upper endoscopy were performed in positive GERD patients. Forced expiratory volume in 1 second (FEV1%) predicted was detected. RESULTS: pH-MII was positive in 17/31 (54.8%) patients (mean age: 12.4 years; range: 4-17 years). pH monitoring detected an average of 64.6 acid reflux events 4.4 episodes >5 minutes in duration. The DeMeester score was 38.5. Impedance identified a mean number of reflux episodes of 66 (65.2% acid; 32% weakly acidic; 2.8% nonacidic), 28% of which reached the proximal esophagus. Esophageal transit and gastric emptying were delayed in 6/13 (46.1%) and in 5/15 (33.3%) cases, respectively. No differences were found in lung function between positive and negative GERD patients (P=0.88). CONCLUSIONS: Pediatric patients with CF have a high incidence of GERD with acidic events. These patients should be investigated with pH-MII and scintigraphy in order to make an early diagnosis and determine the most appropriate follow-up.

Comparison of two different conditioning regimens before autologous transplantation for children with high-risk neuroblastoma.

BACKGROUND: Although high-dose chemotherapy (HDC) represents the standard of treatment for high-risk neuroblastoma (NBL), the most effective conditioning regimen still remains to be identified. PATIENTS AND METHODS: Forty-one high-risk NBL entered into local protocol based on induction chemotherapy, surgery and HDC with either etoposide/thiotepa/cyclophophamide (ETC) or i.v. busulfan and L-PAM (Bu/L-PAM). RESULTS: Thirty-seven patients underwent HDC; 29 with ETC and 8 with Bu/L-PAM. No toxic deaths were recorded. The 5-year progression-free survival (PFS) of patients given ETC was 21% (95% confidence interval CI (9-36%), while PFS for patients given Bu/L-PAM was 88% (95% CI=39-98%) (p<0.05). In multivariate analysis, treatment with the ETC regimen predicted progression/recurrence with a hazard ratio (HR) of 16.8 (p<0.05), as well as MYCN amplification which had an HR of 4.4 (p<0.05). CONCLUSION: Although the number of studied cases is limited, our data suggest that in high-risk NBL the combination of Bu/L-PAM is superior to the ETC regimen.