Late Changes in Renal Volume and Function after Proton Beam Therapy in Pediatric and Adult Patients: Children Show Significant Renal Atrophy but Deterioration of Renal Function Is Minimal in the Long-Term in Both Groups.

To compare late renal effects in pediatric and adult patients with malignancies after PBT involving part of the kidney. A retrospective study was conducted to assess changes in renal volume and function in 24 patients, including 12 children (1-14 years old) and 12 adults (51-80 years old). Kidney volumes were measured from CT or MRI images during follow-up. Dose-volume histograms were calculated using a treatment planning system. In children, the median volume changes for the irradiated and control kidneys were -5.58 (-94.95 to +4.79) and +14.92 (-19.45 to +53.89) mL, respectively, with a relative volume change of -28.38 (-119.45 to -3.87) mL for the irradiated kidneys. For adults, these volume changes were -22.43 (-68.7 to -3.48) and -21.56 (-57.26 to -0.16) mL, respectively, with a relative volume change of -5.83 (-28.85 to +30.92) mL. Control kidneys in children exhibited a marked increase in size, while those in adults showed slight volumetric loss. The percentage of irradiated volume receiving 10 Gy (RBE) (V10) and 20 Gy (RBE) (V20) were significantly negatively associated with the relative volume change per year, especially in children. The CKD stage based on eGFR for all patients ranged from 1 to 3 and no cases with severe renal dysfunction were found before or after PBT. Late effects on the kidneys after PBT vary among age groups. Children are more susceptible than adults to significant renal atrophy after PBT. V10 and V20 might serve as predictors of the degree of renal atrophy after PBT, especially in children. PBT has a minimal impact on deterioration of renal function in both children and adults.

A systematic review and meta-analysis of radiotherapy and particle beam therapy for skull base chondrosarcoma: TRP-chondrosarcoma 2024.

Introduction: Chondrosarcoma is a rare malignant bone tumor. Particle beam therapy (PT) can concentrate doses to targets while reducing adverse events. A meta-analysis based on a literature review was performed to examine the efficacy of PT and photon radiotherapy for skull base chondrosarcoma. Methods: The meta-analysis was conducted using 21 articles published from 1990 to 2022. Results: After PT, the 3- and 5-year overall survival (OS) rates were 94.1% (95% confidence interval [CI]: 91.0-96.2%) and 93.9% (95% CI: 90.6-96.1%), respectively, and the 3- and 5-year local control rates were 95.4% (95% CI: 92.0-97.4%) and 90.1% (95% CI: 76.8-96.0%), respectively. Meta-regression analysis revealed a significant association of PT with a superior 5-year OS rate compared to three-dimensional conformal radiotherapy (p < 0.001). In the studies used in the meta-analysis, the major adverse event of grade 2 or higher was temporal lobe necrosis (incidence 1-18%, median 7%). Conclusion: PT for skull base chondrosarcoma had a good outcome and may be a valuable option among radiotherapy modalities. However, high-dose postoperative irradiation of skull base chondrosarcoma can cause adverse events such as temporal lobe necrosis.

An analysis of muscle growth after proton beam therapy for pediatric cancer.

Retardation of growth and development is a well-known late effect after radiotherapy for pediatric patients. The goal of the study was to examine the effect of proton beam therapy (PBT) on the growth of muscles included in the irradiated area. The subjects were 17 pediatric patients (age ≤ 5 years) who received PBT with a treatment field including a muscle on only one side out of a pair of symmetrical bilateral muscles and had imaging evaluations for at least 1 year after PBT. The thicknesses of the irradiated and non-irradiated (contralateral) muscles were measured retrospectively on CT or MRI axial images collected before and after PBT. The change of thickness divided by the period (years) for each muscle was compared between the irradiated and contralateral sides. Correlations of muscle growth with irradiation dose and age at the start of treatment were also evaluated. The median observation period was 39.2 months. The measurement sites included the erector spinae (n = 9), gluteus maximus (n = 5) and rhomboids + trapezius (n = 3) muscles. The average changes in muscle thickness were 0.24 mm/year on the irradiated side and 1.19 mm/year on the contralateral side, showing significantly reduced growth on the irradiated side (P = 0.001). Younger patients had greater muscle growth. Irradiation dose was not significant, but muscle growth tended to decrease as the dose increased, and muscles irradiated at >50 Gy (RBE) showed little growth. These results show that muscle growth is affected by PBT and that long-term follow-up is needed to evaluate muscle growth retardation.

The CXCL10-CXCR3 axis plays an important role in Kawasaki disease.

The precise pathogenesis of Kawasaki disease remains unknown. In an attempt to elucidate the pathogenesis of KD through the analysis of acquired immunity, we comprehensively examined the immunophenotypic changes in immune cells such as lymphocytes and monocytes along with various cytokines, focusing on differences between pre- and post- treatment samples. We found high levels of CXCL9 and CXCL10 chemokines that decreased with treatment, which coincided with a post-treatment expansion of Th1 cells expressing CXCR3. Our results show that the CXCL10-CXCR3 axis plays an important role in the pathogenesis of KD.

Acute monocytic leukemia with KMT2A::LASP1 developed 9 months after diagnosis of acute megakaryoblastic leukemia in a 2-year-old boy.

Acute myeloid leukemia (AML) is known as one of the subsequent malignant neoplasms that can develop after cancer treatment, but it is difficult to distinguish from relapse when the preceding cancer is leukemia. We report a 2-year-old boy who developed acute megakaryoblastic leukemia (AMKL, French-American-British classification [FAB]: M7) at 18 months of age and achieved complete remission with multi-agent chemotherapy without hematopoietic stem cell transplantation. Nine months after diagnosis and 4 months after completing treatment for AMKL, he developed acute monocytic leukemia (AMoL) with the KMT2A::LASP1 chimeric gene (FAB: M5b). The second complete remission was achieved using multi-agent chemotherapy and he underwent cord blood transplantation 4 months after AMoL was diagnosed. He is currently alive and disease free at 39 and 48 months since his AMoL and AMKL diagnoses, respectively. Retrospective analysis revealed that the KMT2A::LASP1 chimeric gene was detected 4 months after diagnosis of AMKL. Common somatic mutations were not detected in AMKL or AMoL and no germline pathogenic variants were detected. Since the patient's AMoL was different from his primary leukemia of AMKL in terms of morphological, genomic, and molecular analysis, we concluded that he developed a subsequent leukemia rather than a relapse of his primary leukemia.

Analysis of person-hours required for proton beam therapy for pediatric tumors.

Proton beam therapy (PBT) is effective for pediatric tumors, but patients may require sedation and other preparations, which extend the treatment time. Pediatric patients were classified into sedation and non-sedation cases. Adult patients were classified into three groups based on irradiation from two directions without or with respiratory synchronization and patch irradiation. Treatment person-hours were calculated as follows: (time from entering to leaving the treatment room) × (number of required personnel). A detailed analysis showed that the person-hours required for the treatment of pediatric patients are about 1.4-3.5 times greater than those required for adult patients. With the inclusion of additional time for the preparation of pediatric patients, PBT for pediatric cases is two to four times more labor-intensive than for typical adult cases.

Longitudinal health-related quality of life analysis in childhood cancer survivors after proton beam therapy.

PURPOSE: Whilst proton beam therapy (PBT) for children with cancer is expected to reduce their comorbidities, to date only a limited number of studies have been published. To analyze the long-term comorbidity and health-related quality of life (HRQoL) of childhood cancer survivors (CCSs) after PBT, we conducted a questionnaire-based study. METHODS: Questionnaires were sent to CCSs who underwent PBT at the University of Tsukuba Hospital during the period from 1984 to 2020. Scores from 41 CCSs who did not undergo PBT (noPBT-CCSs) and from the general population were used for comparison. RESULTS: In total, 110 individuals who underwent PBT participated in the study. Among them, 40 individuals were longitudinally analyzed. The range of change in the scores was significantly greater in the CCSs whose initial scores were low. Although the comorbidity levels were more severe, HRQoL tended to be better in the PBT-CCSs than in the noPBT-CCSs with central nervous system (CNS) or solid tumors, respectively. When compared with the general population, the psychosocial health summary scores and its components were not different in the noPBT-CNS-CCSs. On the other hand, the psychosocial health summary scores and/or at least one of the scores of emotional, social, and school functioning were significantly higher in the other CCSs groups. CONCLUSIONS: The HRQoL scores of CCSs with low initial scores can be greatly changed over time. Appropriate psychosocial support for this population is warranted. PBT may avoid reduction in HRQoL in terms of the psychosocial functioning of CCSs with CNS tumors.

Antigen-specific T cell balance reveals Why patients with atopic dermatitis fail to achieve immune tolerance.

The number of regulatory T cells (Tregs) and how they behave in the pathogenesis of atopic dermatitis (AD) are still controversial. We identified and quantified Tregs, mite-specific Tregs, and mite-specific effector T cells (Teffs) in patients with AD and healthy controls (HCs). We collected peripheral blood and analyzed the cells using flow cytometry after stimulation with mite antigens. Mite-specific Tregs and mite-specific Teffs were recognized by the expression of CD137 and CD154, respectively. Patients with AD had more Tregs than HCs; however, when focusing on a single antigen, the ratio of mite-specific Tregs/Teffs was lower in patients with AD than in HCs. Furthermore, the mite-specific Teffs in patients with AD were more likely to produce proinflammatory cytokines interleukin (IL)-4 and IL-13. This Teff-dominant imbalance is thought to be the cause of development of atopic status in patients with AD without immune tolerance.

Gastrointestinal bleeding/ulcer among paediatric cancer patients after proton beam therapy.

BACKGROUND: The details of gastrointestinal bleeding/ulcer in paediatric cancer patients treated with proton beam therapy have not been reported previously. METHODS: Patients aged 15 years or younger at the time of proton beam therapy and whose gastrointestinal tract was included in the irradiated field participated. RESULTS: A total of 124 patients participated in the study; their median age at irradiation was 5.4 years. Concurrent chemotherapies were vincristine-cyclophosphamide (16 patients), irinotecan-based treatment (16 patients), vincristine-cyclophosphamide-ifosfamide-etoposide (14 patients), other chemotherapy (27 patients) and no chemotherapy (51 patients). Gastrointestinal bleeding/ulcer occurred in four patients (3.2%), with no death due to the bleeding/ulcer. The sites of the gastrointestinal bleeding/ulcer were the stomach (two patients) and the duodenum (two patients). The ages of the four patients at PBT were 5.3, 13.8, 14.2 and 14.8 years, which were significantly older than those of patients without GI bleeding/ulcer (p = 0.017). The maximum irradiated doses to the GI tract in the four patients were 43.2, 45, 50.4 and 50.4 gray equivalent, respectively. The concomitant chemotherapy was vincristine-cyclophosphamide-ifosfamide-etoposide 3 and vincristine-cyclophosphamide 1. Weeks from proton beam therapy to bleeding/ulcer were 15, 20, 22 and 264. DISCUSSION AND CONCLUSIONS: Patients who developed gastrointestinal bleeding/ulcer were treated concurrently with vincristine-cyclophosphamide-ifosfamide-etoposide or vincristine-cyclophosphamide, and their ages were older than those of patients without gastrointestinal bleeding/ulcer. Bleeding occurred in the upper gastrointestinal tract in all the cases, and most cases occurred early and during chemotherapy. Upper gastrointestinal irradiation in older children undergoing intensive chemotherapy may increase the risk of developing gastrointestinal complications.

A Retrospective Study of Renal Growth Changes after Proton Beam Therapy for Pediatric Malignant Tumor.

The purpose of this study was to analyze renal late effects after proton beam therapy (PBT) for pediatric malignant tumors. A retrospective study was performed in 11 patients under 8 years of age who received PBT between 2013 and 2018. The kidney was exposed in irradiation of the primary lesion in all cases. Kidney volume and contour were measured on CT or MRI. Dose volume was calculated with a treatment-planning system. The median follow-up was 24 months (range, 11-57 months). In irradiated kidneys and control contralateral kidneys, the median volume changes were -5.63 (-20.54 to 7.20) and 5.23 (-2.01 to 16.73) mL/year; and the median % volume changes at 1 year were -8.55% (-47.52 to 15.51%) and 9.53% (-2.13 to 38.78%), respectively. The median relative volume change for irradiated kidneys at 1 year was -16.42% (-52.21 to -4.53%) relative to control kidneys. Kidneys irradiated with doses of 10, 20, 30, 40, and 50 GyE had volume reductions of 0.16%, 0.90%, 1.24%, 2.34%, and 8.2% per irradiated volume, respectively. The larger the irradiated volume, the greater the kidney volume was lost. Volume reduction was much greater in patients aged 4-7 years than in those aged 2-3 years. The results suggest that kidneys exposed to PBT in treatment of pediatric malignant tumor show continuous atrophy in follow-up. The degree of atrophy is increased with a higher radiation dose, greater irradiated volume, and older age. However, with growth and maturation, the contralateral kidney becomes progressively larger and is less affected by radiation.

Initial manifestations in Patients with Inborn Errors of Immunity Based on Onset Age: a Study from a Nationwide Survey in Japan.

PURPOSE: Patients with inborn errors of immunity (IEI) manifest various initial symptoms; however, those that are critical for the early diagnosis of IEI have not been identified. Also, the significance of the ten warning signs of primary immunodeficiency (PID) among infants has not been established. This study aimed to conduct a nationwide survey of IEI in Japan and investigated the initial manifestations based on onset age. METHODS: Among 1298 patients, data regarding the initial manifestation were available from 505 patients. Patients with autoinflammatory diseases, complement deficiency, and phenocopies of IEI were excluded. RESULTS: The ten warning signs were positive in 67.3% of the cases. The positivity rate was low (20.5%) in patients with immune dysregulation. Although the positivity rate was low (36.6%) in patients aged less than 3 months, they were highly positive for family history of IEI (26.8%). Infectious symptoms were the most commonly observed in all age groups and in all disease categories. Symptoms of "immune dysregulation" were present in approximately 15% of the patients. Regarding the anatomical category, almost all initial symptoms were "systemic" infections in patients with X-linked severe combined immunodeficiency. Moreover, "respiratory" symptoms were the most common in patients with IEI aged ≥ 1 year and accounted for more than 50% in all age groups in patients with common variable immunodeficiency. CONCLUSION: These results highlight the significance of the 10 warning signs and may serve as clinical indicators for early diagnosis, considering the initial presentation of IEI.

Recovery of lymphocyte subpopulations is incomplete in the long-term setting in pediatric solid tumor survivors.

BACKGROUND: Childhood cancer survivors (CCSs) may have comorbidities including a long-term abnormality in the immune system. Immune reconstitution in CCSs after treatment for acute leukemia has been reported previously, while analyses of immune reconstitution in CCSs with solid tumors have been limited. METHODS: Childhood cancer survivors who received chemotherapy for solid tumors and who visited University of Tsukuba Hospital between November 2019 and March 2021 were included the study. Peripheral blood was collected for flow cytometry analysis. RESULTS: Forty-nine samples from 35 CCSs (18 male, 17 female) were included in the study. High-dose chemotherapy and cerebral spinal irradiation were conducted in 14 CCSs (40%) and in five CCSs (14%), respectively. The median time between the completion of chemotherapy and the collection of the present samples was 15.0 months (range, 0-286 months). The total lymphocyte count, B cells, and CD8-positive T cells recovered to the normal range of controls (NR-CTLs) in 0 (0%), four (66.7%), and four (66.7%) of six samples at 0-3 months after the completion of chemotherapy, and in three (60%), four (80%), and three (60%) of five samples at 3-12 months after the completion of chemotherapy, respectively. Meanwhile, CD4-positive T cells remained lower than NR-CTLs in 0 (0%) of six samples, one (20%) of five samples, and seven (63.7%) of 11 samples at 0-3, 3-12 and 12-60 months after the completion of chemotherapy, respectively. CONCLUSIONS: Recovery to the NR-CTLs was rapidly achieved in B cells and CD8-positive T cells, while the recovery was slower and incomplete in CD4-positive T cells. Careful observation of infection in long-term follow-up clinics is needed.

Effect of Germline MEFV Polymorphisms on the Prognosis of Japanese Children with Cancer: A Regional Analysis.

INTRODUCTION: MEFV is the gene responsible for familial Mediterranean fever. It encodes pyrin, which controls inflammation. Besides, previous studies have reported that some germline MEFV variants were associated with tumour susceptibility. MATERIALS AND METHODS: The loci of 12 germline MEFV variants were genotyped in 153 Japanese children with cancer, and the frequencies of these variants among the patient groups were compared with those in the general Japanese population. Additionally, the relationship between these variants and clinical data, including relapse and death, was investigated. RESULTS: Minor allele frequencies did not differ between patients and the general population, or between sex, age at diagnosis, and diagnosis among patients. P369S/R408Q associated with significantly lower relapse-free survival in all patient analyses and in patients with solid tumours. Additionally, although the results were not significant, E148Q/L110P was likely to associate with worse relapse-free survival in patients with solid tumours. DISCUSSION/CONCLUSION: Despite several limitations, this study provided the novel insight that the germline MEFV variants are associated with the clinical outcome of paediatric cancer.

Time course of peripheral immunophenotypes of multisystem inflammatory syndrome in children.

The etiology of multiple inflammatory syndrome in children (MIS-C) remains poorly understood. As clues to elucidate the pathogenic condition, several characteristic peripheral immunophenotypes have been reported in MIS-C. However, no report has demonstrated the time course of the peripheral immunophenotype along with the clinical course in the same patient. Herein, we clarified the immunological characteristics of a Japanese patient with MIS-C. There was an initial cytokine storm followed by T-cell activation, especially of CD8+ T cells, with the expansion of T-cell receptor Vß 21.3-expressing cells, which suggests superantigen-mediated T-cell activation. In addition, we also found an increase in IgG-producing cells (plasmablasts and switched memory B cells), which were accompanied by elevated serum levels of anti-SARS-CoV-2 spike antigen-specific IgG antibodies. These time course of peripheral immunophenotypes support that immunological activation against SARS-CoV-2 spike protein plays a central role in the etiology of MIS-C.

Vaccination for Patients with Inborn Errors of Immunity: a Nationwide Survey in Japan.

We conducted a nationwide survey of inborn errors of immunity (IEI) in Japan for the second time in 10 years, focusing on protective measures for IEI patients against infectious diseases. Questionnaires were sent to various medical departments nationwide, and a total of 1307 patients were reported. The prevalence of IEI was 2.2 patients per 100,000 population, which was comparable with the previous nationwide study. The most common disease category was autoinflammatory disorders (25%), followed by antibody deficiencies (24%) and congenital defects of phagocyte number or function (16%). We found that a significant number of patients received contraindicated vaccines, principally because the patients were not diagnosed with IEI by the time of the vaccination. Regarding diseases for which BCG vaccination is contraindicated, 43% of patients had actually received BCG, of which 14% developed BCG-related infections. BCG-related infections were mainly observed among patients with CGD and MSMD. In order to prevent IEI patients from receiving inadequate vaccines, continuous education to parents and physicians is needed, along with the expansion of newborn screening, but efforts to screen IEI at the site of vaccination also remain important.

Cancer predisposition genes in Japanese children with rhabdomyosarcoma.

Rhabdomyosarcoma (RMS) is one of the most common soft tissue sarcomas in children. Germline mutations in cancer-predisposition genes have been detected in approximately 10% of pediatric cancers. However, the genetic background of RMS is still unclear, especially in Asian children. DNA was extracted from the peripheral blood of children with RMS and cancer-associated genes analyzed using targeted re-sequencing. Twenty patients participated in this study. There were three deaths due to RMS. One patient developed a second neoplasm. Nine patients had long-term co-morbidities. Six pathogenic variants were found in five patients: one nonsense variant of DICER1, one exon deletion of TP53, and three missense variants of BUB1B, LIG4, and MEN1. Two of the five patients had a family history of cancer. Two patients with missense variants of LIG4 had long-term co-morbidities of drug-induced cardiomyopathy. The missense variants of LIG4, essential for DNA double-strand break repair, were detected in two unrelated patients. While this is the first report of the germline genetic analysis of Japanese children with RMS with detailed clinical information, the frequency of the variant was almost equivalent to that of previous reports from western countries. Unbiased exon sequencing may be useful to clarify the pathogenesis of RMS in children and in predicting the clinical course of these patients.

Cancer-Predisposition Genetic Analysis in Children with Brain Tumors Treated at a Single Institution in Japan.

Brain tumors affect one-third of all children with cancer. Approximately 10% of children with cancer carry variants in cancer-predisposition genes. However, germline analyses in large cohorts of Asian children have not been reported. Thirty-eight Japanese patients with pediatric brain tumors were included in this study (19 boys, 19 girls). DNA was extracted from the patients' peripheral blood, and cancer-associated genes were analyzed using targeted resequencing. Rare variants with allele frequencies <0.1% in the general population and variants suspected to be pathogenic were extracted and analyzed. Pathogenic variants were found in 7 patients (18%): 2 nonsense variants of CHEK2 and FANCI; 2 frameshift deletions in SMARCB1 and PTCH1; and 3 missense variants of TSC1, WRN, and MLH1. The median age at diagnosis was 9.1 years, and three of the 7 patients had a family history of cancer. One patient diagnosed with basal cell nevus syndrome, also called Gorlin syndrome, developed a second neoplasm, and another with an SMARCB1 variant and an atypical teratoid/rhabdoid tumor developed a thyroid adenomatous nodule. This is the first cancer-related germline analysis with detailed clinical information reported in Japanese children with brain tumors. The prevalence was almost equivalent to that in white children.

Proton beam therapy with concurrent chemotherapy is feasible in children with newly diagnosed rhabdomyosarcoma.

BACKGROUND: The optimal treatment for rhabdomyosarcoma (RMS) requires multidisciplinary treatment with chemotherapy, surgery, and radiotherapy. Surgery and radiotherapy are integral to the local control (LC) of RMS. However, postsurgical and radiotherapy-related complications could develop according to the local therapy and tumor location. In this study, we conducted a single-center analysis of the outcomes and toxicity of multidisciplinary treatment using proton beam therapy (PBT) for pediatric RMS. MATERIALS AND METHODS: RMS patients aged younger than 20 years whose RMS was newly diagnosed and who underwent PBT at University of Tsukuba Hospital (UTH) during the period from 2009 to 2019 were enrolled in this study. The patients' clinical information was collected by retrospective medical record review. RESULTS: Forty-eight patients were included. The 3-year progression-free survival (PFS) and overall survival (OS) rates of all the patients were 68.8% and 94.2%, respectively. The 3-year PFS rates achieved with radical resection, conservative resection, and biopsy only were 65.3%, 83.3%, and 67.6%, respectively (p = 0.721). The 3-year LC rates achieved with radical resection, conservative resection, and biopsy only were 90.9%, 83.3%, and 72.9%, respectively (p = 0.548). Grade 3 or higher mucositis/dermatitis occurred in 14 patients. Although the days of opioid use due to mucositis/dermatitis during the chemotherapy with PBT were longer than those during the chemotherapy without PBT [6.1 and 1.6 (mean), respectively, p = 0.001], the frequencies of fever and elevation of C-reactive protein were equivalent. CONCLUSIONS: Multidisciplinary therapy containing PBT was feasible and provided a relatively fair 3-year PFS, even in children with newly diagnosed RMS without severe toxicity.