Intracranial volumetric evaluation in postnatally repaired myelomeningocele infants.

INTRODUCTION: Most myelomeningocele (MMC) cases present with ventriculomegaly or hydrocephalus, yet a comprehensive volumetric assessment of MMC intracranial structures is lacking. This study aimed to provide baseline data on intracranial structural volumes immediately after birth in MMC infants who underwent repair surgeries after birth (postnatal repair). METHODS: In this retrospective single-center study, we analyzed 52 MMC infants undergoing postnatal repair, utilizing head computed tomography scans at birth for volumetric assessment. Intracranial volume (ICV), lateral ventricles volume (LVV), choroid plexus volume (CPV), and posterior cranial fossa volume (PCFV) were measured. Hydrocephalus was classified into no hydrocephalus, progressive hydrocephalus, and hydrocephalus at birth. Comparative analysis employed the Wilcoxon rank-sum test. Receiver operating characteristic (ROC) analysis discriminated cases with and without ventriculoperitoneal shunt (VPS). RESULTS: The median values were 407.50 mL for ICV, 33.18 mL for LVV, 0.67 mL for CPV, and 21.35 mL for PCFV. Thirty-seven cases (71.15%) underwent VPS. ROC analysis revealed an LVV cut-off value of 6.74 mL for discriminating cases with and without VPS. Progressive hydrocephalus showed no significant difference in ICV but significantly larger LVV compared to no hydrocephalus. Hydrocephalus at birth demonstrated statistically larger ICV and LVV compared to the other two types. CONCLUSION: Baseline volumetric data were provided, and volumetric analysis exhibited statistical differences among three hydrocephalus types. These findings enhance our understanding of intracranial volumetric changes in MMC, facilitating more objective assessments of MMC cases.

Growth patterns and ratios of posterior cranial fossa structures in the Japanese pediatric population: a study utilizing CT scans.

PURPOSE: The changes in the proportion of posterior cranial fossa structures during pediatric development remain unclear. This retrospective study aimed to investigate the growth patterns and ratios of these structures using CT scans. METHODS: Head CT scans of pediatric patients with minor head trauma from Osaka Women's and Children's Hospital between March 2006 and May 2023 were analyzed. The study segmented the intracranial volume (ICV), posterior cranial fossa volume (PCFV), cerebellum volume (CBMV), and brainstem volume (BSV). Correlation coefficients were calculated among the parameters. Patients aged 0 to 10 years were divided into 15 age-related clusters, and mean and standard deviation values were measured. Growth curves were created by plotting mean values sequentially. Ratios such as PCFV/ICV and (CBMV + BSV)/PCFV were examined. Statistical analyses, including unpaired t tests and logarithmic curve fitting, were performed. RESULTS: A total of 234 CT scans (97 from females, 115 from infants under 1 year of age) were analyzed. Positive correlations were observed among the parameters, with the strongest between PCFV and CBMV. The growth curves for ICV, PCFV, CBMV, and BSV exhibited a two-phase process, with rapid growth until approximately 4 years of age, followed by stabilization. The ratios PCFV/ICV and (CBMV + BSV)/PCFV showed increasing trends from birth onwards, stabilizing by 4 and 1 years of age, respectively. CONCLUSION: This study provides insights into the growth patterns and ratios of posterior cranial fossa structures in the pediatric population. The findings demonstrate a two-phase growth process and increasing trends in the examined ratios.

Maintenance of WT1 expression in tumor cells is associated with a good prognosis in malignant glioma patients treated with WT1 peptide vaccine immunotherapy.

We have previously revealed the overexpression of Wilms' tumor gene 1 (WT1) in malignant glioma and developed WT1 peptide vaccine cancer immunotherapy. A phase II clinical trial indicated the clinical efficacy of the WT1 peptide vaccine for recurrent malignant glioma. Here, we aimed to investigate the immunological microenvironment in glioma tissues before and after WT1 peptide vaccine treatment. Paired tissue samples were obtained from 20 malignant glioma patients who had received the WT1 peptide vaccine for > 3 months and experienced tumor progression, confirmed radiographically and/or clinically, during vaccination. We discovered that the expression of WT1 and HLA class I antigens in the tumor cells significantly decreased after vaccination. Maintenance of WT1 expression, which is the target molecule of immunotherapy, in tumor cells during the vaccination period was significantly associated with a longer progression-free and overall survival. A high expression of HLA class I antigens and low CD4+/CD8+ tumor-infiltrating lymphocytes (TIL) ratio in pre-vaccination specimens, were also associated with a good prognosis. No statistically significant difference existed in the number of infiltrating CD3+ or CD8+ T cells between the pre- and post-vaccination specimens, whereas the number of infiltrating CD4+ T cells significantly decreased in the post-vaccination specimens. This study provides insight into the mechanisms of intra-tumoral immune reaction/escape during WT1 peptide vaccine treatment and suggests potential clinical strategies for cancer immunotherapy.

[Distraction Osteogenesis for Craniosynostosis].

Distraction osteogenesis is the standard surgical procedure for cranioplasty in children over 6 months of age. This technique carries a risk of detachment of the extender and infection during the course, but such troubles can be reduced by accumulating surgical experience. In addition, furing distraction osteogenesis, the cranium can be sufficiently expanded by slowly stretching the scalp, while adjustment ensures that the facial appearance does not change too much. In this paper, I will explain the surgical technique and postoperative management, focusing on FOA(Fronto-orbital advancement)for trigonocephaly or brachycephaly and BPE(Bilateral parietal expansion)for scaphocephaly. The point of surgery in FOA is the osteotomy of the orbital bar. The osteotomy can be performed safely and easily using a wire saw. The aim of surgery in BPE is to extend an osteotomy up to the front of the coronal suture and down to the part near the cranial floor. This allows improvements of the cranial shape while sufficiently increasing the cranial volume.

Association of WT1 IgG antibody against WT1 peptide with prolonged survival in glioblastoma multiforme patients vaccinated with WT1 peptide.

We previously evaluated Wilms' tumor gene 1 (WT1) peptide vaccination in a large number of patients with leukemia or solid tumors and have reported that HLA-A*24:02 restricted, 9-mer WT1-235 peptide (CYTWNQMNL) vaccine induces cellular immune responses and elicits WT1-235-specific cytotoxic T lymphocytes (CTLs). However, whether this vaccine induces humoral immune responses to produce WT1 antibody remains unknown. Thus, we measured IgG antibody levels against the WT1-235 peptide (WT1-235 IgG antibody) in patients with glioblastoma multiforme (GBM) receiving the WT1 peptide vaccine. The WT1-235 IgG antibody, which was undetectable before vaccination, became detectable in 30 (50.8%) of a total of 59 patients during 3 months of WT1 peptide vaccination. The dominant WT1-235 IgG antibody subclass was Th1-type, IgG1 and IgG3 . WT1-235 IgG antibody production was significantly and positively correlated with both progression-free survival (PFS) and overall survival (OS). Importantly, the combination of WT1-235 IgG antibody production and positive delayed type-hypersensitivity (DTH) to the WT1-235 peptide was a better prognostic marker for long-term OS than either parameter alone. These results suggested that WT1-235 peptide vaccination induces not only WT1-235-specific CTLs as previously described but also WT1-235-specific humoral immune responses associated with antitumor cellular immune response. Our results indicate that the WT1 IgG antibody against the WT1 peptide may be a useful predictive marker, with better predictive performance in combination with DTH to WT1 peptide, and provide a new insight into the antitumor immune response induction in WT1 peptide vaccine-treated patients.

Wilms tumor 1 peptide vaccination combined with temozolomide against newly diagnosed glioblastoma: safety and impact on immunological response.

To investigate the safety of combined Wilms tumor 1 peptide vaccination and temozolomide treatment of glioblastoma, a phase I clinical trial was designed. Seven patients with histological diagnosis of glioblastoma underwent concurrent radiotherapy and temozolomide therapy. Patients first received Wilms tumor 1 peptide vaccination 1 week after the end of combined concurrent radio/temozolomide therapy, and administration was continued once per week for 7 weeks. Temozolomide maintenance was started and performed for up to 24 cycles, and the observation period for safety encompassed 6 weeks from the first administration of maintenance temozolomide. All patients showed good tolerability during the observation period. Skin disorders, such as grade 1/2 injection-site reactions, were observed in all seven patients. Although grade 3 lymphocytopenia potentially due to concurrent radio/temozolomide therapy was observed in five patients (71.4 %), no other grade 3/4 hematological or neurological toxicities were observed. No autoimmune reactions were observed. All patients are still alive, and six are on Wilms tumor 1 peptide vaccination without progression, yielding a progression-free survival from histological diagnosis of 5.2-49.1 months. Wilms tumor 1 peptide vaccination was stopped in one patient after 12 injections by the patient's request. The safety profile of the combined Wilms tumor 1 peptide vaccination and temozolomide therapy approach for treating glioblastoma was confirmed.

Clinical and radiological features of endodermal cyst in the oculomotor nerve: A case report.

We present a 9-year-old girl with an endodermal cyst of the oculomotor nerve in the left interpeduncular cistern, who had a history of left ptosis. We suggest that a cyst localized at the exit of the oculomotor nerve from the midbrain associated with oculomotor palsy may suggest this rare entity.

Unexpected Cerebral Hyperperfusion after Transient Hypoperfusion Associated with Stroke-like Migraine Attacks after Radiation Therapy Syndrome.

Stroke-like migraine attacks after radiation therapy (SMART) syndrome, a delayed sequela of cranial radiotherapy encountered rarely, occurs due to transient neurological deficits coupled with migraine episodes. This case report describes an occurrence of SMART syndrome in an individual 8 years after receiving medulloblastoma treatment. The subject, a 21-year-old male, experienced abrupt aphasia and right-sided hemiparesis. Arterial spin labeling (ASL) revealed initial cerebral hypoperfusion in the left temporal and parietal regions, with no tumor resurgence or notable ischemic alterations. Two days later, the symptoms disappeared completely; nevertheless, at that time, ASL presented cerebral hyperperfusion in the same lobule. The subject experienced a pulsating headache and nausea the next day. In the context of SMART syndrome, this fluctuation in cerebral blood flow indicated by ASL is a unique finding. The significance of this case lies in the documentation of the dynamic evolution of cerebral perfusion in SMART syndrome via ASL, thereby elucidating its underlying pathophysiology. As hemiplegic migraine shows a similar cerebral perfusion pattern to SMART syndrome, we inferred an unexplored but shared pathophysiology among hemiplegic migraine and SMART syndrome. Through this successful capture of these distinct cerebral blood flow alterations, from hypoperfusion to hyperperfusion, our understanding of the pathophysiological intricacies inherent to SMART syndrome will be enhanced.

Normal growth curve of choroid plexus in children: implications for assessing hydrocephalus due to choroid plexus hyperplasia.

OBJECTIVE: Pediatric hydrocephalus requires evaluation while accounting for growth of the intracranial structures, but information on choroid plexus growth in children is lacking. This study aimed to create normal growth curves for intracranial volume, choroid plexus volume, and lateral ventricles volume. Additionally, the authors aimed to objectively assess the degree of hydrocephalus caused by choroid plexus hyperplasia (CPH) and to examine the impact of surgical procedures. METHODS: This retrospective study analyzed the head CT scans of pediatric patients with minor head trauma treated at Osaka Women's and Children's Hospital between March 2006 and May 2023. The study segmented and calculated intracranial, choroid plexus, and lateral ventricles volumes. The study also calculated the correlation coefficients among these 3 parameters. Patients aged 0 to 10 years were divided into 15 age-related clusters, and mean ± SD values were calculated for each cluster. Growth curves were created by plotting mean values sequentially. Volume obtained from patients with CPH were z-normalized using mean and SD values and compared. RESULTS: A total of 229 CT scans (94 from females) were analyzed, and positive correlations were observed among intracranial volume, choroid plexus volume, and lateral ventricles volume, with the strongest correlation between the choroid plexus and lateral ventricles volumes. The growth rate of intracranial volume was rapid until approximately 20 months of age, while those of choroid plexus volume and lateral ventricles volume increased rapidly until approximately 1 year of age. Subsequently, choroid plexus volume and lateral ventricles volume plateaued at 1.5 ml and 10 ml, respectively. Three patients with CPH were enrolled and quantitatively evaluated on the basis of the z-normalized volume. Notable abnormal volumes of the choroid plexus (range z-normalized values 24.11-51.17) and lateral ventricles (46.78-122.36) were observed. In 2 patients, improvements in the z-normalized values of intracranial volume and lateral ventricles volume were observed after surgical interventions. Additionally, in 1 patient, choroid plexus volume was reduced by approximately 24% (range z-normalized values 51.17-38.93) after bilateral endoscopic plexus coagulation. CONCLUSIONS: This study provides normal growth curves for intracranial volume, choroid plexus volume, and lateral ventricles volume. Knowledge of these normal values holds the potential for objective assessment of abnormal values associated with hydrocephalus and choroid plexus diseases such as CPH.

Six-month survival of a monochorionic monoamniotic twin with sirenomelia.

BACKGROUND: Sirenomelia is a congenital malformation of the lower body characterized by a single midline lower limb and severe urogenital and gastrointestinal malformations. Sirenomelia is rare (estimated incidence of approximately 1/100,000) and usually lethal in the perinatal period. CASE: A 2,042 g Japanese male infant, one of monochorionic monoamniotic twins, was born at 34 weeks of gestation by elective caesarean section. Sirenomelia was prenatally diagnosed. Single midline lower limb, bilateral dysplastic kidneys, an omphalomesenteric fistula, colon atresia, imperforate anus, indiscernible genital structures, and myelomeningocele were detected at birth. The amniotic fluid volume was normal throughout the pregnancy course, which led to appropriate lung maturation of the twin with sirenomelia. Although renal replacement therapy was initiated soon after birth, stable peritoneal dialysis was difficult because of the limited intraperitoneal space, and the infant frequently developed peritonitis. He died of sudden cardiorespiratory arrest at 6 months of age. Postmortem examination showed bilateral dysplastic kidneys, agenesis of the ureters and urinary bladder, abnormal branching and agenesis of the distal colon, bilateral inguinal hernias, and small testes. CONCLUSION: Infants with sirenomelia, even those with end-stage kidney disease at birth, may survive if they have a stable cardiorespiratory status at birth and renal replacement therapy is appropriately initiated.

A survey of disclosure of diagnosis to patients with glioma in Japan.

BACKGROUND: There have been few studies investigating neuro-oncologists' attitudes toward the disclosure of the diagnosis. This study aimed to determine the current status of disclosure to glioma patients in Japan and to analyze the factors associated with disclosure. METHODS: A set of questionnaires about disclosure to patients with malignant glioma was distributed by e-mail to 191 physicians participating in the 27th Annual Meeting of the Japan Society for Neuro-Oncology. RESULTS: The response rate was 73.8% (141/191). Of these, 44.3% disclosed the correct diagnosis to glioblastoma patients aged < 60 years and 41.4% disclosed the correct diagnosis to those aged ≥ 70 years; for anaplastic astrocytoma patients, these proportions were 61.5 and 51.9%, respectively. Physicians working at facilities performing surgery on more than 50 cases of glioma per year, those in metropolitan areas, and those with other patient psychosocial support systems available disclosed the diagnosis and prognosis more frequently. The physicians' gender and postgraduate period of practice did not influence disclosure. When the family opposed disclosing the diagnosis to the patient, more than half of the physicians respected the family's wishes. CONCLUSIONS: This survey revealed that most of the physicians told at least the malignant nature of the disease to patients with malignant glioma, but they did not always tell the exact diagnosis. Physicians tended to modify their attitudes toward disclosing a diagnosis or prognosis of glioma depending on the histopathological grading, the hospital volume of cases, the location, the availability of patient psychological support systems, and the patient's family's wishes.

Distinct difference in tumor-infiltrating immune cells between Wilms' tumor gene 1 peptide vaccine and anti-programmed cell death-1 antibody therapies.

BACKGROUND: Wilms' tumor gene 1 (WT1) peptide vaccine and anti-programmed cell death-1 (anti-PD-1) antibody are expected as immunotherapies to improve the clinical outcome of glioblastoma. The aims of this study were to clarify how each immunotherapy affects tumor-infiltrating immune cells (TIIs) and to determine whether the combination of these two therapies could synergistically work. METHODS: Mice were transplanted with WT1 and programmed cell death-ligand 1 doubly expressing glioblastoma cells into brain followed by treatment with WT1 peptide vaccine, anti-PD-1 antibody, or the combination of the two, and survival of each therapy was compared. CD45+ cells were positively selected as TIIs from the brains with tumors, and TIIs were compared between WT1 peptide vaccine and anti-PD-1 antibody therapies. RESULTS: Most mice seemed to be cured by the combination therapy with WT1 peptide vaccine and anti-PD-1 antibody, which was much better survival than each monotherapy. A large number of CD4+ T cells, CD8+ T cells, and NK cells including WT1-specific CD8+ and CD4+ T cells infiltrated into the glioblastoma in WT1 peptide vaccine-treated mice. On the other hand, the number of TIIs did not increase, but instead PD-1 molecule expression was decreased on the majority of the tumor-infiltrating CD8+ T cells in the anti-PD-1 antibody-treated mice. CONCLUSION: Our results clearly demonstrated that WT1 peptide vaccine and anti-PD-1 antibody therapies worked in the different steps of cancer-immunity cycle and that the combination of the two therapies could work synergistically against glioblastoma.

Effects of concomitant temozolomide and radiation therapies on WT1-specific T-cells in malignant glioma.

OBJECTIVE: Immunotherapy targeting the Wilms' tumour 1 gene product has been proven safe and effective for treating malignant glioma in a phase II clinical study. Currently, radiation/temozolomide therapy is the standard treatment with only modest benefit. Whether combining radiation/temozolomide therapy with WT1 immunotherapy will have a negating effect on immunotherapy is still controversial because of the significant lymphocytopaenia induced by the former therapy. To address this issue, we investigated the changes in frequency and number of WT1-specific T-cells in patients with malignant gliomas. METHODS: Twenty-two patients with newly diagnosed malignant glioma who received standard radiation/temozolomide therapy were recruited for the study. Blood samples were collected before treatment and on the sixth week of therapy. The frequencies and numbers of lymphocytes, CD8(+) T-cells, WT1-specific T-cells, regulatory T-cells, natural killer cells and natural killer T-cells were measured and analysed using T-tests. RESULTS: Analysis of the frequency of T lymphocytes and its subpopulation showed an increase in regulatory T-cells, but no significant change was noted in the populations of T-cells, WT1-specific T-cells, NK cells and NKT cells. Reductions in the total numbers of T-cells, WT1-specific T-cells, NK cells and NKT cells were mainly a consequence of the decrease in the total lymphocyte count. CONCLUSIONS: Radiation/temozolomide therapy did not significantly affect the frequency of WT1-specific T-cells, suggesting that the combination with WT1 immunotherapy may be possible, although further assessment in the clinical setting is warranted.

Immunohistochemical analysis of adhesion molecules and matrix metalloproteinases in malignant CNS lymphomas: a study comparing primary CNS malignant and CNS intravascular lymphomas.

Two distinct forms of malignant lymphomas can invade the central nervous system (CNS). Although primary CNS malignant lymphomas (PCNSMLs) invade the brain parenchyma, intravascular lymphomas (IVLs) form tumor cell aggregates in the vasculature and produce stroke-like symptoms and cognitive impairment. Although the tumor cells are mostly of B-cell origin in both types of lymphoma, their biological behavior is different, and the detailed mechanism(s) underlying this difference are not well understood. We studied the expression level of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1) and integrin-beta1 in tumor tissue samples from patients with primary CNS lymphoma (n = 8) and intravascular lymphoma (n = 2) using immunohistochemical analysis. We also assessed the expression of the matrix metalloproteinases (MMP)-2 and MMP-9. ICAM-1 was positive in six and integrin-beta1 was positive in seven patients among eight PCNSML patients. MMP-2 and MMP-9 were expressed in all PCNSML. In contrast, none of them was positive in both IVL cases. Our findings suggest that adhesion molecules and MMPs are essential for malignant lymphoma cell invasion from the vasculature into the brain parenchyma and that they may be the key determinants for malignant lymphoma cells to behave as PCNSML or IVL cells.

Influence of region-of-interest designs on quantitative measurement of multimodal imaging of MR non-enhancing gliomas.

A number of studies have revealed the usefulness of multimodal imaging in gliomas. Although the results have been heavily affected by the method used for region of interest (ROI) design, the most discriminatory method for setting the ROI remains unclear. The aim of the present study was to determine the most suitable ROI design for 18F-fluorodeoxyglucose (FDG) and 11C-methionine (MET) positron emission tomography (PET), apparent diffusion coefficient (ADC), and fractional anisotropy (FA) obtained by diffusion tensor imaging (DTI) from the viewpoint of grades of non-enhancing gliomas. A total of 31 consecutive patients with newly diagnosed, histologically confirmed magnetic resonance (MR) non-enhancing gliomas who underwent FDG-PET, MET-PET and DTI were retrospectively investigated. Quantitative measurements were performed using four different ROIs; hotspot/tumor center and whole tumor, constructed in either two-dimensional (2D) or three-dimensional (3D). Histopathological grading of the tumor was considered as empirical truth and the quantitative measurements obtained from each ROI was correlated with the grade of the tumor. The most discriminating ROI for non-enhancing glioma grading was different according to the different imaging modalities. 2D-hotspot/center ROI was most discriminating for FDG-PET (P=0.087), ADC map (P=0.0083), and FA map (P=0.25), whereas 3D-whole tumor ROI was best for MET-PET (P=0.0050). In the majority of scenarios, 2D-ROIs performed better than 3D-ROIs. Results from the image analysis using FDG-PET, MET-PET, ADC and FA may be affected by ROI design and the most discriminating ROI for non-enhancing glioma grading was different according to the imaging modality.

Introduction of High Throughput Magnetic Resonance T2-Weighted Image Texture Analysis for WHO Grade 2 and 3 Gliomas.

Reports have suggested that tumor textures presented on T2-weighted images correlate with the genetic status of glioma. Therefore, development of an image analyzing framework that is capable of objective and high throughput image texture analysis for large scale image data collection is needed. The current study aimed to address the development of such a framework by introducing two novel parameters for image textures on T2-weighted images, i.e., Shannon entropy and Prewitt filtering. Twenty-two WHO grade 2 and 28 grade 3 glioma patients were collected whose pre-surgical MRI and IDH1 mutation status were available. Heterogeneous lesions showed statistically higher Shannon entropy than homogenous lesions (p = 0.006) and ROC curve analysis proved that Shannon entropy on T2WI was a reliable indicator for discrimination of homogenous and heterogeneous lesions (p = 0.015, AUC = 0.73). Lesions with well-defined borders exhibited statistically higher Edge mean and Edge median values using Prewitt filtering than those with vague lesion borders (p = 0.0003 and p = 0.0005 respectively). ROC curve analysis also proved that both Edge mean and median values were promising indicators for discrimination of lesions with vague and well defined borders and both Edge mean and median values performed in a comparable manner (p = 0.0002, AUC = 0.81 and p < 0.0001, AUC = 0.83, respectively). Finally, IDH1 wild type gliomas showed statistically lower Shannon entropy on T2WI than IDH1 mutated gliomas (p = 0.007) but no difference was observed between IDH1 wild type and mutated gliomas in Edge median values using Prewitt filtering. The current study introduced two image metrics that reflect lesion texture described on T2WI. These two metrics were validated by readings of a neuro-radiologist who was blinded to the results. This observation will facilitate further use of this technique in future large scale image analysis of glioma.

Different spatial distribution between germinal center B and non-germinal center B primary central nervous system lymphoma revealed by magnetic resonance group analysis.

BACKGROUND: MRI group analysis is a powerful tool for elucidating pathological conditions in the brain that are challenging to reveal from single subject analysis. This research aimed to elucidate special distribution characteristics of primary central nervous system lymphoma (PCNSL) within the brain with respect to molecular marker expression patterns. METHODS: MR images from 100 treatment-naive PCNSL patients were collected and registered onto averaged standard anatomical MRI (MNI152). Gadolinium-enhanced lesions were extracted, and a lesion frequency map was created. Lymphoma subtypes were classified as germinal center B (GCB) or non-GCB by immunohistochemistry in 90 patients. RESULTS: A PCNSL frequency map showed that these tumors tended to occur around the lateral, third and fourth ventricles. Moreover, GCB (27 cases) and non-GCB (63 cases) PCNSL frequency maps showed GCB lymphomas located at the upper tegmentum and cerebellum around the fourth ventricle, while non-GCB lymphomas tended to occupy the anterior fornix. These differences were significant and confirmed by the existence of voxels with P values <.05 (random permutation analysis with voxel-wise Fisher' exact test). This is the very first report to address phenotypical and spatial distributional differences between GCB and non-GCB PCNSL using an MR group analytical method.

Use of (11)C-methionine PET parametric response map for monitoring WT1 immunotherapy response in recurrent malignant glioma.

OBJECT: Immunotherapy targeting the Wilms tumor 1 (WT1) gene product is a promising treatment modality for patients with malignant gliomas, and there have been reports of encouraging results. It has become clear, however, that Gd-enhanced MR imaging does not reflect prognosis, thereby necessitating a more robust imaging evaluation system for monitoring response to WT1 immunotherapy. To meet this demand, the authors performed a voxel-wise parametric response map (PRM) analysis of (11)C-methionine PET (MET-PET) in WT1 immunotherapy and compared the data with the overall survival after initiation of WT1 immunotherapy (OS(WT1)). METHODS: Fourteen patients with recurrent malignant glioma were included in the study, and OS(WT1) was compared with: 1) volume and length change in the contrast area of the tumor on Gd-enhanced MR images; 2) change in maximum uptake of (11)C-methionine; and 3) a more detailed voxel-wise PRM analysis of MET-PET pre- and post-WT1 immunotherapy. RESULTS: The PRM analysis was able to identify the following 3 areas within the tumor core: 1) area with no change in (11)C-methionine uptake pre- and posttreatment; 2) area with increased (11)C-methionine uptake posttreatment (PRM(+MET)); and 3) area with decreased (11)C-methionine uptake posttreatment. While the results of Gd-enhanced MR imaging volumetric and conventional MET-PET analysis did not correlate with OS(WT1) (p = 0.270 for Gd-enhanced MR imaging length, p = 0.960 for Gd-enhanced MR imaging volume, and p = 0.110 for MET-PET), the percentage of PRM(+MET) area showed excellent correlation (p = 0.008) with OS(WT1). CONCLUSIONS: This study describes the limited value of Gd-enhanced MR imaging and highlights the potential of voxel-wise PRM analysis of MET-PET for monitoring treatment response in immunotherapy for malignant gliomas. Clinical trial registration no.: UMIN000002001.

Prognostic value of WT1 protein expression level and MIB-1 staining index as predictor of response to WT1 immunotherapy in glioblastoma patients.

The use of Wilms' tumor 1 (WT1) immunotherapy is considered to be an innovative approach for the treatment of malignant gliomas. Because of its novelty, tools that can accurately predict response to this therapy are still lacking. In this article, we investigated the role of WT1 protein expression level (score 1-4) and MIB-1 staining index in predicting survival outcome after therapy in patients with recurrent or progressive glioblastoma multiforme. Tumor samples from 37 patients enrolled in a phase II clinical trial on WT1 immunotherapy were immunohistochemically analyzed for WT1 levels and MIB-1 index. Results showed that median progression-free survival (PFS) was longer in the WT1 high expression group (score 3 and 4) compared with that of the low expression group (score 1 and 2) (20.0 weeks vs. 8.0 weeks; P = 0.022), and that the median overall survival (OS) was likewise longer in the former compared to the latter group (54.4 weeks vs. 28.4 weeks; P = 0.035). Furthermore, within the WT1 high expression group, tumors with intermediate staining intensity (WT1 score 3) have both the longest median PFS and OS, 24.4 weeks and 69.4 weeks, respectively. On the other hand, no significant correlation was noted between MIB-1 staining index and survival. In conclusion, our study has shown that WT1 protein expression level, not MIB-1 staining index, can be used as a prognostic marker to foretell outcome after immunotherapy, and that patients whose tumors have intermediate WT1 expression have the best survival outcome.

[Immunotherapy targeting the Wilms' tumor 1 gene product for patients with malignant brain tumors].

In this paper, we review the current status of immunotherapy targeting Wilms' tumor 1 (WT1) peptide in malignant brain tumors as well as in other hematological and solid malignancies. WT1 is expressed in various kinds of malignancies, and is involved in oncogenesis. The titers of antibodies against WT1 and the frequency of WT1-specific cytotoxic T lymphocytes (CTLs) were higher in cancer patients than in healthy donors, indicating that WT1 protein has immunogenic function. These findings provided us with a rationale for developing cancer immunotherapy that targets the WT1 peptide. Clinical trials of the WT1 peptide vaccination were initiated, and definite immunological and clinical responses were observed. The disease control rate of 57.1% was obtained especially in the case of recurrent glioblastomas, with a median progression-free survival period of 20.0 weeks and progression-free survival rate at 6 months of 33.3%. The trial showed that WT1 vaccination for malignant gliomas, which is generally believed to be an intractable disease, was safe and elicited a favorable clinical response. Further clinical studies of WT1 vaccination in patients with malignant gliomas as well as other cancers are warranted. An enhancement of the efficacy of WT1 vaccination can be expected with a combined treatment using the WT1-specific helper peptide or anti-cancer chemotherapeutic agents. Administration of WT1 vaccination along with other therapeutic modalities during initial treatment or in the case showing minimal residual disease may prolong the survival time of the cancer patients.