A Unique Case Report of Infant-Type Hemispheric Glioma (Gliosarcoma Subtype) with TPR-NTRK1 Fusion Treated with Larotrectinib.

Herein, we present a rare case of a nine-month-old boy diagnosed with infant-type hemispheric glioma (gliosarcoma subtype) at the left frontal lobe. Following subtotal resection, the patient started chemotherapy with the BABY POG protocol. We describe the clinical diagnosis, histological characteristics, radiological features, molecular aspects, and management of this tumor. A comprehensive molecular analysis on the tumor tissue showed a TPR-NTRK1 gene fusion. The patient was treated with a TRK inhibitor, larotrectinib, and exhibited a stable disease with residual lesion following 8 months of target therapy. The present study is the first report of an infantile gliosarcoma harboring NTRK1 rearrangement treated with larotrectinib.

NRG/RTOG 1122: A phase 2, double-blinded, placebo-controlled study of bevacizumab with and without trebananib in patients with recurrent glioblastoma or gliosarcoma.

BACKGROUND: Targeting vascular endothelial growth factor (VEGF) alone does not improve overall survival (OS) in recurrent glioblastoma (rGBM). The angiopoiein (Ang)-TIE2 system may play a role in tumor survival under VEGF inhibition. We conducted a phase 2, double-blinded, placebo-controlled trial of bevacizumab plus trebananib (a novel Fc fusion protein that sequesters Ang1/Ang2) over bevacizumab alone in rGBM. METHODS: Patients ≥18 years of age with a Karnofsky performance status ≥70 and GBM or variants in first or second relapse were randomized to bevacizumab 10 mg/kg every 2 weeks plus trebananib 15 mg/kg every week or bevacizumab plus placebo. The primary endpoint was 6-month progression-free survival (PFS). RESULTS: After an initial 6-patient lead-in cohort confirmed the safety of combining bevacizumab and trebananib, 115 eligible patients were randomized to the control (n = 58) or experimental treatment (n = 57). In the control arm, 6-month PFS was 41.1%, median survival time was 11.5 months (95% CI, 8.4-14.2 months), median PFS was 4.8 months (95% CI, 3.8-7.1 months), and radiographic response (RR) was 5.9%. In the experimental arm, 6-month PFS was 22.6%, median survival time was 7.5 months (95% CI, 6.8-10.1 months), median PFS was 4.2 months (95% CI, 3.7-5.6 months), and RR was 4.2%. The rate of severe toxicities was not significantly different between arms. CONCLUSION: The combination of bevacizumab and trebananib was well tolerated but did not significantly improve 6-month PFS rate, PFS, or OS for patients with rGBM over bevacizumab alone. The shorter PFS in the experimental arm with a hazard ratio of 1.51 (P = .04) suggests that the addition of trebananib to bevacizumab is detrimental.

Synthesis and in vitro anti-tumor activity of carboranyl levodopa.

Reactions of closo-1-Me-2-Iodobutyl-1,2-closo-dicarborane, 1-Me-2-I(CH2)4-C2B10H10, with l-dopa methyl ester can produce carboranyl l-dopa methyl esters in 54% yield in the presence of sodium hydroxide. The appended closo-carboranes can be decapitated with sodium hydroxide in a mixed solvent of ethanol and deionized water to produce highly water-soluble carboranyl levodopa in 64% yield. All the new compounds were characterized by 1H, 13C, 11B NMR, FT-IR spectroscopy and elemental analysis. The highly water soluble carboranyl levodopa 4 shows promising efficacy of anti-tumors in vitro in the presence of slow neutron beams.

Pediatric gliosarcoma treated with adjuvant radiotherapy and temozolomide.

PURPOSE: Primary pediatric gliosarcoma (pPGS) is an extremely rare entity with only 25 cases reported in the English literature. The value of concurrent and adjuvant temozolomide is not known in this group of patient. METHODS: Five patients of pPGS treated from 2006 to 2011 were included in this retrospective analysis. All patients underwent maximal safe surgical resection. Adjuvant therapy included conformal radiation 60 Gy in 30 fractions (2 Gy daily for 5 days in a week) with concurrent temozolomide 75 mg/m(2) daily followed by six cycles of maintenance temozolomide 150-200 mg/m(2) (day 1 to day 5) every 4 weeks. We combined the survival data of 25 patients (already published) and five of our patients and analyzed them in terms of progression free survival (PFS) and overall survival (OS) using Kaplan-Meier method. RESULTS: Male to female ratio was 1:4 and median age was 12 years (range, 7-19 years). All but one patient underwent gross total resection and four patients completed adjuvant radiotherapy as well as concurrent and adjuvant temozolomide. At a median follow up of 22.6 months (range, 0 to 45.3 months), two patients were dead and two were alive without disease while one was lost to follow up. For the pooled data, estimated median PFS and OS of all 30 patients reported in literature were 12 and 43 months, respectively. Two years PFS and OS rate for all patients was 44.2 and 62.9%, respectively. CONCLUSION: Adjuvant radiotherapy and temozolomide is well tolerated and show an encouraging survival in pPGS.

Long-term survival (>13 years) in a child with recurrent diffuse pontine gliosarcoma: a case report.

Pediatric gliosarcoma (GS) is a rare variant of glioblastoma multiforme. The authors describe the case of an unusual pontine location of GS in a 9-year-old boy who was initially diagnosed with low-grade astrocytoma (LGA) that was successfully controlled for 4 years. Subsequently, his brain tumor transformed into a GS. Prior treatment of his LGA included subtotal tumor resection 3 times, standard radiation therapy, and Gamma Knife procedure twice. His LGA was also treated with a standard chemotherapy regimen of carboplatin and vincristine, and his GS with subtotal resection, high-dose cyclophosphamide, and thiotepa with stem cell rescue and temozolomide. Unfortunately, he developed disseminated disease with multiple lesions and leptomeningeal involvement including a tumor occupying 80% of the pons. Upon presentation at our clinic, he had rapidly progressing disease. He received treatment with antineoplastons (ANP) A10 and AS2-1 for 6 years and 10 months under special exception to our phase II protocol BT-22. During his treatment with ANP his tumor stabilized, then decreased, and, ultimately, did not show any metabolic activity. The patient's response was evaluated by magnetic resonance imaging and positron emission tomography scans. His pathology diagnosis was confirmed by external neuropathologists, and his response to the treatment was determined by central radiology review. He experienced the following treatment-related, reversible toxicities with ANP: fatigue, xerostomia and urinary frequency (grade 1), diarrhea, incontinence and urine color change (grade 2), and grade 4 hypernatremia. His condition continued to improve after treatment with ANP and, currently, he complains only of residual neurological deficit from his previous surgery. He achieved a complete response, and his overall and progression-free survival is in excess of 13 years. This report indicates that it is possible to obtain long-term survival of a child with a highly aggressive recurrent GS with diffuse pontine involvement with a currently available investigational treatment.

Annexin A5-functionalized nanoparticle for multimodal imaging of cell death.

Techniques for visualizing cell death can provide noninvasive assessment of both disease states and response to therapeutic intervention. The purpose of this study was to develop and evaluate a multimodal imaging nanoplatform for the detection of cell death. In this study, we evaluated 111In-labeled annexin A5-conjugated core-cross-linked polymeric micelles (CCPMs) for multimodal imaging of cell death in various disease models. Three different models were conducted, including tumor apoptosis, hepatic apoptosis, and inflammation. Both micro single-photon emission tomography/computed tomography (µSPECT/CT) and fluorescence molecular tomography (FMT) were performed. Biodistribution and immunohistochemistry assays were carried out to validate the selectivity of cell death imaging. In all disease models, cell death was clearly visualized by both µSPECT/CT and FMT. In contrast, there was relatively low signal in the corresponding tissues of control mice. Moreover, the radioactive signal from 111In-labeled annexin A5-CCPM colocalized with its fluorescence signal, and both signals were confined to regions of dying cells. 111In-labeled annexin A5-CCPM allows visualization of cell death by both nuclear and optical techniques at the whole-body level as well as at the microscopic level. It has the potential to aid the diagnosis of disease states or tissue responses involving abnormal cell death.

Temozolomide use in adult patients with gliosarcoma: an evolving clinical practice.

The purpose of this study is to determine the factors that impact overall survival (OS) in adult patients with gliosarcoma in the modern era treated at a single institution compared with a cohort from the SEER registry. A total of 46 adult patients with pathologically confirmed gliosarcoma at MD Anderson Cancer Center from 2000 to 2010 were retrospectively analyzed. Demographic and treatment were obtained. For comparison, a total of 218 patients with gliosarcoma in the SEER database from 1991 to 2008 were analyzed. Survival analysis was conducted using the Kaplan-Meier log rank test. At MD Anderson, the overall incidence of gliosarcoma over the specified time interval was 1.5 %. Gliosarcoma was more common in males (n = 31, 67.4 %) with a median age of 56 years (range 24-92 years). Median survival in all patients was 12.5 months. A total of 17 patients (37 %) received temozolomide (TMZ) concurrently with RT and adjuvantly, with a 24 month OS of 20.0 %, compared with 10.2 % among those not treated with this regimen (p = 0.68). In contrast, the 2 year OS rate in the SEER database was 24.2 % during 2006-2008, compared to 12.1 % among those diagnosed in 2000-2003 (p = 0.03), presumably related to the widespread adoption of the chemoradiation regimen. Patients with gliosarcoma treated with TMZ at a single institution improved OS although this finding did not reach statistical significance. Patients diagnosed in the TMZ era in the SEER database display an improved OS, although the explanation for this finding requires further elucidation.

An autopsy case of primary gliosarcoma with multiple extracranial metastases: pathology after administration of bevacizumab and genetic profile.

Gliosarcoma (GS), a morphological variant of glioblastoma, pathologically shows a biphasic pattern with gliomatous and sarcomatous components. It has been reported that GS has much higher metastatic capacity than glioblastoma. A few reports on the pathology of the extracranial metastasis of GS have shown that metastatic lesions had a sarcomatous component alone or a mixture of gliomatous and sarcomatous ones. Therefore, it is considered that GS tends to disseminate hematogenously due to its mesenchymal sarcomatous component. Herein, we report an autopsy case of GS with multiple extracranial metastases treated by craniotomy, radiotherapy, and bevacizumab. In this case, metastatic lesions at autopsy contained a gliomatous component alone, but no sarcomatous component. In addition, the sarcomatous component disappeared from the intracranial lesion at autopsy after the administration of bevacizumab. In this report, we discuss the clinical course and pathological findings at the initial state, recurrence, and autopsy, including the results of whole-genome analysis.

Evaluation of the relationship between MR estimates of blood oxygen saturation and hypoxia: effect of an antiangiogenic treatment on a gliosarcoma model.

PURPOSE: To assess the reproducibility of the magnetic resonance (MR) estimate of blood oxygen saturation (sO(2)) in the rat brain, to evaluate the relationship between low MR estimate of sO(2) values and tissue hypoxia in a hypoxic and necrotic glioscarcoma model (9L gliosarcoma cells), and to evaluate the capability of the MR estimate of sO(2) parameter to help identify modifications induced by an antiangiogenic treatment (sorafenib) in 9L gliosarcoma tumors. MATERIALS AND METHODS: Experiments were performed with permits from the French Ministry of Agriculture. Forty-eight male rats bearing a 9L gliosarcoma were randomized in untreated and treated (sorafenib) groups. MR blood volume fraction and MR estimate of sO(2) parameters were estimated 1 day before and 1, 3, 5, and 8 days after the start of the treatment. The in vivo MR estimate of sO(2) measurement was correlated with the ex vivo hypoxia assessment by using pimonidazole staining. Paired and unpaired t tests, as well as parametric Pearson tests, were used for the statistical analyses. RESULTS: In healthy tissues, MR estimate of sO(2) measurements were comparable to literature values and were reproducible (mean across all animals, 68.0% ± 6.5 [standard deviation]). In untreated tumors, MR estimate of sO(2) and immunohistochemical analysis yielded correlated fractional hypoxic-necrotic areas (R(2) = 0.81). In tumors treated with antiangiogenic therapy, tumor MR estimate of sO(2) was decreased with respect to the healthy tissue (P< .001). CONCLUSION: Results of this study suggest that the MR estimate of sO(2) is a reproducible estimate that could be used as an in vivo probe of hypoxia in brain tumors and as a sensitive reporter of the hypoxic effects of antiangiogenic therapies.

Chalcone JAI-51 improves efficacy of synchrotron microbeam radiation therapy of brain tumors.

Microbeam radiation therapy (MRT), a preclinical form of radiosurgery, uses spatially fractionated micrometre-wide synchrotron-generated X-ray beams. As MRT alone is predominantly palliative for animal tumors, the effects of the combination of MRT and a newly synthesized chemotherapeutic agent JAI-51 on 9L gliosarcomas have been evaluated. Fourteen days (D14) after implantation (D0), intracerebral 9LGS-bearing rats received either MRT, JAI-51 or both treatments. JAI-51, alone or immediately after MRT, was administered three times per week. Animals were kept up to ∼20 weeks after irradiation or sacrificed at D16 or D28 after treatment for cell cycle analysis. MRT plus JAI-51 increased significantly the lifespan compared with MRT alone (p = 0.0367). JAI-51 treatment alone had no effect on rat survival. MRT alone or associated with JAI-51 induced a cell cycle blockade in G2/M (p < 0.01) while the combined treatment also reduced the proportion of G0/G1 cells. At D28 after irradiation, MRT and MRT/JAI-51 had a smaller cell blockade effect in the G2/M phase owing to a significant increase in tumor cell death rate (<2c) and a proportional increase of endoreplicative cells (>8c). The combination of MRT and JAI-51 increases the survival of 9LGS-bearing rats by inducing endoreduplication of DNA and tumor cell death; further, it slowed the onset of tumor growth resumption two weeks after treatment.

Photodynamic effect of protoporphyrin IX in gliosarcoma 9l/lacZ cell line.

Photodynamic Therapy (PDT) is an oncologic treatment, producing reactive oxygen species (ROS) to induce the death of cancer cells. This study aimed to evaluate the action of PDT on gliosarcoma cells, using protoporphyrin IX as PS by incubation with the precursor aminolevulinic acid (ALA). An LED device was used with a light dose of 10 J/cm². The success of the therapy proved to be dependent on the concentration of ALA, and an incubation time of 4 h required for an effective response. Cell death was prevalent due to necrosis when assessed 18 h post-PDT. ALA proved to be an option to PDT in cells of the 9 L/lacZ, with the protocol tested.

O6-methylguanine DNA methyltransferase status determined by promoter methylation and immunohistochemistry in gliosarcoma and their clinical implications.

O(6)-methylguanine-DNA methyltransferase (MGMT) is known as a DNA repair protein, and loss of function in MGMT is related to an increase in survival in patients with malignant gliomas treated with alkylating agents. In the present study, we determined the status of MGMT using methylation-specific polymerase chain reaction (PCR) and immunohistochemistry on paraffin-embedded specimens in 12 human gliosarcomas, and these results were then related to overall survival (OS) and response to alkylating agents. The MGMT promoter was methylated in six patients. Immunostaining of MGMT was positive in 58.3% of patients. MGMT methylation status was correlated with immunostaining results in five patients (41.7%). The median OS and progression-free survival (PFS) of the whole population were 13.4 months [95% confidence interval (CI), 12.3-14.5 months] and 8.3 months (95% CI, 7.4-9.2 months), respectively. In patients with methylated MGMT promoter, median OS was 15.0 months, compared with 11.3 months in the unmethylated group. Median PFS of gliosarcoma patients was 10.3 months for the methylated group, whereas it was 7.3 months for the unmethylated group. On multivariate analysis, patients with methylated MGMT promoter had better prognosis than patients with unmethylated MGMT promoter with respect to OS and PFS (P = 0.045 and 0.034, respectively). However, there was no statistical significance between MGMT protein expression and survival. The results show that a significant fraction of gliosarcomas have MGMT promoter methylation and protein expression, and suggest that patient survival is associated with MGMT methylation status.

Combination of 6-thioguanine, capecitabine, and celecoxib with temozolomide or lomustine for recurrent high-grade glioma.

We evaluated the efficacy of temozolomide (TMZ) or lomustine (CCNU) in combination with 6-thioguanine, capecitabine, and celecoxib for the treatment of recurrent high-grade glioma. Forty-three patients with recurrent glioblastoma and 31 patients with recurrent anaplastic glioma (AG) were enrolled in this open-label, non-comparative study. Patients previously treated with TMZ received CCNU while all others received TMZ; all patients received 6-thioguanine, capecitabine, and celecoxib. Endpoints were 12-month progression-free survival (PFS) for patients with AG, 6-month PFS for patients with glioblastoma, duration of PFS, and MRI-based objective response rates. Results from the TMZ and CCNU treatment arms were combined in the final analysis because there was no statistically significant difference between them. Thirty-eight patients with glioblastoma were treated with the lomustine-based regimen, and five received the TMZ-based regimen. For the 43 glioblastoma patients, the objective response rate was 12 and 33% had stable disease; the 6-month PFS was 14% and median overall survival 32 weeks. For the 31 AG patients, the combined objective response rate was 26 and 42% had stable disease; the 12 month PFS was 44%. Treatment was reasonably well tolerated with hematological toxicity common and more frequent with CCNU than TMZ. The combination therapy with 6-thioguanine, capecitabine and celecoxib plus CCNU or TMZ does not appear to be more effective than other alkylating agent schedules for patients with recurrent glioblastoma. The combination, however, is promising for patients with recurrent high-grade AG.

Treatment of 9L gliosarcoma in rats by ferrociphenol-loaded lipid nanocapsules based on a passive targeting strategy via the EPR effect.

PURPOSE: To study a passive targeting strategy, via the enhanced permeability and retention effect following systemic administration of lipid nanocapsules (LNCs) loaded with ferrociphenol, FcdiOH. METHODS: Long chains of polyethylene glycol (DSPE-mPEG2000) were incorporated onto the surface of LNCs by post-insertion technique. Stealth properties of LNCs were investigated by in vitro complement consumption and macrophage uptake, and in vivo pharmacokinetics in healthy rats. Antitumour effect of FcdiOH-loaded LNCs was evaluated in subcutaneous and intracranial 9L gliosarcoma rat models. RESULTS: LNCs and DSPE-mPEG2000-LNCs presented low complement activation and weak macrophage uptake. DSPE-mPEG2000-LNCs exhibited prolonged half-life and extended area under the curve in healthy rats. In a subcutaneous gliosarcoma model, a single intravenous injection of FcdiOH-LNCs (400 µL, 2.4 mg/rat) considerably inhibited tumour growth when compared to the control. DSPE-mPEG2000-FcdiOH-LNCs exhibited a strong antitumour effect by nearly eradicating the tumour by the end of the study. In intracranial gliosarcoma model, treatment with DSPE-mPEG2000-FcdiOH-LNCs and FcdiOH-LNCs statistically improved median survival time (28 and 27.5 days, respectively) compared to the control (25 days). CONCLUSION: These results demonstrate the interesting perspectives for the systemic treatment of glioma thanks to bio-organometallic chemotherapy via lipid nanocapsules.

Viral vector transduction of the human deoxycytidine kinase cDNA sensitizes glioma cells to the cytotoxic effects of cytosine arabinoside in vitro and in vivo.

Cytosine arabinoside (ara-C) is a cytidine analog that incorporates into replicating DNA and induces lethal DNA strand breaks. Although ara-C is a potent antitumor agent for hematologic malignancies, it has only minimal activity against most solid tumors. The rate-limiting step in intracellular ara-C activation is phosphorylation of the prodrug by deoxycytidine kinase (dCK). The present results demonstrate that both retroviral and adenoviral vector-mediated transduction of the dCK cDNA results in marked sensitization of glioma cells lines to the cytotoxic effects of ara-C in vitro. We also demonstrate that ara-C treatment of established intradermal and intracerebral gliomas transduced with dCK results in significant antitumor effects in vivo. These data suggest that viral vector transduction of the dCK gene followed by treatment with ara-C represents a new chemosensitization strategy for cancer gene therapy.

Analysis of the effects of Photodynamic therapy with Photodithazine on the treatment of 9l/lacZ cells, in vitro study.

Gliosarcoma is an aggressive brain tumor. Photodynamic Therapy (PDT) is a treatment that can be used for various cancers of the CNS. The aim of this study was to analyze the effects of PDT with Photodithazine (PDZ) in the treatment of gliosarcoma, using 9 L/lacZ cells and serial concentrations of 200 µg/mL to 3.1 µg/mL of PDZ. The samples were divided into two groups: dark and light (10 J/cm²). The PDZ was internalized along all the cytoplasmic extension. Viability tests demonstrated a reduction in viable cells after PDT. The production of ROS was concentration-dependent and PDZ was found in mitochondria and lysosomes, presenting a discrete connection with α-tubulin. However, this structure is likely damaged, evidenced by changes in the morphological analysis. Thus, according to the parameters of this study, PDZ proved to be an interesting PS in PDT for the treatment of gliosarcoma, with the inherent limitations of an in vitro study.

Captopril inhibits Matrix Metalloproteinase-2 and extends survival as a temozolomide adjuvant in an intracranial gliosarcoma model.

BACKGROUND: Captopril is a well-characterized, FDA-approved drug that has demonstrated promise as a repurposed oncology therapeutic. Captopril's known anti-cancer effects include inhibition of Matrix Metalloproteinase-2 (MMP-2), an endopeptidase which selectively breaks down the extracellular matrix to promote cell migration. MMP-2 is a known therapeutic target in gliomas, tumors with significant clinical need. Using an aggressive gliosarcoma model, we assessed captopril's effects on MMP-2 expression in vitro and in vivo as well as its efficacy as an adjuvant in combination therapy regimens in vivo. METHODS: Following captopril treatment, MMP-2 protein expression and migratory capabilities of 9 L gliosarcoma cells were assessed in vitro via western blots and scratch wound assays, respectively. Rats were intracranially implanted with 9 L gliosarcoma tumors, and survival was assessed in the following groups: control; captopril (30 mg/kg/day); temozolomide (TMZ) (50 mg/kg/day), and captopril+TMZ. In vivo experiments were accompanied by immunohistochemistry for MMP-2 from brain tissue. RESULTS: In vitro, captopril decreased MMP-2 protein expression and reduced migratory capacity in 9 L gliosarcoma cells. In a gliosarcoma animal model, captopril decreased MMP-2 protein expression and extended survival as a TMZ adjuvant relative to untreated controls, captopril monotherapy, and TMZ monotherapy groups (27.5 versus 14 (p < 0.001), 16 (p < 0.001), and 23 (p = 0.018) days, respectively). CONCLUSIONS: Captopril decreases gliosarcoma cell migration, which may be mediated by reduction in MMP-2 protein expression. Captopril provided a survival advantage as a TMZ adjuvant in a rat intracranial gliosarcoma model. Captopril may represent a promising potential adjuvant to TMZ therapy in gliosarcoma as a modulator of the MMP-2 pathway.

Genomic landscape of gliosarcoma: distinguishing features and targetable alterations.

Gliosarcoma is an aggressive brain tumor with histologic features of glioblastoma (GBM) and soft tissue sarcoma. Despite its poor prognosis, its rarity has precluded analysis of its underlying biology. We used a multi-center database to characterize the genomic landscape of gliosarcoma. Sequencing data was obtained from 35 gliosarcoma patients from Genomics Evidence Neoplasia Information Exchange (GENIE) 5.0, a database curated by the American Association of Cancer Research (AACR). We analyzed genomic alterations in gliosarcomas and compared them to GBM (n = 1,449) and soft tissue sarcoma (n = 1,042). 30 samples were included (37% female, median age 59 [IQR: 49-64]). Nineteen common genes were identified in gliosarcoma, defined as those altered in > 5% of samples, including TERT Promoter (92%), PTEN (66%), and TP53 (60%). Of the 19 common genes in gliosarcoma, 6 were also common in both GBM and soft tissue sarcoma, 4 in GBM alone, 0 in soft tissue sarcoma alone, and 9 were more distinct to gliosarcoma. Of these, BRAF harbored an OncoKB level 1 designation, indicating its status as a predictive biomarker of response to an FDA-approved drug in certain cancers. EGFR, CDKN2A, NF1, and PTEN harbored level 4 designations in solid tumors, indicating biological evidence of these biomarkers predicting a drug-response. Gliosarcoma contains molecular features that overlap GBM and soft tissue sarcoma, as well as its own distinct genomic signatures. This may play a role in disease classification and inclusion criteria for clinical trials. Gliosarcoma mutations with potential therapeutic indications include BRAF, EGFR, CDKN2A, NF1, and PTEN.

Assessment of multiexponential diffusion features as MRI cancer therapy response metrics.

The aim of this study was to empirically test the effect of chemotherapy-induced tissue changes in a glioma model as measured by several diffusion indices calculated from nonmonoexponential formalisms over a wide range of b-values. We also compared these results to the conventional two-point apparent diffusion coefficient calculation using nominal b-values. Diffusion-weighted imaging was performed over an extended range of b-values (120-4000 sec/mm(2) ) on intracerebral rat 9L gliomas before and after a single dose of 1,3-bis(2-chloroethyl)-1-nitrosourea. Diffusion indices from three formalisms of diffusion-weighted signal decay [(a) two-point analytical calculation using either low or high b-values, (b) a stretched exponential formalism, and (c) a biexponential fit] were tested for responsiveness to therapy-induced differences between control and treated groups. Diffusion indices sensitive to "fast diffusion" produced the largest response to treatment, which resulted in significant differences between groups. These trends were not observed for "slow diffusion" indices. Although the highest rate of response was observed from the biexponential formalism, this was not found to be significantly different from the conventional monoexponential apparent diffusion coefficient method. In conclusion, parameters from the more complicated nonmonoexponential formalisms did not provide additional sensitivity to treatment response in this glioma model beyond that observed from the two-point conventional monoexponential apparent diffusion coefficient method.

Analysis of the effect of photodynamic therapy with Fotoenticine on gliosarcoma cells.

Gliosarcoma is a highly aggressive malignant neoplasm and a histopathological variant of wild-type glioblastoma multiforme isocitrate dehydrogenase (HDI). The current standard treatment consists of chemotherapy, radiotherapy and surgical resection, however, despite advances in these techniques, the patient's prognosis remains unfavorable. Photodynamic therapy (PDT) is a noninvasive technique that has been highlighted as an alternative form of cancer treatment because it does not present the side effects associated with systemic treatments. The objective of this study was to evaluate the cell viability and the intracellular localization of photosensitizer (PS) chlorin e6 Fotoenticine in 9L/lacZ cells. Therefore, tests of cytotoxicity, morphology, and location of PS were performed. The viability test showed no cytotoxicity in the dark at all concentrations and 100 % cell death at the highest concentrations after PDT. The mitochondrial activity test showed a reduction in all groups after PDT. The production of reactive oxygen species (ROS) was higher in the PDT groups and dependent on the PS concentration. Morphological analysis after PDT showed apparent cytoplasmic destruction in all the tested concentrations, with the presence of rounded cells due to the loss of their extensions and absence of nuclear alterations. The PS accumulation in the mitochondria and cytoskeleton was observed by the confocal microscopy; however, there is no evidence of its internalization in the lysosomes. It was concluded that PDT with Fotoenticine is a promising alternative therapy showing decreased cell viability, increased ROS production and adequate localization to trigger cell death.