Cox proportional hazards deep neural network identifies peripheral blood complete remission to be at least equivalent to morphologic complete remission in predicting outcomes of patients treated with azacitidine-A prospective cohort study by the AGMT.

The current gold standard of response assessment in patients with myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML), and acute myeloid leukemia (AML) is morphologic complete remission (CR) and CR with incomplete count recovery (CRi), both of which require an invasive BM evaluation. Outside of clinical trials, BM evaluations are only performed in ~50% of patients during follow-up, pinpointing a clinical need for response endpoints that do not necessitate BM assessments. We define and validate a new response type termed "peripheral blood complete remission" (PB-CR) that can be determined from the differential blood count and clinical parameters without necessitating a BM assessment. We compared the predictive value of PB-CR with morphologic CR/CRi in 1441 non-selected, consecutive patients diagnosed with MDS (n = 522; 36.2%), CMML (n = 132; 9.2%), or AML (n = 787; 54.6%), included within the Austrian Myeloid Registry (aMYELOIDr; NCT04438889). Time-to-event analyses were adjusted for 17 covariates remaining in the final Cox proportional hazards (CPH) model. DeepSurv, a CPH neural network model, and permutation-based feature importance were used to validate results. 1441 patients were included. Adjusted median overall survival for patients achieving PB-CR was 22.8 months (95%CI 18.9-26.2) versus 10.4 months (95%CI 9.7-11.2) for those who did not; HR = 0.366 (95%CI 0.303-0.441; p < .0001). Among patients achieving CR, those additionally achieving PB-CR had a median adjusted OS of 32.6 months (95%CI 26.2-49.2) versus 21.7 months (95%CI 16.9-27.7; HR = 0.400 [95%CI 0.190-0.844; p = .0161]) for those who did not. Our deep neural network analysis-based findings from a large, prospective cohort study indicate that BM evaluations solely for the purpose of identifying CR/CRi can be omitted.

Safety and efficacy of tafasitamab with or without lenalidomide added to first-line R-CHOP for DLBCL: the phase 1b First-MIND study.

Anti-CD19 immunotherapy tafasitamab is used in combination with lenalidomide in patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) who are ineligible for autologous stem cell transplant. Open-label, phase 1b, First-MIND study assessed safety and preliminary efficacy of tafasitamab + R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) ± lenalidomide as first-line therapy in patients with DLBCL. From December 2019 to August 2020, 83 adults with untreated DLBCL (International Prognostic Index 2-5) were screened and 66 were randomly assigned (33 per arm) to R-CHOP-tafasitamab (arm T) or R-CHOP-tafasitamab-lenalidomide (arm T/L) for 6 cycles. Primary end point was safety; secondary end points included end-of-treatment (EoT) overall response rate (ORR) and complete response (CR) rate. All patients had ≥1 treatment-emergent adverse event, mostly grade 1 or 2. Grade ≥3 neutropenia and thrombocytopenia occurred, respectively, in 57.6% and 12.1% (arm T) and 84.8% and 36.4% (arm T/L) of patients. Nonhematologic toxicities occurred at similar rates among arms. R-CHOP mean relative dose intensity was ≥89% in both arms. EoT ORR was 75.8% (CR 72.7%) in arm T and 81.8% (CR 66.7%) in arm T/L; best ORR across visits was 90.0% and 93.9%. Eighteen-month duration of response and of CR rates were 72.7% and 74.5% (arm T) and 78.7% and 86.5% (arm T/L); 24-month progression-free and overall survival rates were 72.7% and 90.3% (arm T) and 76.8% and 93.8% (arm T/L). Manageable safety and promising signals of efficacy were observed in both arms. Potential benefit of adding tafasitamab + lenalidomide to R-CHOP is being investigated in phase 3 frontMIND (NCT04824092). This study is registered at www.clinicaltrials.gov as #NCT04134936.

Attrition Rates in Multiple Myeloma Treatment under Real World Conditions-An Analysis from the Austrian Myeloma Registry (AMR).

Multiple myeloma (MM) is characterized by serial relapses, necessitating the application of sequential lines of therapy (LoT). Reports on attrition rates (ARs) vary widely. The present study analysed ARs from the Austrian Myeloma Registry. Attrition was defined as being either deceased, progressive without having received another LoT, or lack of follow-up for ≥5 years. A total of 571 patients diagnosed between January 2009 and August 2021 were included (median age: 72 years; median follow-up: 50.8 months). Some 507 patients received at least one LoT. Of the total, 43.6% underwent autologous stem cell transplantation (SCT, transplant eligible = TE)) with primarily VRd (Bortezomib/Lenalidomide/Dexamethasone) given as induction (26.5%), followed by lenalidomide maintenance in 55.7% of cases. Transplant-ineligible (NTE) patients were predominantly treated with Vd (Bortezomib/Dexamethasone, 21.6%), receiving maintenance in 27.1%. A total of 37.5% received a second LoT. ARs across one to five LoTs were 16.7-27%. Frontline induction/ SCT followed by maintenance reduced ARs associated with age and achievement of deep remission in the frontline. Deep remission prolongs follow-up and time-to-next-treatment (TTNT), while high-risk-cyctogenetics negatively affected these outcomes. Our results demonstrate considerably lower ARs for MM patients within the AMR data versus other healthcare systems. Young age and the achievement of significant remissions after optimal frontline therapy resulted in particularly low ARs. These promising results support a key role for the ease of drug access and reimbursement policies in governing long-term MM patient outcomes.

Pooled Analysis on the Effectiveness and Safety of Lipegfilgrastim in Patients With Urological Malignancies in the Real-World Setting.

Lipegfilgrastim is a long-acting glycopegylated granulocyte-colony stimulating factor (G-CSF) approved for the management of chemotherapy-induced neutropenia. In general, there is little information on the use of any G-CSFs specifically in patients with urological malignancies receiving chemotherapy. This report combines information from two prospective non-interventional studies on the prophylactic use of lipegfilgrastim in urological cancer patients receiving chemotherapy in the real-world setting. Data were derived from two phase IV studies (NADIR and LEOS) with similar protocols conducted in nine European countries. Analysis included 228 patients (142 prostate, 50 testicular, 27 bladder, and 9 other urological cancers). Chemotherapy-induced febrile neutropenia risk was classified as high (43.0%), intermediate (49.1%), or low (7.5%). Lipegfilgrastim was administered as primary (n=180, 78.9%) or secondary (n=29, 12.7%) prophylaxis. The incidence of febrile neutropenia over all chemotherapy cycles (n=998) and first cycles (n=228) for which lipegfilgrastim was administered for prophylaxis was 2.6% and 1.3%, respectively. Corresponding results for Grade 3/4 neutropenia were 2.2% and 0.9%, respectively. Adverse drug reactions occurred in 24 patients (10.5%): those in more than one patient were bone pain (n=6, 2.6%) and pyrexia (n=3, 1.3%). The use of lipegfilgrastim for the prophylaxis of chemotherapy-induced neutropenia was effective and well tolerated in patients with urological malignancies in the real-world setting.

Olaratumab plus anthracyline in advanced/metastatic soft tissue sarcoma : Data of real-world utilization in Austria.

BACKGROUND: Olaratumab is a humanized monoclonal antiplatelet-derived growth factor receptor alpha antibody that has been approved in combination with doxorubicin for the treatment of patients with metastatic soft tissue sarcoma (STS). The purpose of this retrospective study was to assess the clinical efficacy in STS patients treated with olaratumab in a real-world setting in Austria. METHODS: Retrospectively collected longitudinal data from patients treated between November 2016 and September 2018 at 9 Austrian centers were obtained from the respective medical charts. All patients who received at least one dose of olaratumab were eligible. Parameters of most interest were response rates, progression-free survival (PFS) and overall survival (OS). RESULTS: Altogether 55 patients were included in the analysis. The median age was 58 years. In total, 65.5% (n = 36), 21.8% (n = 12) and 12.7% (n = 7) received olaratumab as first, second or ≥third line treatment, respectively. Olaratumab was administered either in combination with doxorubicin (81.8%, n = 45) or liposomal doxorubicin (16.4%, n = 9); one patient received olaratumab as upfront monotherapy. The median PFS and OS were 2.6 and 11.4 months, respectively. The objective response rate was 11.4% and the disease control rate was 40.9%. CONCLUSION: In this real-world analysis the outcome was less pronounced compared to the results of both the phase Ib/II approval trial and the confirmatory phase III trial. The latter failed to show an improvement in OS and PFS for the doxorubicin/olaratumab combination. As such, olaratumab should not be used anymore in patients with STS.

Comparison of nab-paclitaxel plus gemcitabine in elderly versus younger patients with metastatic pancreatic cancer: Analysis of a multicentre, prospective, non-interventional study.

BACKGROUND: Pancreatic cancer (PC) ranks among the deadliest malignancies worldwide. In the MPACT study, first-line nab-paclitaxel plus gemcitabine (nab-P/G) demonstrated activity (median overall survival [OS], 8.7 months) and tolerability in patients with metastatic PC (mPC). However, the clinical evidence of nab-P/G in the elderly (>70 years), who account for the majority of patients with mPC, is limited. This is the first prospective, multicentre, non-interventional study evaluating the tolerability and effectiveness of nab-P/G in younger (≤70 years) versus elderly (>70 years) patients with mPC in the daily clinical routine. METHODS: Eligible patients with mPC were treated with nab-P/G and observed until disease progression or unacceptable toxicity. The primary objectives were safety and tolerability of nab-P/G, and the secondary objectives were efficacy and real-life dosing. RESULTS: A total of 317 patients with mPC (median age, 70 years) were recruited, of which 299, aged ≤70 (n = 162) and >70 (n = 137) years, were eligible for analysis. Baseline characteristics and the safety profile were comparable between the groups. However, fatigue (22.8% versus 13.0%) and decreased appetite (8.8% versus 1.2%) were more frequent in elderly patients. Younger versus elderly patients equally benefited in terms of objective response rate (36% versus 48%), median progression-free survival (5.6 versus 5.5 months; hazard ratio [HR] = 1.03; p = 0.81) and OS (10.6 versus 10.2 months; HR = 0.89; p = 0.4). In addition, the median treatment duration (5 versus 4 cycles), relative dose intensity (70% versus 74%) or reasons for treatment discontinuation were similar. Most patients (56.2% versus 47.4%) benefited from a second-line therapy. CONCLUSION: This prospective real-world analysis confirms the feasibility and tolerability of nab-P/G treatment and reveals OS data similar for younger patients and elderly patients aged >70 years. CLINICALTRIALS. GOV REGISTRATION: NCT02555813. AUSTRIAN NIS REGISTRY: NIS005071.

A multicenter retrospective evaluation of Chronic Myeloid Leukemia (CML) therapy in Austria assessing the impact of early treatment response on patient outcomes in a real-life setting : R-EFECT study.

BACKGROUND: Several clinical trials in chronic phase (CP) chronic myeloid leukemia (CML) showed that early response to tyrosine kinase inhibitor (TKI) treatment results in an improved long-term survival and progression-free survival. This study assessed whether patients achieving early treatment response (ETR; partial cytogenetic response or BCR-ABL1 mRNA ≤10% at 3 months) in daily practice also have a long-term survival benefit. METHODS: The Retrospective Evaluation of Early response in CML for long-term Treatment outcome (R-EFECT), a multicenter, retrospective chart review, documented patients with newly diagnosed CML-CP starting first-line TKI therapy in routine clinical practice. The primary aim was to assess the 5­year overall survival rate. RESULTS: Of the 211 patients from 12 centers across Austria (January 2004-May 2010), 176 (median age, 56 years) were included in the analysis. All patients received first-line therapy with imatinib. Overall, 136 patients (77.3%) achieved ETR (ETR+ group), whereas 40 (22.7%) did not reach ETR (ETR- group). The ETR+ group had higher 5­year overall survival (92.5% vs. 77.5%, P = 0.018) and progression-free survival (95.6% vs. 87.5%, P = 0.06) rates compared with the ETR- group. As expected, more patients in the ETR- group were switched to another TKI. At the last contact, 120 patients were still on imatinib and 44 had switched to another TKI (25 to nilotinib, 15 to dasatinib, and 4 to bosutinib). CONCLUSION: The data are in line with randomized trials demonstrating that ETR is associated with improved survival and thus confirmed these results in patients treated in daily clinical routine.

The AST/ALT (De Ritis) ratio predicts clinical outcome in patients with pancreatic cancer treated with first-line nab-paclitaxel and gemcitabine: post hoc analysis of an Austrian multicenter, noninterventional study.

BACKGROUND: The pretreatment De Ritis ratio [aspartate transaminase (AST)/alanine transaminase (ALT)] has been shown to be an adverse prognostic marker in various cancer entities. However, its relevance to advanced pancreatic ductal adenocarcinoma (PDAC) has not yet been studied. In the present study we investigated the AST/ALT ratio as a possible predictor of treatment response and disease outcome in patients with advanced PDAC treated with first-line gemcitabine/nab-paclitaxel. METHODS: A post hoc analysis of a prospective, multicenter, noninterventional study was performed. A total of 202 patients with advanced PDAC treated with first-line gemcitabine/nab-paclitaxel for whom the AST/ALT ratio was measured were included in this analysis. RESULTS: Median and 1-year progression-free survival estimates were 4.8 months and 5.1%, respectively in patients with an AST/ALT ratio above the 75th percentile of its distribution, and 6.0 months and 18.7%, respectively in patients with an AST/ALT ratio less than or equal to this cutoff, respectively (log-rank p = 0.004). In univariable Cox regression, a doubling of the AST/ALT ratio was associated with a 1.4-fold higher relative risk of progression or death [hazard ratio = 1.38, 95% confidence interval (CI): 1.06-1.80, p = 0.017]. The prognostic association was also found in multivariable analysis adjusting for Eastern Cooperative Oncology Group performance status and lung metastases (hazard ratio per AST/ALT ratio doubling = 1.32, 95% CI: 1.00-1.75, p = 0.047). In treatment response analysis, a doubling of the AST/ALT ratio was associated with a 0.5-fold lower odds of objective response (odds ratio = 0.54, 95% CI: 0.31-0.94, p = 0.020). CONCLUSIONS: The pretreatment serum AST/ALT ratio predicts poor disease outcome and response rate in patients with advanced PDAC treated with gemcitabine/nab-paclitaxel and might represent a novel and inexpensive marker for individual risk assessment in the treatment of pancreatic cancer.

Compatibility of ciprofloxacin with commercial peritoneal dialysis solutions.

Intraperitoneal administration of antibiotics together with peritoneal dialysis fluids (PDFs) remains the preferable route for treatment of peritoneal dialysis-related peritonitis. For home based therapy, antibiotic-containing PDFs are stored for up to two weeks and warmed up to body-temperature before administration. The present study investigated the compatibility of ciprofloxacin with five commercial PDFs at refrigeration-temperature, room-temperature and body-temperature. Ciprofloxacin concentrations were determined using high-performance liquid chromatography. Drug-diluent stability was evaluated by measurement of pH-values and visual inspection at each sampling point. The antimicrobial activity of ciprofloxacin was assessed by an E. coli disk diffusion method. Ciprofloxacin was stable at refrigeration-temperature and body-temperature in all PDFs evaluated over the whole study period of 14 days and 24 hours, respectively. At room-temperature, in contrast, ciprofloxacin demonstrated only limited stability in particular when tested in mixed Physioneal. Except for Physioneal 1.36%, no relevant drug adsorption was observed and the antimicrobial activity of ciprofloxacin was found to be preserved in each PDF at each storage condition investigated. Intraperitoneal ciprofloxacin might be used for inpatient and home based therapy of peritoneal dialysis-related peritonitis and no compensatory dose adjustment is needed when stored for up to two weeks at refrigeration-temperature before use.

Compatibility of linezolid with commercial peritoneal dialysis solutions.

PURPOSE: Results of a compatibility and stability study of linezolid admixed in commercial peritoneal dialysis (PD) solutions stored at various temperatures are reported. METHODS: Test samples were prepared by adding linezolid i.v. injection (2 mg/mL) to infusion bags of 4 PD solutions (Extraneal, Nutrineal, Physioneal 40 Glucose 1.36%, and Physioneal 40 Glucose 2.27%, all from Baxter Healthcare Corporation). Assessments were conducted at various time points during storage of test samples at refrigeration temperature (6 °C) or room temperature (25 °C) for 14 days and at body temperature (37 °C) for 24 hours. Linezolid concentrations over time were determined by high-performance liquid chromatography, physical compatibility was determined by pH measurement and visual inspection, and antimicrobial activity was monitored by a disk diffusion method. The influence of solution warming by heating plate on drug stability was investigated. RESULTS: Linezolid was stable in all tested solutions for 14 days at refrigeration and room temperatures and for 24 hours at body temperature. No linezolid adsorption to container material was detected. There were only minor variations in pH values, and visual inspection revealed no diluent abnormalities. With 1 exception, antimicrobial activity of >90% was retained in all PD solution samples for the duration of the study under all temperature conditions. CONCLUSION: Linezolid injection 2 mg/mL remained stable and was compatible with the PD solutions studied for up to 2 weeks at refrigeration or room temperature and up to 24 hours at body temperature.

Influence of different peritoneal dialysis fluids on the in vitro activity of fosfomycin against Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa.

Peritonitis is still the main infectious complication among patients on peritoneal dialysis. For treatment of peritoneal dialysis-related peritonitis, the intraperitoneal administration of antibiotics admixed to peritoneal dialysis fluids (PDFs) should be preferred. However, the influence of diverse PDFs on the activity of frequently used antibiotics has been investigated insufficiently. Thus, the present study set out to investigate the in vitro activity of fosfomycin against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Staphylococcus aureus in commercially available PDFs. Time-kill curves in four different PDFs (Dianeal®, Extraneal®, Nutrineal®, and Physioneal®) were performed over 24 h with two different concentrations of fosfomycin (150 and 400 mg/L) and without antibiotics as control. Cation-adjusted Mueller Hinton broth (CA-MHB) was used as a comparator solution. In blank PDFs, bacterial growth of each organism evaluated was reduced when compared to CA-MHB. For S. aureus in blank Physioneal®, a reduction under the limit of detection was observed within 24 h. The activity of fosfomycin was reduced in all PDFs when compared to CA-MHB except for P. aeruginosa in Nutrineal® where the activity of fosfomycin was increased when investigated at 400 mg/L. Against E.coli, bactericidal activity was demonstrated in Extraneal®, Nutrineal®, and Physioneal®. Fosfomycin resistance (MIC > 1024 mg/L) was observed for P. aeruginosa in CA-MHB at both concentrations and in Nutrineal® at 150 mg/L. Fosfomycin is active in PDFs particularly against the frequently isolated enterobacterium E. coli. The choice of the respective PDF considerably influences the microbiological outcome in vitro. Further studies are warranted to investigate the clinical relevance of these findings.

Compatibility of Meropenem with Different Commercial Peritoneal Dialysis Solutions.

♦ BACKGROUND: Intraperitoneal administration of antimicrobial agents is recommended for the treatment of peritoneal dialysis (PD)-related peritonitis. For home-based antimicrobial therapy it is common to supply patients with PD fluid bags with admixed antibiotic. Thus, the compatibility of meropenem with different PD fluids (PDFs), namely Extraneal, Physioneal 1.36% and Physioneal 2.27% (all Baxter Healthcare Corp., Deerfield, IL, USA), was investigated under varying storage conditions. ♦ METHODS: Meropenem (Venus Pharma, Werne, Germany) was stored at 6°C and 25°C over 14 days and at 37°C over 24 hours. Drug concentration over time was determined using high performance liquid chromatography, drug activity by a diffusion disk method, diluent stability by visual inspection and drug adsorption was calculated. Blank PD fluids and deionized water were used as comparator solutions. ♦ RESULTS: Compared to water, the stability of meropenem was minimally lower in Extraneal but markedly reduced in both Physioneal solutions. No significant drug adsorption was detected for any PDF investigated. ♦ CONCLUSIONS: Meropenem is stable and compatible with Extraneal and might be stored for up to a week at refrigeration temperature (6°C). A loss of ~20% of meropenem after 2 days at room temperature should be considered. Mixed Physioneal appears not suitable for storage at any temperature after meropenem has been admixed. A considerable drug degradation due to the warming up to body temperature through heating plates should further be taken into account in clinical practice.

Influence of Different Peritoneal Dialysis Fluids on the In Vitro Activity of Cefepime, Ciprofloxacin, Ertapenem, Meropenem and Tobramycin Against Escherichia Coli.

♦ BACKGROUND: Peritonitis is a major problem among patients on peritoneal dialysis (PD). The influence of diverse PD fluids on the activity of frequently used antibiotics has been insufficiently investigated. Thus, the present study set out to investigate the impact of different PD fluids on the activity of cefepime, ciprofloxacin, ertapenem, meropenem, and tobramycin against Escherichia coli. ♦ METHODS: Time-kill curves in 4 different PD fluids (Dianeal PDG4, Extraneal, Nutrineal PD4 and Physioneal 40, all Baxter Healthcare Corp., Deerfield, IL, USA) were performed over 24 hours with 4 different concentrations (1 × minimum inhibitory concentration [MIC], 4 × MIC, 8 × MIC, 30 × MIC) of each antibiotic evaluated and without antibiotics as control. Cation-adjusted Mueller Hinton broth (CA-MHB) was used as comparator solution. ♦ RESULTS: In all PD fluids investigated, bacterial growth and antimicrobial activity of all antibiotics tested was significantly reduced compared with the CA-MHB comparator solution. Except at high concentrations of 30 × MIC, cefepime, ertapenem and meropenem demonstrated a strongly reduced activity in all PD fluids investigated. Ciprofloxacin and tobramycin were highly active and bactericidal in all PD fluids and demonstrated dose-dependent activity. ♦ CONCLUSION: The antimicrobial activity of cefepime, ertapenem and meropenem is limited or even nullified in certain PD fluids in vitro, whereas ciprofloxacin and tobramycin show excellent activity. The choice of PD fluids can impact the activity of antimicrobial agents and might influence microbiological outcome. Further studies are required to verify the clinical relevance of our findings.

An Open, Randomized, Single-Center, Crossover Pharmacokinetic Study of Meropenem after Intraperitoneal and Intravenous Administration in Patients Receiving Automated Peritoneal Dialysis.

The objective of this study was to determine the pharmacokinetic profile of meropenem in automated peritoneal dialysis (APD) patients. In 6 patients without peritonitis, a single dose of 0.5 g of meropenem was applied intraperitoneally (i.p.) or intravenously (i.v.) and concentrations in serum and dialysate were measured at specified intervals over 24 h with high-performance liquid chromatography-mass spectrometry. The mean maximum concentrations of meropenem in serum (Cmax) were 27.2 mg/liter (standard deviation [SD], ±6.9) and 10.1 mg/liter (SD, ±2.5) and in dialysate were 3.6 mg/liter (SD, ±2.3) and 185.8 mg/liter (SD, ±18.7) after i.v. and i.p. administrations, respectively. The mean areas under the curve from 0 to 24 (AUC0-24) of meropenem in serum were 173.5 mg · h/liter (SD, ±29.7) and 141.4 mg · h/liter (SD, ±37.5) (P = 0.046) and in dialysate were 42.6 mg · h/liter (SD, ±20.0) and 623.4 mg · h/liter (SD, ±84.1) (P = 0.028) after i.v. and i.p. administrations, respectively. The ratios for dialysate exposure over plasma exposure after i.v. and i.p. treatments were 0.2 (SD, ±0.1) and 4.6 (SD, ±0.9), respectively (P = 0.031). A mean target value of 40% T>MIC (time for which the free meropenem concentration exceeds the MIC) for clinically relevant pathogens with EUCAST susceptibility breakpoints of 2 mg/liter was reached in serum after i.p. and i.v. administrations and in dialysate after i.p. but not after i.v. administration. The present data indicate that low i.p. exposure limits the i.v. use of meropenem for PD-associated peritonitis. In contrast, i.p. administration not only results in superior concentrations in dialysate but also might be used to treat systemic infections.

Quantification of serial changes in cerebral blood volume and metabolism in patients with recurrent glioblastoma undergoing antiangiogenic therapy.

OBJECTIVES: To evaluate the usefulness of quantitative advanced magnetic resonance imaging (MRI) methods for assessment of antiangiogenic therapy (AAT) response in recurrent glioblastoma multiforme (GBM). METHODS: Eighteen patients with recurrent GBM received bevacizumab and 18 patients served as control group. Baseline MRI and two follow-up examinations were acquired every 3-5 months using dynamic susceptibility-weighted contrast (DSC) perfusion MRI and (1)H-MR spectroscopic imaging ((1)H-MRSI). Maps of absolute cerebral blood volume (aCBV) were coregistered with choline (Cho) and N-acetyl-aspartate (NAA) concentrations and compared to usually used relative parameters as well as controls. RESULTS: Perfusion significantly decreased in responding and pseudoresponding GBMs but also in normal appearing brain after AAT onset. Cho and NAA concentrations were superior to Cr-ratios in lesion differentiation and showed a clear gap between responding and pseudoresponding lesions. Responders to AAT exceptionally frequently (6 out of 8 patients) showed remote GBM progression. CONCLUSIONS: Quantification of CBV reveals changes in normal brain perfusion due to AAT, which were not described so far. DSC perfusion MRI seems not to be suitable for differentiation between response and pseudoresponse to AAT. However, absolute quantification of brain metabolites may allow for distinction due to a clear gap at 6-9 months after therapy onset.