Prospective observational study on the complications and tolerability of a peripherally inserted central catheter (PICC) in neuro-oncological patients.

PURPOSE: The use of central venous catheters with peripheral insertion (PICC) has increased rapidly in recent years, particularly in cancer patients. The benefits provided may occasionally be affected by relevant complications, such as infections and thrombotic events, especially in neuro-oncological patients. To date, the risk of PICC-related complications in this subset of patients is unknown, as is tolerability. As a primary objective, this study aimed to collect complications related to PICCs in primary neuro-oncological patients. As a secondary objective, the study aimed to evaluate PICC tolerability. METHODS: Neuro-oncological patients with PICCs that were placed as part of normal clinical practice at IRCCS Neurologico C. Besta were consecutively enrolled in the study. PICC-related complications were recorded immediately (during the procedure), early (within 1 week after PICC insertion), and late (1-3-5 months after PICC placement). At the same time points, all patients were also evaluated for tolerability through interviews with semi-structured, open-ended questions. RESULTS: Sixty patients were enrolled (41 males and 19 females, with a median age of 56.2 years). Excluding loss to follow-up, 33/49 patients developed at least one complication related to the PICC. Immediate complications mainly included hematoma (8), accidental arterial puncture (4), and primary malpositioning (3). Regarding early and late complications, 3 device-related infections, 8 thrombotic events, and 20 mechanical complications were registered. Semi-structured interviews revealed an overall positive experience with the device. The most negative impact was on hygiene habits, with 34 patients becoming caregiver-dependent. Over time, almost all patients became used to the device and perceived greater security during chemotherapy. A strongly negative issue was the difficulty of relying on competently trained healthcare personnel in outpatient setting. CONCLUSION: The results showed a nonnegligible increased thromboembolic risk in neuro-oncological patients with PICCs, almost double that in historical oncological populations. It is essential to extend the study to a greater number of patients to achieve reliable results and to identify patients at high risk. The device seems to be positively accepted by the majority of patients, without affecting activities of daily living.

Stroke-like events after brain radiotherapy: a large series with long-term follow-up.

BACKGROUND AND PURPOSE: Patients with a history of brain radiotherapy can experience acute stroke-like syndromes related to the delayed effects of brain radiation, including stroke-like migraine attacks after radiation therapy syndrome, peri-ictal pseudoprogression and acute late-onset encephalopathy after radiation therapy syndrome. The aim of this study was to collect evidence on the long-term outcome and treatment of these conditions, whose knowledge is undermined by their rarity and fragmented description. METHODS: Cases were collected, both prospectively and retrospectively, amongst six neuro-oncology departments. Inclusion criteria were as follows: (i) history of brain radiotherapy (completed at least 6 months before the acute episode); (ii) new onset of acute/subacute neurological symptoms; (iii) exclusion of all etiologies unrelated to brain irradiation. A review of current literature on stroke-like syndromes was performed to corroborate our findings. RESULTS: Thirty-two patients with acute neurological conditions attributed to the delayed effects of radiation were identified, including 26 patients with stroke-like syndromes. Patients with stroke-like syndromes commonly presented with a mosaic of symptoms, including focal deficits (77%), encephalopathy (50%), seizures (35%) and headache (35%). Seventy-three percent of them had acute consistent magnetic resonance imaging alterations. Treatment included high-dose steroids in 65% of cases. Twenty-two patients recovered completely (85%). Sixteen patients (62%) experienced relapses (median follow-up 3.5 years). A literature review identified 87 additional stroke-like cases with similar characteristics. CONCLUSIONS: Stroke-like events related to brain irradiation may be associated with permanent sequelae. Steroids are often administered on empirical grounds, as they are thought to accelerate recovery. Relapses are common, highlighting the need to elaborate adequate prevention strategies.

Extra central nervous system metastases from glioblastoma: a new possible trigger event?

Extra-cranial metastases of glioblastoma (GBM) represent a rare event, and the biological-genetic mechanisms involved in the pathogenesis have not yet been determined. We report the case of a young patient with multiple visceral and osseous metastases occurred after 4 years after first diagnosis of GBM. The strangeness as well as the rarity of this event does not allow to identify an effective treatment for GBM metastases, making the management of this ominous tumor an even greater challenge.

Safety and efficacy of primary central nervous system lymphoma treatment in elderly population.

Elderly patients represent an important subgroup in primary central nervous system lymphoma (PCNSL) that accounts for approximately half the cases. Furthermore age represents one of the heaviest prognostic factors and in some cases it has more effect on survival than therapies. We performed a retrospective analysis to assess the toxicity and the efficacy of high-dose methotrexate (HDMTX) chemotherapy in a PCNSL population older than 70 years. Seventeen consecutive immunocompetent patients older than 70 years, with histologically confirmed PCNSL, without systemic involvement, treated with HDMTX at our institution between May 2005 and April 2013, were retrospectively evaluated. Main outcome measures were acute toxicity and tumour response. No evidence of haematological toxicity was recorded in 47 % of patients and no deaths related to toxicity grade were reported. Patients achieved a partial response after 3 cycles of chemotherapy in 53 % of cases. The median overall survival (m-OS) from diagnosis was 20.9 months (range 5.2-34 months), with OS-12 of 58.8 % and an OS-24 of 45.4 %. Since there is no standard of care in the treatment of PCNSL in elderly population, it should be taken into account that elderly patients not always can be considered "fragile" and the general tendency to less treat to avoid severe toxicity should not be the rule.

A case of medulloblastoma in adult patient affected by anaplastic oligoastrocytoma.

Medulloblastomas and high-grade gliomas (HGG) are two distinct brain tumor, with different peculiarities in terms of age of onset, localizations and prognosis. The coexistence of the two neoplasms in the same adult patient is an extremely rare event. We present the case of a woman treated with radio-chemotherapy for an HGG, who developed a cerebellar medulloblastoma 7 years later. Considering the poor prognosis of these tumors, the lack of knowledge about the mechanisms of onset as well as effective therapies, it is necessary to determine the exact role of irradiation and the presence of any potential molecular genetic abnormalities in the developing of the two tumors.

Cognitive strategies and quality of life of patients with high-grade glioma.

The purpose of this study was to analyze the psychological well-being, quality of life, and cognitive strategies activated by patients with high-grade glioma. We hypothesized that the self-perceived quality of life is modulated by physical and psychological factors and that in order to understand this modulation more psychometric approaches are necessary. Data were collected from a sample of 73 consecutive patients with a histological diagnosis of primary malignant brain cancer (grade IV glioblastoma and grade III anaplastic astrocytoma) hospitalized in a specialized Italian center. The Functional Assessment of Cancer Therapy (FACT) scale and the Schedule of Evaluation of Individual Quality of Life-Direct Weighting (SEIQoL-DW) scale were used to assess quality of life. The mean FACT-Brain (Br) score was 122.37. Similarly, the median SEIQoL-DW score was 72.9 out of a maximum value of 100. No gender effect was found in relation to overall quality of life. Patients with high depression and/or anxiety scores reported lower quality of life (QoL) scores in all the instruments considered. We did not find any gender effect concerning depression and anxiety levels. However, we found that men and women, though having similar physical and functional well-being, reported different QoL determinants, since men seem to rely more on physical adjustment, while women activate more introspective strategies. Positive actions, family issues, negative thoughts, health, and positive thoughts were found to be the most reported themes. In conclusion, the present study strongly suggests that a positive psychological adjustment is possible also in the event of a severe diagnosis and during aggressive treatments, but QoL determinants might be considered too in order to help health professionals to understand patients' experience and to meet their needs.

Headache in cerebral venous thrombosis associated with extracranial tumors: a clinical series.

Cerebral venous thrombosis (CVT) may represent the clinical onset of malignancies or complicate their course, also in phase of quiescence. In literature, there are several case reports on the association between CVT and tumors, but there are few articles on its clinical characteristics in cancer patients (Pts). Our aim was to analyze the clinical characteristics of CVT associated with extracranial tumors. We identified nine cases of CVT in adults affected by extracranial tumors in 6 years from six hospitals. The median age was 40 years; eight Pts were female. Associated tumors were: lymphoma (4/9); breast (2/9), rhinopharynges (1/9) and gastric (1/9) carcinomas. One patient presented a kidney tumor and a melanoma at the same time. Multiple sinuses were affected in seven Pts. MRI showed parenchymal lesions in most cases (7/9). Clinical manifestations were: focal deficits (7/9), headache (6/9), early seizures (4/9) and consciousness disorders (3/9). Headache was the onset symptom in six Pts. In four of these Pts, headache preceded the onset of the focal deficit and/or seizures than 2-15 days. The characteristics of the headache were variable in intensity, location and type but all the Pts agreed in saying that it was an unusual headache, unresponsive to common pain medications. Five of the six Pts complaining of headache in the course of CVT presented focal deficits and parenchymal lesions at admission to the emergency room. All nine Pts were anticoagulated without further haemorrhagic complications. At discharge, the Pts presented a complete recovery in four cases, mild sequelae in four and moderate sequelae in one. In conclusion, we would like to underline the importance of particular care to cancer Pts complaining of headache, since the early diagnosis and the appropriate anticoagulant treatment could prevent the appearance of parenchymal lesions and the consequent neurological deficits. Also in the cases of normal brain CT, a brain MRI/MR venography should be performed in emergency setting if CVT is suspected.

Update on treatment strategies for anaplastic glioma: a review of literature.

Anaplastic gliomas (AG) include 6-10% of all newly diagnoses of primary brain tumors. They have an unfavourable prognosis and, to date, there is not an established treatment universally recognized. Four recent randomized clinical trials were identified for a total of 1,170 patients (anaplastic-astrocytomas, anaplasticoligoastrocytoma, anaplastic-oligodendroglioma), in order to define the better sequence and timing of chemo-radiotherapy, Three studies compared radiotherapy (RT) treatment vs. radio-chemotherapy with procarbazine-lomustine-vincristine (PCV) or temozolomide (TMZ) or dibromodulcitol and bichloroethylnitrosurea (DBD/BCNU) and only one compared RT vs chemotherapy (CT) with PCV or TMZ. Results show no significant differences in terms of PFS/OS between RT/CT alone or combined treatment although a trend toward an improvement of OS was observed after RT + CT treatment (m-OS in RT + adjuvant PCV was 42.3 vs. 30.6 months in RT alone p=0.0003). Grade 3-4 mielotoxicity has been observed in almost all cases of patients treated with PCV + RT. None of four studies reviewed conducted a head to head comparison between PCV vs. TMZ. Only a study randomized patients to PCV/TMZ without however providing data in terms of PSF and OS between the two treatments. It found no significant differences in PFS from initial RT and adjuvant CT (PCV-TMZ) at progression compared to initial CT followed by RT at progression. The optimal treatment of AG should reasonably consider not only the histology as well as the molecular markers of the tumor, but also clinical conditions, age of patients, life expectancy, Karnofsky-performance-status and tumor resection to achieve in future the personalization of care.

Safety of bevacizumab in patients with malignant gliomas: a systematic review.

Angiogenesis has recently become a major target for the development of new antineoplastic drugs. The most serious adverse events linked to angiogenesis inhibitors are venous or arterial thromboembolism and haemorrhage. Thus, there is need to define with more certainty the impact of these new drugs in terms of adverse effects in neurological patients. The aim of the study is to assess the risk of venous thromboembolism (VTE) and bleeding in patients with malignant gliomas treated with bevacizumab with or without concomitant anticoagulant therapy. A review of published literature was performed in Medline, from which 476 records were identified. A total of 27 full-text articles, including retrospective analyses, retrospective reviews, and open label trials, were assessed for eligibility. The investigated drugs included bevacizumab alone, bevacizumab plus chemotherapy with/without concomitant radiation therapy; only two articles dealt with bevacizumab in association with anticoagulant treatment. A total of 2,208 patients with malignant gliomas, were identified and included in the analysis. From data it appears that patients receiving bevacizumab had a major risk of developing VTE that increased when bevacizumab is associated with radio-chemotherapy (4.27 vs 7.46 %). Regarding bleeding, data showed that patients treated with anticoagulant had a significantly increased risk of severe central nervous system (CNS) bleeding compared to patients not receiving anticoagulant therapy (0.6 vs 8.2 %). The use of bevacizumab combined with chemo-radiotherapy seems to be associated with a higher risk for VTE compared to patients receiving antiangiogenic therapy alone. The associated use of anticoagulants and bevacizumab far increases the risk of developing CNS and non-CNS bleeding higher than grade 3, compared to patients receiving bevacizumab alone.

Sleep and bodily functions: the physiological interplay between body homeostasis and sleep homeostasis.

Body homeostasis and sleep homeostasis may both rely on the complex integrative activity carried out by the hypothalamus. Thus, the three main wake-sleep (WS) states (i.e. wakefulness, NREM sleep, and REM sleep) may be better understood if the different cardio-respiratory and metabolic parameters, which are under the integrated control of the autonomic and the endocrine systems, are studied during sleep monitoring. According to this view, many physiological events can be considered as an expression of the activity that physiological regulations should perform in order to cope with the need to fulfill body and sleep homeostasis. This review is aimed at making an assessment of data showing the existence of a physiological interplay between body homeostasis and sleep homeostasis, starting from the spontaneous changes observed in the somatic and autonomic activity during sleep, through evidence showing the deep changes occurring in the central integration of bodily functions during the different WS states, to the changes in the WS states observed when body homeostasis is challenged by the external environment and when the return to normal ambient conditions allows sleep homeo- stasis to run without apparent physiological restrictions. The data summarized in this review suggest that an approach to the dichotomy between NREM and REM sleep based on physiological regulations may offer a framework within which observations that a traditional behavioral approach may overlook can be interpreted. The study of the interplay between body and sleep homeostasis appears, therefore, to be a way to understand the function of complex organisms beyond that of the specific regulations.

Short-course radiotherapy in elderly patients with glioblastoma: feasibility and efficacy of results from a single centre.

BACKGROUND: The incidence of glioblastoma (GBM) in the elderly population is currently increasing, with a peak seen between 65 and 84 years. The optimal treatment in terms of both efficacy and quality of life still remains a relevant and debated issue today. The purpose of our study was to evaluate the feasibility of short-course hypofractionated accelerated radiotherapy (HART) in GBM patients aged over 70 years and with a good Karnofsky performance score (KPS). METHODS: A review of medical records at the "Istituto Neurologico C. Besta" was undertaken; patients aged ≥ 70 years who had undergone adjuvant HART for GBM between January 2000 and January 2004 were included in the study. HART was administered to a total dose of 45 Gy, 2.5 Gy/fraction, in three daily fractions for three consecutive days/cycle fractions each, delivered in two cycles (split 15 days). RESULTS: A total of 33 patients were evaluable for the current analysis. Median follow-up was 10 months. According to CTCAE (version 3.0) criteria, none of the patients developed radiation-induced neurological status deterioration or necrosis. KPS evaluation after HART was found to be stable in 73 % of patients, improved in 24 %, and worse in 3 %. The median overall survival time of the entire study population was 8 months (range 2-24). CONCLUSIONS: Our findings suggest that a hypofractionated accelerated schedule can be a safe and effective option in the treatment of GBM in the elderly.

Liposomal cytarabine in neoplastic meningitis from primary brain tumors: a single institutional experience.

Neoplastic meningitis (NM) is diagnosed in 1-2 % of patients with primary brain tumors. Standard treatment of NM includes single-agent or combination chemotherapy, with compounds such as methotrexate, thiotepa, and cytarabine (Ara-C) or its injectable, sustained-release formulation Depocyte(®). In this Report, we reported the data of efficacy and tolerability of an intrathecal Depocyte(®) regimen for patients presenting with NM from primary brain tumors. We described 12 patients with NM confirmed at magnetic resonance imaging (MRI) and with a positive cerebrospinal fluid (CSF) cytology. Patients were treated with repeated courses of intrathecal Depocyte(®) (once every 2 weeks for 1 month of induction therapy and as consolidation therapy on a monthly base in responding patients). Twelve patients (10 males and 2 females) were treated by our Institution. The diagnosis of primitive brain tumor was medulloblastoma in six patients, germinoma in two patients, pylocitic astrocytomas with spongioblastic aspects, teratocarcinoma, meningeal melanoma, and ependimoma in the other four patients. The total number of Depocyte(®) cycles ranged from one to nine. In 7/12 patients, there was clinical and/or radiological response after Depocyte(®), and the toxicity was moderate and transient, mainly due to the lumbar puncture procedure. In the two patients with germinoma, we observed a normalization of MRI Imaging and negativization of CSF with disappearance of the tumor cells. OS was 180 days (range 20-300, CI 95 %).

Adult medulloblastoma: multiagent chemotherapy with cisplatinum and etoposide: a single institutional experience.

In 1991, a prospective phase II trial was initiated to evaluate the efficacy of treatment for adults with medulloblastoma (MB). After surgery, patients were staged with a neuroradiologic examination of the brain and neuroaxis and by cerebrospinal fluid cytology. All patients received three cycles of upfront cisplatinum (cisplatinum) and etoposide (VP16) chemotherapy followed by cranio-spinal radiation therapy. The current article reports on the long-term results from that trial. After a median follow-up of 14.9 years, among a total of 28 adults with MB, the overall progression-free survival and overall survival (OS) rates at 5 years were 57.6 and 80%, respectively. The median OS for the whole group of patients was 11.3 years. The observed toxicity was mainly hematological, with leukopenia and thrombocytopenia (16% of grades 3 and 4). In summary, in our small series of patients, the role of combination administration of CDDP + VP16 started before the initiation of radiotherapy in reducing recurrences, particularly distant recurrences, remains unclear. To know whether adding chemotherapy to craniospinal radiation in adult therapy increases relapse-free and overall survival, we must await the results of a larger randomized controlled clinical trial.

Brain tuberculoma (Mycobacterium africanum): high index of suspicion helps in avoiding biopsy/surgery.

Partial seizures can be due to a growing cerebral lesion, which may be tumoral or inflammatory/infectious in nature. The differential diagnosis is obviously important; increasing immigration to Europe from Africa is leading to an increase of infectious disease involving also the central nervous system. The authors report imaging the a case of a brain tuberculoma due to Mycobacterium africanum mimicking brain tumor, in which diagnosis was possible by inoculum in guinea-pig of material obtained by mediastinal biopsy of enlarged lymph nodes. Specific treatment led to marked reduction in the size of the brain lesion.

The role of body mass index in the development of thromboembolic events among cancer patients with PICCs: a systematic review.

OBJECTIVE: Peripherally inserted central catheters (PICC) guarantee a stable and safe vascular access to administer irritants or vesicants therapies. However, they may occasionally be affected by relevant thrombotic complications especially in patients with hypercoagulability such as oncological patients. Among the identification of independent risk factors, the role of body mass index (BMI) ≥25 kg/m2 is now emerging in literature with conflicting results. The aim of this systematic review is to analyze the available scientific literature in order to determine whether BMI could represent a risk factor in the development of thromboembolic event among cancer patients with PICCs. DATA SOURCES AND REVIEW METHODS: A scientific literature review was performed in Pubmed, Embase and Cinahl from Jan 1, 2010 to September 10, 2020 in which we identified 100 records. Of these, 88 were excluded and 14 were reviewed in full text. Among the reviewed records, 6 articles satisfied the inclusion criteria for analysis. These criteria included the English language, oncological patients with PICCs, the evaluation of catheter-related thrombosis as well as the stratification of patients according to BMI. Studies off topic and lacking data on PICC related complications among overweight and underweight patients were excluded. The includedstudies, judged with Newcastle-Ottawa Scale, was fair-lower quality. The primary endpoint was the relative risk (RR) of PICC-related thrombosis of overweight/obese vs normal weight/underweight (i.e., BMI ≥25 vs <25 kg/m2) in cancer patients. RESULTS: A total of 2431 patients were included in the analysis. Overall, 15.1% of patients developed PICC-related thrombosis within a median time of 23.2 days (range 11.0-42.5) after PICC implantation. Concerning BMI, 52.6% of the entire population was overweight/obese. We assessed the proportion of patients with PICC-related thrombotic events in the two groups, with 28% (95% CI, 12%-45%) of events registered in the overweight/obese patients cohort, and 13% (95% CI, 6%-19%) in the normal weight/underweight cohort. The pooled relative risk (RR) was 2.06 (95% CI, 1.21-3.49, p<0.001) in overweight/obese vs normal weight/underweight patients. CONCLUSION: This review showed a two-fold risk of thrombosis in overweight/obese compared to normal weight/underweight oncological patients with PICCs. Underweight condition could also play a role in thrombosis development, especially in nasopharyngeal and digestive system cancer. Future prospective studies are needed to achieve reliable results and produce useful conclusion.

Neuro-oncological diagnosis in patients without histological confirmation.

The impossibility to conduct a histological diagnosis could be due to different reasons: (1) patient's refusal to undergo surgery/biopsy. (2) Technical difficulties: despite the advance in surgical procedures, the removal of lesions that are located either in critical or in deep areas represents a considerable risk for patients. (3) Quality/quantity of the sample. In rare cases even when the surgical sample is achieved it could be impossible to reach a histological confirmation, for example due to the small amount of tissue obtained. The lack of histology leads to suboptimal therapy, incorrect prognosis, and misinterpretation of clinical trials and furthermore undermines the possibility to perform most radiation and chemotherapy protocols. In this setting the morphological data obtained with conventional MR imaging may be integrated with the metabolic, structural and perfusional information provided by new MR and metabolic techniques (spectroscopy, SPECT, PET in particular).

Malignant gliomas: early diagnosis and clinical aspects.

Brain tumor symptoms vary greatly from person to person because of two factors: location and size of tumors. The size of a tumor, however, does not necessarily affect the severity of symptoms. Manifestations depend on the cause of the symptoms: an increase in ICP, direct compression of gray or white matter, shifting of intracranial contents, or secondary cerebral ischemia. Symptoms may be non-specific and include headache, altered mental status, ataxia, nausea, vomiting, weakness, and gait disturbance. Left-sided weakness may be seen in a patient with a tumor pressing on the contra-lateral motor strip or speech difficulties may occur if a tumor is in the dominant hemisphere. Up to a third of people report having seizures prior to being diagnosed with a brain tumor. Rarely, brain tumor can present with psychiatric symptoms but without other neurological signs or symptoms. Evaluation for brain tumor is indicated in any patient with chronic, persistent headache associated with protracted nausea, vomiting, seizures, changes in headache pattern, neurologic symptoms, and change in personality.

Lecture: fotemustine in brain tumors.

Fotemustine (FTMS) is a third-generation nitrosourea, in preclinical studies, FTMS compared favorably with carmustine (BCNU) and lomustine (CCNU) against several human tumor cell lines. In conventional schedule, FTMS is administered at a dose of 100 mg/sqm/week for three consecutive weeks as induction (I) treatment, followed by 100 mg/sqm every three weeks, after a 5-week rest, as maintenance (M). Several Italian groups reported the results using FTMS in malignant glioma patients recurring after temozolomide standard treatment. In these papers, the 6-progression free survival are ranging from 20 to 52%. With the schedule (I + M) myelosuppression is observed in more than 30% of patients, and thrombocytopenia and leukopenia are more frequent and significant in Temozolomide pretreated patients. On the bases of the hematological toxicities several authors experimented new schedules of FTMS administrated at low doses. Recently, some authors reported the interesting results of a multicenter study on recurrent glioblastoma multiforme patients combining FTMS with new antiangiogentic agent bevacizumab.

Metabolic, electrolytes disorders and tromboembolic risk in malignant glioma patients.

In malignant gliomas, the management of symptoms and minimization of side effects assume major importance. Corticosteroids provide transient relief from neurological symptoms. However, treatment with steroids is also commonly associated with considerable side-effects including: hyperglycemia, osteoporosis, myopathy, lymphopenia and others. Sometimes, antiepileptic drugs may contribute to clinical decline of neuro-oncological patients in stable disease not only by neuropsychological impairment but also by metabolic interations. Several studies have demonstrated a high frequency of hyponatremia among patients treated with carbamazepine and particularly with oxacarbamazepine. Venous thromboembolism is a common complication in patients with cancer and it is particularly high in malignant gliomas, occurring in approximately 20-30% of such patients. Prophylactic treatment in patients with glioblastoma is a key topic. The role of prophylaxis has not yet been established with certainty. Overall the data show a clear reduction of venous thromboembolic events in patients treated with intermittent pneumatic compression (IPC). The addition of enoxaparin dose of 6.000 UI, starting in the perioperative period, induces an increase of major bleeding events. In the absence of availability of IPC, the use of enoxaparin 4.000 UI in addition to graduated compression stockings, reduces thromboembolic events without major bleeding events.

Rechallenge with temozolomide in recurrent glioma.

Despite a confirmed survival benefit associated with adjuvant radio- and chemotherapy, the majority of patients with malignant glioma relapse after initial therapy. Recurrent malignant glioma treatment has not been standardised and usually the response rate to standard chemotherapy protocols for recurrent malignant glioma is less than 30%. The growing body of evidence demonstrating the clinical importance of O6-methylguanine methyltransferase (MGMT) has generated a considerable interest in the exploration of strategies to overcome MGMT-mediated resistance to alkylating agents; for example protracted administration of Temozolomide (TMZ) may result in more extensive and sustained depletion of MGMT; for this reason a variety of dosing schedules that increase the duration of exposure and the cumulative dose of TMZ are being investigated for the treatment of patient with recurrent malignant glioma after standard treatment. The most widely studied regimens in this setting include (1) 21 of 28-day schedule at a dose of 75-100 mg/m(2)/day; (2) 7 of 14-day schedule at a dose of 150 mg/m(2)/day, also referred to as the ''one week on/one week off'' schedule; (3) Continuous daily schedule at a dose of 50 mg/m(2)/day. An alternative dosing schedule of TMZ may be a reasonable option in patients having high-grade gliomas with recurrence after standard therapy.