3-D conformal radiotherapy with concomitant and adjuvant temozolomide for patients with glioblastoma multiforme and evaluation of prognostic factors

Glucose-corrected standardized uptake value in the differentiation of high-grade glioma versus post-treatment changes

Background

Standardized uptake values (SUVs) of fluorine-18 fluorodeoxyglucose PET (¹⁸F-FDG PET) are used widely to differentiate residual or recurrent high-grade gliomas from post-treatment changes in patients with brain tumors. The aim of this study is to assess the accuracy of SUV corrected by blood glucose level (SUV_gluc) compared with various quantitative methods in this role.

Materials and methods

In 55 patients with dynamic ¹⁸F-FDG PET scans, there were 97 glioma lesions: glioblastoma (n=60), grade III gliomas (n=22), grade III or IV gliomas (n=6), grade I/II (n=7), and prebiopsy lesions (n=2). The final actual diagnosis was made on the basis of pathology (n=33) and clinical outcome (n=64). Dynamic ¹⁸F-FDG PET scans were processed to generate parametric images of SUV_gluc, SUV_max, and glucose metabolic rate (GMR). Lesion to cerebellum ratios (SUV_Rc) and contralateral white matter ratios (SUV_Rw) were also measured. The SUV_gluc was calculated as SUV_max×blood glucose level/100.

Results

Using the thresholds of SUV_max>4.6, SUV_Rc>0.9, SUV_Rw>1.8, SUV_gluc>4.3, and GMR>12.2 μmol/min/100 g to represent positivity for viable tumors, the accuracies were the same for the SUV_gluc and SUV_Rw (80%) and were higher than the conventional SUV_max (72%). The area under the receiver operating characteristic curve for the SUV_gluc (0.8933) was better than that for the SUV_max (0.8266) (P<0.01) and was similar to those of the GMR (0.8622), SUV_Rc (0.8606), and SUV_Rw (0.8981).

Conclusion

These results suggest that SUV_gluc may aid in the differentiation of residual or recurrent high-grade tumor from post-treatment changes in patients with abnormal blood glucose levels. The simplicity of the SUV_gluc avoids the complexity of kinetic analysis or the requirement of a reference tissue.

Glioblastoma patients in Slovenia from 1997 to 2008

BACKGROUND

Glioblastoma is the most common primary brain tumour. It has a poor prognosis despite some advances in treatment that have been achieved over the last ten years. In Slovenia, 50 to 60 glioblastoma patients are diagnosed each year. In order to establish whether the current treatment options have any influence on the survival of the Slovenian glioblastoma patients, their data in the period from the beginning of the year 1997 to the end of the year 2008 have been analysed.

PATIENTS AND METHODS

All patients treated at the Institute of Oncology Ljubljana from 1997 to 2008 were included in the retrospective study. Demographics, treatment details, and survival time after the diagnosis were collected and statistically analysed for the group as a whole and for subgroups.

RESULTS

From 1997 to 2008, 527 adult patients were diagnosed with glioblastoma and referred to the Institute of Oncology for further treatment. Their median age was 59 years (from 20 to 85) and all but one had the diagnosis confirmed by a pathologist. Gross total resection was reported by surgeons in 261 (49.5%) patients; good functional status (WHO 0 or 1) after surgery was observed in 336 (63.7%) patients, radiotherapy was performed in 422 (80.1%) patients, in 317 (75.1%) of them with radical intent, and 198 (62.5 %) of those received some form of systemic treatment (usually temozolomide). The median survival of all patients amounted to 9.7 months. There was no difference in median survival of all patients or of all treated patients before or after the chemo-radiotherapy era. However, the overall survival of patients treated with radical intent was significantly better (11.4 months; p < 0.05). A better survival was also noticed in radically treated patients who received additional temozolomide therapy (11.4 vs. 13.1 months; p = 0.014). The longer survival was associated with a younger age and a good performance status as well as with a more extensive tumour resection. In patients treated with radical intent, having a good performance status, and receiving radiotherapy and additional temozolomide therapy, the survival was significantly longer, based on multivariate analysis.

CONCLUSIONS

We observed a gradual increase in the survival of glioblastoma patients who were treated with radical intent over the last ten years. Good functional surgery, advances in radiotherapy and addition of temozolomide all contributed to this increase. Though the increased survival seems to be more pronounced in certain subgroups, we have still not been able to exactly define them. Further research, especially in tumour biology and genetics is needed.

Treatment outcomes and survival in patients with primary central nervous system lymphomas treated between 1995 and 2010 - a single centre report

BACKGROUND.: Primary central nervous system lymphomas (PCNSL) are rare variants of extranodal non-Hodgkin's lymphomas that are nowadays primarily treated with high-dose methotrexate or methotrexate-based chemotherapy with or without radiation therapy. The optimal treatment of PCNSL is still unknown and there are differences in clinical practice. PATIENTS AND METHODS.: With a retrospective research we evaluated our series of patients with PCNSL in regards to the patient's characteristics, treatment results, disease specific survival and overall survival. Fifty nine patients who attended the Institute of Oncology Ljubljana between 1995 and 2010 were treated according to the protocol that was valid at the time of the patient's admission. Between 1995 and 1999, the systemic treatment was classical CHOP (cyclophosphamide, doxorubicin, vincristine, steroids) chemotherapy, and later on high-dose methotrexate either alone or in combination with other agents. From 1999 onwards, radiation therapy was applied according to the patient's age and response to chemotherapy, prior to that all patients treated with CHOP were also irradiated. Patients ineligible for the systemic treatment were treated with sole radiation therapy. RESULTS.: There was a strong female predominance in our series and the median age at diagnosis was 59.8 years. Patients had predominantly aggressive B cell lymphomas (69.5%), one patient had marginal cell lymphoma and two patients T cell lymphoma. In total, 20.3% of patients were treated just with chemotherapy, 33.9% with combined therapy and 42.4% with sole radiation therapy. The overall response rate to the primary treatment in patients treated with sole chemotherapy was 33.3%, in patients treated with combined therapy 65% and in patients treated only with radiation therapy 56%, respectively. In terms of response duration, significantly better results were achieved with combined therapy or radiation therapy alone compared to sole chemotherapy (p<0.0006). The median overall survival of the whole cohort was 11 months and the overall survival was significantly affected by the patient's age. The longest overall survival was observed in patients treated with combined therapy (median survival of 39 months). Patients treated just with radiation therapy had a median overall survival of 9 months and those treated with sole chemotherapy of 4.5 months, respectively. CONCLUSIONS.: The treatment outcomes in ordinary clinical practice are definitely inferior to the ones reported in clinical trials. The now standard treatment with high-dose methotrexate with or without radiation therapy is sometimes too aggressive and, therefore, a careful selection on the basis of patient's age, performance status and concomitant diseases of those eligible for such treatment is mandatory. According to our results from a retrospective study, radiation therapy should not be excluded from the primary treatment.