Is a reduction of radiation dose feasible in patients affected by glioblastoma undergoing radio-chemotherapy according to MGMT promoter methylation status without jeopardizing survival?

OBJECTIVE: To explore therapeutic results of different radiotherapy (RT) dose schedules combined to Temozolomide (TMZ)-RT treatment in newly diagnosed glioblastoma (GB), according to the O (6)-methylguanine-DNA methyltransferase (MGMT) methylation status. PATIENTS AND METHODS: Patients with newly diagnosed GB received either standard (60-59.4 Gy) or reduced (54-52 Gy) dose radiation therapy (RT) with concurrent and adjuvant TMZ between June 2010 and October 2016. We retrospectively evaluated the therapeutic effectiveness of the RT ranges schedules in terms of overall survival (OS) with univariate and multivariate analysis, after analyzing the MGMT methylation status. RESULTS: One hundred and seventeen patients were selected for the present analysis out of 146 total treated patients accrued. Seventy-two out of the selected cases received the standard RT-TMZ course (SDRT-TMZ) whereas the remaining 45 underwent the reduced dose schedule (RDRT-TMZ). The analysis according to the MGMT promoter methylation status showed that, in methylated-MGMT GB patients, SDRT-TMZ and RDRT-TMZ groups did not show different median OS (p = ns) according to the two RT schedules, independently by the extent of surgical resection. Instead, a difference in survival outcomes was confirmed in unmethylated-MGMT GB patients with better survival for patients undergoing to SDRT, particularly in sub-total resection. CONCLUSION: In our experience, a reduction of radiation dose schedule does not seem to jeopardize survival in methylated-MGMT patients independently by the extent of resection. A therapeutic approach to a standard reduction of RT dose for the methylated subset of patients may be feasible and could deserve prospective trials for validation.

Magnetic-Resonance-Imaging Texture Analysis Predicts Early Progression in Rectal Cancer Patients Undergoing Neoadjuvant Chemoradiation.

BACKGROUND: We hypothesized that texture analysis (TA) from the preoperative MRI can predict early disease progression (ePD), defined as the percentage of patients who relapsed or showed distant metastasis within three months from the radical surgery, in patients with locally advanced rectal cancer (LARC, stage II and III, AJCC) undergoing neoadjuvant chemoradiotherapy (C-RT). METHODS: This retrospective monoinstitutional cohort study included 49 consecutive patients in total with a newly diagnosed rectal cancer. All the patients underwent baseline abdominal MRI and CT scan of the chest and abdomen to exclude distant metastasis before C-RT. Texture parameters were extracted from MRI performed before C-RT (T1, DWI, and ADC sequences) using LifeX Software, a dedicated software for extracting texture parameters from radiological imaging. We divided the cohort in a training set of 34 patients and a validation set of 15 patients, and we tested the data sets for homogeneity, considering the clinical variables. Then we performed univariate and multivariate analysis, and a ROC curve was also generated. RESULTS: Thirteen patients (26.5%) showed an ePD, three of whom with lung metastases and ten with liver relapse. The model was validated based on the prediction accuracy calculated in a previously unseen set of 15 patients. The prediction accuracy of the generated model was 82% (AUC = 0.853) in the training and 80% (AUC = 0.833) in the validation cohort. The only significant features at multivariate analysis was DWI GLCM Correlation (OR: 0.239, p < 0.001). CONCLUSION: Our results suggest that TA could be useful to identify patients that may develop early progression.

3D bone texture analysis as a potential predictor of radiation-induced insufficiency fractures.

BACKGROUND: The aim of our work is to assess the potential role of texture analysis (TA), applied to computed tomography (CT) simulation scans, in relation to the development of insufficiency fractures (IFs) in patients undergoing radiation therapy (RT) for pelvic malignancies. METHODS: We analyzed patients undergoing pelvic RT from Jan-2010 to Dec-2016, 31 of whom had developed IFs of the pelvis. We analyzed CT simulation scans using LifeX Software©, and in particular we selected three regions of interest (ROI): L5 body, the sacrum and both the femoral heads. The ROI were automatically contoured using the treatment planning software Raystation©. TA parameters included parameters from the gray-level histogram, indices from sphericity and from the matrix of GLCM (gray level co-occurrence matrix). The IFs patients were matched (1:1 ratio) with control patients who had not developed IFs, and were matched for age, sex, type of tumor, menopausal status, RT dose and use of chemotherapy. Univariate and multivariate analyses (logistic regression) were used for statistical analysis. RESULTS: Significant TA parameters on univariate analysis included both parameters from the histogram distribution, as well from the matrix of GLCM. On logistic regression analysis the significant parameters were L5-energy [P=0.033, odds ratio (OR): 1.997, 95% CI: 1.059-3.767] and FH-Skewness (P=0.014, OR: 2.338, 95% CI: 1.191-4.591), with a R2: 0.268. A ROC curve was generated from the binary logistic regression, and the AUC was 0.741 (95% CI: 0.627-0.855, P=0.001, S.E.: 0.058). CONCLUSIONS: In our experience, 3D-bone CT TA can be used to stratify the risk of the patients to develop radiation-induced IFs. A prospective study will be conducted to validate these findings.

Texture analysis as a predictor of radiation-induced xerostomia in head and neck patients undergoing IMRT.

PURPOSE: Image texture analysis (TA) is a heterogeneity quantifying approach that cannot be appreciated by the naked eye, and early evidence suggests that TA has great potential in the field of oncology. The aim of this study is to evaluate parotid gland texture analysis (TA) combined with formal dosimetry as a factor for predicting severe late xerostomia in patients undergoing radiation therapy for head and neck cancers. METHODS: We performed a retrospective analysis of patients treated at our Radiation Oncology Unit between January 2010 and December 2015, and selected the patients whose normal dose constraints for the parotid gland (mean dose < 26 Gy for the bilateral gland) could not be satisfied due to the presence of positive nodes close to the parotid glands. The parotid gland that showed the higher V30 was contoured on CT simulation and analysed with LifeX Software©. TA parameters included features of grey-level co-occurrence matrix (GLCM), neighbourhood grey-level dependence matrix (NGLDM), grey-level run length matrix (GLRLM), grey-level zone length matrix (GLZLM), sphericity, and indices from the grey-level histogram. We performed a univariate and multivariate analysis between all the texture parameters, the volume of the gland, the normal dose parameters (V30 and Mean Dose), and the development of severe chronic xerostomia. RESULTS: Seventy-eight patients were included and 25 (31%) developed chronic xerostomia. The TA parameters correlated with severe chronic xerostomia included V30 (OR 5.63), Dmean (OR 5.71), Kurtosis (OR 0.78), GLCM Correlation (OR 1.34), and RLNU (OR 2.12). The multivariate logistic regression showed a significant correlation between V30 (0.001), GLCM correlation (p: 0.026), RLNU (p: 0.011), and chronic xerostomia (p < 0.001, R2:0.664). CONCLUSIONS: Xerostomia represents an important cause of morbidity for head and neck cancer survivors after radiation therapy, and in certain cases normal dose constraints cannot be satisfied. Our results seem promising as texture analysis could enhance the normal dose constraints for the prediction of xerostomia.

Epidermal Growth Factor Receptor Expression Predicts Time and Patterns of Recurrence in Patients with Glioblastoma After Radiotherapy and Temozolomide.

BACKGROUND AND OBJECTIVE: The aim of this study was to investigate the potential role of epidermal growth factor receptor (EGFR) protein expression in predicting the modality of treatment failure in glioblastoma (GB). METHODS: Patients with unifocal GB undergoing surgery and postoperative radiochemotherapy from February 2008 to July 2015 were included into the study. The EGFR protein expression level was assessed by immunohistochemistry in GB tissues and classified into high and low expression. Time to progression (TTP) and pattern of recurrence (PR) were evaluated. PRs were classified as central, in-field, marginal, or distant recurrences. RESULTS: After a median follow-up time of 13 months (range, 6-67 months), 102 patients (79.1%) showed recurrences that were detectable on magnetic resonance imaging. Median TTP was 9 months after the completion of radiochemotherapy. EGFR expression was significantly correlated with TTP (log-rank test, P = 0.003) and PR (Fisher exact test, P = 0.01). The low-EGFR group had a median TTP of 13 months and a prevalence of central/in-field recurrences (accounting to a total 81%). The high-EGFR group had a shorter median TTP (6 months) and a higher rate of marginal/distant recurrences (55.6%). CONCLUSIONS: Different modality of recurrence related to EGFR expression in patients with GB envisages implication for target contouring of radiotherapy volumes and other therapeutic strategies.

Patients Affected by Unmethylated O(6)-Methylguanine-DNA Methyltransferase Glioblastoma Undergoing Radiochemotherapy May Benefit from Moderately Dose-Escalated Radiotherapy.

PURPOSE: To compare the therapeutic results of two radiotherapy (RT) dose schedules in combined temozolomide- (TMZ-) RT treatment in newly diagnosed glioblastoma (GB), according to the O(6)-methylguanine-DNA methyltransferase (MGMT) methylation status. MATERIAL AND METHOD: Patients received either standard (60 Gy) or moderately escalated dose (70 Gy) radiotherapy (RT) with concomitant and adjuvant TMZ between June 2006 and October 2013. We retrospectively evaluated the therapeutic effectiveness of RT schedules in terms of Overall Survival (OS) and Progression-Disease Free Survival (PDFS) analyzing the MGMT methylation status. RESULTS: One hundred and seventeen patients were selected for the present analysis. Seventy-two out of the selected cases received the standard RT-TMZ course (SDRT-TMZ) whereas the remaining 45 underwent the escalated schedule (HDRT-TMZ). The analysis according to the MGMT promoter methylation status showed that, in unmethylated-MGMT GB patients, HDRT-TMZ and SDRT-TMZ groups had different median OS (p = 0,01) and PDFS (p = 0,007), that is, 8 months and 5 months for the SDRT-TMZ group and 14 months and 9 months for the HDRT-TMZ group, respectively. No difference in survival outcomes was found in methylated MGMT patients according to the two RT schedules (p = 0,12). CONCLUSIONS: In our experience, unmethylated-MGMT GB patients benefited from a moderately escalated dose of RT plus TMZ.

Perilesional edema in brain metastasis from non-small cell lung cancer (NSCLC) as predictor of response to radiosurgery (SRS).

Radiosurgery (SRS) is widely used in the treatment of brain oligo-metastases from NSCLC. The aim of present study is to evaluate the extent of perilesional edema in brain metastases as predictive factor of treatment response. This single center retrospective study included 42 consecutive patients (January 2011-December 2014) with 1-2 brain metastasis from NSCLC treated with Radiosurgery (SRS). Extent of perilesional edema was measured as maximal extension from the edge of lesion and classified as minor (<10 mm) or major (≥10 mm). We analyzed Modality of Brain Recurrence (MBR), classified as in-field or out-of- field, and Brain Progression Free-Survival (BPFS) after treatment stratified according to extent of perilesional edema. Analyzing modality of brain recurrence and BPFS, after a median follow-up of 6 months, we found that patients with minor edema had a better radiological response to SRS with none in-field recurrences and a lower risk of the onset of new brain lesions (out-of-field recurrence). Instead, patients group with major edema had a worse response rate of lesions treated, further, a higher risk of out-of-field brain relapse. Extent of perilesional edema in brain metastasis from NSCLC could be a predictive factor of response and brain progression after SRS treatment alone.

The combined EGFR protein expression analysis refines the prognostic value of the MGMT promoter methylation status in glioblastoma.

BACKGROUND/AIMS: To investigate the combined prognostic value of the EGFR expression level and the MGMT promoter methylation status in Glioblastoma (GB). METHODS: We assessed the EGFR protein expression level by immune-histochemical (IHC) evaluation and the MGMT promoter methylation status by Polymerase Chain Reaction (PCR) in 169 patients affected by GB. We assessed the prognostic significance of combined MGMT methylation status and EGFR expression level in terms of Overall Survival (OS) with univariate and multivariate analysis, and validated this finding using an external data set of GB patient. RESULTS: Clustering survival analysis for the methylation status of MGMT (methMGMT/unmethMGMT) and EGFR expression (High EGFR: H-EGFR; Low EGFR: L-EGFR), identified three different prognostic groups (p=0.001), as follows. Patients with unmethMGMT/H-EGFR had the shortest survival time (median OS: 5 months) and patients co-expressing methMGMT/L-EGFR had the best prognosis (median OS: 35 months), as compared to the other two sub-groups (methMGMT/H-EGFR; unmethMGMT/L-EGFR), which had respectively median OSs of 11 and 12 months. The combined MGMT methylation and EGFR amplification status analysis showed a similar prognostic impact in an independent series, which we used for validation (p=0.001). CONCLUSIONS: The EGFR expression evaluation refines the prognostic value of MGMT methylation status in GBs.

Prognostic Value of MR Imaging Texture Analysis in Brain Non-Small Cell Lung Cancer Oligo-Metastases Undergoing Stereotactic Irradiation.

UNLABELLED: BACKGROUND : Stereotactic irradiation is widely used in brain oligo-metastases treatment. The aim of this study is to evaluate the prognostic value of magnetic resonance imaging (MRI) texture analysis (TA) of brain metastases (BM) of non-small cell lung cancer (NSCLC). MATERIALS AND METHODS : This study included thirty-eight consecutive patients undergoing stereotactic irradiation, that is, stereotactic fractionated radiotherapy (SRT) or radiosurgery (SRS), from January 2011 to December 2014 for 1-2 brain BM from NSCLC. Whole-brain radiotherapy (WBRT) was not delivered. The diagnostic MRI DICOM (Digital Imaging and Communications in Medicine) images were collected and analyzed with a homemade ImageJ macro, and typical TA parameters (mean, standard deviation, skewness, kurtosis, entropy, and uniformity) were evaluated for: brain progression-free survival; modality of brain metastatic progression (local progression or/and new metastases); and overall survival, after SRT/SRS. RESULTS: After SRT/SRS 14 patients (36.8%) experienced recurrence in the brain, with a recurrence in the irradiated site (five patients, 13.2%), new metastases (11 patients, 28.9%), local recurrence and new metastases (two patients, 5.25%). Nineteen patients (50%) died of tumor progression or other causes. Entropy and uniformity were significantly associated with local progression, whereas kurtosis was significantly associated with both local progression and new brain metastases. CONCLUSIONS : These results appear promising, since the knowledge of factors correlated with the modality of brain progression after stereotactic irradiation of brain oligo-metastatic foci of NSCLC might help in driving the best treatment in these patients (association of SRT/SRS with WBRT? Increase of SRT/SRS dose?). Our preliminary data needs confirmation in large patient series.

[Radiotherapy of malignant gliomas: results from conventional treatment methods and the prospects of advanced techniques].

PURPOSE: The results of post-operative radiation therapy of malignant gliomas are disappointing, with mean survival time (MST) of 16-70 weeks and 2-year survival rates ranging from 8.5% to 25% in the literature. A slightly more favourable prognosis is found in the following cases: in anaplastic astrocytomas with respect to glioblastoma multiforme; in younger patients with respect to the more elderly; the longer the duration of symptoms before diagnosis; and in the event in which surgery has been macroscopically radical. An improvement in treatment outcome is foreseeable with the use of advanced volume definition techniques for radiation therapy. MATERIALS AND METHODS AND RESULTS: Our experience with conventional radiation treatment shows therapeutic results in agreement with other institutions. In the overall 134 cases MST was 50 weeks and the 2-year survival rate was 10%. In patients affected by anaplastic astrocytoma MST was 58% and 2-year survival rate was 17%, whereas the figures for glioblastoma multiforme were 47 weeks and 8% (p>0.05, not statistically significant, probably due to the small number of cases). Patients of sixty years of age or less showed a more statistically favourable prognosis: MST was 59 weeks and 2-year survival rate was 16%, compared with 44 weeks and 4% in patients above 60 years of age (p<0.05). The duration of symptoms of 6 months or less had a less favourable prognosis with respect to symptom onset of greater than 6 months: in the former MST was 49 weeks and 2-year survival was 7%, and in the latter the figures were 68 weeks and 40% (P<0.05). Lastly, the presence of residual neoplastic tissue after surgery is an unfavourable element: in this case MST was 41 weeks and 2-year survival was 7%, compared with 68 weeks and 13% (P<0.05) after macroscopically radical surgery. DISCUSSION AND CONCLUSIONS: Computed tomography (CT) is still today an indispensable technique for radiation therapy planning. Magnetic Resonance (MR) imaging, nonetheless, provides greater definition of the neoplastic extension. The possibility of combining CT and MR neuroimaging data together with stereotactic radiotherapy techniques enables the optimal development of the three-dimensional treatment plane. This translates into high dose delivery to the neoplastic volumes without affecting the regions of the brain with no tumour involvement. Furthermore, a real improvement in the prognosis of malignant gliomas must also consider the results from research in the fields of tumour biology and functional neuroimaging.