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Legnago, Italy

Mukundan H.,Radiotherapy | Sarin A.,Radiology and Radiotherapy | Gill B.S.,Nuclear Medicine | Neelakantan A.,PSM
Medical Journal Armed Forces India | Year: 2014

Background: Treatment of patients with head and neck cancers includes surgery, radiation therapy and chemotherapy due to which the complex anatomy in this region is further complicated by post surgical or radiation changes making the distinction between post therapy changes and recurrence or residual tumor challenging. We decided to compare the diagnostic performance of FDG-PET/CT and MRI scans in the response assessment of patients with Head and Neck Squamous Cell Carcinomas (HNSCC). Methods: Fifty consecutive patients with carcinoma of the head and neck region undergoing treatment at our center were enrolled in the study and evaluated with both MRI scan and PETeCT scan at presentation, at 12 weeks after treatment and at 24 weeks post-treatment. Results: Post treatment evaluation at 24 weeks revealed a sensitivity, specificity, PPV, NPV of 95.83%, 82.37%, 78.91%, 96.3% for MRI respectively while corresponding values for PETeCT scans were 95.83%, 91.97%, 85.45% and 96.3%. Evaluation by treatment modality showed a concurrence rate of positive biopsies of 71.33% and 74.54% respectively for MRI and PETeCT scans in surgical patients, 93.33% and 91.25% respectively for the chemo-radiotherapy and 71.43% and 85.71% respectively for patients treated with surgery and radiotherapy. Conclusion: In our study, both modalities were useful for evaluation at 12 weeks, however by 24 weeks PETeCT was superior. Both the modalities suffer from high negative predictive values and relatively low positive predictive values. These persisted irrespective of the treatment modality with MRI being slightly better for patients on chemo-radiotherapy while PETeCT scans were better if surgery was one of the modalities of treatment. © 2014, Armed Forces Medical Services (AFMS). All rights reserved.

Hatt M.,French Institute of Health and Medical Research | Tixier F.,French Institute of Health and Medical Research | Cheze Le Rest C.,Nuclear Medicine | Pradier O.,Radiotherapy | Visvikis D.,French Institute of Health and Medical Research
European Journal of Nuclear Medicine and Molecular Imaging | Year: 2013

Purpose: Intratumour uptake heterogeneity in PET quantified in terms of textural features for response to therapy has been investigated in several studies, including assessment of their robustness for reconstruction and physiological reproducibility. However, there has been no thorough assessment of the potential impact of preprocessing steps on the resulting quantification and its predictive value. The goal of this work was to assess the robustness of PET heterogeneity in textural features for delineation of functional volumes and partial volume correction (PVC). Methods: This retrospective analysis included 50 patients with oesophageal cancer. PVC of each PET image was performed. Tumour volumes were determined using fixed and adaptive thresholding, and the fuzzy locally adaptive Bayesian algorithm, and heterogeneity was quantified using local and regional textural features. Differences in the absolute values of the image-derived parameters considered were assessed using Bland-Altman analysis. The impact on their predictive value for the identification of patient nonresponders was assessed by comparing areas under the receiver operating characteristic curves. Results: Heterogeneity parameters were more dependent on delineation than on PVC. The parameters most sensitive to delineation and PVC were regional ones (intensity variability and size zone variability), whereas local parameters such as entropy and homogeneity were the most robust. Despite the large differences in absolute values obtained from different delineation methods or after PVC, these differences did not necessarily translate into a significant impact on their predictive value. Conclusion: Parameters such as entropy, homogeneity, dissimilarity (for local heterogeneity characterization) and zone percentage (for regional characterization) should be preferred. This selection is based on a demonstrated high differentiation power in terms of predicting response, as well as a significant robustness with respect to the delineation method used and the partial volume effects. © 2013 Springer-Verlag Berlin Heidelberg.

Napolitano M.,Immunology Unit | D'Alterio C.,Immunology Unit | Cardone E.,Colorectal Surgery | Trotta A.M.,Immunology Unit | And 10 more authors.
Oncotarget | Year: 2015

Short-course preoperative radiotherapy (SC-RT) followed by total mesorectal excision (TME) is one therapeutic option for locally advanced rectal cancer (LARC) patients. Since radio-induced DNA damage may affect tumor immunogenicity, Myeloid-derived suppressor cells (MDSCs) and T regulatory cells (Tregs) were evaluated in 13 patients undergoing SC-RT and TME for LARC. Peripheral Granulocytic-MDSCs (G-MDSC) [LIN-/HLA-DR-/CD11b+/CD14-/CD15+/CD33+], Monocytic (M-MDSC) [CD14+/HLA-DR-/lowCD11b+/CD33+] and Tregs [CD4+/CD25hi+/FOXP3+- CTLA-4/PD1] basal value was significantly higher in LARC patients compared to healthy donors (HD). Peripheral MDSC and Tregs were evaluated at time 0 (T0), after 2 and 5 weeks (T2-T5) from radiotherapy; before surgery (T8) and 6-12 months after surgery (T9, T10). G-MDSC decreased at T5 and further at T8 while M-MDSC cells decreased at T5; Tregs reached the lowest value at T5. LARC poor responder patients displayed a major decrease in M-MDSC after SC-RT and an increase of Treg-PD-1. In this pilot study MDSCs and Tregs decrease during the SC-RT treatment could represent a biomarker of response in LARC patients. Further studies are needed to confirm that the deepest M-MDSC reduction and increase in Treg-PD1 cells within 5-8 weeks from the beginning of treatment could discriminate LARC patients poor responding to SC-RT.

Pota M.,National Research Council Italy | Scalco E.,CNR Institute of Neuroscience | Sanguineti G.,Radiotherapy | Cattaneo G.M.,San Raffaele Scientific Institute | And 2 more authors.
Biosystems Engineering | Year: 2015

During radiotherapy treatment of patients with head-and-neck cancer, the possibility that parotid glands shrink was evidenced, connected with increasing risk of acute toxicity. In this ambit, the early identification of patients in danger is of primary importance, in order to treat them with adaptive therapy. This work studies different approaches for classifying parotid gland samples, taking into account textural features extracted from computed tomography (CT) images of monitored patients. A real dataset is used, and accuracy, sensitivity and specificity are counted as classification performances. Therefore, firstly, different procedures to define classes are compared in terms of their physical meaning and classification performances. Then, different methods for extracting knowledge from the dataset are implemented and compared in terms of performances and model interpretability. First-rate performance was obtained by using Likelihood-Fuzzy Analysis (LFA), which is a recently developing method based on the use of statistical information by means of Fuzzy Logic. The interpretable models extracted with LFA also allow identifying among textural features those able to predict parotid shrinkage. Some of these features are already known and are confirmed here, others are new, and some of them are very early predictors. Finally, an example of textural feature monitoring and classification of a patient is presented, through a reasoning scheme similar to human reasoning, based on the interpretation of simple rule-based models using linguistic variables. © 2015 IAgrE.

Rancati T.,Prostate Program | Fiorino C.,San Raffaele Scientific Institute | Fellin G.,Radiotherapy | Vavassori V.,Radiotherapy | And 8 more authors.
Radiotherapy and Oncology | Year: 2011

Background and purpose: To fit an NTCP model including clinical risk factors to late rectal toxicities after radiotherapy for prostate cancer. Methods and materials: Data of 669 patients were considered. The probability of late toxicity within 36 months (bleeding and incontinence) was fitted with the original and a modified Logit-EUD model, including clinical factors by fitting a subset specific TD 50s: the ratio of TD 50s with and without including the clinical variable was the dose-modifying factor (D mod). Results: Abdominal surgery (surg) was a risk factor for G2-G3 bleeding, reflecting in a TD 50 = 82.7 Gy and 88.4 Gy for patients with and without surg (D mod = 0.94; 0.90 for G3 bleeding); acute toxicity was also an important risk factor for G2-G3 bleeding (D mod = 0.93). Concerning incontinence, surg and previous diseases of the colon were the clinical co-factors. D mod(surg) and D mod(colon) were 0.50 and 0.42, respectively for chronic incontinence and 0.73 and 0.64, respectively for mean incontinence score ≥1. Best-fit n values were 0.03-0.05 and 1 for bleeding and incontinence, respectively. The inclusion of clinical factors always improved the predictive value of the models. Conclusions: The inclusion of predisposing clinical factors improves NTCP estimation; the assessment of other clinical and genetic factors will be useful to reduce parameter uncertainties. © 2011 Elsevier Ltd. All rights reserved.

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