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Purpose Low-dose-rate brachytherapy is a key treatment for low-risk or favorable intermediate-risk prostate cancer. The number of radioactive seeds inserted during the procedure depends on prostate volume, and is not easy to predict without pre-planning. Consequently, a large number of unused seeds may be left after treatment. The objective of the present study was to predict the exact number of seeds for future patients using machine learning and a database of 409 treatments. Material and methods Database consisted of 18 dosimetric and efficiency parameters for each of 409 cases. Nine predictive algorithms based on machine-learning were compared in this database, which was divided into training group (80%) and test group (20%). Ten-fold cross-validation was applied to obtain robust statistics. The best algorithm was then used to build an abacus able to predict number of implanted seeds from expected prostate volume only. As an evaluation, the abacus was also applied on an independent series of 38 consecutive patients. Results The best coefficients of determination R2 were given by support vector regression, with values attaining 0.928, 0.948, and 0.968 for training set, test set, and whole set, respectively. In terms of predicted seeds in test group, mean square error, median absolute error, mean absolute error, and maximum error were 2.55, 0.92, 1.21, and 7.29, respectively. The use of obtained abacus in 38 additional patients resulted in saving of 493 seeds (393 vs. 886 remaining seeds). Conclusions Machine-learning-based abacus proposed in this study aims at estimating the necessary number of seeds for future patients according to past experience. This new abacus, based on 409 treatments and successfully tested in 38 new patients, is a good alternative to non-specific recommendations.

Highlights • Hotspots can be easily identified on the pretherapeutic PET in patients with cervical cancer. • Registration of PET with planning CT allows for the dosimetric coverage evaluation of these hotspots. • The initial hotspot was not entirely included in the CTV-high risk in 40% of patients who recur during the follow-up, compared to 7% in patients without recurrence. • Hotspot was not entirely included in the CTV-high risk in 40% of patients who recur-Hotspots-guided radiotherapy could be applied easily in daily routine., Introduction Areas of high uptake on pre-treatment 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT), denoted as “hotspots”, have been identified as preferential sites of local relapse in locally advanced cervical cancer (LACC). The purpose of this study was to analyze the dosimetric coverage of these hotspots with high dose-rate brachytherapy (BT). Methods For each patient, a rigid registration of the CT from the pre-treatment PET/CT with the radiotherapy planning CT was performed using 3D SlicerTM, followed by a manual volume correction by translation and deformation if necessary. The fuzzy locally adaptive Bayesian (FLAB) algorithm was applied to PET images to simultaneously define an overall tumour volume and the high-uptake sub-volume V1. The inclusion of V1 in the high-risk clinical target volume (CTV HR) and its dosimetric coverage were evaluated using 3D SlicerTM. The average of the 3–4 BT sessions was reported. Results Forty-two patients with recurrence after chemoradiotherapy (CRT) for LACC were matched to 42 patients without recurrence. Mean ± standard deviation follow-up was 26 ± 11 months. In the recurrence group, V1 was not included in the CTV HR and not covered by the 85 Gy isodose in 17/42 patients (41%) (1/20 with pelvic recurrence and 16/22 with distant recurrence) and not by the 80 Gy isodose in 7/42 patients (17%) (all with distant recurrence). In the non-recurrence group, V1 was not included in CTV HR and not covered by the 85 Gy isodose in 3 patients only (7%). The hotspots coverage by the 85 Gy isodose was significantly better in patients who did not recur, but only when compared to patients with distant relapse (p

Purpose: To evaluate the efficacy and safety of a second course of stereotactic radiotherapy (SRT2) treatment for a local recurrence of brain metastases previously treated with SRT (SRT1), using the Hypofractionated Treatment Effects in the Clinic (HyTEC) reporting standards and the European Society for Radiotherapy and Oncology guidelines. Methods: From December 2014 to May 2021, 32 patients with 34 brain metastases received salvage SRT2 after failed SRT1. A total dose of 21 to 27 Gy in 3 fractions or 30 Gy in 5 fractions was prescribed to the periphery of the PTV (99% of the prescribed dose covering 99% of the PTV). After SRT2, multiparametric MRI, sometimes combined with 18F-DOPA PET-CT, was performed every 3 months to determine local control (LC) and radionecrosis (RN). Results: After a median follow-up of 12 months (range: 1–37 months), the crude LC and RN rates were 68% and 12%, respectively, and the median overall survival was 25 months. In a multivariate analysis, the performance of surgery was predictive of a significantly better LC (p = 0.002) and survival benefit (p = 0.04). The volume of a normal brain receiving 5 Gy during SRT2 (p = 0.04), a dose delivered to the PTV in SRT1 (p = 0.003), and concomitant systemic therapy (p = 0.04) were associated with an increased risk of RN. Conclusion: SRT2 is an effective approach for the local recurrence of BM after initial SRT treatment and is a potential salvage therapy option for well-selected people with a good performance status. Surgery was associated with a higher LC.

The standard therapy strategy for high-grade glioma (HGG) is based on the maximal surgery followed by radio-chemotherapy (RT-CT) with insufficient control of the disease. Recurrences are mainly localized in the radiation field, suggesting an interest in radiotherapy dose escalation to better control the disease locally. We aimed to identify a similarity between the areas of high uptake on O-(2-[18F]-fluoroethyl)-L-tyrosine (FET) positron emission tomography/computed tomography (PET) before RT-CT, the residual tumor on post-therapy NADIR magnetic resonance imaging (MRI) and the area of recurrence on MRI. This is an ancillary study from the IMAGG prospective trial assessing the interest of FET PET imaging in RT target volume definition of HGG. We included patients with diagnoses of HGG obtained by biopsy or tumor resection. These patients underwent FET PET and brain MRIs, both after diagnosis and before RT-CT. The follow-up consisted of sequential brain MRIs performed every 3 months until recurrence. Tumor delineation on the initial MRI 1 (GTV 1), post-RT-CT NADIR MRI 2 (GTV 2), and progression MRI 3 (GTV 3) were performed semi-automatically and manually adjusted by a neuroradiologist specialist in neuro-oncology. GTV 2 and GTV 3 were then co-registered on FET PET data. Tumor volumes on FET PET (MTV) were delineated using a tumor to background ratio (TBR) ≥ 1.6 and different % SUVmax PET thresholds. Spatial similarity between different volumes was performed using the dice (DICE), Jaccard (JSC), and overlap fraction (OV) indices and compared together in the biopsy or partial surgery group (G1) and the total or subtotal surgery group (G2). Another overlap index (OV’) was calculated to determine the threshold with the highest probability of being included in the residual volume after RT-CT on MRI 2 and in MRI 3 (called “hotspot”). A total of 23 patients were included, of whom 22% (n = 5) did not have a NADIR MRI 2 due to a disease progression diagnosed on the first post-RT-CT MRI evaluation. Among the 18 patients who underwent a NADIR MRI 2, the average residual tumor was approximately 71.6% of the GTV 1. A total of 22% of patients (5/23) showed an increase in GTV 2 without diagnosis of true progression by the multidisciplinary team (MDT). Spatial similarity between MTV and GTV 2 and between MTV and GTV 3 were higher using a TBR ≥ 1.6 threshold. These indices were significantly better in the G1 group than the G2 group. In the FET hotspot analysis, the best similarity (good agreement) with GTV 2 was found in the G1 group using a 90% SUVmax delineation method and showed a trend of statistical difference with those (poor agreement) in the G2 group (OV’ = 0.67 vs. 0.38, respectively, p = 0.068); whereas the best similarity (good agreement) with GTV 3 was found in the G1 group using a 80% SUVmax delineation method and was significantly higher than those (poor agreement) in the G2 group (OV’= 0.72 vs. 0.35, respectively, p = 0.014). These results showed modest spatial similarity indices between MTV, GTV 2, and GTV 3 of HGG. Nevertheless, the results were significantly improved in patients who underwent only biopsy or partial surgery. TBR ≥ 1.6 and 80–90% SUVmax FET delineation methods showing a good agreement in the hotspot concept for targeting standard dose and radiation boost. These findings need to be tested in a larger randomized prospective study.

BackgroundModern radiotherapy (RT) planning techniques and the use of oral supportive care have reduced the occurrence of acute radiation-induced toxicities. Oral mucositis remains a major concern in patients with head and neck cancer as it can compromise treatment compliance and outcome.ObjectiveTo report the rate of mucositis with the preventive use of surface low-level laser therapy in patients with head and neck cancer.MethodsForty patients treated with definitive (n=27) or adjuvant (n=13) RT using volumetric arc therapy between August 2014 and October 2015 for squamous cell carcinoma of the head and neck were included. All patients were treated using photobiomodulation using surface low-level laser therapy (Heltschl kind FL 3500, 350 mW), 3 times a week during the whole treatment course. The grade of mucositis was obtained from week 1 to week 7 and at 1 month.ResultsThe median RT dose was 70 Gy (64–70). Concomitant chemotherapy was administered in 29 patients. According to the Common Terminology Criteria for Adverse Events (CTCAE) v. 3, grade 0, 1, 2 and 3 mucositis was observed in 9 (22.5%), 9 (22.5%), 16 (40%) and 6 (15%) patients at week 7, and 32 (80%), 2 (5%), 3 (7.5%) and 3 (7.5%) patients at 1 month following treatment. No grade 4 occurred. Median average and maximum dose to the oral mucosa was 42 Gy (12.9–66.3) and 66.6 Gy (39–76), respectively.ConclusionDespite a substantial dose to the oral mucosa, the rate of acute radiation-induced mucositis of grade ≥3 remains low in patients receiving extraoral low-energy laser during RT.

Standard treatment for locally advanced cervical cancer (LACC) is chemoradiotherapy followed by brachytherapy. Despite radiation therapy advances, the toxicity rate remains significant. In this study, we compared the prediction of toxicity events after radiotherapy for locally advanced cervical cancer (LACC), based on either dose-volume histogram (DVH) parameters or the use of a radiomics approach applied to dose maps at the voxel level. Toxicity scores using the Common Terminology Criteria for Adverse Events (CTCAE v4), spatial dose distributions, and usual clinical predictors for the toxicity of 102 patients treated with chemoradiotherapy followed by brachytherapy for LACC were used in this study. In addition to usual DVH parameters, 91 radiomic features were extracted from rectum, bladder and vaginal 3D dose distributions, after discretization into a fixed bin width of 1 Gy. They were evaluated for predictive modelling of rectal, genitourinary (GU) and vaginal toxicities (grade ≥ 2). Logistic Normal Tissue Complication Probability (NTCP) models were derived using clinical parameters only or combinations of clinical, DVH and radiomics. For rectal acute/late toxicities, the area under the curve (AUC) using clinical parameters was 0.53/0.65, which increased to 0.66/0.63, and 0.76/0.87, with the addition of DVH or radiomics parameters, respectively. For GU acute/late toxicities, the AUC increased from 0.55/0.56 (clinical only) to 0.84/0.90 (+DVH) and 0.83/0.96 (clinical + DVH + radiomics). For vaginal acute/late toxicities, the AUC increased from 0.51/0.57 (clinical only) to 0.58/0.72 (+DVH) and 0.82/0.89 (clinical + DVH + radiomics). The predictive performance of NTCP models based on radiomics features was higher than the commonly used clinical and DVH parameters. Dosimetric radiomics analysis is a promising tool for NTCP modelling in radiotherapy.

International audience; Purpose: (Chemo)-radiotherapy (RT) is the gold standard treatment for patients with locally advanced lung cancer non accessible for surgery. However, current toxicity prediction models rely on clinical and dose volume histograms (DVHs) and remain unsufficient. The goal of this work is to investigate the added predictive value of the radiomics approach applied to dose maps regarding acute and late toxicities in both the lungs and esophagus.Methods: Acute and late toxicities scored using the CTCAE v4.0 were retrospectively collected on patients treated with RT in our institution. Radiomic features were extracted from 3D dose maps considering Gy values as grey-levels in images. DVH and usual clinical factors were also considered. Three toxicity prediction models (clinical only, clinical + DVH and combined, i.e., including clinical + DVH + radiomics) were incrementally trained using a neural network on 70% of the patients for prediction of grade ≥2 acute and late pulmonary toxicities (APT/LPT) and grade ≥2 acute esophageal toxicities (AET). After bootstrapping (n = 1000), optimal cut-off values were determined based on the Youden Index. The trained models were then evaluated in the remaining 30% of patients using balanced accuracy (BAcc).Results: 167 patients were treated from 2015 to 2018: 78% non small-cell lung cancers, 14% small-cell lung cancers and 8% other histology with a median age at treatment of 66 years. Respectively, 22.2%, 16.8% and 30.0% experienced APT, LPT and AET. In the training set (n = 117), the corresponding BAcc for clinical only/clinical + DVH/combined were 0.68/0.79/0.92, 0.66/0.77/0.87 and 0.68/0.73/0.84. In the testing evaluation (n = 50), these trained models obtained a corresponding BAcc of 0.69/0.69/0.92, 0.76/0.80/0.89 and 0.58/0.73/0.72.Conclusion: In patients with a lung cancer treated with RT, radiomic features extracted from 3D dose maps seem to surpass usual models based on clinical factors and DVHs for the prediction of APT and LPT.

Glioblastomas are frequent malignant brain tumours with a very poor prognosis and a need for new and efficient therapeutic strategies. With the approval of anti-TRK targeted therapies to treat patients with advanced NTRK-rearranged cancers, independent of the type of cancer, potential new treatment opportunities are available for the 0.5-5% of patients with NTRK-rearranged glioblastomas. Identification of these rare NTRK-rearranged glioblastomas requires efficient diagnostic tools and strategies which are evaluated in this study. We compared the results of NTRK1, NTRK2 and NTRK3 fluorescent in situ hybridisation (FISH) assays to those of pan-TRK immunohistochemistry (IHC) using two EPR17341 and A7H6R clones in a set of 196 patients with glioblastomas. Cases with at least 15% of positive nuclei using FISH analyses were further analysed using RNA sequencing. Above the 15% threshold, seven positive glioblastomas (3.57%) were identified by FISH assays (4 NTRK1, 3 NTRK2, no NTRK3). NTRK rearrangements were confirmed by RNA sequencing analyses in four cases [1 LMNA-NTRK1, 1 PRKAR2A-NTRK2, 1 SPECC1L-NTRK2 and 1 NACC2-NTRK2 fusions, i.e., 4/196 (2%) of NTRK-rearranged tumours in our series] but no rearrangement was detected in three samples with less than 30% of positive tumour nuclei as determined by NTRK1 FISH. Pan-TRK immunostaining showed major discrepancies when using either the EPR17341 or the A7H6R clones for the following criteria: main intensity, H-Score based scoring and homogeneity/heterogeneity of staining (Kappa values

International audience; Purpose: The aim of this study was to prospectively investigate tumor volume delineation by amino acid PET and multiparametric perfusion magnetic resonance imaging (MRI) in patients with newly diagnosed, untreated high grade glioma (HGG).Materials and methods: Thirty patients with histologically confirmed HGG underwent O-(2-[18F]-fluoroethyl)-l-tyrosine (18F-FET) positron emission tomography (PET), conventional Magnetic Resonance Imaging (MRI) as contrast-enhanced (CE) and fluid-attenuated inversion recovery (FLAIR) and multiparametric MRI as relative cerebral blood volume (rCBV) and permeability estimation map (K2). Areas of MRI volumes were semi-automatically segmented. The percentage overlap volumes, Dice and Jaccard spatial similarity coefficients (OV, DSC, JSC) were calculated.Results: The 18F-FET tumor volume was significantly larger than the CE volume (median 43.5 mL (2.5-124.9) vs. 23.8 mL (1.4-80.3), p = 0.005). The OV between 18F-FET uptake and CE volume was low (median OV 0.59 (0.10-1)), as well as spatial similarity (median DSC 0.52 (0.07-0.78); median JSC 0.35 (0.03-0.64)). Twenty-five patients demonstrated both rCBV and CE on MRI: The median rCBV tumor volume was significantly smaller than the median CE volume (p < 0.001). The OV was high (median 0.83 (0.54-1)), but the spatial similarity was low (median DSC 0.45 (0.04-0.83); median JSC 0.29 (0.07-0.71)). Twenty-eight patients demonstrated both K2 and CE on MRI. The median K2 tumor volume was not significantly larger than the median CE volume. The OV was high (median OV 0.90 (0.61-1)), and the spatial similarity was moderate (median DSC 0.75 (0.01-0.83); median JSC 0.60 (0.11-0.89)).Conclusion: We demonstrated that multiparametric perfusion MRI volumes (rCBV, K2) were highly correlated with CE T1 gadolinium volumes whereas 18F-FET PET provided complementary information, suggesting that the metabolically active tumor volume in patients with newly diagnosed untreated HGG is critically underestimated by contrast enhanced MRI. 18F-FET PET imaging may help to improve target volume delineation accuracy for radiotherapy planning.

Purpose Brachytherapy (BrT) is a standard treatment for low-risk to favorable-intermediate-risk prostate cancer but is a relative contraindication for patients with obstructive symptoms. We aimed to assess the feasibility and urinary toxicity of a minimal photovaporization (mPVP) before implantation. Materials and Methods Between 04/2009 and 08/2016, 50 patients candidates for BrT but with International Prostate Symptom Score (IPSS)>15, uroflowmetry Results Two patients (4%) did not have sufficient improvement and did not undergo BrT, although it would have been possible at 3 months. For the 48 (96%) other patients, at the baseline, mean IPSS was 15.5 (±5.3), vs. 8.6 (±4.4) after mPVP (p = 1 × 10−6), and uroflowmetry 11.7 mL/s (±4), vs. 17.4 (±5.4) (p = 1.4 × 10−5). We did not experience any difficulty for BrT. Mean IPSS did not significantly increase 1, 3, or 6 months after BrT. With a median followup of 60 months [30–120], (92% assessed at last followup), only 4 patients (4/48 = 8.3%) experienced urinary retention and 5 (10.4%) needed surgery for urinary toxicity. In addition, only 2 patients (4%) needed medical treatment at last followup. Considering the 8 patients with de novo incontinence at 1 year, only 2 (4%) had persistent mild symptoms at last followup (36 months) (ICS1-2). Conclusions These results suggest that a two-step approach with an mPVP at least 6 weeks before BrT is feasible, with no excessive urinary toxicity, and may be a good strategy for obstructive patients seeking BrT.

Purpose During radiotherapy (RT) for prostate cancer (PCa), interfraction and intrafraction movements can lead to decreased target dose coverage and unnecessary over-exposure of organs at risk. New image-guided RT techniques accuracy allows planning target volume (PTV) margins reduction. We aim to assess the feasibility of a kilovoltage intrafraction monitoring (KIM) to track the prostate during RT. Methods and materials Between November 2017 and April 2018, 44 consecutive patients with PCa were included in an intrafraction prostate motion study using the Truebeam Auto Beam Hold® tracking system (Varian Medical Systems, United State) triggered by gold fiducials localization on kilovoltage (kV) imaging. A 5-mm PTV was considered. A significant gating event (SGE) was defined as the occurrence of an automatic beam interruption requiring patient repositioning following the detection of one fiducial outside a 5-mm target area around the marker during more than 45 seconds. Results Six patients could not benefit from the KIM because of technical issues (loss of one fiducial marker = 1, hip prosthesis = 4, morbid obesity causing table movements = 1). The mean rate of SGE per patient was 14 ± 19%, and the fraction average delivery time was increased by 146 ± 86 seconds. For a plan of 39 fractions of 2 Gy, the additional radiation dose increased by 0.13 ± 0.09 Gy. The mean rates of SGE were 2% and 18% (P = 0.002) in patients with planned fraction 90 seconds respectively, showing that duration of the session strongly interfered with prostate intrafraction movements. No other significant clinical and technical parameter was correlated with the occurrence of SGE. Conclusion Automated intrafraction kV imaging can effectively perform autobeam holds due to intrafraction movement of the prostate in the large majority of patients. The additional radiation dose and delivery time are acceptable. This technique may be a cost-effective alternative to electromagnetic transponder guidance.

The aim of this study was to prospectively investigate tumor volume delineation by amino acid PET and multiparametric perfusion magnetic resonance imaging (MRI) in patients with newly diagnosed, untreated high grade glioma (HGG).Thirty patients with histologically confirmed HGG underwent O-(2-[TheWe demonstrated that multiparametric perfusion MRI volumes (rCBV, K2) were highly correlated with CE T1 gadolinium volumes whereas

O-(2-[18F]fluoroethyl)-l-tyrosine positron-emission tomography/computed tomography (18F-FET PET/CT) is well known in brain tumor management. Our study aimed to identify the prognostic value of 18F-FET PET/CT in high-grade gliomas (HGG) according the current 2016 World Health Organization (WHO) classification. Patients with histologically proven WHO 2016 HGG were prospectively included. A dynamic 18F-FET PET/CT was performed allowing to obtain 2 static PET frames (static frame 1: 20–40 minutes and static frame 2: 2–22 minutes). We analyzed static parameters (standard uptake value [SUV]max, SUVmean, SUVpeak, TBRmax, TBRmean, tumoral lesion glycolysis, and metabolic tumoral volume) for various isocontours (from 10% to 90%). PET parameters, clinical features, and molecular biomarkers were compared with progression-free survival (PFS) and overall survival (OS) in univariate and multivariate analysis. Twenty-nine patients were included (grade III n = 3, grade IV n = 26). Mean PFS and OS were, respectively, 8.8 and 13.9 months. According to univariate analysis, SUVmean, SUVpeak, TBRmax, and TBRmean were significantly correlated with OS. In static 1 analysis, TBRmax seemed to be the best OS prognostic parameter (P = .004). In static 2 analysis, TBRmean was the best parameter (P = .01). In static 1 analysis, only SUVpeak was significant (P = .05) for PFS. Good performance status (PS

Simple Summary Approximately 30% of patients diagnosed with cancer will ultimately develop brain metastases. Many improvements have been made in systemic and local cancer treatments, which have increased overall survival but also, as a consequence, the number of patients who present with local recurrence following intracranial stereotactic radiotherapy. The management of these recurrences remains controversial. The aim of our review is to evaluate the efficacy and tolerance of a second course of stereotactic radiotherapy. Abstract Recent advances in cancer treatments have increased overall survival and consequently, local failures (LFs) after stereotactic radiotherapy/radiosurgery (SRS/SRT) have become more frequent. LF following SRS or SRT may be treated with a second course of SRS (SRS2) or SRT (SRT2). However, there is no consensus on whenever to consider reirradiation. A literature search was conducted according to PRISMA guidelines. Analysis included 13 studies: 329 patients (388 metastases) with a SRS2 and 135 patients (161 metastases) with a SRT2. The 1-year local control rate ranged from 46.5% to 88.3%. Factors leading to poorer LC were histology (melanoma) and lack of prior whole-brain radiation therapy, large tumor size and lower dose at SRS2/SRT2, poorer response at first SRS/SRT, poorer performance status, and no controlled extracranial disease. The rate of radionecrosis (RN) ranged from 2% to 36%. Patients who had a large tumor volume, higher dose and higher value of prescription isodose line at SRS2/SRT2, and large overlap between brain volume irradiated at SRS1/SRT1 and SRS2/SRT2 at doses of 18 and 12 Gy had a higher risk of developing RN. Prospective studies involving a larger number of patients are still needed to determine the best management of patients with local recurrence of brain metastases

Purpose: Inadequate clinical target volume (CTV) definition is likely to be a major contributing factor to local recurrence (LR) rate after radiotherapy. Our aims were to identify sites of prostate cancer LR in biochemical recurrence post-prostatectomy using 18F-Fluorocholine (18F-FCH) positron emission tomography/computed tomography (PET/CT) and to compare different CTV-delineation guidelines in a cohort of postoperative patients.Material and methods: Thirty-six patients presenting with LR within the prostatic bed on 18F-FCH PET/CT between 10/2011 and 06/2016 were included in this retrospective study. Median PSA at the time of 18F-FCH PET/CT was 2.7 ng/mL (0.8–9.4) and median PSA doubling time was 11 months (3–28). For each patient, the CTVRTOG, CTVFROGG and CTVEORTC following the corresponding guidelines were outlined and compared. Forty-one LR were delineated using a gradient-based method and the percentage of FCH uptake included in each CTV was evaluated.Results: The anastomosis was the most c...

Cetuximab, a chimeric monoclonal antibody against EGFR sensitizes tumors to radiotherapy (RT), but is associated with skin and mucosal toxicity. We report outcomes and tolerance of definitive RT in association with cetuximab in patients with locally advanced squamous cell carcinoma (LASCC) of the head and neck. Between 2006 and 2011, 92 consecutive patients with LASCC of the head and neck were treated with RT and concomitant weekly cetuximab. Median age was 61.7 years. Most patients presented with oropharyngeal tumors (52.2%) and stage IV disease (77.2%). Sixty-nine patients received at least 7 cycles of cetuximab. Cetuximab was stopped at the first infusion following allergic reactions in four patients. During RT, 37% of patients developed grade ≥ 3 dermatitis; grade ≥ 2 cetuximab-induced rash occurred in 43 patients (46.7%). Severe mucositis (grade ≥ 3) affected 57.6% of patients. Ten percent of patients did not receive the full course of RT, and temporary discontinuation due to acute toxicity was frequent and affected 37 patients (53%). The median RT overall treatment time (OTT) in patients with interrupted RT was 56 days (47–75) compared to 51 days (47–65) in patients who did not require toxicity-related radiation interruptions (p

Personalized medicine aims at offering optimized treatment options and improved survival for cancer patients based on individual variability. The success of precision medicine depends on robust biomarkers. Recently, the requirement for improved non-biologic biomarkers that reflect tumor biology has emerged and there has been a growing interest in the automatic extraction of quantitative features from medical images, denoted as radiomics. Radiomics as a methodological approach can be applied to any image and most studies have focused on PET, CT, ultrasound, and MRI. Here, we aim to present an overview of the radiomics workflow as well as the major challenges with special emphasis on the use of multiparametric MRI datasets. We then reviewed recent studies on radiomics in the field of pelvic oncology including prostate, cervical, and colorectal cancer.

The aim of this retrospective multicentric study was to develop and evaluate a prognostic

Introduction The aim of this study was to analyze the impact of inhomogeneous versus homogeneous dose distribution on local control (LC) and radionecrosis (RN) in patients treated with fractionated stereotactic radiotherapy (SRT) for newly-diagnosed brain metastases (BM). Patients and methods From 2014 to 2017, 134 patients (median age 61 years) underwent SRT for BM (n = 114 with ≤2, n = 20 with 3–6 BM) at our institution. Treatment was delivered using volumetric modulated arc therapy on a linear accelerator. Ninety-one consecutive patients (BM = 136) were irradiated at a dose of 21–23.1 Gy in 3 fractions delivered homogeneously (99% of the dose had to cover 99% of the planning target volume (PTV)) (group 1) whereas the following 43 patients (BM = 72) received an inhomogeneous dose of 10 or 11 Gy prescribed to the isocenter with the 70% isodose line covering the PTV (group 2). Variables analyzed included dose distribution, age, gender, histology, diagnosis-specific Graded Prognostic Assessment score, number of brain metastases, presence of extracranial metastases, and tumor volumes. Results After a median follow-up of 12.4 months (range, 1.4–33.1), the 1-year LC and RN rate were 78% and 7.5% in group 1 and 93% and 0% in group 2, respectively (p = 0.005). In multivariate analysis, improved LC was significantly correlated with SRT dose distribution (p = 0.009) and tumor volume (p = 0.03). The number of metastases (p = 0.03) and SRT dose distribution (p = 0.04) were both associated with increased risk of RN. Conclusion SRT delivered with inhomogeneous dose distribution resulted in better LC and a lower risk of RN compared to homogeneous distribution.

F-fluoroethyltyrosine (FET) is a well-established PET tracer for the imaging of cerebral gliomas. Recent studies reported interest in meningiomas. A study published by Cornelius et al concludes that FET PET may provide additional information for noninvasive grading of meningiomas. Indeed, the combination of tumor background ratio with a cutoff value of 2.3 associated with time activity curve pattern slightly improved the differentiation of high-grade from low-grade meningiomas (accuracy, 92%; P = 0.001). We present the case of a 75-year-old man that underlined the need to confirm the performance of these tools (curve pattern, tumor background ratios) to characterize meningiomas.

Introduction et but de l’etude L’objectif de cette etude etait de developper et d’evaluer une signature radiomique en utilisant l’imagerie tomographique par emission de positons (TEP/TDM) chez des patients atteints d’un cancer du poumon non a petites cellules traites par irradiation stereotaxique. Materiel et methodes Il s’agit d’une etude retrospective multicentrique portant sur 87 patients atteints d’un atteints d’un cancer du poumon non a petites cellules de stade T1-T2 traite dans quatre centres du Grand Ouest. Les patients des trois premiers centres (n = 27, 29 et 8) constituaient le groupe d’apprentissage, et ceux du quatrieme (n = 23) le groupe de validation. Le critere d’evaluation principal etait le controle local. En tout, 184 parametres radiomiques ont ete extraits (92 de chaque modalite) et sept parametres cliniques, histologiques et therapeutiques ont ete consideres. En raison des differents scanographes et protocoles d’acquisition des institutions, nous avons utilise la methode ComBat pour harmoniser les parametres de texture. Resultats et analyse statistique En analyse unifactorielle, deux parametres issus de la TEP et deux de la scanographie etaient significativement predictifs du controle local, a l’inverse des variables cliniques. Le meilleur modele predictif du groupe d’apprentissage etait obtenu en associant deux parametres TEP (IC2 et strength), avec une sensibilite de 100 % et une specificite de 88 %, et un hazard ratio indefini (p Conclusion Notre etude a permis d’identifier deux parametres de textures derives de la TEP/scanographie comme facteurs predictifs independants associes a la recidive locale chez les patients atteints d’un cancer du poumon non a petites cellules traites par irradiation stereotaxique. Ce modele merite d’etre confirme sur une cohorte plus consequente et pourrait etre utilise en clinique pour guider une eventuelle escalade de dose.

The aim of this retrospective multicentric study was to develop and evaluate a prognostic 18F-FDG PET/CT radiomic signature in early-stage non-small cell lung cancer patients treated with stereotactic body radiotherapy (SBRT). Methods: Patients from 3 different centers (n = 27, 29, and 8) were pooled to constitute the training set, whereas the patients from a fourth center (n = 23) were used as the testing set. The primary endpoint was local control. The primary tumor was semiautomatically delineated in the PET images using the fuzzy locally adaptive Bayesian algorithm, and manually in the low-dose CT images. In total, 184 Image Biomarkers Standardization Initiative-compliant radiomic features were extracted. Seven clinical and treatment parameters were included. We used ComBat to harmonize radiomic features extracted from the 4 institutions relying on different PET/CT scanners. In the training set, variables found significant in the univariate analysis were fed into a multivariate regression model, and models were built by combining independent prognostic factors. Results: Median follow-up was 21.1 mo (range, 1.7-63.4 mo) and 25.5 mo (range, 7.7-57.8 mo) in training and testing sets, respectively. In univariate analysis, none of the clinical variables, 2 PET features, and 2 CT features were significantly predictive of local control. The best predictive models in the training set were obtained by combining one feature from PET (Information Correlation 2) and one feature from CT (flatness), reaching a sensitivity of 100% and a specificity of 96%. Another model combining 2 PET features (Information Correlation 2 and strength) reached sensitivity of 100% and specificity of 88%, both with an undefined hazard ratio (P < 0.001). The latter model obtained an accuracy of 0.91 (sensitivity, 100%; specificity, 81%), with a hazard ratio undefined (P = 0.023) in the testing set; however, other models relying on CT radiomic features only or the combination of PET and CT features failed to validate in the testing set. Conclusion: We showed that 2 radiomic features derived from 18F-FDG PET were independently associated with local control in patients with non-small cell lung cancer undergoing SBRT and could be combined in an accurate predictive model. This model could provide local relapse-related information and could be helpful in clinical decision making.