[Moderately hypofractionated dose escalation radiotherapy for localized prostate cancer, ESHYPRO: Results of a retrospective single-centre series evaluating safety and efficacy]. / Escalade de dose en radiothérapie modérément hypofractionnée pour les cancers de la prostate localisés, ESHYPRO : résultats d'une série monocentrique rétrospective évaluant la toxicité et l'efficacité.

PURPOSE: Prostate cancer is the most frequent cancer among men and radiotherapy hypofractionation regimens have become standard treatments for the localized stages, but the absence of increased risk of acute and late genitourinary or gastrointestinal toxicity of the dose escalation still must be demonstrated. MATERIAL AND METHODS: The study population included all patients with localized prostatic adenocarcinoma treated at the institut Curie from February 2016 to March 2018 by external radiation delivered by a linear accelerator using an image-guided conformal intensity modulation technique at a total dose of 75Gy in 30 fractions of 2.5Gy in the planning target volume that included the prostate and the proximal seminal vesicles, and could be paired with a prophylactic lymph node radiotherapy at 46Gy in 23 fractions with simultaneous integrated boost. RESULTS: A total of 166 patients were included. Among them, 68.6% were unfavourable intermediate or (very) high risk. The median age and follow-up were 71.4years and 3.96years. One hundred and forty-nine patients received prophylactic lymph node radiotherapy (89.8%). One hundred and thirty-one patients received hormonotherapy (78.9%). Genito-urinary toxicity events of grades 2 or above during radiotherapy, at 6months, 1year and 5years were respectively 36.7%, 8.8%, 3.1% and 4.7%. Two patients had late grade 4 toxicity at 5years (1.6%). Grade 2 gastrointestinal toxicity events during radiotherapy, 6months, 1year and 5years were respectively 15.1%, 1.9%, 14.6% and 9.3%. Of these, eight patients had grade 3 toxicity (6.2%). There was no grade 4 toxicity. Analyses did not reveal any predictive factor for toxicity. The 5-year overall, progression-free, and specific survival rates were respectively 82.4%, 85.7%, and 93.3%. Serum prostate specific antigen concentration and cardiovascular risk factors were found to be predictive factors of deterioration in overall survival (P=0.0028 for both). CONCLUSION: External radiotherapy for localized prostatic cancer with our moderately hypofractionated dose escalation regimen is well tolerated. In the absence of increased late toxicity, the analysis of the modes of long-term relapses will be interesting to determine the benefit of this dose escalation on local and distant relapses.

Scaling high-speed counter-current chromatography for preparative neodymium purification: Insights and challenges.

Efficient rare earth element (REE) separations are becoming increasingly important to technologies ranging from renewable energy and high-performance magnets to applied radioisotope separations. These separations are made challenging by the extremely similar chemical and physical characteristics of the individual elements, which almost always occupy the 3+ oxidation state under ambient conditions. Herein, we discuss the development of a novel REE separation aimed at obtaining purified samples of neodymium (Nd) on a multi-milligram scale using high-speed counter-current chromatography (HSCCC). The method takes advantage of the subtle differences in ionic radii between neighboring REEs to tune elution rates in dilute acid through implementation of the di-(2-ethylhexyl)phosphoric acid (HDEHP)-infused stationary phase (SP) of the column. A La/Ce/Nd/Sm separation was demonstrated at a significantly higher metal loading than previously accomplished by HSCCC (15 mg, RNd/REE > 0.85), while the Pr/Nd separation was achieved at lower metal loadings (0.3 mg, RNd/Pr = 0.75 - 0.83). The challenges associated with scaling REE separations via HSCCC are presented and discussed within.

Late hepatic toxicity after breast cancer intensity-modulated radiotherapy using helicoidal tomotherapy.

PURPOSE: Helical tomotherapy (HT) is a rotational intensity-modulated radiation therapy (IMRT) technique that allows target conformal irradiation and efficient organs at risk (OAR) sparing in the case of complex target volumes and specific anatomic considerations, but increases the "low-dose bath" to non-target volumes. The aim of this study was to analyze the delayed hepatotoxicity after rotational IMRT (HT) radiation therapy for non-metastatic breast cancer. PATIENTS AND METHODS: This single-center retrospective study included all non-metastatic breast cancer patients with a normal pre-radiotherapy biological hepatic function who were treated with tomotherapy between January 2010 and January 2021 and for whom the dosimetric parameters for the whole liver were assessable. A logistic regression analysis was employed. The selected covariates for the multivariate analysis were those with a P-value that was less or equal to 0.20 in the univariate analysis. RESULTS: Forty-nine patients were included in this study: 11 patients (22%) received Trastuzumab for 1 year in tumors with an HER2-expression; 27 patients (55%) received radiation therapy for cancer of the right or bilateral breasts; 43 patients (88%) received lymph node irradiation and 41 patients (84%) received a tumor bed boost. Mean and maximum doses to the liver were 2.8Gy [0.3-16.6] and 26.9Gy [0.7-51.7], respectively. With a median follow-up after irradiation was 5.4 years (range, 6 to 115 months), 11 patients (22%) had developed delayed low grade biological hepatic abnormalities: all patients had grade 1 delayed hepatotoxicity; 3 patients (6%) had additional grade 2 delayed hepatotoxicity. There was no hepatotoxicity at grade 3 or higher. According to the univariate and multivariate analysis, Trastuzumab was a significant predictive variable of late biological hepatotoxicity (OR=4.4 [1.01-20.18], P=0.04). No other variable was statistically associated with delayed biological hepatotoxicity. CONCLUSION: Delayed hepatotoxicity after multimodal non-metastatic breast cancer management including rotational IMRT was negligible. Consequently, the liver doesn't have to be considered like an organ-at-risk in the analysis of breast cancer radiotherapy but future prospectives studies are needed to confirm these findings.