A major advance of tropical Andean glaciers during the Antarctic cold reversal.

The Younger Dryas stadial, a cold event spanning 12,800 to 11,500 years ago, during the last deglaciation, is thought to coincide with the last major glacial re-advance in the tropical Andes. This interpretation relies mainly on cosmic-ray exposure dating of glacial deposits. Recent studies, however, have established new production rates for cosmogenic (10)Be and (3)He, which make it necessary to update all chronologies in this region and revise our understanding of cryospheric responses to climate variability. Here we present a new (10)Be moraine chronology in Colombia showing that glaciers in the northern tropical Andes expanded to a larger extent during the Antarctic cold reversal (14,500 to 12,900 years ago) than during the Younger Dryas. On the basis of a homogenized chronology of all (10)Be and (3)He moraine ages across the tropical Andes, we show that this behaviour was common to the northern and southern tropical Andes. Transient simulations with a coupled global climate model suggest that the common glacier behaviour was the result of Atlantic meridional overturning circulation variability superimposed on a deglacial increase in the atmospheric carbon dioxide concentration. During the Antarctic cold reversal, glaciers advanced primarily in response to cold sea surface temperatures over much of the Southern Hemisphere. During the Younger Dryas, however, northern tropical Andes glaciers retreated owing to abrupt regional warming in response to reduced precipitation and land-surface feedbacks triggered by a weakened Atlantic meridional overturning circulation. Conversely, glacier retreat during the Younger Dryas in the southern tropical Andes occurred as a result of progressive warming, probably influenced by an increase in atmospheric carbon dioxide. Considered with evidence from mid-latitude Andean glaciers, our results argue for a common glacier response to cold conditions in the Antarctic cold reversal exceeding that of the Younger Dryas.

Reproducibility of Deep-Inspiration Breath Hold treatments on Halcyon™ performed using the first clinical version of AlignRT InBore™: Results of CYBORE study.

Background and purpose: To investigate the reproducibility of deep-inspiration breath hold (DIBH) breast cancer treatments on Halcyon™ performed using the first clinical version of AlignRT InBore™ (Vision RT Ltd., London, UK), a Halcyon's SGRT dedicated solution. Materials and methods: The ease and feasibility of DIBH treatments was retrospectively investigated for the initial 22 left breast cancer patients treated on Halcyon™ using AlignRT InBore™. Setup time, Cone beam computed tomography (CBCT) imaging and analysis time as well as overall treatment time were recorded. Online and offline review of CBCT images was undertaken to verify the compliance of breast, heart, spine, sternum and diaphragmatic domes positions. Results: Mean duration of patient setup, CBCT analysis and overall treatment time were 4 min, 1.1 min and 14 min respectively. Online review of 520 CBCT acquisitions by therapists showed minimal positioning shifts with AlignRT InBore™ guidance with mean value of vertical, longitudinal, and lateral shifts of 1.7 mm, -1.7 mm, and -0.2 mm respectively. Meanwhile, offline review of 115 CBCTs by the radiation oncologist, showed reproducible breath hold (BH) with average deviation of breast, heart, spine, sternum and diaphragmatic domes respectively within 2.4 mm, 2.9 mm, 3.3 mm, 3.2 mm and 4.5 mm in magnitude. Conclusion: AlignRT InBore™ allows for accurate and reproducible DIBH on Halcyon™ with breast and heart organs' positions within 3 mm in magnitude of expected position and fully compliant with planning margins (5 mm anisotropic CTV-PTV margins).

[Prognosis factors after lung stereotactic body radiotherapy for non-small cell lung carcinoma]. / Facteurs de récidive après radiothérapie stéréotaxique des cancers bronchiques non à petites cellules.

Lung cancer is the fourth most common cancer in France with a prevalence of 30,000 new cases per year. Lobectomy surgery with dissection is the gold standard treatment for T1-T2 localized non-small cell lung carcinoma. A segmentectomy may be proposed to operable patients but fragile from a respiratory point of view. For inoperable patients or patients with unsatisfactory pulmonary function tests, local treatment with stereotactic radiotherapy may be proposed to achieve local control rates ranging from 85 to 95% at 3-5 years. Several studies have examined prognostic factors after stereotaxic pulmonary radiotherapy. We conducted a general review of the literature to identify factors affecting local control.

[Radiotherapy for ovarian carcinoma management: Literature review]. / Place de la radiothérapie dans le traitement des cancers ovariens : revue de la littérature.

Ovarian cancer is the fifth most common cancer in women in France with 4714 new cases in 2017. More than 70% of patients whose disease is initially locally advanced will present locoregional or distant recurrence. Therapeutic options in this situation are not consensual. They are based on chemotherapy possibly associated with an iterative cytoreductive surgery when it is bearable by the patient. The place of radiotherapy in the management of the disease is hidden in the vast majority of national or international standards. We conducted a general review of the literature to clarify the role of irradiation in the global management of ovarian cancers, particularly in recurrence.

[Adjuvant contact radiotherapy for conjunctival malignancies: Preliminary results of a series of 14 patients treated with the Papillon 50 machine]. / Radiothérapie de contact adjuvante des tumeurs malignes de la conjonctive : résultats préliminaires d'une série de 14 patients traités avec l'appareil Papillon 50.

PURPOSE: To evaluate the results of an adjuvant contact irradiation using 50kV photons after resection of conjunctival malignancies. MATERIALS AND METHOD: From 2012 to 2014, 14 patients (male: nine; female: five) have been treated by contact irradiation after resection of a malignant tumor of the conjunctiva (melanoma: five patients; malignant fibrous histiocytoma: one patient; carcinoma: eight patients) The treatment was performed using the Papillon 50 machine (Ariane). Three to four sessions were delivered, each giving a dose of 10Gy. The median follow-up in survivors was 33 months. RESULTS: The tolerance was good. A cataract was seen in one patient, and a moderate eye dryness in one. There was no corneal ulcer. One patient died of intercurrent disease. One patient with carcinoma recurred locally. CONCLUSION: Adjuvant contact radiotherapy provides a good local control after resection of conjunctival malignancies (melanoma, malignant histiocytofibroma, carcinoma). Thanks to its precision, this technique is well tolerated with a low rate of complications. Furthermore, it is delivered on an ambulatory basis.

Twin machines validation for VMAT treatments using electronic portal-imaging device: a multicenter study.

PURPOSE: To verify the accuracy of volumetric arc therapy (VMAT) using the RapidArc™ device when switching patients from one single linear accelerator (linac) to a paired energy and mechanics "twin" linac without reoptimization of the original treatment plan. PATIENTS AND METHODS: Four centers using 8 linacs were involved in this study. Seventy-four patients previously treated with the 6MV photon RapidArc™ technique were selected for analysis, using 242 measurements. In each institution, all patients were planned on linac A, and their plans were verified both on linac A and on the twin linac B. Verifications were done using the amorphous silicium electronic portal imager (EPID) of the linacs and were analyzed with the EpiQa software (Epidos, Bratislavia, Slovakia). The gamma index formalism was used for validation with a double threshold of 3 % and 3 mm with a measurement resolution of 0.39 mm/pixel, and a smoothed resolution of approximately 2.5 mm. RESULTS: The number of points passing the gamma criteria between the measured and computed doses was 94.79 ± 2.57 % for linac A and 94.61 ± 2.46 % for linac B. Concerning the smoothed measurement analysis, 98.67 ± 1.26 % and 98.59 ± 1.20 % points passing the threshold were obtained for linacs A and B, respectively. The difference between the 2 dose matrices acquired on the EPID was very small, with 99.92 ± 0.06 % of the points passing the criteria. CONCLUSION: For linacs sharing the same mechanical and energy parameters, this study tends to indicate that patients may be safely switched from treatment with one linac to treatment with its twin linac using the same VMAT plan.

[Tolerance and efficacy of conformal radiotherapy for hepatocellular carcinoma in cirrhotic patients. Results of the French RTF1 phase II trial]. / Tolérance et efficacité de la radiothérapie de conformation en cas de carcinome hépatocellulaire chez le patient cirrhotique. Résultats de l'essai de phase II RTF1.

PURPOSE: While some patients presenting with hepatocellular carcinoma (HCC) benefit from curative therapies (transplantation, surgery, percutaneous ablation), others are only candidates for palliative options such as chemoembolization or symptomatic care. Although conventional external-beam radiotherapy of the liver is regarded as little efficient and potentially toxic in cirrhotic patients, 3-dimensional conformal radiotherapy (CRT), by decreasing the amount of normal liver included in the radiation portal, allows dose escalation to occur without increasing the risk of radiation-induced hepatitis. This trial was designed to assess the efficacy and tolerance of CRT for small-size HCC in cirrhotic patients. PATIENTS AND METHODS: Prospective phase II trial including stage A/B cirrhotic patients with small-size HCC not suitable for curative treatments; CRT consisted in a standard fractionation radiation, with a total dose of 66 Gy. RESULTS: Twenty-seven patients were included, 15 of whom had previously been treated for HCC; mean age was 68. Among the 23 assessable patients, 18 (78%) presented with complete response, 3 (13%) with partial response, and 2 with no response. Acute complications occurred in 24 patients, and were mainly acceptable (grade 1/2: 22 patients, grade 3/4: 11 patients, 4 (15%) of whom had clinical and/or hematological toxicities). Only 2 (9%) grade 3/4 clinical and/or hematological late toxicities are reported. CONCLUSION: CRT is a non-invasive curative technique highly suitable for small-size HCC in cirrhotic patients; further investigations are needed to compare it to the other available treatments, and to integrate it into the curative therapeutic algorithm of HCC.

[Chemoradiation for pancreatic adenocarcinoma]. / Chimioradiothérapie des adénocarcinomes pancréatiques.

Surgery remains the cornerstone treatment for pancreatic adenocarcinoma. However, 5% to 20% of tumors only are regarded as resectable, and, among them, only few benefit from an histological complete resection, major survival parameter. These data explain the overall poor prognosis of this disease, with a respectively 20% and 5% 1- and 5-year survival rates. These results justify an adjuvant or neoadjuvant therapeutic approach, mainly based on concurrent chemoradiation, with and without surgery. This paper reviews the different therapeutic approaches of non metastatic pancreatic adenocarcinoma.

Feasibility of high-dose three-dimensional radiation therapy in the treatment of localised non-small-cell lung cancer.

PURPOSE: Chemoradiotherapy is the standard treatment of inoperable and/or non-resectable IIIA/B non-small-cell lung cancer (NSCLC). Aware of the necessity to increase local control in locally advanced NSCLC, we analyzed the feasibility of high-dose three-dimensional conformal radiation therapy (3D-CRT) in the treatment of localised NSCLC. PATIENTS AND METHODS: We undertook a retrospective analysis of consecutive patients with non-resectable NSCLC treated with high-dose (74Gy) standard-fractionation 3D-CRT, with particular attention to the relationship between lung and heart radiation-induced toxicities. RESULTS: Fifty patients (41 males, 9 females) were included. A total of 35 (70%) patients received the planned total dose of 74Gy. Patients irradiated to inferior doses interrupted the treatment because of limiting toxicities. Induction and concurrent chemotherapy was delivered to 39 (78%) and 14 (28%) patients, respectively. Eight (16%) patients experienced grade 3-4 acute lung toxicity, all of them having a history of pulmonary disease, a FEV1 below 1.6 L, and a lung V(20) of at least 25%. Three (6%) patients were deemed to experience radiation-induced cardiac toxicity. CONCLUSIONS: This study assesses the feasibility of delivering a total dose of 74 Gy combined with chemotherapy in locally advanced NSCLC. High lung and heart V(20) increases the risk of radiation-induced lung and cardiac toxicity, the later being highly difficult to precisely assess, as late deaths are rarely documented, and responsibility of the treatment might be often underestimated. The precise evaluation of cardiac condition may be helpful to spare fragile patients from potentially toxic effects of high-dose radiation, especially in controlled trials.

Simulating the amplification of orbital forcing by ocean feedbacks in the last glaciation.

According to Milankovitch theory, the lower summer insolation at high latitudes about 115,000 years ago allowed winter snow to persist throughout summer, leading to ice-sheet build-up and glaciation. But attempts to simulate the last glaciation using global atmospheric models have failed to produce this outcome when forced by insolation changes only. These results point towards the importance of feedback effects-for example, through changes in vegetation or the ocean circulation-for the amplification of solar forcing. Here we present a fully coupled ocean-atmosphere model of the last glaciation that produces a build-up of perennial snow cover at known locations of ice sheets during this period. We show that ocean feedbacks lead to a cooling of the high northern latitudes, along with an increase in atmospheric moisture transport from the Equator to the poles. These changes agree with available geological data and, together, they lead to an increased delivery of snow to high northern latitudes. The mechanism we present explains the onset of glaciation-which would be amplified by changes in vegetation-in response to weak orbital forcing.