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Radiotherapy is a medical modality that has been constantly revolutionizing with the offer of three-dimensional computational for treatment planning systems (TPS), providing greater security in the release of the radiation dose in the target volume, improving the therapeutic response and minimizing the radiobiological effects unwanted. The incorporation of modern radiotherapy techniques, along with studies that contribute to the development of radiotherapy protocols in veterinary medicine, may contribute to improve the quality of treatments and survival of animals affected by cancer. A TPS applied in a human radiotherapy clinic was used and the radiometric, clinical and anatomical parameters were adequate for the feasibility of use in veterinary radiotherapy. Tomographic images of the pelvic region of wild animals assisted by the School of Veterinary Medicine and Animal Science (FMVZ/UNESP) were used to perform them. The simulations were made with institutional images and in vivo animals were not used. Protocols for the implementation of computational planning in veterinary medicine were verified by analyzing the homogeneity of the radiation dose distribution in the planned treatment volume (PTV) and ensuring the protection of the organs surrounding the PTV. The methodology applied for the use of TPS Eclipse in veterinary radiotherapy planning proved to be feasible and can present itself as an important tool to improve veterinary oncological therapeutic approaches. [ABSTRACT FROM AUTHOR]

Résumé La toxicité cérébrale de la radiothérapie n’est pas rare. L’épargne de cet organe à risque constitue un enjeu pour la préservation cognitive, en particulier en cas de longue survie. Le diagnostic clinique, physiopathologique et radiologique de la radionécrose reste difficile. Les contraintes de doses utilisées en radiothérapie conformationnelle avec modulation d’intensité (RCMI), en radiochirurgie et en radiothérapie stéréotaxique sont critiquables. Elles ont été élaborées à partir d’études rétrospectives clinicodosimétriques anciennes. Le rapport α/β et l’architecture — en série ou en parallèle — des organes à risque sont discutables. Ils peuvent conduire à mésestimer les doses équivalentes (BED) par le modèle linéaire-quadratique ou la dose équivalente à une irradiation de 2 Gy par fraction (EQD2), en particulier en cas d’hypofractionnement. Les modèles mathématiques se heurtent à l’hétérogénéité spatiale de la relation dose-réponse, aux différents fractionnements et étalements ainsi qu’à l’irradiation partielle des organes à risque induites par les forts gradients de doses. Ces limites doivent être connues en pratique clinique courante. À partir d’une revue de la littérature, notre article propose une mise au point sur le tronc cérébral, les hippocampes et l’encéphale. La pertinence des valeurs rapportées fait l’objet de discussions et de pistes de réflexions. Cerebral radiation-induced toxicities after radiotherapy (RT) of brain tumors are frequent. The protection of organs at risk (OAR) is crucial, especially for brain tumors, to preserve cognition in cancer survivors. Dose constraints of cerebral OAR used in conventional RT, radiosurgery (SRS) and stereotactic radiotherapy (SRT) are debated. In fact, they are based on historical cohorts or calculated with old mathematical models. Values of α/β ratio of cerebral OAR are also controversial leading to misestimate the equivalent dose in 2 Gy fractions or the biological equivalent dose, especially during hypofractionated RT. Although recent progresses in medical imaging, the diagnosis of radionecrosis remains difficult. In this article, we propose a large review of dose constraints used for three major cerebral OAR: the brain stem, the hippocampus and the brain. [ABSTRACT FROM AUTHOR]

Résumé La radiothérapie des lésions primitives ou secondaires abdominopelviennes en techniques conformationnelle ou stéréotaxique est en plein développement. L’intestin grêle, possédant une radiosensibilité élevée, est le principal organe à risque limitant les doses de prescription. Cette revue de la littérature a pour objectif de définir les contraintes de doses à l’intestin grêle et au duodénum en radiothérapie conformationnelle ou stéréotaxique. L’intestin grêle comprenant le duodénum, le jéjunum et l’iléon est délinéé sur la tomodensitométrie de simulation. La toxicité intestinale radio-induite est précoce, liée à la dépopulation cellulaire de la muqueuse intestinale, et tardive, de physiopathologie plus complexe, associant déplétion de cellules souches, microangiopathie, inflammation chronique et fibrose. Le facteur prédictif principal de toxicité intestinale est le ratio dose–volume. En radiothérapie conformationnelle, les contraintes de dose au duodénum sont : V25 Gy < 45 % (V x Gy : volume recevant x Gy) et V35 Gy < 20 %. Les contraintes de dose dans le jéjunum et l'iléon sont, pour une délinéation par anse intestinale ou pour la cavité péritonéale, respectivement : V15 Gy < 275 mL ou V15 Gy < 830 mL et V45 Gy < 150 mL. En radiothérapie stéréotaxique, les contraintes de dose dans l’intestin grêle dépendent du fractionnement et sont définies sur un faible volume et sur une dose maximale en un point. La toxicité intestinale dépend également de facteurs intrinsèques au patient et de radiosensibilisants comme les thérapies ciblées ou chimiothérapies. Avec l’essor des nouvelles techniques permettant une escalade de dose sur la tumeur et le développement de la planification inverse, la définition des contraintes de doses à l’intestin grêle est primordiale pour la pratique courante. Radiotherapy of abdominopelvic primary or secondary lesions in conformational or stereotactic techniques is in full development. The small bowel is highly sensitive to irradiation and is the main organ at risk limiting prescription doses. This literature review aims to define the dose constraints to the small bowel and the duodenum in conformational and stereotactic body radiotherapy. The small bowel including the duodenum, jejunum and ileum is delineated on the simulation scanner. The radio-induced intestinal toxicities are acute related to the cellular depopulation of the intestinal mucosa, and late of more complex pathophysiology associating depletion in stem cells, microangiopathy, chronic inflammation and fibrosis. The main predictive factor of intestinal toxicity is the dose–volume ratio. In conformational radiotherapy, the dose constraints to the duodenum are: V25 Gy < 45% and V35 Gy < 20%. The jejunum and ileum dose constraints are for delineation by intestinal loop or peritoneal cavity respectively: V15 Gy < 275 mL or V15 Gy < 830 mL and V45 Gy < 150 mL. In stereotactic body radiotherapy, small bowel dose constraints depend on fractionation and are defined on a small volume and on a maximum dose at one point. Intestinal toxicity is also dependent on factors intrinsic to the patient and radiosensitizers such as targeted therapies or chemotherapies. With the development of new techniques allowing dose escalation on the tumour and the development of inverse planning, the definition of dose constraints to the small bowel is essential for current practice. [ABSTRACT FROM AUTHOR]

New developments and new technologies in radiation therapy are concerning the anatomical definition of the targets which are to be treated and of the critical organs which should be spared. These objectives can be reached by using modern imaging techniques: (US, PET Scan, CT Scan, MRI) allowing image-guided radiation Therapy (IGRT). Modern concepts of dose distribution (inverse dosimetry) lead to the tri-dimensional conformal Radiation Therapy (3D - CRT), intensity modulated Radiation Therapy (IMRT) and technological applications as helicoïdal tomotherapy, radiostereotaxy. New dose distribution techniques are also in progress: high dose rate (HDR), pulsed-dose-rate (PDR) brachytherapy, intraoperative Radiation Therapy and new medical applications of neutrons, protons, ions carbone. Moreover, improvements in radiation therapy administrations are expected by using biological investigations to know in real time tumor radiosensitization and radio tolerance of normal tissues in order to choose the most appropriate fractionation mode of the radiation treatment. These technical and biologic developments are also associated to a better concept for using radiation therapy in a global strategy which has to be adapted to each patient and each clinical situation. [ABSTRACT FROM AUTHOR]

Radiotherapy for epithelioid hemangioendothelioma (EHE) using volumetric intensity-modulated arc radiotherapy (VMAT). A 48-year-old woman was referred for curative irradiation of a vertebral EHE after failure of surgery. A comparison between VMAT and conventional conformal tridimensional (3D) dosimetry was performed and potential advantage of VMAT for sparing critical organs from irradiation׳s side effects was discussed. The total delivered dose on the planning target volume was 54 Gy in 27 fractions. The patient was finally treated with VMAT. The tolerance was excellent. There was no acute toxicity, including no increase in pain. With a follow-up of 18 months, no delayed toxicity was reported. The clinical response consisted of a decrease in the dorsal pain. The D max for the spinal cord was reduced from 55 Gy (3D-radiotherapy [RT]) (which would be an unacceptable dose to the spine because of the risk of myelopathy) to 42.8 Gy (VMAT), which remains below the recommended dose threshold (45 Gy). The dose delivered to 20% of organ volume (D 20 ) was reduced from 47 Gy (3D-RT) to 3 Gy (VMAT) for the spinal cord. The study shows that VMAT allows the delivery of curative treatment for vertebral EHEs because of critical organ sparing. [ABSTRACT FROM AUTHOR]

Abstract: We evaluated the early clinical outcome of patients with solitary bone plasmacytoma (SP) or a solitary lesion of multiple myeloma (MM) treated with helical tomotherapy (HT) compared with 3D conformal radiotherapy (3D-CRT), in terms of target coverage and exposure of critical organs. Ten patients with SP and 3 patients with a solitary lesion of MM underwent radiation therapy (RT) delivered by HT, to a dose of 40 Gy in 20 fractions. Treatment planning was then performed with 3D-CRT and the dosimetric parameters of both techniques were compared. Patients were also assessed for response to treatment and acute toxicities. With a median follow-up of 13 months, 78% of patients with pain before RT had resolution of their symptoms. Coverage of target lesion was adequate with both techniques in 12 of 13 patients. Target coverage was significantly lower for HT (V95% = 98.55% vs. 97.15%; p = 0.04, for 3D-CRT and HT, respectively). Target overdoses were also lower with HT (V105% = 2.01% vs. 0.19%; p= 0.16), although nonsignificant. Finally, there were no significant differences in organs-at-risk irradiation between both techniques. The early treatment tolerance was excellent, with no toxicity higher than grade I. RT of SP and MM with a solitary lesion can be safely delivered with HT, with no major acute side effects and good symptomatic control. Finally, HT provides a dosimetry similar to that of 3D-CRT in terms of organs-at-risk sparing and target volume coverage. [Copyright &y& Elsevier]

Phantoms made of synthetic materials are commonly used in conformational radiotherapy to verify the proper operation of therapeutic medical equipment. The main objective of the paper is to design and build a prostate phantom to be used in the calibration of planning systems. The proposed phantom is made of nylon and acrylic. These inexpensive materials are readily available in Peru and have comparable density to soft tissue and bone. The phantom was used in the calibration of a planning system. Final results showed an average error of 5.49% between the measurements made on the phantom and planned values. These results are in the range of uncertainty recommended by the International Commission on Radiation Units and Measurements (ICRU). [ABSTRACT FROM PUBLISHER]

Purpose: To assess the efficacy of alternating chemoradiotherapy combined with extended-field conformal radiotherapy for patients with high-risk cervical cancer. Methods and Materials: Patients with previously untreated cervical cancer, with Stage III/IVA disease, or Stage IB/II with high-risk factor (primary tumor diameter ≥50 mm or positive lymph node) were entered into this study. Three cycles of chemotherapy with 3,500 mg/m2 of 5-fluorouracil (5-FU) and nedaplatin (NDP) were accompanied with pelvic irradiation of 45.6–51.3 Gy in 24–27 fractions over 6 weeks. Prophylactic (36 Gy/20 fractions) or definitive (45–56 Gy) irradiation for para-aortic region was followed by pelvic irradiation. Results: Between 1998 and 2004, 40 patients were recruited for this protocol study. Eighteen patients from Phase I setting were registered. Twenty-two patients were treated with NDP of 140 mg/m2 (the recommended dose) in the Phase II segment. Twenty-five patients had T3 disease, and 25 patients had nodal disease including para-aortic involvement (n = 5). Overall/progression-free survival rates at 5 years were 78.8 and 66.5%, respectively. The median follow-up time was 61.8 months (25.5–106.7). Hematologic and gastrointestinal Grade 3 or more toxicities were relatively high rate (27.5–45%); however, they were well manageable. Two for bladder toxicity of Grade 3 were noted. Comparing the data from historical control group evaluated by magnetic resonance imaging, alternating chemoradiotherapy revealed a significant favorable factor for survival and disease recurrence in multivariate analysis (p < 0.05). Conclusion: Acquired results from our unique protocol for cervical cancer with high-risk factor were thought to be promising, considering that the majority of our cohort consisted of high-risk population. [Copyright &y& Elsevier]

Résumé Les évolutions technologiques récentes ont permis de développer le concept de « radiothérapie hépatique focalisée ». Il convient de distinguer les tumeurs primitives de celles secondaires car les indications sont restreintes et doivent être discutées en alternative aux traitements chirurgicaux ou médicaux. Dans ce cas, pour les carcinomes hépatocellulaires de 5 à 10 cm (voire plus), une irradiation conformationnelle avec ou sans modulation d’intensité est réalisée. La radiothérapie en conditions stéréotaxiques est en cours d’évaluation et est souvent préférée à la radiofréquence pour les tumeurs primitives ou secondaires (en général de moins de 5 cm). Les mouvements de la tumeur (et du foie) liés à la respiration doivent être pris en compte. Il faut respecter des critères dosimétriques stricts avec une attention toute particulière sur les histogrammes dose–volume (HDV) du foie non tumoral ainsi que des organes creux, notamment en cas de radiothérapie en conditions stéréotaxiques. Recent technological developments led to develop the concept of focused liver radiation therapy. We must distinguish primary and secondary tumors as the indications are restricted and must be discussed as an alternative to surgical or medical treatments. For hepatocellular carcinoma 5 to 10 cm (or more), a conformational radiation with or without intensity modulation is performed. Stereotactic body radiotherapy (SBRT) is being evaluated and is increasingly proposed as an alternative to radiofrequency ablative treatment for primary or secondary tumors (typically less than 5 cm). Tumor (and liver) movements induced by respiratory motions must be taken into account. Strict dosimetric criteria must be met with particular attention to the dose–volume histograms to liver and the hollow organs, including cases of SBRT. [ABSTRACT FROM AUTHOR]

Cerebral radiation-induced toxicities after radiotherapy (RT) of brain tumors are frequent. The protection of organs at risk (OAR) is crucial, especially for brain tumors, to preserve cognition in cancer survivors. Dose constraints of cerebral OAR used in conventional RT, radiosurgery (SRS) and stereotactic radiotherapy (SRT) are debated. In fact, they are based on historical cohorts or calculated with old mathematical models. Values of α/β ratio of cerebral OAR are also controversial leading to misestimate the equivalent dose in 2Gy fractions or the biological equivalent dose, especially during hypofractionated RT. Although recent progresses in medical imaging, the diagnosis of radionecrosis remains difficult. In this article, we propose a large review of dose constraints used for three major cerebral OAR: the brain stem, the hippocampus and the brain., (Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.)

Radiotherapy of abdominopelvic primary or secondary lesions in conformational or stereotactic techniques is in full development. The small bowel is highly sensitive to irradiation and is the main organ at risk limiting prescription doses. This literature review aims to define the dose constraints to the small bowel and the duodenum in conformational and stereotactic body radiotherapy. The small bowel including the duodenum, jejunum and ileum is delineated on the simulation scanner. The radio-induced intestinal toxicities are acute related to the cellular depopulation of the intestinal mucosa, and late of more complex pathophysiology associating depletion in stem cells, microangiopathy, chronic inflammation and fibrosis. The main predictive factor of intestinal toxicity is the dose-volume ratio. In conformational radiotherapy, the dose constraints to the duodenum are: V25Gy<45% and V35Gy<20%. The jejunum and ileum dose constraints are for delineation by intestinal loop or peritoneal cavity respectively: V15Gy<275mL or V15Gy<830mL and V45Gy<150mL. In stereotactic body radiotherapy, small bowel dose constraints depend on fractionation and are defined on a small volume and on a maximum dose at one point. Intestinal toxicity is also dependent on factors intrinsic to the patient and radiosensitizers such as targeted therapies or chemotherapies. With the development of new techniques allowing dose escalation on the tumour and the development of inverse planning, the definition of dose constraints to the small bowel is essential for current practice., (Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.)

Recent technological developments led to develop the concept of focused liver radiation therapy. We must distinguish primary and secondary tumors as the indications are restricted and must be discussed as an alternative to surgical or medical treatments. For hepatocellular carcinoma 5 to 10cm (or more), a conformational radiation with or without intensity modulation is performed. Stereotactic body radiotherapy (SBRT) is being evaluated and is increasingly proposed as an alternative to radiofrequency ablative treatment for primary or secondary tumors (typically less than 5cm). Tumor (and liver) movements induced by respiratory motions must be taken into account. Strict dosimetric criteria must be met with particular attention to the dose-volume histograms to liver and the hollow organs, including cases of SBRT., (Copyright © 2016. Published by Elsevier SAS.)

Abstract: Radiation therapy is now widely accepted as an efficacious treatment of localized prostate cancer. The technical developments of recent years have enabled the evolution of a three-dimensional conformal radiotherapy, offering a better adaptation of the dose distribution, and leading therefore to preserve organs at risk. In addition, the required dose delivered to the target volume permit physician to increase the total dose if necessary. This requires a thorough knowledge of the radio-anatomy of the prostate, the natural history of the disease but also the ballistics and dosimetry. The objectives of this work were to detail epidemiology and radio-anatomy of the prostate cancer. In addition, conformal radiation modalities are illustrated by a case report. [ABSTRACT FROM AUTHOR]

Abstract: Cancers of the paranasal sinuses are rare tumors, with treatment based on a multidisciplinary approach. Surgery and radiation therapy, possibly associated with chemotherapy are used to obtain 5 years specific survival rate of 60–70 %. Advances in radiotherapy, including the use of imaging for 3D conformal approach require precise knowledge of the radioanatomy for this type of tumor to determine the different volumes of interest. Purpose of this study was to specify radioanatomy and conformal radiation modalities for cancers of the sinuses, and is illustrated by a case report. [ABSTRACT FROM AUTHOR]