title: FEASIBILITY FOR USING HYPOFRACTIONATED STEREOTACTIC VOLUMETRIC MODULATED ARC RADIOTHERAPY (VMAT) WITH ADAPTIVE PLANNING FOR TREATMENT OF THYMOMA IN RABBITS: 15 CASES.
abstract: Thymoma is a relatively common tumor in rabbits. Treatment with surgery, radiation therapy, and chemotherapy alone or in combination has been reported with varying outcomes. Stereotactic volumetric modulated arc radiotherapy delivered in a hypofractionated manner allows high doses of radiation to be delivered to the target volume while allowing sparing of adjacent critical structures. This therapy is ideally suited for thymomas in rabbits given their size, the difficulty of multiple anesthesia episodes and the complexity of the radiotherapy plans required due to the tumor's proximity to the heart, lungs, and mediastinal structures. Fifteen rabbits with thymoma were prospectively recruited for this observational, single institution, single arm clinical study. All rabbits were imaged with both computed tomography (CT) and magnetic resonance imaging (MRI). A total dose of 40 Gy in six fractions was delivered using a single arc over an 11-day period with repeat CT simulation done every other fraction for adaptive planning. Follow-up evaluation was done through repeat CT and MRI imaging and revealed complete responses using the Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Two rabbits had died at 618 and 718 days, 10 were alive and three were lost to follow-up. Observed acute and late effects were graded according to the Veterinary Radiation Therapy Oncology Group (VRTOG) criteria and were found to be minimal.
authors.affiliation: La Cittadina Fondazione Studi e Ricerche Veterinarie Strada per la Cittadina, 26014, Romanengo (CR), Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Dolera
authors.affiliation: La Cittadina Fondazione Studi e Ricerche Veterinarie Strada per la Cittadina, 26014, Romanengo (CR), Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Malfassi
authors.affiliation: La Cittadina Fondazione Studi e Ricerche Veterinarie Strada per la Cittadina, 26014, Romanengo (CR), Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mazza
authors.affiliation: Azienda Ospedaliera della Provincia di Lodi, Lodi (LO), Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Urso
authors.affiliation: La Cittadina Fondazione Studi e Ricerche Veterinarie Strada per la Cittadina, 26014, Romanengo (CR), Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Sala
authors.affiliation: La Cittadina Fondazione Studi e Ricerche Veterinarie Strada per la Cittadina, 26014, Romanengo (CR), Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Marcarini
authors.affiliation: La Cittadina Fondazione Studi e Ricerche Veterinarie Strada per la Cittadina, 26014, Romanengo (CR), Italy.
authors.forename: Nancy
authors.initials: N
authors.lastname: Carrara
authors.affiliation: La Cittadina Fondazione Studi e Ricerche Veterinarie Strada per la Cittadina, 26014, Romanengo (CR), Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Pavesi
authors.affiliation: La Cittadina Fondazione Studi e Ricerche Veterinarie Strada per la Cittadina, 26014, Romanengo (CR), Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Finesso
authors.affiliation: Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, CA, 95616.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kent
mesh_terms: D000818:Animals; D008279:Magnetic Resonance Imaging; D011817:Rabbits; D011880:Radiotherapy Planning, Computer-Assisted / Q000662:veterinary*; D050397:Radiotherapy, Intensity-Modulated / Q000662:veterinary*; D013945:Thymoma / Q000532:radiotherapy / Q000662:veterinary*; D013950:Thymus Gland / Q000000981:diagnostic imaging; D013953:Thymus Neoplasms / Q000532:radiotherapy / Q000662:veterinary*; D014057:Tomography, X-Ray Computed
keywords: VMAT; rabbits; radiation therapy; stereotactic body radiotherapy; thymoma; veterinary