title: [Differential diagnosis of local tumor recurrence or radionecrosis after stereotactic radiosurgery for treatment of brain metastasis].
abstract: Magnetic resonance imaging (MRI) is a method of choice for follow-up of irradiated brain metastasis. It is difficult to differentiate local tumour recurrences from radiation induced-changes in case of suspicious contrast enhancement. New advanced MRI techniques (perfusion and spectrometry) and amino acid positron-emission tomography (PET) allow to be more accurate and could avoid a stereotactic biopsy for histological assessment, the only reliable but invasive method. We report the case of a patient who underwent surgery for a single, left frontal brain metastasis of a breast carcinoma, followed by adjuvant stereotactic radiotherapy in the operative bed. Seven months after, she presented a local change in the irradiated area on the perfusion-weighted MRI, for which the differentiation between a local tumour recurrence and radionecrosis was not possible. PET with 2-deoxy-((18)F)-fluoro-D-glucose (FDG) revealed a hypermetabolic lesion. After surgical resection, the histological assessment has mainly recovered radionecrosis with few carcinoma cells. The multimodal MRI has greatly contributed to refine the differential diagnosis between tumour recurrence and radionecrosis, which remains difficult. The FDG PET is helpful, in favour of the diagnosis of local tumour recurrence when a hypermetabolic lesion is found. Others tracers (such as carbon 11 or a fluoride isotope) deserve interest but are not available in all centres. Stereotactic biopsy should be discussed if any doubt remains.
authors.affiliation: Service d'oncologie médicale, institut de cancérologie de l'Ouest Paul-Papin, 2, rue Moll, 49000 Angers, France.
authors.forename: A
authors.initials: A
authors.lastname: Patsouris
authors.affiliation: Service d'oncologie médicale, institut de cancérologie de l'Ouest Paul-Papin, 2, rue Moll, 49000 Angers, France.
authors.forename: P
authors.initials: P
authors.lastname: Augereau
authors.affiliation: Service de radiologie, centre hospitalier universitaire, université d'Angers, 4, rue Larrey, 49933 Angers cedex 9, France; Université Nantes Angers Le Mans (Unam), 4, rue Larrey, 49933 Angers cedex 9, France.
authors.forename: J-Y
authors.initials: JY
authors.lastname: Tanguy
authors.affiliation: Service de médecine nucléaire, institut de cancérologie de l'Ouest Paul-Papin, 2, rue Moll, 49000 Angers, France.
authors.forename: O
authors.initials: O
authors.lastname: Morel
authors.affiliation: Université Nantes Angers Le Mans (Unam), 4, rue Larrey, 49933 Angers cedex 9, France; Service de neurochirurgie, centre hospitalier universitaire, université d'Angers, 4, rue Larrey, 49933 Angers cedex 9, France.
authors.forename: P
authors.initials: P
authors.lastname: Menei
authors.affiliation: Université Nantes Angers Le Mans (Unam), 4, rue Larrey, 49933 Angers cedex 9, France; Service d'anatomopathologie, centre hospitalier universitaire, université d'Angers, 4, rue Larrey, 49933 Angers cedex 9, France.
authors.forename: A
authors.initials: A
authors.lastname: Rousseau
authors.affiliation: Service d'oncologie radiothérapie, institut de cancérologie de l'Ouest Paul-Papin, 2, rue Moll, 49000 Angers, France. Electronic address: amaury.paumier@ico.unicancer.fr.
authors.forename: A
authors.initials: A
authors.lastname: Paumier
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000556:secondary / Q000601:surgery*; D001943:Breast Neoplasms / Q000473:pathology; D002277:Carcinoma / Q000473:pathology / Q000556:secondary; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D049268:Positron-Emission Tomography; D011832:Radiation Injuries / Q000175:diagnosis* / Q000209:etiology; D019275:Radiopharmaceuticals; D016634:Radiosurgery / Q000009:adverse effects*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Brain metastasis; IRM perfusion; Métastases cérébrales; Perfusion RMI; Radionecrosis; Radionécrose; Radiothérapie stéréotaxique; Stereotactic radiotherapy