title: Usefulness of FDG-PET imaging for the radiotherapy treatment planning of pyothorax-associated lymphoma.
abstract: Pyothorax-associated lymphoma (PAL) is a non-Hodgkin's lymphoma developing in the pleural cavity after a long-standing history of chronic pyothorax (CP). F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is a useful modality for determination of disease extent of various malignant tumors, including malignant lymphoma, but there have been no reports describing the usefulness of FDG-PET imaging in PAL. Here we report a case of PAL that relapsed after chemotherapy and was successfully treated by radiotherapy. FDG-PET imaging revealed that the tumor was localized to a soft-tissue attenuation mass behind the CP cavity in the right thorax, but did not infiltrate the CP cavity. A total dose of 40 Gy was administered to the area that included the PET-positive lesion, instead of including the entire CP cavity in the radiation field. Although computed tomography (CT) showed a residual mass, no FDG uptake was indicated by FDG-PET imaging performed just after the end of radiotherapy, and additional irradiation was not performed. No sign of relapse was found by FDG-PET imaging 3 months later. FDG-PET imaging was useful for both the planning of radiotherapy and assessing the treatment response of PAL.
authors.affiliation: Department of Radiology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan. askr@kms.ac.jp
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Asakura
authors.forename: Taro
authors.initials: T
authors.lastname: Togami
authors.forename: Masahiro
authors.initials: M
authors.lastname: Mitani
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Takashima
authors.forename: Koiku
authors.initials: K
authors.lastname: Yokoe
authors.forename: Yuka
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Nishiyama
authors.forename: Toshihide
authors.initials: T
authors.lastname: Monden
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Toyama
authors.forename: Motoomi
authors.initials: M
authors.lastname: Ohkawa
mesh_terms: D000368:Aged; D016724:Empyema, Pleural / Q000150:complications / Q000000981:diagnostic imaging*; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging* / Q000209:etiology / Q000532:radiotherapy*; D010997:Pleural Neoplasms / Q000000981:diagnostic imaging* / Q000209:etiology / Q000532:radiotherapy*; D049268:Positron-Emission Tomography / Q000379:methods; D011379:Prognosis; D019275:Radiopharmaceuticals; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D011881:Radiotherapy, Computer-Assisted / Q000379:methods; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18