title: Thallium-201-chloride scintigraphy in staging and monitoring radiotherapy response in follicular lymphoma patients.
abstract: OBJECTIVE
  To study thallium-201-chloride scintigraphy (201Tl-S) in staging and monitoring response after radiotherapy in follicular lymphoma (FL) patients.
  
  
  METHODS
  Forty-one consecutive and unselected FL patients were examined by 'Conventional Standard Staging' (CSS) procedures (history and physical examination, ultrasound, CT scans, biopsies and fine needle aspiration cytology) prior to irradiation. Eight standardized potentially affected lymphoma localizations (neck, axilla, mediastinum, spleen, paraaortic, parailiac, femoral and extranodal) per patient were separately studied, resulting in the investigation of 328 localizations. Thirty minutes after the intravenous administration of a tracer dose of 150 MBq thallium-201-chloride total body images were made, immediately followed by single photon emission computed tomography acquisition. All lymphoma localizations were subsequently irradiated. Patients were re-examined after a median of 4 weeks (range 3-6 weeks) by all CSS modalities and 201Tl-S. Diagnostic performance was evaluated both per site and per patient, both in the diagnostic phase of the study as well as in the post-treatment re-evaluation phase.
  
  
  RESULTS
  In staging, 201Tl-S was positive in 82 of the 129 initial positive regions by CSS (64%). This percentage increased to 70% when eliminating upper abdominal lymph nodes from the analysis. In 24 patients all lesions were visualized by 201Tl-S, in 11 patients some but not all lesions were detected. In six patients none of the lesions were detected by 201Tl-S. In four patients, four additional lesions were initially found by 201Tl-S only. After irradiation, 83 of the total 86 positive regions reached a complete or partial remission by CSS. Eighty-one of these were also diagnosed as remission by 201Tl-S and two as stable disease. In 31 out of 35 patients (89%; 95% CI: 73-97%) the overall response in all irradiated sites was identical by 201Tl-S and CSS. Only two patients, in remission on CSS modalities, showed stable disease on 201Tl-S, while two others were diagnosed as CR by CSS and PR by 201Tl-S.
  
  
  CONCLUSIONS
  201Tl-S has limited additional value in staging FL patients, since only two-thirds of all localizations are detected. However, 201Tl-S is accurate in monitoring radiation treatment response in FL patients. If an FL patient with a positive 201Tl-S at diagnosis is treated by irradiation, the treatment response can be reliably ascertained by only performing a 201Tl-S.
authors.affiliation: Department of Radiotherapy, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, Amsterdam 1066 CX, The Netherlands.
authors.forename: Rick L M
authors.initials: RL
authors.lastname: Haas
authors.forename: Renato A
authors.initials: RA
authors.lastname: Valdés-Olmos
authors.forename: Cornelis A
authors.initials: CA
authors.lastname: Hoefnagel
authors.forename: Marcel
authors.initials: M
authors.lastname: Verheij
authors.forename: Daphne
authors.initials: D
authors.lastname: de Jong
authors.forename: Augustinus A M
authors.initials: AA
authors.lastname: Hart
authors.forename: Harry
authors.initials: H
authors.lastname: Bartelink
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008224:Lymphoma, Follicular / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D009367:Neoplasm Staging / Q000379:methods*; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes; D016896:Treatment Outcome
chemical_list: D013794:Thallium Radioisotopes