Integrated FDG-PET/CT for detection, therapy monitoring and follow-up of granulocytic sarcoma

Summary

Aim: Granulocytic sarcomas (GS) are rare extramedullary manifestations of myeloid or lymphoblastic leukaemia. Laboratory examinations are of limited use for diagnosis of extramedullary disease. Radiological imaging based on morphology is challenging. To date, the possible role of FDG-PET/CT as a method for combined metabolic and morphologic imaging is unclear. We present a series of 10 patients to evaluate the potential role of FDGPET/ CT in the management of GS. Patients, materials, methods: A retrospective evaluation of 18 FDG-PET/CT exams in 10 patients with histologically proven GS was performed. All scans included a contrast enhanced CT. The FDG uptake of GS was analyzed and the sensitivity of lesion detection was compared to PET and CT alone. The changes in FDG uptake after therapy were compared to morphological changes detected by CT and follow-up / clinical outcome. Results: 52 untreated or recurrent GS lesions were detected by FDG-PET/CT and all showed an increased FDG uptake with a mean SUVmax and SUVavg of 5.1 and 3.4, respectively. GS was multifocal in 8/10 patients. Combined PET/CT avoided 5 false positive findings compared to PET alone and 13 false negative findings and 1 false positive compared to CT alone. Changes in FDG uptake after therapy correlated with clinical outcome and were more reliable than CT assessment alone. PET/CT identified recurrent GS in 3 patients. Conclusion: Viable GS are FDG-avid. Using this metabolic information and morphologic CT criteria, combined FDG-PET/CT was more accurate in lesion detection than FDG-PET or CT alone. Changes in FDG uptake after therapy might be a useful additional parameter for therapy monitoring. Therefore, FDG-PET/CT appears to be a promising diagnostic and monitoring tool in the management of patients with GS.

Zusammenfassung

Ziel: Granuloyztische Sarkome (GS) sind seltene extramedulläre Manifestationen von myelotischen oder lymphoblastischen Leukämien. Laboruntersuchungen sind zur Diagnose und zum Therapiemonitoring der extramedullären Erkrankung nur begrenzt geeignet. Die radiologisch- morphologische Beurteilung ist in ihrer Sensitivität limitiert. Die potenzielle Rolle der kombinierten metabolischen und morphologischen Bildgebung mit der FDG-PET/CT ist bisher unklar. Wir stellen eine Serie von 10 Patienten vor, um die mögliche Rolle der FDGPET/ CT im Management von GS zu evaluieren. Patienten, Methoden: Retrospektive Auswertung von 18 FDG-PET/CT-Untersuchungen inklusive diagnostischer CT bei 10 Patienten mit histologisch gesichertem GS. Analyse des FDG-Uptake und Vergleich der Sensitivität der Detektion von Läsionen mit der FDG-PET und der CT allein. Vergleich der änderung im FDGUptake nach Therapie mit morphologischen änderungen nach CT-Kriterien und dem weiteren klinischen Krankheitsverlauf. Ergebnisse: 52 unbehandelte oder rezidivierte GS wurden mittels FDG-PET/CT detektiert und zeigten einen erhöhten FDG-uptake mit einem mittleren SUVmax und SUVavg von 5,1 bzw. 3,4. GS waren bei 8/10 Patienten multifokal. Die kombinierte FDG-PET/CT vermied 5 falsch-positive Befunde im Vergleich zur FDGPET und 13 falsch-negative und einen falschpositiven Befund im Vergleich zur CT. Die änderungen im FDG-Uptake nach Therapie korrelierten mit dem klinischen Behandlungserfolg verlässlicher als die Ergebnisse der CT. Rezidive von GS konnten bei 3 Patienten mittels FDG-PET/CT detektiert werden. Schlussfolgerung: Vitale GS nehmen vermehrt FDG auf. Die Kombination dieser metabolischen Information mit CT-morphologischen Kriterien in der FDG-PET/CT verbesserte die Genauigkeit der Detektion von Läsionen im Vergleich zur FDG-PET oder CT alleine. Die änderung im FDG-Uptake nach Therapie könnte ein nützlicher zusätzlicher Parameter zur Therapiekontrolle sein. Die FDG-PET/CT scheint damit ein viel versprechendes diagnostisches Instrument beim Management von Patienten mit GS zu sein.

Keywords

FDG - PET/CT - granulocytic sarcoma - leukaemia

Schlüsselwörter

FDG - PET/CT - granulozytisches Sarkom - Leukämie

• References

• 1 Au WY, Shek TW, Ma SK. et al. Myeloblastoma (chloroma) in leukemia: case 2. Meningeal granulocytic sarcoma (chloroma) in essential thrombocythemia. J Clin Oncol 2000; 18: 3996-3997.
• 2 Békassy AN, Hermans J, Gorin NC. et al. Granulocytic sarcoma after allogeneic bone marrow transplantation: a retrospective European multicenter survey. Acute and Chronic Leukemia Working Parties of the European Group for Blood and Marrow Transplantation. Bone Marrow Transplant 1996; 17: 801-808.
• 3 Bruzzi JF, Macapinlac H, Tsimberidou AM. et al. Detection of Richter's transformation of chronic lymphocytic leukemia by PET/CT. J Nucl Med 2006; 47: 1267-1273.
• 4 Byrd JC, Edenfield WJ, Shields DJ. et al. Extramedul- lary myeloid cell tumors in acute nonlymphocytic leukemia: a clinical review. J Clin Oncol 1995; 13: 1800-1816.
• 5 Eade T, Tan B, Mansberg R. et al. An unusual case of chloroma without marrow involvement demonstrated on Ga-67 scintigraphy. Clin Nucl Med 2002; 27: 359-360.
• 6 Endo T, Sato N, Koizumi K. et al. Localized relapse in bone marrow of extremities after allogeneic stem cell transplantation for acute lymphoblastic leukemia. Am J Hematol 2004; 76: 279-282.
• 7 Finnegan DP, Jones FG, McMullin MF. Acute myeloid leukemia with concurrent myeloid sarcoma treated with autologous bone marrow transplantation: two illustrative cases and a literature review. Hematol Oncol 2005; 23: 133-135.
• 8 Guermazi A, Feger C, Rousselot P. et al. Granulocytic sarcoma (chloroma): imaging findings in adults and children. Am J Roentgenol 2002; 178: 319-325.
• 9 Inoue T, Takahashi T, Shimizu H. et al. Spinal granulocytic sarcoma manifesting as radiculopathy in a nonleukemic patient. Neurol Med Chir (Tokyo) 2008; 48: 131-136.
• 10 Karlin L, Itti E, Pautas C. et al. PET-imaging as a useful tool for early detection of the relapse site in the management of primary myeloid sarcoma. Haematologica. 2006 91. ECR54.
• 11 Kostakoglu L, Goldsmith SJ. Positron emission tomography in lymphoma: comparison with computed tomography and Gallium-67 single photon emission computed tomography. Clin Lymphoma. 2000; 1: 67-74.
• 12 Krause BJ, Beyer T, Bockisch A. et al. FDG-PET/CT in oncology. German Guideline. Nuklearmedizin 2007; 46: 291-301.
• 13 Kuenzle K, Taverna C, Steinert HC. Detection of extramedullary infiltrates in acute myelogenous leukemia with whole-body positron emission tomography and 2-deoxy-2-[¹⁸F]-fluoro-D-glucose. Mol Imaging Biol 2002; 4: 179-183.
• 14 La Fougere C, Hundt W, Brockel N. et al. Value of PET/CT versus PET and CT performed as separate investigations in patients with Hodgkin's disease and non-Hodgkin's lymphoma. Eur J Nucl Med Mol Imaging 2006; 33: 1417-1425.
• 15 Luddy RE, Levy BE, Schwartz AD. 67Ga scintigraphy in granulocytic sarcoma. Cancer 1980; 46: 1357-1359.
• 16 Mantzarides M, Bonardel G, Fagot T. et al. Granulocytic sarcomas evaluated with ¹⁸F-fluorodeoxy- glucose PET. Clin Nucl Med 2008; 33: 115-117.
• 17 Menasce LP, Banerjee SS, Beckett E. et al. Extra-medullary myeloid tumour (granulocytic sarcoma) is often misdiagnosed: a study of 26 cases. Histopath- ology 1999; 34: 391-398.
• 18 Nakajo M, Jinnouchi S, Inoue H. et al. FDG PET findings of chronic myeloid leukemia in the chronic phase before and after treatment. Clin Nucl Med 2007; 32: 775-778.
• 19 Neiman RS, Barcos M, Berard C. et al. Granulocytic sarcoma: a clinicopathologic study of 61 biopsied cases. Cancer 1981; 48: 1426-1437.
• 20 Takalkar A, Yu JQ, Kumar R. et al. Diffuse bone marrow accumulation of FDG in a patient with chronic myeloid leukemia mimics hematopoietic cytokine- mediated FDG uptake on positron emission tomography. Clin Nucl Med 2004; 29: 637-639.
• 21 Therasse P, Arbuck SG, Eisenhauer EA. et al. New guidelines to evaluate the response to treatment in solid tumors. European Organization for Research and Treatment of Cancer, National Cancer Institute of the United States, National Cancer Institute of Canada. J Natl Cancer Inst 2000; 92: 205-216.
• 22 Tsimberidou AM, Kantarjian HM, Estey E. et al. Outcome in patients with nonleukemic granulo- cytic sarcoma treated with chemotherapy with or without radiotherapy. Leukemia 2003; 17: 1100-1103.
• 23 Weber WA, Figlin R. Monitoring cancer treatment with PET/CT: does it make a difference?. J Nucl Med 2007; 48: 36S-44S.
• 24 Yamauchi K, Yasuda M. Comparison in treatments of nonleukemic granulocytic sarcoma: report of two cases and a review of 72 cases in the literature. Cancer 2002; 94: 1739-1746.
• 25 Young H, Baum R, Cremerius U. et al. Measurement of clinical and subclinical tumour response using [¹⁸F]-fluorodeoxyglucose and positron emission tomography: Review and 1999 EORTC Recommendations. Eur J Cancer 1999; 35: 1773-1782.