Granulocytic Sarcomas Evaluated With F-18-Fluorodeoxyglucose PET

Extramedullary tumors remain an obstacle to curing more acute leukemia patients. Their incidence is unknown because the presence of occult tumors that contribute to relapse is not routinely sought as in other cancers. No standard approach exists for treating tumors at most sites, apparent clinical response is typically followed by further tumors, and achievement of lengthy remission is uncommon. Body scanning with 18 FDG PET/CT now provides a means to identify the extent of occult tumors that enables directed tumor eradication and a way to evaluate tumor response. To evaluate its potential benefits, analysis was undertaken of 124 published cases scanned after apparent tumors were diagnosed. Clinical and radiologic exams underestimated extent of disease in over half of 100 cases. Among 70 cases that reported scans after various treatments, 70% achieved negative scans. Half relapsed subsequently but disease-free survivals up to 6 years were documented. These reported cases add to our knowledge of extramedullary leukemia in showing that further tumors are more likely than marrow relapse, clinical and radiologic evaluation of response is inadequate, intensive chemotherapy alone generally does not prevent progression and is associated with significant mortality, and tumor-directed plus systemic therapies appears the most effective approach, particularly to AML tumors. This analysis suggests this technology could increase our ability to eradicate all foci of leukemia, and identify tumors responsible for refractory, residual, and relapsed disease.

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“…Among 57 AML cases, scans documented treatment resistance in 13 and only partial tumor response in 6 . Negative scans were achieved in 38.…”

Section: Resultsmentioning

confidence: 99%

¹⁸FDG‐PET/CT: 21st century approach to leukemic tumors in 124 cases

Cunningham

Kohno

2016

American J Hematol

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“…Although there have been no established strategies for surveillance of EM relapse after SCT, recent reports have suggested a usefulness of FDG-PET/CT in the detection of EM relapse of AML. [33][34][35][36] The present study had several limitations. It was a retrospective study including a relatively small number of patients, and the patient characteristics were highly heterogeneous.…”

Section: Discussionmentioning

confidence: 99%

Incidence of extramedullary relapse after haploidentical SCT for advanced AML/myelodysplastic syndrome

Yoshihara

Ikegame

Kaida

et al. 2011

Bone Marrow Transplant

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Extramedullary (EM) relapse of leukemia after allo-SCT in patients with AML/myelodysplastic syndrome has been increasingly reported. The reduced effectiveness of the GVL effect in EM sites, as compared with BM, has been suggested to underlie this problem. We retrospectively analyzed the pattern of relapse after haploidentical SCT (haplo-SCT), performed as the first or second SCT. Among 38 patients who received haplo-SCT as their first SCT, the cumulative incidences of BM and EM relapse at 3 years were 40.5 and 10.9%, respectively. Among 19 patients who received haplo-SCT as their second SCT, the cumulative incidences of BM and EM relapse were 30.9 and 31.9%, respectively. Moreover, most of the patients who underwent repeat haplo-SCT for the treatment of EM relapse had further EM relapse at other sites. Post-relapse survival did not differ significantly with different patterns of relapse. The frequent occurrence of EM relapse after haplo-SCT, particularly when performed as a second SCT, suggests that the potent GVL effect elicited by an HLA disparity also occurs preferentially in BM. Our findings emphasize the need for a treatment strategy for EM relapse that recognizes the reduced susceptibility of EM relapse to the GVL effect.

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“…9 Recent case reports have shown that 18 F-FDG-PET/CT might be a useful tool in detecting extramedullary AML. [10][11][12][13] In two retrospective studies of 5 and 6 patients with EM-AML, 18 F-FDG-PET was more or at least equally effective in the detection of extramedullary disease.…”

Section: Introductionmentioning

confidence: 99%