Contributions
Abstract: PB2031
Type: Publication Only
Background
The role of 18F-FDG PET/CT in the diagnosis and follow-up of gastric lymphomas is still controversial. As 18F-FDG PET/CT staging role in gastric DBLC is well established, several studies haven’t still clarified the detection rate of PET/CT imaging in gastric MALT lymphomas.
Aims
The aim of our retrospective study is to evaluate the role of 18F-FDG PET/CT in the diagnosis and follow-up of gastric lymphoma.
Methods
Thirty-two patients with histological confirmed gastric lymphoma (MALT: 19; DLBCL: 13) underwent a 18F-FDG PET/CT for initial staging and post therapy evaluation. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUV MAX) and compared with Ann Arbor stage, Lugano staging system for gastrointestinal lymphomas, epidemiological (age, sex), histological /morphological (presence of gastritis, ulcers, H. pylori infection, tumor size, superficial lesions or mass-forming) characteristics.
Results
From January 2007 to November 2016, in our institution, we analyzed 32 gastric lymphoma: 19 patients had histological diagnosis of MALT lymphoma, whereas 13 patients received histological diagnosis of DLBCL. At diagnosis, 15 patients with MALT lymphoma had positive PET/CT-mean lesion SUV max of 6.14 (4.0-18.2) at the corresponding gastric lesion, the remaining 4 were not 18F-FDG avid. Nine patients were H. pylori positive. On the other hand, all 13 patients with DLBCL had positive PET/CT, as expected, with mean lesion SUV max of 17.1 (4-17.1). At post-treatment evaluation, all the patients had histological and radiological complete remission. The overall sensitivity of 18F-FDG PET/CT was 87% (CI 95%: 71-96.5) and specificity 100% (CI 95%: 89.1-100) (p value<0.0001) in our cohort. In MALT lymphoma PET sensitivity was 78% (CI 95%: 54.4-93.5) and specificity 100% (CI 95%: 82.3-100) (p value<0.0001), whereas in DLBCL the sensitivity (CI 95%: 75.3-100) and specificity (CI 95%: 75.3-100) were 100% (p value<0.0001).
Conclusion
Based on our data, 18F-FDG PET/CT appears to be accurate for initial staging and post treatment follow up in patients with MALT lymphoma and DLBCL. According to our observations, 18F-FDG PET/CT might be used to detect early relapse together with the histological evaluation. Our results should be considered as a preliminary study, limited at our cohort of 32 patients, which will be enlarged with new data.
Session topic: 20. Indolent Non-Hodgkin lymphoma – Clinical
Keyword(s): Gastric MALT lymphoma, PET
Abstract: PB2031
Type: Publication Only
Background
The role of 18F-FDG PET/CT in the diagnosis and follow-up of gastric lymphomas is still controversial. As 18F-FDG PET/CT staging role in gastric DBLC is well established, several studies haven’t still clarified the detection rate of PET/CT imaging in gastric MALT lymphomas.
Aims
The aim of our retrospective study is to evaluate the role of 18F-FDG PET/CT in the diagnosis and follow-up of gastric lymphoma.
Methods
Thirty-two patients with histological confirmed gastric lymphoma (MALT: 19; DLBCL: 13) underwent a 18F-FDG PET/CT for initial staging and post therapy evaluation. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUV MAX) and compared with Ann Arbor stage, Lugano staging system for gastrointestinal lymphomas, epidemiological (age, sex), histological /morphological (presence of gastritis, ulcers, H. pylori infection, tumor size, superficial lesions or mass-forming) characteristics.
Results
From January 2007 to November 2016, in our institution, we analyzed 32 gastric lymphoma: 19 patients had histological diagnosis of MALT lymphoma, whereas 13 patients received histological diagnosis of DLBCL. At diagnosis, 15 patients with MALT lymphoma had positive PET/CT-mean lesion SUV max of 6.14 (4.0-18.2) at the corresponding gastric lesion, the remaining 4 were not 18F-FDG avid. Nine patients were H. pylori positive. On the other hand, all 13 patients with DLBCL had positive PET/CT, as expected, with mean lesion SUV max of 17.1 (4-17.1). At post-treatment evaluation, all the patients had histological and radiological complete remission. The overall sensitivity of 18F-FDG PET/CT was 87% (CI 95%: 71-96.5) and specificity 100% (CI 95%: 89.1-100) (p value<0.0001) in our cohort. In MALT lymphoma PET sensitivity was 78% (CI 95%: 54.4-93.5) and specificity 100% (CI 95%: 82.3-100) (p value<0.0001), whereas in DLBCL the sensitivity (CI 95%: 75.3-100) and specificity (CI 95%: 75.3-100) were 100% (p value<0.0001).
Conclusion
Based on our data, 18F-FDG PET/CT appears to be accurate for initial staging and post treatment follow up in patients with MALT lymphoma and DLBCL. According to our observations, 18F-FDG PET/CT might be used to detect early relapse together with the histological evaluation. Our results should be considered as a preliminary study, limited at our cohort of 32 patients, which will be enlarged with new data.
Session topic: 20. Indolent Non-Hodgkin lymphoma – Clinical
Keyword(s): Gastric MALT lymphoma, PET