FDG-PET in the assessment of patients with follicular lymphoma treated by ibritumomab tiuxetan Y 90: multicentric study.

BACKGROUND: The aim of this study is the 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) evaluation following radioimmunotherapy (RIT) with ibritumomab tiuxetan Y 90 in patients with non-Hodgkin's follicular lymphoma (FL). MATERIALS AND METHODS: We retrospectively analyzed data from 59 relapsed or refractory FL patients treated with ibritumomab tiuxetan Y 90 in four different PET centers who had a PET scan carried out before and after RIT. Possible predictive factors of progression-free survival (PFS) were studied through univariate and multivariate analysis. RESULTS: The post-RIT PET documented 45.8% complete responders (CR), 25.4% partial responders (PR) and 28.8% nonresponders [stable disease + progressive disease], with an overall survival of 71.2% (range 59.5%-90.9%). With a median follow-up period of 23 months, the univariate analysis documented a statistically significant relation between disease extent before RIT and response to treatment with respect to PFS (P = 0.015), while all the other prognostic factors showed no significant correlation. When carrying out the multivariate analysis, post-RIT PET resulted as the lonely independent predictor of PFS (P < 0.00001). CONCLUSIONS: RIT is an effective therapy in FL patients, as confirmed in our study too. Disease extension before treatment and response to RIT, as assessed by FDG-PET, result as main predictors of PFS, with the post-RIT PET result being the only independent predictive factor.

The role of bone SPET study in diagnosis of single vertebral metastases.

The spine is the preferential site of metastases from several neoplasms. In the past years whole body bone scan (BS) with 99mTc-diphosphonates has been considered the first choice in detecting the skeletal involvement. However the presence of vertebral non-neoplastic pathology in oncologic patients can cause several false positive results and this increases the difficulty in defining the etiology of a focal uptake. Nowadays, technological development has provided new gamma cameras, which are able to perform tomographic acquisition (single photon emission tomography, SPET). This technique allows one to better define the anatomical location of the areas of increased uptake. In our study, 81 cancer patients, with suspected single skeletal metastases not defined by BS, were studied by SPET. The skeletal involvement was confirmed during at least 12 months follow up by means of clinical, radiological and nuclear medicine examinations. The overall malignant bone alterations were 14 while the benign ones were 67. The performances of SPET were: diagnostic sensitivity 92.8% (13/14), specificity 92.5% (62/67) positive predictive value 72.2% (13/18), negative predictive value 98.4% (62/63), accuracy 92.6% (75/81). Our conclusion is that bone SPET proved to be a very reliable tool in differentiating benign disease from metastatic involvement.

Assessment of mediastinal involvement in lung cancer with technetium-99m-sestamibi SPECT.

UNLABELLED: This study evaluated the clinical role of SPECT with sestamibi versus CT in the presurgical staging of lung cancer. METHODS: Forty-seven consecutive patients (44 men, 3 women; mean age 63.3 yr, range 49-82 yr) with clinical and radiological suspicion of lung cancer were enrolled in this study. Staging procedures including radiography, CT, fiberoptic bronchoscopy and sestamibi SPECT of the thorax. Radionuclide imaging was performed after intravenous injection of 740-925 MBq of sestamibi. In 36 patients a histological diagnosis was made, and these patients were evaluated for the study of mediastinal lymph node involvement. RESULTS: Mediastinal lymph node involvement was demonstrated in 11 of the 36 patients evaluated. Sestamibi SPECT correctly staged 10 of 11 patients with and 21 of 25 without mediastinal nodes, showing a diagnostic sensitivity of 91% and a specificity of 84%. Computed tomography gave 8 true-positive and 15 true-negative results, with a sensitivity of 73% and a specificity of 60%. Sestamibi SPECT results were also better than those of CT with regard to positive and negative predictive values and accuracy. CONCLUSION: The clinical role of sestamibi SPECT can be fully appreciated when the technique is used in selected patients, combined with CT or MRI, or both, to assess mediastinal involvement and avoid any invasive staging procedures.