18F-FDG-PET metabolic metrics and International Prognostic Score for risk assessment in HIV-infected patients with Hodgkin lymphoma.

OBJECTIVES: Baseline metabolic metrics on fluorine-18-fluorodeoxyglucose PET (F-FDG PET) have prognostic value in Hodgkin lymphoma. International Prognostic Score (IPS) is used in the risk stratification of Hodgkin lymphoma. We compared the metabolic indices in HIV-infected and the IPS in HIV-infected and uninfected patients with Hodgkin lymphoma. PATIENTS AND METHODS: We retrospectively reviewed the data of HIV-infected and HIV-uninfected patients with classic Hodgkin lymphoma who had F-FDG PET for staging and compared the maximum standardized uptake value, mean standardized uptake value, metabolic tumor volume, and total lesion glycolysis between the two groups. We also compared the IPS and other prognostic indicators and correlated them with the metabolic indices in the two groups. RESULTS: We studied 160 patients, which included 57 patients who were infected with HIV. The mean age was 33.84±11.88 years, with 38% (n=61) being female. The median cluster of differentiation 4 count and HIV viral load were 259 cells/mm and 4837.50 copies/ml, respectively. No significant difference in maximum standardized uptake value, mean standardized uptake value, metabolic tumor volume, and total lesion glycolysis between the two groups was found. Among the seven parameters of the IPS, only male sex (HIV-uninfected group higher, P=0.005) and serum albumin less than 4 g/dl were significantly different. The other parameters were not significantly different between the two groups. Other prognostic indicators including bulky disease, extranodal involvement, and the number of nodal groups involved were not significantly different between the two groups. CONCLUSION: There was no significant difference in F-FDG metabolic parameters, IPS, and other risk indicators between HIV-infected and HIV-uninfected patients with Hodgkin lymphoma.

68Ga-PSMA PET/CT Replacing Bone Scan in the Initial Staging of Skeletal Metastasis in Prostate Cancer: A Fait Accompli?

PURPOSE: 68Ga ligands targeting prostate-specific membrane antigen (PSMA) are rapidly emerging as a significant step forward in the management of prostate cancer. PSMA is a type II transmembrane protein with high expression in prostate carcinoma cells. We prospectively evaluated the use of 68Ga-PSMA positron emission tomography/computed tomography (PET/CT) in patients with prostate cancer and compared the results to those for technetium-99m (99mTc)-10-metacyloyloxydecyl dihydrogen phosphate (MDP) bone scintigraphy (BS). PATIENTS AND METHODS: A total 113 patients with biopsy-proven prostate cancer referred for standard-of-care BS were prospectively enrolled onto this study. 68Ga-PSMA PET/CT was performed after BS. Metastasis diagnosed on each technique was compared against a final diagnosis based on CT, magnetic resonance imaging, skeletal survey, clinical follow-up, and histologic correlation. RESULTS: Ninety-one bone lesions were interpreted as bone metastases in 25 men undergoing 68Ga-PSMA PET/CT compared to only 61 lesions in 19 men undergoing 99mTc-MDP BS. Of the 7 bone scans that missed skeletal metastases, 54% of these missed lesions were due to either marrow or lytic skeletal metastases. The median standardized uptake value in all malignant bone lesions was 13.84. 68Ga-PSMA PET/CT showed significantly higher sensitivity and accuracy than BS (96.2% vs. 73.1%, and 99.1% vs. 84.1%) for the detection of skeletal lesions. For extraskeletal lesions, 68Ga-PSMA PET/CT showed an additional 96 unexpected lesions with a median standardized uptake value of 17.6. CONCLUSION: 68Ga-PSMA PET/CT is superior to and can potentially replace bone scan in the evaluation for skeletal metastases in the clinical and trial setting because of its ability to detect lytic and bone marrow metastases.

The role of F-18 FDG PET/CT in evaluating the impact of HIV infection on tumor burden and therapy outcome in patients with Hodgkin lymphoma.

BACKGROUND: To evaluate the impact of HIV infection on tumor burden and therapy outcome following treatment with chemotherapy in patients with Hodgkin lymphoma. METHODS: A total of 136 patients with classical Hodgkin lymphoma were studied (mean age ± SD = 32.31 ± 1.39 years, male = 86, female = 50). Advanced disease (stage III and IV) was present in 64% of patients. HIV infection was present in 57 patients while 79 patients were HIV-negative. Baseline F-18 FDG PET/CT was obtained in all patients. SUVmax, MTV and TLG were determined on the baseline scan to evaluate for tumor burden. All patients completed a standard regimen of adriamycin, bleomycin, vinblastine and dacarbazine (ABVD). After a median period of 8 weeks (range = 6 to 17 weeks), a repeat F-18 FDG PET/CT scan was obtained to evaluate response to therapy using Deauville 5-point scoring system. RESULTS: The HIV-positive and HIV-negative groups were similar with regards to age and disease stage. The groups were heterogeneous with respect to gender (p = 0.029). The SUVmax, MTV and TLG of lesions were not significant different between the two groups. Complete response was seen in 72.8% of the study population. Presence of HIV infection was associated with higher rate of treatment failure with 40.4% of the HIV-positive patients having treatment failure while only 17.7% of the HIV-negative patients had treatment failure (p = 0.0034). HIV infection was a significant predictor of response to chemotherapy. Effects of SUVmax, MTV, TLG and Ann Arbor stage of the disease were not statistically significant as predictors of therapy outcome. In a multiple logistic regression, presence of HIV infection still remained an independent predictor of therapy outcome in the presence of other factors such as SUVmax, MTV, TLG and the Ann Arbor stage of the disease. CONCLUSIONS: HIV infection is not associated with a higher tumor burden in patients with Hodgkin lymphoma. HIV infection is, however, a strong predictor of poor therapy outcome in patients treated with standard regimen of ABVD.

A comparison of 18F-FDG PET/CT findings in HIV positive compared to HIV negative patients with recurrent cervical cancer.

OBJECTIVE: HIV-positive women with cervical cancer have higher recurrence and death rates with shorter time to recurrence and death compared with HIV-negative subjects. The objective of this study was to compare the recurrence patterns in HIV-positive women with invasive cervical cancer to their HIV-negative counterparts using 18F-FDG PET/CT. SUBJECTS AND METHODS: We evaluated 40 HIV- seropositive and 79 HIV-seronegative patients with recurrent cervical carcinoma using 18F-FDG PET/CT. The PET/CT datasets were interpreted by two independent readers blinded to the HIV status of the patients. Areas of disagreement were resolved by consensus. Cervical cancer recurrence was confirmed by biopsy and histological examination of tissue, correlation with conventional imaging (CT and MRI) and by follow-up 18F-FDG PET/CT. RESULTS: HIV-positive patients were 9 years younger than the HIV-negative patients at the time of diagnosis; mean age 39 years versus 48 years respectively. Initial treatment was comparable in both groups. Time to recurrence was shorter in HIV-infected compared with HIV-uninfected women (11 versus 24 months). The commonest sites of metastatic recurrence was in the lymph nodes. HIV-infected patients demonstrated significant higher recurrence in lymph nodes and lungs (P<0.05). No significant difference in the recurrence rate in liver or bone (P>0.05) between both groups. HIV-infected patients showed unusual metastases to brain, spleen and skin. CONCLUSION: By using the 18F-FDG PET/CT scan we showed that the time to recurrence is shorter among HIV seropositive patients with the commonest site of metastatic recurrence being in the lymph nodes. Nodal and liver metastases are significantly higher in HIV seropositive patients compared with seronegative patients.