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.

Higher preablative serum thyroid-stimulating hormone level predicts radioiodine ablation effectiveness in patients with differentiated thyroid carcinoma.

INTRODUCTION: Radioiodine ablation of remnant thyroid tissue is an important adjuvant therapy of differentiated thyroid carcinoma (DTC) after thyroidectomy. Elevated serum thyroid-stimulating hormone (TSH) level is necessary for successful ablation. The optimum level of serum TSH level necessary for successful radioiodine ablation of well-DTC is, however, yet to be defined. We aimed to determine whether higher serum TSH level will result in a better rate of complete ablation of well-DTC using iodine-131 (I) following initial thyroidectomy. PATIENTS AND METHODS: A total of 109 patients with differentiated thyroid cancer were divided into four treatment groups on the basis of serum TSH levels. They were followed up from 6 to 12 months after treatment with stimulated serum thyroglobulin level and a diagnostic whole-body scan with radioactive iodine I to determine early response. RESULTS: Sixty-four patients had papillary thyroid carcinoma, whereas 45 patients had follicular carcinoma. An excellent response was observed in 66.7% of patients with TSH level more than 90 µIU/ml, 72.2% in the group with TSH level of 60-89 µIU/ml, 48.5% when TSH was 30-59 µIU/ml and 26.7% when TSH was less than 30 µIU/ml (P=0.002). CONCLUSION: Higher preablative serum TSH predicts a better rate of ablation in patients with differentiated thyroid cancer treated with I after thyroidectomy.