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.

The effectiveness of radionuclide scintigraphy in confirming testicular torsion at delayed presentation.

Background: Testicular torsion (TT) is a urological emergency that needs early diagnosis and intervention to prevent testicular death and necrosis. This study aimed to determine the efficacy of testicular scintigraphy (TS) in confirming the clinical diagnosis of TT and how this imaging method correlates with the surgical findings. Methods: A retrospective cohort review of clinical data was performed for 68 patients referred for TS from January 2016 to December 2021 to rule out possible TT. The final diagnosis was confirmed at surgery for all those with TS positive for TT. Results: The median age of the patients was 18.5 years, interquartile range of 15-31 years. Commonly presenting symptoms were pain (99%) and swelling (68%). Only 6% had history of trauma. TT was diagnosed by technetium-99m (99mTc)-pertechnetate in 35 (51%) patients all of whom underwent surgical exploration. Of this group, 7 (20%) had manual detorsion intraoperatively (intermittent torsion), in 20 (57%) missed (complete) torsion was confirmed and 8 (23%) had a necrotic testis. Of the remaining 33 patients with results negative for torsion, 10 were normal and 23 were diagnosed with either epididymitis 13/23 (57%), orchitis 3/23 (13%) or 7/23 (30%) with epididymo-orchitis. TT was more common in patients under 15 and 15-19 years (P<0.05). The mean presentation time was 5 days with a range of 1-30 days. Conclusions: The 99mTc-pertechnetate scan remains an effective investigation in the diagnosis of TT and may serve as a gate-keeper for surgery even in patients who present late for treatment.

Critical Appraisal of Radionuclide Calibrators and Gamma Cameras Prior to Lutetium-177 Internal Dosimetry at Two South African Hospitals.

Introduction The functionality of radionuclide dose calibrator and nuclear medicine imaging systems hasa direct effect on the accuracy and preciseness of internal dosimetry evaluations. Our study, therefore, aimed to critically appraise the radionuclide calibrators and gamma cameras prior to Lutetium-177 ( 177 Lu) internal dosimetry in a developing country. Materials and Methods Two radionuclide calibrators' and three gamma cameras at two South African hospitals were critically appraised in preparation for internal dosimetry of 177 Lu. The radionuclide calibrators' accuracy, linearity, and sample volume abilities were appraised. For the three gamma cameras, the uniformity, energy resolution, center of rotation, and collimator sensitivity were appraised. These appraisals were performed between the years 2014 and 2019. Results The radionuclide calibrators' constancy, accuracy, linearity, and sample volume were within ± 5%. We also integrated a 177 Lu calibration factor into one radionuclide calibrator's library. The three gamma cameras' uniformity was within 2 to 5%, energy resolution within 11%, center of rotation within 2 mm, and the sensitivity recorded for all low energy high resolution collimator. Conclusion Our radionuclide calibrators passed the critical appraisal and may be confidently used for assaying 177 Lu. All three cameras also passed critical appraisal and may be used to assess organ absorbed dose.

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.

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.

Clinical and brain SPECT scan response to zolpidem in patients after brain damage.

UNLABELLED: Previous reports document transient improvements after daily zolpidem (CAS 82626-48-0) in patients with brain damage. This multi-patient study evaluates the response to zolpidem in neurologically disabled patients, using 99mTcHMPAO brain SPECT scans and clinical rating scales. METHOD: 23 of 41 consecutive adult patients, at least 6 months after brain damage were identified as neurologically disabled patients by scoring less than 100/100 on the Barthel Index. Causes of their brain damage included stroke (n = 12), traumatic brain injury (n = 7), anaphylaxis (n = 2), drugs overdose (n = 1) and birth injury (n = 1). The selected 23 patients had a baseline 99mTcHMPAO brain SPECT scan before starting daily zolpidem therapy and a second within two weeks of therapy, performed 1 h after 10 mg oral zolpidem. Scans were designated as improved when at least two of three assessors detected improvement after zolpidem. The rest were designated non improved. After four months daily zolpidem therapy, patients were rated on the Tinetti Falls Efficacy Scale (TFES) before and after zolpidem. The TFES ratings were compared using a Wilcoxon non parametric signed rank test. Scan improvers were compared with non improvers, using a two sample t test with unequal variance. RESULTS: Mean overall improvement after zolpidem on TFES was 11.3%, from 73.4/100 to 62.1/100 (p = 0.0001). 10/23 (43%) patients improved on SPECT scan after zolpidem. Their mean TFES improvement was 19.4% (+/- 16.75) compared with 5.08% (+/- 5.17) in 13/23 non improvers (p = 0.0081). CONCLUSION: This prospective study adds further evidence to previous reports of zolpidem efficacy in patients with established brain damage.