Determination of 226Ra at low levels in environmental, urine, and human bone samples and 223Ra in bone biopsy using alpha-spectrometry and metrological traceability to 229Th/225Ra or 226Ra

²²⁶Ra is a natural radioelement emitting α and γ radiations. It can be highly concentrated in TENORM materials from the petroleum or fertilizer industries. In Switzerland, ²²⁶Ra is currently a radioactive inheritance problem from the watch industry. Furthermore, ²²³Ra is a radium isotope used in nuclear medicine to treat bone metastasis. There exist several methods to measure radium using alpha or gamma spectrometry or using ²²²Rn emanation technique. The limitations of these methods are due to the required detection limits and the nature of the samples. When using alpha spectrometry to reach very low detection limits, critical technical hitches often arise because of the difficulties in separating radium from barium, in removing organics eluted from the separating chromatography column, and in plating radium. Moreover, overall chemical recovery of radium is often not reproducible, depending on the studies. Here we propose a method that separates radium from other alkaline-earth cations using cation exchange chromatography and selective complex formation by EDTA and DCTA. Radium is completely free of the ²²⁹Th tracer and its daughter products, particularly ²²⁵Ac. Organics from the column are removed in a further purification step so that radium can be plated with acceptable yields in a HCl/HNO₃/ethanol solution. We successfully applied the method to soil, water, urine and human bone samples and further extended it to the determination of ²²³Ra in a bone biopsy, using ²²⁶Ra as an internal tracer.

Incidental 18F-FDG Uptake of the Pubic Ramus and Abdominal Muscles due to Athletic Pubalgia During Acute Prostatitis

A 23-year-old African native male patient presented with fever, lumbalgia and dysuria after returning from a trip to Togo. His physical examination revealed pain over the pubic symphysis and rectal tenderness on digital exam. The C-reactive protein (CRP) level was elevated along with positive blood and urinary cultures for methicillin-resistant Staphylococcus aureus. An magnetic resonance imaging that has been performed to rule out arthritis/osteomyelitis in the pubis revealed edema of the symphysis. An ¹⁸F-FDG positron emission tomography/computed tomography supported the diagnosis of prostate infection and showed a focal uptake of the pubic symphysis, with diffuse hyper-metabolism of the insertions of the rectus abdominis and longus adductor muscles, corresponding to athletic pubalgia. Fever and CRP responded rapidly to antibiotherapy.

Accuracy of whole-body HDP SPECT/CT, FDG PET/CT, and their combination for detecting bone metastases in breast cancer: an intra-personal comparison

New generation SPECT/CT scanners allow rapid whole-body imaging, and potentially facilitate significantly improved diagnostic accuracy. Thus, the aim of this study was to compare the diagnostic accuracy of whole-body Tc-99m-HDP SPECT/CT, F-18-FDG PET/CT, and their combination for detecting bone metastases in breast cancer. Women with biopsy-proven breast cancer that were referred for whole-body SPECT/CT and FDG PET/CT were consecutively included in this retrospective study. Two blinded readers independently interpreted all scans. In a per-patient analysis, the diagnostic performances of whole-body SPECT/CT, FDG PET/CT, and their combination were compared using receiver operating characteristic (ROC) analysis. In a per-lesion analysis, the performances were compared using figures of merit (FoM) differences in Jackknife alternative free-response ROC analysis, which considers the location information. Follow-up served as reference standard. Overall, 25 consecutive women (median age: 55; range 38-82) with 117 lesions were included. The median follow-up was 21 months (2-46 months). The per-patient analysis revealed no significant differences in diagnostic performance (P = 0.16), while the per-lesion analysis revealed a diagnostic superiority of whole-body SPECT/CT over FDG PET/CT (P = 0.004). Specifically, the PET/CT FoM was significantly lower than the SPECT/CT FoM (FoM difference = -0.11, 95% CI [-0.21; -0.02], P = 0.021). No significant difference was observed between SPECT/CT and the combination of SPECT/CT and PET/CT. The per-lesion analysis suggest that SPECT/CT has a higher diagnostic accuracy than FDG PET/CT for the detection of bone metastases. Thus, SPECT/CT may be a useful adjunct to FDG PET/CT for staging of breast cancer patients.

Asymptomatic Urolithiasis Complicated by Nephrocutaneous Fistula

Asymptomatic spontaneous nephrocutaneous fistula is a rare and severe complication of chronic urolithiasis. We report a case of 56-year-old woman with a nephrocutaneous fistula (NFC) which developed from a superinfected urinoma following calyceal rupture due to an obstructing calculus in the left ureter. The patient was clinically asymptomatic and came to the emergency department for a painless left flank fluctuating mass. This urinoma was superinfected, with a delayed development of renal abscesses and perirenal phlegmon found on contrast-enhanced uro-computed tomography (CT), responsible for left renal vein thrombophlebitis and left psoas abscess. Thereafter, a 99 mTc dimercaptosuccinic acid (DMSA) scintigraphy revealed a nonfunctional left kidney, leading to the decision of left nephrectomy. Chronic urolithiasis complications are rare and only few cases are reported in medical literature. A systematic medical approach helped selecting the best imaging modality to help diagnosis and treatment. Indeed, uro-CT scan and renal scintigraphy with 99 mTc-DMSA are the most sensitive imaging modalities to investigate morphological and functional urinary tract consequences of NFC, secondary to chronic urolithiasis.

Target Definition in Salvage Radiotherapy for Recurrent Prostate Cancer: The Role of Advanced Molecular Imaging

Salvage radiotherapy (SRT) represents the main treatment option for relapsing prostate cancer in patients after radical prostatectomy. Several open questions remain unanswered in terms of target volumes definition and delivered doses for SRT: the effective dose necessary to achieve biochemical control in the SRT setting may be different if the tumor recurrence is micro- or macroscopic. At the same time, irradiation of only the prostatic bed or of the whole pelvis will depend on the localization of the recurrence, local or locoregional. In the “theragnostic imaging” era, molecular imaging using positron emission tomography (PET) constitutes a useful tool for clinicians to define the site of the recurrence, the extent of disease, and individualize salvage treatments. The best option currently available in clinical routine is the combination of radiolabeled choline PET imaging and multiparametric magnetic resonance imaging (MRI), associating the nodal and distant metastases identification based on PET with the local assessment by MRI. A new generation of targeted tracers, namely, prostate-specific membrane antigen, show promising results, with a contrast superior to choline imaging and a higher detection rate even for low prostate-specific antigen levels; validation studies are ongoing. Finally, imaging targeting bone remodeling, using whole-body SPECT–CT, is a relevant complement to molecular/metabolic PET imaging when bone involvement is suspected.

PET/MR in Breast Cancer

Breast cancer is an international public health concern in which an optimal treatment plan requires a precise staging. Both MRI and PET imaging techniques have made significant progress in the last decades with constant improvements that made both modalities clinically relevant in several stages of breast cancer management and follow-up. On one hand, specific breast MRI permits high diagnostic accuracy for local tumor staging, and whole-body MRI can also be of great use in distant staging, eventually accompanied by organ-specific MRI sequences. Moreover, many different MRI sequences can be performed, including functional MRI, letting us foresee important improvements in breast cancer characterization in the future. On the contrary, (18)F-FDG-PET has a high diagnostic performance for the detection of distant metastases, and several other tracers currently under development may profoundly affect breast cancer management in the future with better determination of different types of breast cancers allowing personalized treatments. As a consequence PET/MR is a promising emerging technology, and it is foreseeable that in cases where both PET and MRI data are needed, a hybrid acquisition is justified when available. However, at this stage of deployment of such hybrid scanners in a clinical setting, more data are needed to demonstrate their added value beyond just patient comfort of having to undergo a single examination instead of two, and the higher confidence of diagnostic interpretation of these co-registered images. Optimized imaging protocols are still being developed and are prone to provide more efficient hybrid protocols with a potential improvement in diagnostic accuracy. More convincing studies with larger number of patients as well as cost-effectiveness studies are needed. This article provides insights into the current state-of-the-art of PET/MR in patients with breast cancer and gives an outlook on future developments of both imaging techniques and potential applications in the future.

Significance of 18F-fluorocholine PET/CT positive pulmonary lesions in prostate cancer patients

AIM

To assess the frequency and the significance of incidental pulmonary lesions with 18F-fluorocholine (18F-FCH) PET/CT in prostate cancer (PCa) patients.

PATIENTS, METHODS

225 consecutive PCa patients referred for 18F-FCH PET/CT (median age 68 years) were retrospectively evaluated for the presence of lesions in the lungs: 173 referred for restaging and 52 for initial staging regarding their high risk of extra prostatic extension. The final diagnosis was based on histopathological or on clinical and radiological follow-up.

RESULTS

13 patients had 18F-FCH positive pulmonary and 8 patients malignant lesions: 5 patients (38%) had a primary lung cancer (2 squamous cell carcinomas, 1 papillary adenocarcinoma, 1 typical pulmonary carcinoid, 1 bronchioloalveolar carcinoma) and 3 patients (23%) PCa metastases. Benign lesions were found in 5 subjects (38%). SUVmax and maximum diameter were neither significantly different in primary and metastatic tumors nor between malignant and benign lesions.

CONCLUSIONS

Although our results suggest that incidental uptake in the lungs in PCa patients are nonspecific, their detection may have a significant impact on patient management knowing that more than 60% represent malignant disease.

[Single teeth on Brånemark fixtures. A new esthetic approach. Presentation of a clinical case]

The reliability of the Brånemark implant system has been well documented. In addition, the technique has been employed in the anterior portion of the mouth with good cosmetic results. Fundamental to the success of these procedures is the multidisciplinary approach. The "Drilling Guide" is the outcome of an intimate relationship between members of the therapeutic team, this allows for the control of all parameters of aesthetics. The preparation of the prosthetic cradle by selecting splaying and eversion is presented as a new approach. The impression method is atraumatic and employs personalized unitary transfers. This leads to the required emergence profile and guarantees the optimum aesthetic result.

[Dental implants and bone grafts]

The reconstruction of an edentulous maxilla with bone graft is not a challenge. It is considered when the remaining bone cannot provide a firm anchorage for implants. The grafts are harvested from the ilium, the chin or the cranial vault. According to the case, the implants are placed either simultaneously or 6 months later after control with C.T. Scan. They are uncovered after another 6 month period, as in the usual procedure, and osseointegration is checked. The percentage of success on 24 operated cases seems at least equal to the regular cases without bone graft. Longer follow-up is needed for reliable statistics.