[11C]Choline PET/CT detection of bone metastases in patients with PSA progression after primary treatment for prostate cancer: comparison with bone scintigraphy.

PURPOSE: The aim of this study was to evaluate the clinical usefulness of [(11)C]choline positron emission tomography (PET)/CT in comparison with bone scintigraphy (BS) in detecting bone metastases (BM) of patients with biochemical progression after radical treatment for prostate cancer (PCa). METHODS: Seventy-eight consecutive patients with biochemical progression of PCa (mean prostate-specific antigen 21.1 ng/ml, range 0.2-500.0 ng/ml) referred for both [(11)C]choline PET/CT and BS for restaging purposes were retrospectively analysed. The diagnostic accuracy of [(11)C]choline PET/CT and BS was assessed by using morphological imaging and/or follow-up as standards of reference. As equivocal findings were found, the accuracy analysis was performed twice, once including them as positive and once as negative. A separate analysis was also performed in hormone-resistant patients and data compared with those of patients who did not receive anti-androgenic treatment. RESULTS: Equivocal findings occurred in 1 of 78 (1%) cases in [(11)C]choline PET/CT and in 21 of 78 (27%) cases in BS. Depending on their attribution as either positive or negative, the ranges of sensitivity, specificity, positive predictive value, negative predictive value and accuracy for [(11)C]choline PET/CT were 89-89%, 98-100%, 96-100%, 94-96% and 95-96%, respectively. For BS they were 100-70%, 75-100%, 68--100%, 100-86% and 83-90%, respectively. Concordant findings between [(11)C]choline PET/CT and BS occurred in 55 of 78 (71%) cases. The accuracy of [(11)C]choline PET/CT did not significantly (p = 0.30) differ between hormone-resistant patients (97%) and those who did not receive anti-androgenic treatment (95%). CONCLUSION: In clinical practice, [(11)C]choline PET/CT may not replace BS because of its lower sensitivity. However, for its high specificity, [(11)C]choline PET/CT positive findings may accurately predict the presence of BM. Equivocal findings are more frequent in BS than [(11)C]choline PET/CT.

Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) as second-line chemotherapy in HER2-negative, taxane-pretreated metastatic breast cancer patients: prospective evaluation of activity, safety, and quality of life.

BACKGROUND: A prospective, multicenter trial was undertaken to assess the activity, safety, and quality of life of nanoparticle albumin-bound paclitaxel (nab-paclitaxel) as second-line chemotherapy in HER2-negative, taxane-pretreated metastatic breast cancer (MBC). PATIENTS AND METHODS: Fifty-two women with HER2-negative MBC who were candidates for second-line chemotherapy for the metastatic disease were enrolled and treated at three centers in Northern Italy. All patients had previously received taxane-based chemotherapy in the adjuvant or first-line metastatic setting. Single-agent nab-paclitaxel was given at the dose of 260 mg/m(2) as a 30-minute intravenous infusion on day 1 each treatment cycle, which lasted 3 weeks, in the outpatient setting. No steroid or antihistamine premedication was provided. Treatment was stopped for documented disease progression, unacceptable toxicity, or patient refusal. RESULTS: All of the enrolled patients were evaluable for the study endpoints. The objective response rate was 48% (95% CI, 31.5%-61.3%) and included complete responses from 13.5%. Disease stabilization was obtained in 19 patients and lasted >6 months in 15 of them; the overall clinical benefit rate was 77%. The median time to response was 70 days (range 52-86 days). The median progression-free survival time was 8.9 months (95% CI, 8.0-11.6 months, range 5-21+ months). The median overall survival point has not yet been reached. Toxicities were expected and manageable with good patient compliance and preserved quality of life in patients given long-term treatment. CONCLUSION: Our results showed that single-agent nab-paclitaxel 260 mg/m(2) every 3 weeks is an effective and well tolerated regimen as second-line chemotherapy in HER2-negative, taxane-pretreated MBC patients, and that it produced interesting values of objective response rate and progression-free survival without the concern of significant toxicity. Specifically, the present study shows that such a regimen is a valid therapeutic option for that 'difficult to treat' patient population represented by women who at the time of disease relapse have already received the most active agents in the adjuvant and/or metastatic setting (ie, conventional taxanes).

Pulmonary sequestration: a (131)I whole body scintigraphy false-positive result.

A 35-year-old woman affected by a well-differentiated papillary thyroid carcinoma was referred to our hospital to perform a (131)Iodine ((131)I) whole body scintigraphy for restaging purpose. The patient had been previously treated with total thyroidectomy and three subsequent doses of (131)I for the ablation of a remnant jugular tissue and a suspected metastatic focus at the superior left hemi-thorax. In spite of the previous treatments with (131)I, planar and tomographic images showed the persistence of an area of increased uptake at the superior left hemi-thorax. This finding prompted the surgical resection of the lesion. Histological examination of the surgical specimen showed the presence of a pulmonary tissue consistent with pulmonary sequestration. Even though rare, pulmonary sequestration should be included in the potential causes of false-positive results of radioiodine scans.

Restaging clear cell renal carcinoma with 18F-FDG PET/CT.

AIM: The aim of our retrospective study was to assess the usefulness of F-FDG PET/CT in the restaging of clear cell renal cell carcinoma (RCC) patients. PATIENTS AND METHODS: Sixty-nine patients (median age = 62 years; range = 36-86 years) affected by clear cell RCC (TNM at staging: T1, 42 patients; T2, 13 patients; T3, 11 patients; T4, 3 patients; Fuhrman grade: G2, 47 patients; G3, 20 patients; G4, 2 patients) underwent whole-body F-FDG PET/CT to restage the disease after nephrectomy for clinical or radiological suspicion of metastases. Areas of abnormal uptake at PET/CT were classified, taking the liver uptake as reference, as follows: 1 = faint uptake, lower than liver; 2 = moderate uptake, equal to liver; and 3 = high uptake, higher than liver. Validation of F-FDG PET/CT results was established by (1) biopsy (23 patients) and (2) other imaging modalities (addressed BS; c.e.CT; MRI; F-fluoride PET/CT; subsequent F-FDG PET/CT), and/or clinical and radiological follow-up of 12 months (46 patients). RESULTS: F-FDG PET/CT was positive in 42 patients and negative in 27 patients. Sixteen patients presented single lesions and 26 patients presented multiple localizations of the disease. On a patient basis, 40 patients resulted true positive, 2 patient false positive, 23 patients true negative, and 4 patients false negative. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 90%, 92%, 91%, 95%, and 85%, respectively. On a lesion basis, PET/CT detected 114 areas of abnormal uptake in 42 positive patients of which 112 resulted to be true positive. FDG uptake of the true positive lesions resulted to be high in 83 cases, moderate in 17 lesions, and finally faint in 12 lesions. CONCLUSIONS: F-FDG PET/CT demonstrated a good sensitivity in the restaging of clear cell RCC. Most of the lesions showed intense activity. According to our results, it seems that the use of F-FDG PET/CT in the restaging of RCC is feasible because the number of false-negative cases is limited.

¹8F-FDG-PET/CT in malignant mesothelioma.

It is well known the useful role of ¹8F-FDG-PET/CT for differential diagnosis between benign and malignant disease, for staging, for monitoring response and for prognosis regarding mesothelioma. Recently, literature was enriched with new interesting studies regarding the potential applications of ¹8F-FDG-PET/CT in this field. The purpose of this review is to evaluate articles published on line (PubMed) from January 2011 until October 2012 in order to obtain an overview of recent progress of molecular imaging in malignant mesothelioma. The main topics concern the use of ¹8F-FDG-PET/CT in radiation therapy planning, monitoring of treatment (surgery/chemotherapy) response and prognosis assessment.

Evolving role of SPECT/CT in neuroendocrine tumors management: staging, treatment response, and follow-up.

The combined use of SPECT and CT strongly supports the molecular imaging of neuroendocrine tumors (NETs) with somatostatin receptor radiopharmaceuticals or with meta-iodobenzylguanidine. SPECT/CT fusion images provide potential attenuation correction, higher specificity, and accurate localization for the staging, evaluation of treatment response, and follow-up of NETs.

Imaging of a thymoma incidentally detected by C-11 choline PET/CT.

The integrated modality positron emission tomography/computed tomography (PET/CT) with C-11 choline is an established diagnostic tool for restaging prostate cancer patients with a biochemical failure after primary treatment. Thymoma is a rare tumor originating in thymus epithelial cells, asymptomatic in one-third to one-half of patients, and often occurring in the fourth and fifth decades of life. In the present case, C-11 choline PET/CT was performed in a prostate cancer patient with a biochemical relapse, to restage the disease. In addition to the detection of local recurrent disease in prostatic fossa, an abnormal C-11 choline increased uptake in mediastinum was reported. The mediastinal finding was initially wrongly interpreted by clinicians as a lymph nodal metastasis from prostate cancer. However, histopathological analysis confirmed the presence of a thymoma. Although rare, thymoma has to be considered as differential diagnosis in case of mediastinal masses presenting C-11 choline PET/CT positive findings, to avoid inappropriate patient management.