Francesca Chessa

131I SPECT/CT in the Follow-up of Differentiated Thyroid Carcinoma: Incremental Value Versus Planar Imaging

Planar 131I scintigraphy is routinely used to detect radioiodine-avid metastases of differentiated thyroid carcinoma (DTC). However, the modality has limitations, such as low sensitivity and lack of anatomic landmarks. We investigated whether SPECT with integrated low-dose CT may have additional value over planar imaging in detecting residue and metastases in DTC patients. Methods: We studied 117 consecutive thyroidectomized DTC patients. On 2 different hybrid dual-head γ-cameras (55 patients on one camera and 62 on the other), 108 patients underwent 131I diagnostic imaging and SPECT/CT, and 9 underwent posttherapeutic 131I planar imaging and SPECT/CT. We assigned an incremental value to SPECT/CT when it provided better identification and interpretation of the foci of radioiodine uptake, more correct anatomic localization and characterization, and precise differentiation between tumor lesions and physiologic uptake. Results: Planar imaging showed 116 foci of uptake in 52 of 117 patients, and SPECT/CT showed 158 foci in 59 of 117 patients, confirming all foci seen on planar imaging but identifying an additional 28 occult foci in 10 of 52 patients. Fourteen occult foci were shown on SPECT/CT in 7 further patients whose planar imaging findings were negative. SPECT/CT correctly characterized 48 foci unclear on planar imaging, also defining location and extent. SPECT/CT was a determinant in classifying as neoplastic those foci for which planar imaging seemed to exclude malignancy, discriminating between residue and lymph node metastases in the neck, some of which were adjacent to salivary glands and had been missed on planar imaging. SPECT/CT also showed occult lesions in the mediastinum, abdomen, and pelvis and identified small bone metastases unsuspected on planar imaging. Globally, SPECT/CT had an incremental value over planar imaging in 67.8% of patients, modified therapeutic management in 35.6% of positive cases, and avoided unnecessary treatment in 20.3% of patients with only single benign lesions or physiologic uptake. Conclusion: 131I SPECT/CT improved planar data interpretation, showing a higher number of DTC lesions, more precisely localizing and characterizing DTC foci, and more correctly differentiating between physiologic uptake and metastases, thus permitting the most appropriate therapeutic approach to be chosen. A wider use of this method is suggested complementary to planar imaging in selected DTC patients.

Thyroid function in human immunodeficiency virus patients treated with highly active antiretroviral therapy (HAART): a longitudinal study

Objective  Given that few and controversial data have been reported on thyroid function in human immunodeficiency virus (HIV) patients on highly active antiretroviral therapy (HAART), we further investigated whether HAART affects thyroid hormones.

The role of planar scintimammography with high-resolution dedicated breast camera in the diagnosis of primary breast cancer.

Planar scintimammography (SM) acquired with a conventional γ camera has proved a useful complementary tool to mammography (Mx) in breast cancer (BC) diagnosis, but with unsatisfactory sensitivity in small size carcinomas. In this study we assessed the role of planar SM with a high-resolution dedicated breast camera (DBC) in BC diagnosis, comparing the results with those of Mx. A consecutive series of 145 patients scheduled for biopsy for suspected BC underwent Tc-99m tetrofosmin planar SM using a newly developed DBC. Scintigraphic data were compared with Mx findings and correlated to histology. Histopathologic analysis revealed 165 lesions: 143 malignant and 22 benign. SM detected 139/143 carcinomas (overall sensitivity: 97.2%) and was true negative in 19/22 benign lesions (overall specificity: 86.4%). SM sensitivity was 91% in ≤10-mm carcinomas. SM was more accurate than Mx in 42/145 cases (29%), detecting cancer in 9 patients with Mx indeterminate for dense breasts (8/9 tumors were <10 mm), assessing additional tumor foci (all <10 mm) in 5 points with multifocal disease and correctly classifying 28 patients with inconclusive mammographic findings as affected by cancer or by benign disease. Mx was more accurate than SM in 3 patients, in each detecting 1 subcentimeter BC false negative on SM. DBC planar SM seems a highly sensitive diagnostic tool in the detection of BC, even when small in size, and in the assessment of multifocal disease. A wider employment of this procedure is thus suggested, especially in indeterminate or inconclusive mammographic findings to improve sensitivity and specificity of Mx.

99mTc-Tetrofosmin Pinhole-SPECT (P-SPECT) and Radioguided Sentinel Node (SN) Biopsy and in Breast Cancer Axillary Lymph Node Staging

We compared 99mTc-Tetrofosmin P-SPECT with radioguided SN biopsy in 101 T1/T2 BC pts to predict axillary lymph node status. The day before surgery all pts underwent lymphoscintigraphy (LS) to mark the SN, following subdermal injection of 99mTc-colloidal sulphur surrounding the breast lesion. LS was combined with pre and intraoperative gamma probe. Previously, all pts had also undergone P-SPECT. ALND was performed in all cases. The SN(s) was detected in 97/101 cases (96%) by LS and gamma probe; in the 4 missed cases P-SPECT predicted lymph node status. In the 97 comparable cases, radioguided SN biopsy showed a slightly higher accuracy than P-SPECT (94.8% vs 93.8%), but a higher false-negative rate (14.3% vs 8.6%); P-SPECT had a higher NPV (95.2% vs 92.5%). The two procedures when combined achieved 100% accuracy. Radioguided SN biopsy alone had 100% accuracy only in pts with BC < 15 mm. P-SPECT had 3 false negative cases, 2 of which were micrometastatic SNs, and 3 false positives. P-SPECT identified 81.2% of cases with a single node, determined the exact number of nodes in 82.6% of cases with 1 to 3 node and correctly classified 93.7% of pts as having < or = 3 or > 3 metastatic nodes. Radioguided SN biopsy seems indicated in selected, early stage, small BC pts, while P-SPECT shows a high sensitivity independent of primary tumor size, giving additional important preoperative prognostic information. The two procedures combined provided a better axillary lymph node status prediction in T1/T2 carcinomas, and could thus improve ALND pt selection.

Breast Scintigraphy with Breast-Specific γ-Camera in the Detection of Ductal Carcinoma In Situ: A Correlation with Mammography and Histologic Subtype

Ductal carcinoma in situ (DCIS) is a subtype of breast cancer encountered increasingly in clinical practice because of the widespread use of screening mammography. In the present study, we evaluated the usefulness of breast-specific γ-camera (BSGC) scintigraphy in DCIS identification, describing the scintigraphic findings and their correlation with mammography and histologic subtype. Methods: Thirty-three women, aged 41–81 y, with surgically proven DCIS were retrospectively reviewed. Before surgery, all patients underwent breast scintigraphy using a high-resolution semiconductor-based BSGC, starting 10 min after intravenous injection of 740 MBq of 99mTc-tetrofosmin. All patients had previously undergone mammography. A definitive histologic diagnosis was obtained in all cases after scintigraphy, and the scintigraphic findings were correlated with mammography and histologic subtype. Results: Mammography was positive in 30 of 33 patients (sensitivity, 90.9%), showing calcifications in 22 of 30 (73.3%), masses in 3 of 30 (10%), and masses plus calcifications in the remaining 5 of 30 (16.7%). Scintigraphy was positive in 31 of 33 patients (sensitivity, 93.9%), showing patchy irregular uptake in patients with calcifications and focal uptake in masses; sensitivity was higher in low- to intermediate-grade DCIS than in intermediate/high- and high-grade DCIS (100% vs. 91.3%), but the difference was not statistically significant. Two comedo-type DCIS (one 20-mm intermediate/high-grade and one 15-mm high-grade) with heterogeneously or highly dense breasts at mammography and one papillary low/intermediate-grade DCIS associated with Paget disease were true positive only at scintigraphy. Moreover, scintigraphy better assessed disease extent than did mammography in 5 additional patients. Two comedo-type DCIS (one 6-mm intermediate/high-grade and one 15-mm high-grade) were true positive only at mammography. The difference in sensitivity between scintigraphy and mammography was not statistically significant. The combined use of mammography and scintigraphy achieved 100% sensitivity. Conclusion: BSGC scintigraphy proved to be a highly sensitive diagnostic tool in the detection of DCIS, irrespective of histologic subtype, and with a scintigraphic pattern of uptake that correlated well with mammography findings. In our series, BSGC scintigraphy demonstrated a slightly higher sensitivity than mammography and a better assessment of local disease extent. Thus, BSGC scintigraphy should represent a useful adjunctive tool in breast cancer diagnosis.

Planar scintimammography and SPECT in neoadjuvant chemo or hormonotherapy response evaluation in locally advanced primary breast cancer

Conventional imaging procedures have proved of limited value in assessing tumor response to neoadjuvant chemotherapy in locally advanced primary breast cancer (LAPBC). We evaluated the usefulness of radioisotopic procedures comparing planar scintimammography (SM) to SPECT, monitoring pre-surgery neoadjuvant chemo- or hormonotherapy response in 32 LAPBC patients. In all cases, 99mTc-tetrofosmin conventional planar SM and SPECT were acquired by dual-head gamma camera with HR parallel hole collimators. In 15 cases, planar SM with small field of view high resolution dedicated breast camera (DBC) was also acquired. Scintigraphic data always correlated with histopathological findings. At surgery, 4/32 patients had pathological complete remission (pCR), while 28/32 patients had residual tumors. Both conventional planar SM and SPECT were true negative in 4/4 (100%) pCR patients, as was DBC in the only studied case. Conventional planar SM and SPECT detected residual tumors in 23/28 (82%) and in 25/28 (89.2%) cases, respectively. Both procedures missed 2 multifocal, scattered microscopic residues, only evidenced at DBC. Conventional planar SM also missed 3 further macroscopic residues (15-20 mm), while SPECT only one of these, a mucinous BC, in which DBC was not performed. DBC correctly classified all other 12 patients in whom the procedure was performed. Both conventional planar SM and SPECT proved useful diagnostic tools in monitoring neoadjuvant chemo/hormono therapy response in LAPBC with SPECT appearing more sensitive; however, our data, although in a limited number of cases, suggest that sensitivity can further be increased using high resolution DBC, especially in detecting microscopic residual tumor foci.

Going beyond Google Translate

We motivate and describe the design and implementation of a web-based system for the alignment of parallel texts. It builds on the interactive color-highlight interface now deployed at Google Translate. By a series of simple point and click operations translators can mark up equivalent text-ranges in their own translation and in the original. When successful, the visual cues created by this activity should benefit the understanding of readers of limited degrees of bilingualism -- and may also capture aspects of semantic context not readily available to algorithmic statistical machine translation. We provide a working demonstration that treats poetic texts.

The usefulness of Tc-99m-tetrofosmin SPECT/CT in the detection of residual tumors and axillary lymph node metastases in breast cancer patients following neoadjuvant therapy.

Single photon emission computed tomography (SPECT)/CT is emerging as a useful diagnostic tool in several oncological fields. In this prospective study, we assessed the usefulness of Tc-99m-tetrofosmin SPECT/CT in the detection of both residual breast tumors and axillary lymph node metastases following neoadjuvant therapy. Thirty-seven consecutive breast cancer patients scheduled to surgery following neoadjuvant therapy preoperatively underwent a Tc-99m-tetrofosmin SPECT/CT study, using a dual head gamma camera integrated with a x-ray tube for low-dose CT, including both breasts and axillary regions in the field of view. Within 1 week of SPECT/CT, all 37 patients had breast surgery with associated axillary lymph node dissection in 33/37 cases. At surgery, 31/37 patients had breast residues (microscopic in 4/31 cases and macroscopic in 27/31 cases). Axillary lymph node metastases were ascertained in 19/33 cases (N1mi: 2 cases, N1a: 8 cases, N2a: 6 cases, N2b: 3 cases). SPECT/CT sensitivity, specificity, and accuracy in detecting residual tumors were 87%, 100%, and 89.2%, respectively; the corresponding values in detecting axillary lymph node metastases were 36.8%, 92.8%, and 60.6%. SPECT/CT missed breast cancer residues in 4/31 patients, including 2 cases with microscopic residual disease. Moreover, lymph node metastases were missed in 12/19 patients (10/12 with pN1mi or pN1a metastases), all with lymph nodes with post-therapy fibrotic changes and small deposits of metastases. Tc-99m-tetrofosmin SPECT/CT proved a useful diagnostic tool in the detection and in the localization of residual breast tumors following neoadjuvant therapy. The procedure lacked in sensitivity in identifying axillary lymph node metastases, especially in patients with a limited lymph node involvement. According to our data, SPECT/CT may guide the surgeon to the most appropriate breast surgical treatment and to eventually select the most suitable axillary lymph node sampling (axillary lymph node dissection or sentinel node biopsy).

Going beyondGoogle Translate

We motivate and describe the design and implementation of a web-based system for the alignment of parallel texts. It builds on the interactive color-highlight interface now deployed at Google Translate. By a series of simple point and click operations translators can mark up equivalent text-ranges in their own translation and in the original. When successful, the visual cues created by this activity should benefit the understanding of readers of limited degrees of bilingualism -- and may also capture aspects of semantic context not readily available to algorithmic statistical machine translation. We provide a working demonstration that treats poetic texts.

A new quantitative 99mTc HMPAO Brain SPECT analysis in Alzheimer's Disease (AD) and Lewy bodies Dementia (LBD) differential diagnosis

regions. The diagnostic accuracy of conventional EEG in AD is around 80%. Statistical Pattern Recognition (SPR) is a statistical analysis that uses a database of information, in this case features from EEG registration, to identify individuals with aberrant pattern of brain waves. By using this method, the intention is to increase the diagnostic accuracy of EEG in AD. Methods: The participants were 300 patients diagnosed with AD at a Memory Clinic and 400 normal individuals evenly distributed in the age range of 50 90 years. SPR was used to identify the patients using more than 600 features of the EEG registration. A numeric index from 0-100 was established to describe the likelihood of AD in each case. Results: This method correctly identified AD patients when compared to the normal group with >90% accuracy. Furthermore, the AD-index correlated with the severity of the disease as evaluated by the MMSE. The method also correctly identified AD patients when compared to EEG in patients with vascular dementia (VD) with some overlap in patients with mixed VD and AD. Conclusions: By using SPR on features of EEG registration, this method is more sensitive in identifying patients with AD from normal individuals and from patients with VD than conventional EEG. The method is easy to use and is therefore more widely applicable than more specialized methods like MRI or SPECT/PET.