Posttherapeutic (131)I SPECT-CT offers high diagnostic accuracy when the findings on conventional planar imaging are inconclusive and allows a tailored patient treatment regimen.

PURPOSE: The purpose of this prospective study was to determine the diagnostic impact and influence on patient treatment of posttherapeutic (131)I SPECT-CT when the findings on planar posttherapeutic whole-body scintigraphy (ptWBS) were inconclusive. MATERIALS AND METHODS: A total of 53 SPECT-CT scans were performed in 41 patients with thyroid cancer after high-dose (131)I therapy (2.944 to 7.526 GBq (131)I) because of diagnostic uncertainty on ptWBS. Physiological uptake in the salivary glands, gastric mucosa, gut, nasal mucosa, urinary tract and liver were considered to be normal. Any other foci of increased (131)I uptake, except iodine uptake clearly located in the thyroid bed, were considered to be abnormal. The data were evaluated on a lesion and a patient basis. RESULTS: Regarding neck lesions, SPECT-CT provided a diagnostic impact in 26/90 lesions (28.9%) and confirmed the diagnosis in 64/90 lesions (71.1%). On a patient basis, SPECT-CT changed N status in 12/33 patients (36.4%), provided a diagnostic impact in 21/33 patients (63.6%) and led to a treatment change in 8/33 patients (24.2%). Regarding lesions distant from the neck, SPECT-CT confirmed the diagnosis in 62/71 lesions (87.3%) and had a diagnostic impact in 9/71 lesions (12.7%). On a patient basis, SPECT-CT changed M status in 4/19 patients (21.1%), had a diagnostic impact in 14/19 patients (73.7%) and led to a treatment change in 2/19 patients (10.5%). Considering all patients, SPECT-CT led to a treatment change in 10/41 patients (24.4%). CONCLUSION: Integrated SPECT-CT is a useful tool, especially in cases of diagnostic uncertainty and helps to individualize patient management.

Sentinel node SPECT-CT in breast cancer. Can we expect any additional and clinically relevant information?

UNLABELLED: The AIM of this study was to determine the additional value of SPECT/CT in sentinel node scintigraphy in breast cancer. Furthermore, it was our question to determine, whether the low-dose computed tomography component (LD-CT) can be used for axillary lymph node staging of clinically negative patients. PATIENTS, METHODS: 51 patients with invasive breast cancer <3 cm in diameter were included in our prospective investigation. SPECT/CT was performed on a dedicated scanner 30 minutes after subareolar injection of (99m)Tc-Nanocoll. Axillary staging with CT(LD) was performed using standard CT-criteria. SLN were allocated to an axillary level using SPECT alone and SPECT/CT. Additionally, the number of SLN on CT(LD) corresponding to the scintigraphic hot node was notified for each patient and compared to the number of SLN found with the gamma probe. RESULTS: In 45/51 evaluable patients SLN could be localised in level I in 43 patients and in level II in two patients (all positive) using SPECT-CT, whereas a clear allocation could not be obtained by SPECT alone. The number of SLN was discrepant between SPECT and CT(LD) in 13/45 patients. The number of SLN detected with the gamma probe (n = 68) not significantly differed from the number of SLN detected by CT(LD) (n = 65) but was significantly higher than with SPECT (n = 51). CT(LD) yielded a sensitivity of 35.7%, a specificity of 83.9%, a positive predictive value (PPT) of 50%, a negative predictive value (NPV) of 74.3% and a diagnostic accuracy of 68.9% for axillary staging with CT(LD). CONCLUSION: The additional information of SPECT/CT allows a more accurate characterization of the SN concerning size, depth and anatomical location. CT(LD) when performed during (99m)Tc-Nanocoll sentinel-SPECT/CT is not suitable for axillary staging in breast cancer patients with clinical negative axilla due to its low sensitivity and moderate specificity. Therefore, it does not influence the decision for SNB or ALND. The limited resolution of SPECT leads to an underestimation of the number of SLN compared to CT(LD) and the gamma probe.