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It has been validated that sentinel lymph node biopsy (SLNB) shows whether a patient's breast cancer or melanoma has spread to regional lymph nodes. As a result, management of patients with these cancers has been revolutionized. SLNB has replaced axillary lymph node dissection (ALND) as the staging modality of choice for early breast cancer and has replaced complete lymph node dissection as the staging modality of choice for melanoma in patients whose SLNBs indicate no metastases. Recently concluded multicenter, randomized trials for breast cancer with 5- to 10-y outcome data have shown no significant differences in disease-free survival rates or overall survival rates between SLNB and ALND groups but have shown significantly lower morbidity with SLNB than with ALND. The lowest false-negative rates (5.5%-6.7%) were seen in studies that used preoperative lymphoscintigraphy and dual mapping during surgery. To assess the survival impact of SLNB in melanoma, the Multicenter Selective Lymphadenectomy Trial I was performed. Melanoma-specific survival rates were not different between subjects randomized to SLNB with lymphadenectomy for nodal metastasis on biopsy and subjects randomized to observation with lymphadenectomy for nodal relapse. However, the 10-y disease-free survival rates were better for the SLNB group than for the observation group, specifically among patients with intermediate-thickness melanomas or thick melanomas., (© 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.)

Unlabelled: After the extravasation of a therapeutic dose of (131)I-metaiodobenzylguanidine that produced a radiation burn to a patient's forearm, we instituted a catheter placement verification protocol., Methods: Before therapy infusion, proper placement is verified by administering 37 MBq of (99m)Tc-pertechnetate through the catheter, and monitoring activity at the administration site and on the contralateral extremity. A dosimetric model describing both high-rate and low-rate dose components was developed and predicted that the basal epidermal layer received a radiation dose consistent with the observed moist desquamation radiation skin toxicity., Results: No extravasation incidents have occurred since the verification procedure was instituted., Conclusion: To protect against radiation injury from extravasation of therapeutic radionuclides, test administration of a small (99m)Tc dose with probe monitoring of comparable sites in both upper extremities appears to be an effective preventive measure.

Unlabelled: CT and PET are widely used to characterize solitary pulmonary nodules (SPNs). However, most CT accuracy studies have been performed with outdated technology and methods, and previous PET studies have been limited by small sample sizes and incomplete masking. Our objective was to compare CT and PET accuracy in veterans with SPN., Methods: Between January 1999 and June 2001, we recruited 532 participants with SPNs newly diagnosed on radiography and untreated. The SPNs were 7-30 mm. All patients underwent (18)F-FDG PET and CT. A masked panel of 3 PET and 3 CT experts rated the studies on a 5-point scale. SPN tissue diagnosis or 2-y follow-up established the final diagnosis., Results: A definitive diagnosis was established for 344 participants. The prevalence of malignancy was 53%. The average size was 16 mm. Likelihood ratios (LRs) for PET and CT results for combined ratings of either definitely benign (33% and 9% of patients, respectively) or probably benign (27% and 12%) were 0.10 and 0.11, respectively. LRs for PET and CT results for combined ratings of indeterminate (1% and 25%), probably malignant (21% and 39%), or definitely malignant (35% and 15%) were 5.18 and 1.61, respectively. Area under the receiver operating characteristic curve was 0.93 (95% confidence interval, 0.90-0.95) for PET and 0.82 (95% confidence interval, 0.77-0.86) for CT (P < 0.0001 for the difference). PET inter- and intraobserver reliability was superior to CT., Conclusion: Definitely and probably benign results on PET and CT strongly predict benign SPN. However, such results were 3 times more common with PET. Definitely malignant results on PET were much more predictive of malignancy than were these results on CT. A malignant final diagnosis was approximately 10 times more likely than a benign final diagnosis in participants with PET results rated definitely malignant.

Unlabelled: Event rates associated with a normal or low-risk myocardial perfusion SPECT imaging study have been shown by numerous investigators to be associated with <1%/y of follow-up. Thus, the aim of this study was to evaluate the prognostic value of a normal (99m)Tc-tetrofosmin study in a geographically diverse registry of patients undergoing stress myocardial perfusion SPECT. A total of 4,728 consecutively tested patients who underwent stress (99m)Tc-tetrofosmin SPECT at 5 U.S. hospitals were included in this series., Methods: Patients were monitored for the occurrence of major cardiac events and hospitalizations. Uniform methods of data collection and standardized epidemiologic methods for follow-up were used at all centers. We used a risk-adjusted, Cox proportional hazards model to assess time to cardiac death., Results: Of the 4,728 patients, one third underwent adenosine stress SPECT and two thirds underwent treadmill exercise. The observed annualized survival rate for those patients with a normal (99m)Tc-tetrofosmin study was 0.6%. Similarly, excellent survival rates were noted for the male and female subsets of this population as well as for patients who could exercise and for those undergoing pharmacologic stress testing. Compared with prior published outcomes studies on stress (201)Tl or (99m)Tc-sestamibi SPECT, the overall survival rates were similar and ranged from 99.3% to 99.7%., Conclusion: Results from this large multicenter registry provide further supportive evidence that the excellent prognosis associated with a normal SPECT scan is independent of the radiopharmaceutical used.