Sulfur Colloid for Sentinel Node Biopsy for Melanoma in the Head and Neck

The objective of the study is to compare sentinel lymph node (SLN) identification rates and performance characteristics of lymphoscintigraphy using 99mTc-sulfur colloid (SC) and 99mTc-tilmanocept (TL) for head and neck cutaneous melanoma. This study is a retrospective study, conducted at a single, tertiary care cancer center. Patients underwent sentinel lymph node biopsy (SLNB) for head and neck cutaneous melanoma, using SC or TL, between October 2014 and February 2019. Differences in SLN identification rates and performance characteristics between the groups were examined using the Mann-Whitney, or Fisher's exact test. Sixty patients underwent SLNB, of which 19 employed TL. There were no significant differences between SC vs. TL in operative duration (116 vs. 127 min, P = 0.97), radiation dose (530 vs. 547 μCi, P = 0.27), median number of SLNs removed (3 vs. 2, P = 0.32), or median follow-up (46.3 vs. 38.4 months, P = 0.11). The rates of positive SLNs (17% vs. 37%, P = 0.11), intraoperative non-localization (12% vs. 16%, P = 0.70), and false-negative SLNB (5% each, P = 1.00) were not significantly different between groups. In patients with head and neck melanoma undergoing SLNB, 99mTc-tilmanocept may not differ from 99mTc-sulfur colloid in identifying SLNs or other performance characteristics. The added expense related to 99mTc-tilmanocept and lack of favorable performance data should urge caution in its adoption and promote further examination of its value in similar patient cohorts.

Evaluation of Dyspepsia with Optimal and Suboptimal Gastric Emptying Tests in Patients with Euthyroid Goiter

OBJECTIVE

The presence of gastroparesis in patients with dyspepsia can be evaluated by gastric emptying scintigraphy. We aimed to evaluate gastroparesis with optimal solid gastric emptying scintigraphy and suboptimal liquid gastric emptying scintigraphy in euthyroid goiter patients with dyspepsia.

METHODS

We included 67 patients diagnosed with euthyroid goiter with dyspepsia complaints. The patients did not use any medication and did not have any other chronic diseases. Solid and liquid gastric emptying scintigraphy was performed on all patients. In our retrospective study; the images were reevaluated. The region of interest was plotted on the area compatible with the stomach and time-activity curves were obtained. The correlation of solid and liquid gastric emptying test results was evaluated.

RESULTS

Twelve (18%) of the patients were male and the mean age of the patients was 64 (49-75). There is a correlation between solid and liquid gastric emptying scintigraphy (p< 0.0005, r: 0.0880). Solid gastric emptying time was prolonged in 27 patients (40%). Liquid gastric emptying was prolonged in 23 patients (34%). Solid gastric emptying was also prolonged in all patients with prolonged liquid gastric emptying.

CONCLUSION

According to the results of the optimal gastric emptying test performed with radio-labeled solid food. The rate of gastroparesis was low in our patient group with dyspepsia complaints. However, there is a correlation between the optimal test and suboptimal gastric emptying test results in our patient group. Liquid gastric emptying scintigraphy may be preferred in specific patient groups in case of suspected gastroparesis because of its easy application and short duration.

Hybrid Imaging with SPECT-CT and SPECT-MR in Hepatic Splenosis

Splenosis, commonly occurs incidentally and locates to bowel surfaces, parietal peritoneum, mesentery, and diaphragm, but can potentially occur anywhere in the peritoneal cavity. Patients frequently have a history of splenectomy or trauma. On the other hand, hepatic splenosis is a rare entity and may present itself clinically. Indeterminate liver lesions can pose a clinical dilemma and may lead to additional investigations, anxiety, follow-up imaging and even to invasive procedures. MRI usually performs extremely well. In difficult cases, scintigraphy can be of great value -especially with novel SPECT-CT and SPECT-MR techniques-. We describe a case of a 29-year-old lady with hepatic splenosis and the impact of hybrid imaging.

99mTc-sodium phytate is a valid alternative to the gold-standard 99mTc-sulfur colloid in the measurement of gastric emptying among healthy multi-ethnic Asian population: results of a randomized cross-over trial

BACKGROUND

It is unclear if the 99mTc-sodium phytate (99mTc-SP) is as reliable as the gold-standard 99mTc-sulfur colloid (99mTc-SC) for gastric emptying scintigraphy (GES). This study is aimed to compare the emptying rates of both radiotracers in a prospective, randomized cross-over trial and to determine the normative data of a healthy multi-ethnic Asian population.

METHODS

Out of the 44 healthy individuals screened, 31 (14 females; mean age: 28.4 ± 7.0 years) were enrolled and underwent GES using the standardized egg-white meal. All participants were randomly assigned to either 99mTc-SP or 99mTc-SC on the first GES session before crossed over to the other formulation after 2 weeks.

RESULTS

Both kits achieved the radiochemical purities of > 95%. The median rate (95th upper normative limit) of gastric emptying, reported as total gastric meal retention between 99mTc-SP and 99mTc-SC, was found to be comparable at all measured time points: 0.5 h [85.0% (96.6%) vs. 82.0% (94.0%)], 1 h [70.0% (86.4%) vs. 65.0% (86.6%)], 2 h [31.0% (55.8%) vs. 25.0% (64.4%)], 3 h [7.0% (26.3%) vs. 5.0% (29.9%)], and 4 h [3.0% (10.3%) vs. 2.0% (9.9%)]; P > 0.05. In addition, both radiotracers correlated well (Kendall's Tau (τ) coefficient = 0.498, P < 0.001) and presented with a good agreement at the 4th-hour time frame based on the Bland-Altman plot analysis.

CONCLUSIONS

99mTc-SP is a valid radiotracer alternative to 99mTc-SC for routine GES examination. The normative values for both radiotracers have also been determined for the healthy multi-ethnic Asian population.

TRIAL REGISTRATION

This trial was registered retrospectively in the Thai Clinical Trials Registry on May 23rd, 2020 (Identifier: TCTR20200526004; http://www.clinicaltrials.in.th/index.php?tp=regtrials&menu=trialsearch&smenu=fulltext&task=search&task2=view1&id=6296 ).

Postoperative imaging findings in children with auxiliary partial orthotopic liver transplant (APOLT)

Auxiliary partial orthotopic liver transplant (APOLT) is a treatment technique for people who have acute hepatic failure secondary to fulminant hepatic failure and might ultimately recover normal liver function. This surgical procedure is complicated, involving the placement of a liver graft while maintaining viability of the remaining native portion of the liver. This method allows the native liver to recover hepatic function, therefore eliminating the need for long-term immunosuppression, as is typically needed in post-transplant settings. Postoperative imaging in these cases can be challenging given the complex anatomy, specifically the vascular anastomosis. Therefore it is important for radiologists and clinicians to be aware of the anatomy as well as the variable imaging appearances of the liver. We review the imaging findings in children who have undergone auxiliary partial orthotopic liver transplant (APOLT).

Measuring total liver function on sulfur colloid SPECT/CT for improved risk stratification and outcome prediction of hepatocellular carcinoma patients. EJNMMI Res. 2016;6:57. [PMID: 27349530 PMCID: PMC4923007 DOI: 10.1186/s13550-016-0212-9]

Background

Assessment of liver function is critical in hepatocellular carcinoma (HCC) patient management. We evaluated parameters of [^99mTc] sulfur colloid (SC) SPECT/CT liver uptake for association with clinical measures of liver function and outcome in HCC patients.

Methods

Thirty patients with HCC and variable Child-Turcotte-Pugh scores (CTP A5-C10) underwent [^99mTc]SC SPECT/CT scans for radiotherapy planning. Gross tumor volume (GTV), anatomic liver volume (ALV), and spleen were contoured on CT. SC SPECT image parameters include threshold-based functional liver volumes (FLV) relative to ALV, mean liver-to-spleen uptake ratio (L/S_mean), and total liver function (TLF) ratio derived from the product of FLV and L/S_mean. Optimal SC uptake thresholds were determined by ROC analysis for maximizing CTP classification accuracy. Image metrics were tested for rank correlation to composite scores and clinical liver function parameters. Image parameters of liver function were tested for association to overall survival with Cox proportional hazard regression.

Results

Optimized thresholds on SC SPECT were 58 % of maximum uptake for FLV, 38 % for L/S_mean, and 58 % for TLF. TLF produced the highest CTP classification accuracy (AUC = 0.93) at threshold of 0.35 (sensitivity = 0.88, specificity = 0.86). Higher TLF was associated with lower CTP score: TLF_A = 0.6 (0.4–0.8) versus TLF_B = 0.2 (0.1–0.3), p < 10⁻⁴. TLF was rank correlated to albumin and bilirubin (|R| > 0.63). Only TLF >0.30 was independently associated with overall survival when adjusting for CTP class (HR = 0.12, 95 % CI = 0.02–0.58, p = 0.008).

Conclusions

SC SPECT/CT liver uptake correlated with differential liver function. TLF was associated with improved overall survival and may aid in personalized oncologic management of HCC patients.

Cysteine rhenium colloid: a novel radiocolloid for identifying sentinel lymph nodes in breast cancer surgery

BACKGROUND

Medical isotopes are required for sentinel node lymphoscintigraphy in breast cancer, but are in critical shortage. Our center uses a modification of the standard SC, called CRC, that has been shown to require less medical isotope for the same procedure. Our objective was to determine if there was a significant difference between SC and CRC in successful lymph node identification in breast cancer patients.

PATIENTS AND METHODS

This was a retrospective cohort study using prospectively-collected data on 1205 consecutive early, clinically node-negative breast cancer patients who underwent a SNB between 2002 and 2008 at 2 tertiary hospitals in Canada.

RESULTS

There was no difference in successful lymph node identification rate (P = .50) or in the mean number of positive nodes identified between the 2 colloids (P = .88). The CRC group had a significantly lower rate of delayed adverse events (4.91% vs. 0.59%, P < .0001) even after adjusting for whether axillary dissection occurred on the same day as the biopsy (adjusted odds ratio, 0.12; 95% confidence interval, 0.04-0.40; P = .001).

CONCLUSION

Our findings suggest that there is no significant difference between CRC and SC in detecting sentinel nodes; however, CRC uses less medical isotopes. In the current climate of critical shortages of medical radioisotopes, radiocolloids should be selected for use based on amount of radioisotope required.