A Pilot Nonrandomized Controlled Trial Examining the Use of Artificial Tears on the Radioactivity of Tears After Radioactive Iodine Treatment for Thyroid Cancer.

Background: Nasolacrimal duct obstruction (NLDO) is an adverse effect of high dose radioactive iodine (RAI) therapy for thyroid carcinoma. There are currently no established preventive measures. This study assesses whether preservative free artificial tears (PFATs) can decrease the 131I sodium iodide (131I) activity in the tears of patients following RAI therapy for thyroid carcinoma, and potentially serve as a preventive measure for RAI-associated NLDO. Methods: This non-randomized prospective pilot clinical trial recruited contact-lens wearing patients undergoing RAI therapy for thyroid cancer to self-administer PFATs into the right eye for four days starting on the day of RAI ingestion. Left eyes were the controls. While wearing contacts, patients self-administered PFATs per the following-Day 1: every 15 minutes for 2 hours, then every 30 minutes until bedtime, day 2: every hour for at least 12 hours, day 3: four times a day, and day 4: two times a day. Contact lenses were changed daily, and all lenses were collected one week later. Levels of 131I activity were measured by a well counter, decay-corrected, and converted to units of becquerel. Statistical analyses were performed to compare the 131I activities of the experimental and control eyes. Results: Sixteen eyes of eight patients treated with an average of 145.7 mCi (range 108-159) of 131I for papillary thyroid cancer were included. On day 1, artificial tears decreased the geometric mean 131I activity by 26% in the experimental eyes (p = 0.008). Artificial tears also decreased the geometric mean area under the curve over four days by 23% (p = 0.002). Conclusions: 131I is present in the tears following RAI therapy for thyroid carcinoma. Frequent PFATs starting on the day of RAI ingestion may decrease the level of 131I in the tears. This finding could have implications for lowering the risk of NLDO. Future multi-center clinical trials are needed to determine whether the use of artificial tears after RAI therapy may decrease the risk of NLDO. Clinical Trial Registration: NCT04327999.

Factors Associated With Radioactive Iodine Therapy-Acquired Nasolacrimal Duct Obstruction.

OBJECTIVE: To identify factors associated with radioactive iodine (RAI)-acquired nasolacrimal duct obstruction (NLDO). METHODS: Retrospective chart review and telephone surveys of patients who received RAI therapy for thyroid carcinoma at an academic institution were conducted. Telephone surveys were used to screen for post-RAI NLDO diagnoses. Databases were reviewed for documented NLDO, demographics, RAI dose, total number of RAI treatments, and sialadenitis. Routine post-RAI whole-body scintigraphy (WBS) images were analyzed for the presence or absence of 131I sodium iodide (I-131) in the nasolacrimal duct. Intranasal I-131 activity was graded as none, low, moderate, and high; those with moderate or high activity were considered to have "increased" activity. Logistic and ordinal logistic regression models were used to evaluate the associations with NLDO while adjusting for I-131 dose. RESULTS: Of the 209 patients who completed the survey, 15 (7%) had NLDO diagnoses. Increased intranasal I-131 activity on WBS, presence of nasolacrimal I-131 WBS activity, presence of documented post-RAI sialadenitis, and history of >1 RAI treatment were associated with the development of NLDO from univariate analyses (P ≤ .013). After adjusting for the administered dose of I-131, the presence of sialadenitis and nasolacrimal I-131 activity on WBS were the remaining 2 factors significantly associated with NLDO development (P < .001 and P = .01, respectively). CONCLUSIONS: The presence of sialadenitis and nasolacrimal I-131 activity on WBS are I-131 dose-independent correlative factors for RAI-associated NLDO. Patients with these characteristics should be counseled on their increased risk of NLDO after RAI therapy for thyroid carcinoma.

A Prospective Comparative Study of Using Ultrasonography, 4D-CT and Parathyroid Dual-Phase Scintigraphy with SPECT in Patients with Primary Hyperparathyroidism.

Thirty-one consecutive patients were included in this study who were planned for parathyroidectomy due to primary hyperparathyroidism. They were studied with US, 4D-CT and dual-phase scintigraphy including SPECT/CT, and possible adenomas were identified in each imaging modality. Imaging data were quantified with US, CT and SPECT. Parathyroidectomies were performed as minimally invasive according to preoperative imaging findings. A total of 16 adenomas were found in 15 patients, and the surgery was negative in four patients. The imaging results were compared with each other and correlated to histology findings and blood biochemistry (S-Ca and P-PTH). Quantitative SPECT found a strong correlation between the quantification methods-Conjugate Gradient with Attenuation and Scatter Correction with a zone map (CGZAS) and Conjugate Gradient with Attenuation and Scatter Correction (CGAS)-measured as SUVmax and kBq/mL. However, a statistically significant correlation between the quantitative parameters (CGZAS and CGAS) and serum biomarkers (S-PTH and S-Ca) was not observed. The sensitivities of the imaging methods were calculated using histopathology as a gold standard. SPECT/CT demonstrated 93% sensitivity, 4D-CT 93% sensitivity and ultrasonography 73% sensitivity. The imaging methods were compared with each other using parathyroid regions because findings and locations varied between the modalities. Our prospective study supports that quantitative SPECT/CT is useful for presurgical assessment of primary hyperparathyroidism.

Early detection of SARS-CoV-2 from staging PET-CT.

OBJECTIVE: SARS-CoV-2 infection may manifest with minimal or no clinical symptoms. However, signs of infection may appear on routine imaging obtained in the care of patients with cancer. The management of patients planned for chemoradiation with asymptomatic or mildly symptomatic SARS-CoV-2 infection is uncertain. METHODS: Here, we present a case study of a mildly symptomatic patient with anal cancer diagnosed with SARS-CoV-2 from a staging PET-CT scan. RESULTS: PET-CT scan for anal cancer staging demonstrated pulmonary avidity suspicious for an infectious, rather than malignant, process. In the setting of these imaging findings and new-onset anosmia, viral polymerase chain reaction was ordered and found to be positive for SARS-CoV-2. To avoid myelosuppression in the setting of active infection, planned chemoradiation was delayed until cessation of viral shedding. CONCLUSION: In the COVID-19 era, oncologists obtaining routine staging imaging should have high diagnostic suspicion for subclinical SARS-CoV-2 infection. To avoid precipitating severe pneumonia and hospitalization, multidisciplinary discussion with risk-benefit analysis is recommended before initiating immunosuppressive therapies such as chemoradiation.

68Ga-DOTATATE: Significance of Uptake in the Tail of the Pancreas in Patients Without Lesions.

PURPOSE: To measure the SUVs in the tail of the pancreas compared with normal liver parenchyma and somatostatin receptor-positive lesions. MATERIALS AND METHODS: Ga-DOTATATE PET/low mAs CT of 35 patients were reviewed. RESULTS: There was no significant difference (P = 0.59) between the SUVaverage of normal liver and the SUVpeak of normal tail. Five patients had uptake in the tail slightly above that of normal liver that were interpreted equivocally. In one of these patients with Ga-DOTATATE uptake in a peripancreatic lymph node, proven neuroendocrine tumor underwent a distal pancreatectomy and pathologic examination revealed islet cell hyperplasia. CONCLUSIONS: Ga-DOTATATE uptake in the tail of the pancreas above that of normal liver indicates a somatostatin receptor-avid lesion. Uptake in the tail of the pancreas equal to the liver can be normal. Patients with uptake equivalent to the liver should undergo further anatomical imaging before procedural intervention.

Qualitative and quantitative comparison of gated blood pool single photon emission computed tomography using low-energy high-resolution and SMARTZOOM collimation.

OBJECTIVE: The aim of this study was to assess the feasibility of IQ-SPECT gated blood pool (MUGA) under conditions of decreased scan time (ST). PATIENTS AND METHODS: Ten patients underwent routine 26-min, two-view planar, followed by LEHR and IQ-SPECT MUGA, on a Siemens dual-head Symbia scanner. Six 'back and forth' 4-min SPECT scans were summed into 4-, 8-, 12-, 16-, 20-, and 24-min equivalent scans, and reconstructed iteratively (IQ-SPECT and LEHR) and with FBP (LEHR). Uniformity, contrast, and wall motion were scored on a five-point scale. Linear regressions of left ventricular (LV) ejection fraction (EF) were performed between FBP, Flash 3D, and IQ-SPECT versus planar and Flash 3D and IQ-SPECT versus FBP. Agreement tables between Flash 3D and IQ-SPECT versus FBP LV EF were generated using a normal versus cardiotoxicity threshold of 50%. RESULTS: IQ-SPECT had the best scores for all STs, and 4, 8, and 16 min IQ-SPECT were judged to be similar to 24-min LEHR FBP, Flash 3D, and planar, respectively. The average LV EF correlation coefficients were 0.69, 0.71, and 0.63 between IQ-SPECT, Flash 3D, and FBP versus planar, respectively; 0.70 between IQ-SPECT and FBP; and 0.88 between Flash 3D and FBP, and all were statistically significant (P<0.05), except for 16-min FBP LEHR versus planar. Agreement tables showed diagnostic equivalence of IQ-SPECT, Flash 3D, and FBP. CONCLUSION: These preliminary results suggest that IQ-SPECT is equivalent to LEHR Flash 3D and FBP for MUGA SPECT, and better at reduced ST. A larger patient population study is necessary for a more definitive assessment.

Contemporary imaging of soft tissue sarcomas.

Imaging plays an important role in the diagnosis, biopsy, staging, and follow-up of patients with soft tissue sarcomas. General principles of imaging diagnosis of soft-tissue sarcomas using radiography, ultrasound, CT, MRI, and PET/CT will be discussed, with emphasis on the role of location, internal fat and calcification, presence of myxoid stroma, and enhancement characteristics.