Diagnostic Performance of Response Assessment FDG-PET/CECT in HNSCC Treated With Definitive Radio(chemo)therapy Using NI-RADS.

OBJECTIVE: To assess the diagnostic performance of response assessment 18F-fluorodeoxyglucose positron emission tomography/contrast-enhanced computed tomography (FDG-PET/CECT) following definitive radio(chemo)therapy in head and neck squamous cell carcinoma (HNSCC) using Neck Imaging Reporting and Data System (NI-RADS). STUDY DESIGN: A retrospective analysis from a prospectively maintained dataset. SETTING: Tertiary-care comprehensive cancer center in a low-middle-income country. METHODS: Adults with newly diagnosed, biopsy-proven, nonmetastatic HNSCC treated with definitive radio(chemo)therapy were included. Posttreatment response assessment FDG-PET/CECT scans were retrospectively assigned NI-RADS categories (1-3) for the primary site, neck, and both sites combined. Locoregional recurrence occurring within 2-years was defined as the event of interest. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy were calculated. Locoregional control stratified by NI-RADS categories was computed with the Kaplan-Meier method and compared using the log-rank test. RESULTS: Posttreatment FDG-PET/CECT scans were available in 190 patients constituting the present study cohort. Sensitivity, specificity, PPV, NPV, and overall accuracy of the NI-RADS template for the primary site was 73.5%, 81.4%, 46.3%, 93.4%, and 80.0%, respectively. Similar metrics for the neck were 72.7%, 87.5%, 43.2%, 96.1%, and 85.8%, respectively. Combining primary site and neck, the corresponding metrics of diagnostic accuracy were 84.4%, 69.7%, 46.3%, 93.5%, and 73.2%, respectively. At a median follow-up of 40 months, Kaplan-Meier estimates of 2-year locoregional control were significantly higher for NI-RADS category 1 (94.2%) compared to NI-RADS category 2 (69.4%) and category 3 (20.4%), respectively (stratified log-rank p < .0001). CONCLUSION: FDG-PET/CECT using the NI-RADS template is associated with good diagnostic performance and prognostic utility in HNSCC treated with definitive radio(chemo)therapy.

Assessment of the impact of 2015 American Thyroid Association guidelines in management of differentiated thyroid cancer patients.

The 2015 American Thyroid Association (ATA) guideline have suggested modifications in the risk stratification (RS) for differentiated thyroid cancer (DTC) patients, introduced the concept of dynamic risk stratification (DRS) and redefined the role of radioactive iodine (RAI) in treatment algorithm. The aim of this retrospective audit was to assess the practical implications of these modifications in management of DTC. METHODS: A total of 138 DTC patients were stratified according to ATA 2009 and 2015 guidelines into low (LR), intermediate (IR) and high (HR) risk groups. Change in RS and in intention of RAI use was calculated. Deviation in administered RAI dosage from the guidelines was assessed. 1-year follow-up data was audited to assess how the DRS modified the initial risk estimate. RESULTS: A total of 11.6% of patients changed their RS categories in 2015 guidelines. A total of 10.1% got upstaged to HR, and 1.4% got downstaged to LR. In 2.17% of patients' intention of RAI use changed to remnant ablation from adjuvant therapy and 65% of the LR patients won't require any RAI therapy. A total of 26.7% of patients had received significantly more RAI dosage according to ATA 2015. At 1-year follow-up according to DRS 84% of LR, 75% of IR and 44% of HR patients showed excellent response (ER). CONCLUSION: More patients changed RS to HR than to LR. Intention of RAI use changed in only a small number of patients. Significantly higher dosage of RAI is being administered to patients in current practice. The effect of DRS in modifying the initial RS was most prominent in IR, with most showing ER to initial therapy.

Combined PET and biopsy evidence of marrow involvement improves prognostic prediction in diffuse large B-cell lymphoma.

UNLABELLED: Bone marrow is an important extranodal site in diffuse large B-cell lymphoma (DLBCL), and marrow histology has been incorporated into the new National Comprehensive Cancer Network international prognostic index. Marrow involvement demonstrated histologically confers poor prognosis but is identified by staging PET in more cases. How information from staging PET and biopsy should be combined to optimize outcome prediction remains unclear. METHODS: The International Atomic Energy Agency sponsored a prospective international cohort study to better define the use of PET in DLBCL. As a planned subsidiary analysis, we examined the interplay of marrow involvement identified by PET and biopsy on clinical outcomes. RESULTS: Eight countries contributed 327 cases with a median follow-up of 35 mo. The 2-y outcomes of cases with no evidence of marrow involvement (n = 231) were 81% (95% confidence interval [CI], 76%-86%) for event-free survival (EFS) and 88% (83%-91%) for overall survival (OS); cases identified only on PET (n = 61), 81% (69%-89%) for EFS and 88% (77%-94%) for OS; cases indentified only on biopsy (n = 10), 80% (41%-95%) for EFS and 100% for OS; or cases identified by both PET and biopsy (n = 25), 45% (25%-64%) for EFS and 55% (32%-73%) for OS. The hazard ratios for PET-negative/biopsy-negative cases versus PET-positive/biopsy-positive cases were 2.67 (95% CI, 1.48-4.79) for EFS and 3.94 (1.93-8.06) for OS. CONCLUSION: This large study demonstrates that positive iliac crest biopsy histology only confers poor prognosis for patients who also have abnormal marrow (18)F-FDG uptake identified on the staging PET scan. Abnormal (18)F-FDG uptake in marrow, when iliac crest biopsy histology is normal, has no adverse effect on outcomes.

Unusual case of adrenal and renal metastases from papillary carcinoma of thyroid.

We report a rare case of adrenal and renal metastases from papillary thyroid carcinoma (PTC). A 30-year-old man underwent total thyroidectomy with left neck dissection for cytology proven nodal metastases from PTC. This was followed by high-dose radioiodine therapy with a dose of 265 mCi (9.805 GBq). Thereafter, patient was lost to follow-up. He presented 2 decades later with low backache radiating to both the lower limbs. Magnetic resonance imaging examination of spine detected left SI joint, dorsal and lumbar vertebral metastases. A whole-body radioiodine scan showed extensive iodine avid foci in thyroid bed, mediastinum, bilateral lungs, liver, bones, and in bilateral lumbar regions. An abdominal single photon emission computed tomography-computed tomography (CT) revealed the lumbar lesions to be within bilateral adrenal glands. Contrast-enhanced CT of abdomen revealed lesions in bilateral adrenals and renal regions suggestive of metastases. A CT-guided biopsy of left adrenal focus confirmed metastasis from the carcinoma of thyroid. A high degree of suspicion with further radiologic and cytologic correlation clinched the diagnosis of both adrenal and renal metastases from PTC, which has been rarely reported. Fortunately, radioiodine concentration in adrenal metastases made them amenable to high-dose radioiodine therapy. Therefore, 225 mCi (8.325 GBq) of radioiodine was administered to this patient. This case is a strong reminder of the fact that regular and long-term follow-up is imperative in the management of thyroid cancer patients.