Madhavi Chawla

Dual Ectopic Thyroid: Case Series and Review of the Literature

Ectopic thyroid tissue is an uncommon congenital aberration. It is further unusual for ectopic thyroid to be present at 2 different sites simultaneously. Only 19 cases of dual ectopic thyroid have been reported in the English literature. Most of the patients were adolescents and presented with anterior neck swelling with or without altered metabolic status. Lingual/sublingual thyroid was the most common ectopic location. Subhyoid was the most common site of a second ectopic thyroid in these patients. The thyroid scan has been used successfully to diagnose ectopic thyroid tissue. We report 4 such cases in which ectopic thyroid tissue was simultaneously present at 2 different locations using thyroid scanning. The literature of already reported cases is reviewed in detail.

Role of PET/PET-CT in the management of sarcomas.

Positron emission tomography (PET) is a functional diagnostic imaging technique that provides very different information from that obtainable with other imaging modalities. The most widely used radiotracer is F-18 fluoro-2-deoxy-D-glucose (FDG), which is an analog of glucose. The FDG uptake in cells is directly proportional to glucose metabolism, which is increased many times in malignant cells. FDG-PET is now the standard of care in initial staging, monitoring the response to therapy and management of various cancers (e.g., breast cancer, lung cancer and lymphoma). However, the paucity of anatomical landmarks on PET images makes a consistent hardware fusion to anatomical cross-sectional data extremely useful. The introduction of combined PET–computer tomography (CT) scanners, which provide not only functional, but also structural information leading to a detection of subcentimeter lesions, made this technique useful in the early detection of the disease process and decreasing false-positive lesions. The aim of this article is to review the clinical applications (i.e., diagnosis, staging, evaluation of treatment response and restaging) using PET in patients with bone and soft-tissue sarcoma.

Role of positron emission tomography-computed tomography in staging and early chemotherapy response evaluation in children with neuroblastoma

Background: To evaluate the role of positron emission tomography-computed tomography (PET-CT) in staging and determining early treatment response to chemotherapy in children with neuroblastoma (NB) and its correlation with the final outcome. Patients and Methods: Seventeen patients of NB with mean age of 51.5 months (age range 2-132 months; 14 males, 3 females) underwent serial 18F-flourodeoxygl ucose (FDG) PET-CT imaging. All 17 patients were for staging before any treatment. Twelve of 17 patients underwent I-131 meta-iodobezylguanidine (MIBG) scan and bone scan. MIBG uptake was seen in the primary lesion in 11/12 patients. MIBG uptake in bones was seen in 3/12 patients. All bone lesions were concordant on MIBG and bone scan. Early response to chemotherapy was evaluated after two cycles using PET-CT. A 30% reduction in longest diameter was taken as cut-off value for response on CT based on the response evaluation criteria in solid tumors criteria. Response on PET-CT was assessed using percentage improvement in lesion to background SUV ratio, taking a value of 50% as cut-off. Final outcome based on follow-up ranging from 6 to 43 months (mean 18.8 months) served as reference. Results: All 17 patients showed increased FDG uptake at the primary site. Seven of the 17 patients (41.2%) showed metastasis. Lymph nodes were the most common site of metastatic disease followed by bone, bone marrow, lung and meninges. For response evaluation, change in the size of the primary tumor was noted in 11/17 (64.7%) patients on CT. Treatment response was noted in 12/17 patients (70.6%) on PET-CT. Eleven out of 17 (65%) patients showed response in both CT and PET-CT. Five out of 17 patients showed no response in both. Discordant findings on CT and PET were noted in one (5.9%) patient where PET showed response but no response was seen on CT. Two patients with initial response but with distant metastases expired during follow-up. Conclusion: PET-CT has potential in the initial staging of NB. PET-CT also appears to be a good modality for response assessment in patients with moderate and high FDG uptake on the baseline scan. However, no significant beneficial effect was seen in patients with low baseline FDG uptake.

PET-CT in detection of meningeal metastasis in neuroblastoma

Neoplastic meningitis is being recognized with increasing frequency in patients with cancer: the common causes being adenocarcinomas originating from the lung, stomach, breast, ovary, malignant melanoma, leukemia, lymphoma, Ewings sarcoma, rhabdomyosarcoma, retinoblastoma and primary CNS malignancies. Meningeal metastases, though rare can be seen in advanced stages of neuroblastoma. Recognition of meningeal metastases is crucial for successful diagnosis and prompt treatment of these patients. Here, we present two patients of neuroblastoma in whom positron emission tomography-computed tomography (PET-CT) examination resulted in detection of meningeal metastases at diagnosis; thus, emphasizing the need of inclusion of brain imaging in PET-CT protocol in all cases of advanced neuroblastoma.

Hyperthyroidism and Jaundice

Development of hyperbilirubinemia, concurrent or subsequent to hyperthyroidism, can be due to thyrotoxicosis per se, or due to drug treatment of hyperthyroidism. Other rare conditions: autoimmune thyroid disease, or causes unrelated to hyperthyroidism like viral hepatitis, alcohol abuse, sepsis, cholangitis, or as a side effect of certain medications. In this article, we review these causes of co-existent hyperthyroidism and jaundice. We also highlight the changes to be expected while interpreting thyroid function tests vis-a-vis liver function tests in this subgroup of patients.

18F-FDG PET/CT in evaluation of radiofrequency ablation of liver metastasis.

Image-guided radiofrequency ablation (RFA) is a minimally invasive therapy option in the treatment of primary and secondary hepatic malignancies, which are not suitable for surgery/chemotherapy, and more recently, for tumors with limited hepatic involvement and solitary liver metastasis. Accurate assessment of treatment response after RFA remains a concern. Conventional imaging modalities have limitations of differentiation between residual/recurrence from post-RFA changes. We illustrate images of 3 patients in whom (18)F-FDG PET/CT was used for response assessment and restaging after RFA in liver tumors.

Screening of Contralateral Breast in Patients with Breast Cancer: Role of MR Imaging and PET/CT Imaging

Breast cancer is one of the most common cancers in women. Contralateral breast carcinoma is the most common second malignancy in patients with breast carcinoma. Bilateral breast carcinomas exist in 2 forms: synchronous, in which both tumors occur at the same time, or metachronous, in which they occur at different times. When breast cancer is diagnosed, the contralateral breast should be carefully evaluated for a synchronous tumor. Screening for occult contralateral breast cancer is very important on initial cancer diagnosis. The detection and treatment of a synchronous tumor allows for informed surgical decision making, especially if tissue reconstruction is being considered. If chemotherapy is necessary, the patient would only need treatment once for bilateral synchronous cancers, not twice, as with metachronous cancers.

PET and PET-CT Imaging in Treatment Monitoring of Breast Cancer.

Breast cancer is one of the more responsive solid tumors with a wide range of systemic therapy options. The treatment of newly diagnosed breast cancer is primarily determined by the extent of disease and generally includes surgery, radiation, and chemotherapy. This article discusses the PET and PET-CT modalities for evaluating treatment response in breast cancer.