Palaniswamy Shanmuga Sundaram

Role of positron emission tomography computed tomography in carcinoma lung evaluation

Lung cancer has graduated from merely a reportable disease of 1912 to being the most common cause of cancer death in developed countries in recent years. The annual number of lung cancer deaths is greater than the combined cancer deaths from breast, colon and prostate. Its association with tobacco has been proved and is related to the type, amount of tobacco used, the age at initiation and duration of use. Significant advances have been made in the diagnosis and management of lung cancer over the past decade. The primary treatment of lung cancer is surgery and the best chance for a complete cure comes from the total resection of localized disease. Once nodal or distant metastases have developed, primary surgical intervention is ruled out and patient is considered for adjuvant chemotherapy with or without radiation therapy. Accurate staging and delineation of disease extent is therefore critical in the treatment planning of lung carcinoma patients. 18 F fluoro deoxy glucose (FDG) positron emission tomography (PET) has been proven to be a valuable noninvasive imaging modality in the evaluation of patients with known or suspected lung cancer and its integration with computed tomography (CT) has changed the face of PET imaging in many ways. This article will review the current role of FDG PET CT in the evaluation of pulmonary nodules, diagnosis, staging and restaging of non-small-cell lung carcinoma (NSCLC), role of PET in small cell lung Carcinoma (Ca), pleural disease and will also discuss its potential future applications.

Detection of atypical metastases in recurrent adenoid cystic carcinoma of parotid gland

We report a known case of adenoid cystic carcinoma of right parotid gland in a 36-year-old Indian male, diagnosed 5 years ago for which he underwent surgery followed by radiotherapy. Now the patient has presented to the surgical oncologist with a mass near angle of right jaw. Computed tomography (CT) performed elsewhere was reported negative for local recurrence. Subsequently, 18 F Fluorodeoxyglucose positron emission tomography-CT (FDG PET-CT) demonstrated local recurrence in right parotid bed. Surprisingly, metabolically active metastatic skeletal deposits were also identified, thus the disease was upstaged and management was changed. Trucut biopsy from left iliac bone lesion confirmed metastases from adenoid cystic carcinoma. Thus a whole body PET-CT has a significant impact on management of patients with salivary gland malignancies in assessing both local recurrence as well as distant metastases, especially in atypical and unsuspected sites.

Tc-99m macro aggregated albumin scintigraphy - indications other than pulmonary embolism: A pictorial essay

Introduction: Tc-99m macro aggregated albumin (MAA) is synonymous for lung perfusion scintigraphy and is part of the study in the evaluation of pulmonary thromboembolism. We wanted to highlight the utilities of Tc-99m MAA other than pulmonary embolism as a pictorial assay. Materials and Methods: Patients referred for Tc-99m MAA scintigraphy under various indications were included in this pictorial essay. Commercially available TechneScan LyoMAA cold kit from Mallinckrodt Medical B.V., Holland was used. Acquisition protocols for different indications are described in this article. Different clinical indications (e.g., pulmonary artery stenosis, hepatopulmonary syndrome, FEV1 calculation in lung surgery planning, selective internal radiation therapy planning, venography for deep venous thrombosis, left to right cardiac shunts, etc.) where Tc-99m MAA scintigraphy was asked for; how it helped in different clinical scenarios and how it can be used clinically is explained with unique and interesting case examples and images. We also reviewed the literature to look for certain remote indications of MAA imaging for the sake of completion like – (shunt scintigraphy, peritoneopleural communication, etc.) Conclusion: Tc-99m MAA is a very useful radiopharmaceutical, which can be used for many other indications apart from the commonly used indication of lung perfusion scan in pulmonary embolism. It can provide useful clinical information in other indications, which we try to highlight in this article.

Isolated skeletal muscle metastatic deposit in a patient with micropapillary carcinoma thyroid identified by 18F FDG PET CT.

Micropapillary carcinoma of thyroid is said to be low risk differentiated thyroid malignancy with excellent prognosis. We report the identification of an isolated FDG avid muscle deposit in a treated case of micropapillary carcinoma of the right lobe and widely invasive follicular carcinoma of the left lobe thyroid gland. Patient was found to have an elevated thyroglobulin level with negative iodine scan (TENIS syndrome) on follow up at 6 months. An 18F FDG PET CT (18 fluorine-fluorodeoxyglucose positron emission computed tomography) whole body study revealed a solitary FDG avid deltoid muscle deposit which was histopathologically confirmed to be metastatic papillary carcinoma. While follicular carcinoma is known to have distant metastases, this may be the first reported case of solitary skeletal metastases from micropapillary carcinoma of thyroid and probably the second reported skeletal muscle deposit from DTC detected on 18F FDG PET CT done following elevated thyroglobulin level and negative 131 iodine WB scan (TENIS). This case also assumes importance because it demonstrates possibility of metastases even from a micropapillary carcinoma in contrast to American Thyroid Association guidelines (2009) which suggests that micropapillary carcinoma of thyroid does not merit further treatment after a Total Thyroidectomy.

Random Synchronous Malignancy in Male Breast: A Case Report

We report here a case of a random synchronous male breast malignancy in a patient with a known base of tongue malignancy that was incidentally detected on a whole body 18-fluorine deoxyglucose positron emission tomography and computed tomography (18F-FDG PET/CT). Patient was referred to us for PET/CT staging and radiotherapy planning for a poorly differentiated squamous cell carcinoma of base of tongue. Histopathologically, the incidentally detected breast lesion was proven to be an invasive ductal carcinoma. 18F-FDG PET/CT being a whole body imaging modality is known to detect a considerable number of synchronous primaries. Synchronous malignancies in the head and neck area and the upper aerodigestive tract are well established. However, synchronous malignancy in male breast is reportedly uncommon. Our case is unique for the fact that a random synchronous dual malignancy of base of tongue and breast in a male patient was detected during a whole body 18F-FDG PET/CT imaging.

Feasibility study of axillary reverse mapping lymphoscintigraphy in carcinoma breast: A concept toward preventing lymphedema.

Objective: In the surgery of breast cancer, axillary reverse mapping (ARM) is the identification and preservation of arm draining lymph node (ARM node) during an axillary dissection. The assumption is that the ARM node is different from node draining breast and is unlikely to be involved even in the patients with axillary nodal metastases. If we can identify and preserve ARM node using lymphoscintigraphy; morbidity of lymphedema, as seen with axillary dissection, may be avoided. Materials and Methods: Pathologically proven 50 breast cancer patients undergoing initial surgery (cTx-4, cN0-2, and Mx-0) were included in this study. Less than 37 MBq, 0.5 ml in equally divided doses of filtered 99mTc sulfur colloid was injected intradermally into the second and third web spaces. ARM nodes in the axilla were identified with the help of Gamma Probe intraoperatively; however, their location was noted with the reference to specific anatomical landmarks and sent for histopathological examination after excision. Results: The ARM node was successfully identified in 47/50 cases (sensitivity - 94%). In 40 out of 47 cases (85%), the location of the ARM node was found to lateral to the subscapular pedicle, above the second intercostobrachial nerve and just below the axillary vein. Of the 47 patients in whom ARM node/s were identified, metastasis was noted in 5 of them (10%). Four out of these 5 patients had the pN3 disease. Conclusion: ARM node exists, and it is feasible to identify ARM node using radio isotope technique with an excellent sensitivity. ARM node seems to have a fairly constant location in more than 80% cases. It is involved with metastasis (10% cases) only when there are multiple lymph nodal metastases in the axilla.

PET/CT in paediatric malignancies - An update

18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a well-established imaging modality in adult oncological practice. Its role in childhood malignancies needs to be discussed as paediatric malignancies differ from adults in tumor subtypes and they have different tumor biology and FDG uptake patterns. This is also compounded by smaller body mass, dosimetric restrictions, and physiological factors that can affect the FDG uptake. It calls for careful planning of the PET study, preparing the child, the parents, and expertise of nuclear physicians in reporting pediatric positron emission tomography/computed tomography (PET/CT) studies. In a broad perspective, FDG-PET/CT has been used in staging, assessment of therapy response, identifying metastases and as a follow-up tool in a wide variety of pediatric malignancies. This review outlines the role of PET/CT in childhood malignancies other than hematological malignancies such as lymphoma and leukemia.

Incidental Detection of Thyroid Neoplasm on 99mTc-SestaMIBI Myocardial Perfusion Scan - A Novel Tumour Tracer Revisted

We report a case of a young Indian male who had an incidental abnormal focal uptake of 99mTechnetium-MIBI (Methoxy Isobutyl Isonitrile) in the right lobe of thyroid while undergoing 99mTc-MIBI myocardial perfusion gated SPECT (Single Photon Emission Computed Tomography) imaging as a part of his myocardial ischemia status evaluation. This focal uptake was eventually detected to be a malignant thyroid nodule for which he underwent total thyroidectomy. His biopsy was reported as Hurthe cell nodule. Though incidental detection of thyroid, breast and lung malignant pathology on 99mTc- MIBI myocardial perfusion scans is well known, this case is a reminder and exemplifies the potential of 99mTc-MIBI not only as an excellent myocardial perfusion agent but also as a non specific tumour tracer (for its larger usage as a tracer for neoplastic survey).

99m)Tc DTPA renogram indentifies Bochdalek hernia with an intra thoracic kidney as its content.

Congenital diaphragmatic hernia (CDH) is a rare anomaly with reported incidence of 1 in 16,000 and is associated with herniation of stomach, intestinal loops, spleen, and kidney through a chest wall defect. We report a case of 1-year-old male child with history of recurrent fever and non-visualization of left kidney on ultrasonogram. Patient was referred to us to look for ectopic left kidney.99mTc-diethylenetriaminepentaacetic acid renogram was performed. An ectopically placed intrathoracic left kidney was identified. Subsequently a chest X-ray was done that showed bowel loops and diagnosis of CDH was confirmed. The patient underwent thoracoscopic repair of CDH and hernial contents were found to be left kidney, intestinal loops and spleen.

Congenital lymphatic hypoplasia in unilateral lower limb with abnormal technetium-99m sulphur colloid uptake in both breasts.

We present a patient with Meige like lymphedema (left lower limb hypoplasia) with asymptomatic minimal accumulation of Technetium-99m sulfur colloid in bilateral breasts. We attribute the possible pathology to accumulation of interstitial fluid in hypoplastic left lower limb leading to dilatation of the remaining outflow tracts and valvular incompetence. This may be causing reversal of flow from subcutaneous tissues into the dermal plexus involving the breast. Other possibilities include formation of spontaneous lymphovenous shunt or lymphatic intercommunication at lower trunk level as a result of increased pressure leading to minimal lymph accumulation in breasts. Later a mammogram was performed which was found to be normal. MR also confirmed no cisterna chyli abnormalities or aberrant lymphatic channels in lower thorax region that may be the explanation for the abnormal sulphur colloid uptake in both breasts.