|Year : 2012 | Volume
| Issue : 2 | Page : 92-97
Abstracts of Poster Presentations
|Date of Web Publication||10-Nov-2012|
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
. Abstracts of Poster Presentations. World J Nucl Med 2012;11:92-7
Comparison of Tc99m-MDP and Tc99m-MIBI for Detection of Malignant Tissue in the Breast
B. K. Das, P. K. Pradhan 1 , S. Deswal
Department of Nuclear Medicine, Utkal Institute of Medical Sciences, Bhubaneswar, 1 S. G. Postgraduate Institute of Medical Sciences, Lucknow, India
Background: Breast cancer has been found to be the first cause of cancer death among women in urban areas in India. Most patients come in stage II and above, many times delayed due to absence of a definitive diagnostic procedure. X-ray mammography and other imaging modalities lack in specificity in comparison to recently introduced scintimammography (SMG) which is performed using Sestamibi or Tetrofosmin. Efforts have been made to use MDP in place of Sestamibi, which is otherwise used for bone scanning and is significantly cheaper and has also the advantage of obtaining bone scan on the same day in one go. The purpose of this study is to compare the efficacy of both agents.
Materials and Methods: One hundred and twenty-three consecutive patients with confirmed diagnosis of breast cancer clinically and histopathologically were subjected to SMG using 20 mCi of Tc 99m -MDP (BRIT, BARC, Mumbai, India) and a dual-headed gamma camera using standard technique. SMG was performed in another 105 consecutive similar patients using the same standard technique and equipment, but with Tc99 m -Sestamibi (Sanlar). Thirty patients clinically suspected of having breast cancer and later confirmed were subjected to SMG using both agents on two separate days. Each scan was evaluated by two nuclear physicians. Ratio of tracer uptake in the lesion and normal tissue was calculated.
Results: Sensitivity and specificity were found to be 96.9% and 92.2%, respectively, in patients with Tc99m-MDP and 98.1% and 93.7%, respectively, in patients using Tc99m-Sestamibi. Out of 30 cases in whom SMG was performed using both agents, 28 (93%) showed concordant findings (both positive 16, both negative 12). In two patients, Sestamibi scans were positive but MDP scans were negative. In 16 MIBI-positive cases, 3 showed concentrations in axillary lymph nodes, which were not seen in MDP scan. In 16 MDP-positive cases, 4 showed metastatic involvement of the skeletal system. The activity ratios in MIBI and MDP scans were similar and varied from 1.3 to 5.7. In one case, a small lesion in the other breast was not visualized in MDP scan.
Conclusions: The sensitivity and specificity found in our studies is higher than in many multicentric studies, which may be due to the fact that most patients were in stage II and higher at the time of diagnosis. Tc99m-Sestamibi is potentially better than Tc99m-MDP in detection of malignant lesions. However, not only is MDP cheaper, but also the whole body bone scan which can be performed in one go can provide vital information regarding metastatic involvement of the skeletal system. Tc 99m Sestamibi remains the choice radiopharmaceutical for early diagnosis of breast cancer. However, Tc99m-MDP can be recommended for diagnosis of breast cancer in cases suspected to be in stage II and higher with the additional benefit of getting vital information regarding involvement of skeletal system.
Utility of FDG PET-CT Scan in Multiple Myeloma Cases
P. Garg, V. R. Lele, H. Shah, S. Gemawat
Department of Nuclear Medicine, Jaslok Hospital, Mumbai, India
Multiple myeloma is one of the malignancies where utility of FDG PET scan is not known much. Like in the other malignancies where FDG PET scan plays a very important role in staging, evaluation of response to therapy, and prognosis determination, utility of FDG PET scan in multiple myeloma would prove to be very useful to the treating medical oncologists. This study includes the clinical presentation, M-band correlation, and imaging findings of patients with proven multiple myeloma. We are studying cases with multiple myeloma in which PET-CT was done. Thirty patients (22 males and 8 females), in the age group of 28-78 years, were included in this study. We included both pre-and post-chemotherapy patients. The uptake pattern in these patients in the axial and appendicular skeleton will be evaluated. Comparison of CT, PET, and PET-CT together as a modality will be studied. If the follow-up study is available till September 2012, it will be included and statistically evaluated.
FDG PET-CT in Fever of Unknown Origin
J. Kapoor, V. R. Lele, P. Joshi
Department of Nuclear Medicine, Jaslok Hospital, Mumbai, India
Aims and Objectives: To delineate the importance of FDG PET-CT in identifying the possible causal source and its impact on clinical management and patient care.
Study Design: A retrospective study was performed that included 25 patients who underwent fluorine-18 fluorodeoxyglucose (F-18 FDG) PET-CT scan for finding out the cause of fever in last 5 months. The performance of PET-CT for identifying the etiology of fever of unknown origin (FUO) was assessed. Final diagnosis was based on histopathology, microbiologic assays, or clinical and imaging follow-up.
Results and Conclusions: PET-CT demonstrated suspected pathologic foci of F-18 FDG uptake in 15 patients (60%); in 9 of these patients source was identified as infection/inflammation, in 4 patients neoplastic etiology, in 1 case mortality occurred before any diagnosis could be reached, and in another patient no diagnosis could be made even after biopsy. In rest of the 10 patients (40%), no focal pathologic disease was diagnosed. Out of these eight patients, fever and other symptoms subsided with no further evidence of any inflammatory, infectious, or malignant process on a clinical follow-up, and in rest of the two patients no relief in symptoms was seen on follow-up to 2 months. 18 F-FDG PET-CT was found to have a good positive predictive value and high negative predictive value in the assessment of patients with FUO. In the clinical context, it could result in lesser number of various investigations and reduce hospital stay and cost. Because of high negative predictive value, it may result in no further evaluation if the FDG PET-CT scan does not show any abnormality.
Relevance to Clinical Nuclear Medicine: In the era where FDG PET-CT has established its role in oncology and is evolving as a modality in the non-neoplastic cases, this non-invasive single-imaging modality may in the future be used as one of the initial diagnostic investigations in patients with FUO.
FDG PET-CT in T-cell Lymphoma
Department of Nuclear Medicine, Narayana Hrudayalaya, Bangalore, India
Background: T-cell lymphomas comprise heterogeneous group of lymphomas, accounting for 12% of all cases of Non-Hodgkin's Lymphoma (NHL). Though relatively rare, they have a poorer prognosis than B-cell lymphomas. Literature on the role of FDG PET-CT in T-cell lymphomas is sparse.
Aims and Objectives: The purpose of this study is to quantify the avidity of FDG in the various histological subtypes of T-cell lymphoma, to highlight the pattern of imaging findings associated with specific disease patterns and to describe the utility of 18 F-FDG PET-CT in initial staging, assessment of response to therapy, and in restaging.
Materials and Methods: Retrospective review of 15 patients with T-cell lymphoma who underwent PET-CT examination for over a period of 2 years was undertaken. WB PET-CT scan was performed after 60 min with GE discovery STE PET-CT. Sites of the disease involvement were documented according to nodal, cutaneous/extranodal, and visceral involvement. Then, 10 mCi of 18 F-FDG was injected. Interpretation of the PET-CT and response assessment was carried out as per the IWC PET criteria.
Results: Fifteen patients with T-cell lymphomas were included. Fourteen PET scans were performed for initial staging; 10 of these patients also underwent second PET scan after completion of chemotherapy for assessment of response to therapy, and 1 patient underwent PET-CT only for restaging during recurrence. Patterns of disease based on sites of lesions at initial staging were noted: 7% had cutaneous involvement, 7% had nasal cavity and nasopharyngeal (extranodal involvement), 86% had nodal involvement, and 20% had visceral involvement. Cutaneous T-cell lymphoma patients showed the SUVmax of 2.5 and patient with visceral involvement showed SUVmax of 23. In the post-treatment PET-CT, 70% (7 / 10) patients showed complete remission, 10% (1 / 10) showed stable disease, and 20% (2 / 10) showed progressive disease.
Conclusion: T-cell lymphoma subtypes evaluated in this study showed variable FDG avidity depending on the histological subtype and pattern of disease. FDG PET-CT is useful in initial staging, assessment of response to therapy, and in restaging during the recurrence.
Intracranial and Intramedullary Tuberculoma in a Case of Pott's Spine Demonstrated on 18F-FDG PET-CT
S. Mahajan, A. Jaimini, M. D'Souza, Sanjeev, Dinesh, R. Sharma, A. Mondal
Department of PET Imaging, Molecular Imaging and Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
An 18-year-old male, a known case of Pott's spine, presented at our institute after completion of 8 months of anti-tubercular treatment. He was referred for F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) for evaluation of response to therapy. Abnormal FDG accumulation was noted in the L1-L2 vertebrae, suggestive of residual disease, and also, a hypometabolic ill-defined rounded lesion was noted in the posterior aspect of right parietal region of the brain. Keeping in mind the possibility of another foci of disease spread, patient was referred for MRI brain, which was suggestive of inflammatory granuloma in the right occipital lobe predominantly isointense to gray matter, with perilesional edema appearing hyperintense on T2 and FLAIR sequences. This case highlights the importance of acquiring whole body scans including brain for disease assessment in patients with spinal tuberculosis, among which 55% present with vertebral body involvement, 39% with intraspinal granulomatous lesions without any other site of involvement, and only 7% with intramedullary lesions. The combination of intramedullary and intracranial tuberculomas is extremely rare and only five cases have been reported in the literature so far. Detection of intracranial tuberculomas is a rare finding on 18 F-FDG PET scan.
F-18 FDG PET in a Case of Lung Carcinoma Co-existing with Pulmonary Tuberculosis
S. Mehta, A. Jaimini, M. D'Souza, Y. Solanki, S. Panday, R. Sharma, A. Mondal
Department of PET Imaging, Molecular Imaging Research Center, INMAS, Delhi, India
We report the case of a 55-year-old patient who had received a 6-month course of antitubercular treatment (ATT) for pulmonary tuberculosis and within a few years of completion of ATT developed neurological symptoms. Brain MRI was performed which showed multiple lesions with the likely possibility of tuberculosis. Possible relapse of tuberculosis was considered, and hence the patient was again put on ATT. The CT scan gave a differential diagnosis of a neoplasm or tuberculosis. The patient was referred to our institute for whole body F-18 FDG PET scan. The PET scan showed hypermetabolic right hilar mass (suspected primary site for lung cancer), multiple other lung lesions, multiple skeletal lesions, bilateral adrenal glands, mediastinal and abdominal lymph nodes, suggesting metastatic lung carcinoma. Cytopathology established that the patient had lung cancer co-existing with tuberculosis. Thus, we conclude that although rare, the possibility of concomitant lung cancer and tuberculosis should be kept in mind.
Role of 18 F-FDG PET-CT in Recurrence on Follow-up in Bone and Soft Tissue Sarcoma
Radiation Medicine Centre, Tata Memorial Centre Complex, Parel, Mumbai, India
Aims and Objectives: To assess the role of 18 F-FDG PET-CT in assessing local, pulmonary and extrapulmonary metastatic recurrence in patients undergoing routine follow-up scan or with suspected recurrence clinically/on conventional imaging modalities.
Materials and Methods: A retrospective study was performed in patients with bone or soft tissue sarcoma undergoing routine follow-up 18 F-FDG WB scan or suspected of having disease recurrence. Acquisition was done on the GE Discovery PET 8-slice CT scanner in our department. The images were evaluated by two experienced nuclear medicine physicians in consensus. Clinical/imaging follow-up and histopathology were taken as the reference standard.
Results: Local recurrence: Totally 13 patients were suspected to have local recurrence (7 patients had suspected recurrence on conventional imaging modalities and 6 patients had clinical suspicion of recurrence/routine follow-up scan). Out of seven patients with suspicious recurrence on conventional imaging modalities, all six patients had local recurrent disease detected on PET-CT. PET-CT detected additional not previously known metastatic sites in two patients out of these six patients. One patient was negative on scan for local recurrence, who was found to be disease free on follow-up. Out of six patients with clinical suspicion of local recurrence/on routine follow-up scan, two had negative scan and were disease free, while three were positive for recurrence of which two had distant metastasis also apart from local recurrence. One patient out of six had prosthesis implantation and suspected recurrence which was ruled out by PET-CT. Extrapulmonary metastatic recurrence: Out of total 11 patients with suspected extrapulmonary recurrence, 3 patients were negative for any recurrence and 8 had recurrent disease on PET-CT. Out of these eight patients, seven had additional metastasis which was not known or suspected previously. Pulmonary metastatic recurrence: Out of 14 patients suspected for pulmonary metastasis, 7 were FDG avid while 6 were FDG non-avid detected on CT alone. But out of these six, two had FDG-avid extrapulmonary metastasis also, which was not previously known. In seven patients with FDG-avid pulmonary metastasis, four had additional not previously known extrapulmonary metastasis detected by PET-CT. Out of total 14, 1 patient was negative for pulmonary metastasis on PET as well as CT scan also.
Conclusion: FDG PET-CT as a single integrated modality is very useful for the evaluation of suspected recurrence in patients with bone and soft tissue sarcoma and has incremental value over conventional imaging modalities, especially with CT alone.
Scintigraphic Evaluation of Unilateral Small Kidney in Kashmir Valley
M. ul Hassan, S. H. Khan, M. Ashraf, S. Najar, F. Shaheen
Department of Nuclear Medicine, Sher-e-Kashmir Institute of Medical Sciences, Srinagar, India
Background: Unilateral small kidney may be caused by congenital hypoplasia, ischemia, reflux nephropathy, post-obstructive atrophy, renal infarction, or radiation nephritis. Nuclear medicine procedures can provide valuable information on renal perfusion and function of individual kidneys and on urinary tract dynamics which will help to establish the cause of unilateral small kidney.
Materials and Methods: The present study was conducted in the Department of Nuclear Medicine at SKIMS, Srinagar, from July 2007 to March 2011. The study included 47 patients with diagnosis of unilateral small kidney on ultrasound. All the patients were subjected to 99m Tc DTPA angiotensin converting enzyme inhibition (ACEI) renal scintigraphy, 99m Tc DMSA scan, and either computed tomography (CT) angiography or magnetic resonance (MR) angiography. Renal angiography was performed in cases with suggestion of renal artery stenosis (RAS) on CT or MR angiography.
Results: Out of 47 cases with unilateral small kidney, the causes were congenital hypoplasia in 38, renal artery stenosis in 4, chronic pyelonephritis in 3, and post-obstructive atrophy in 2. On 99m Tc DTPA ACEI scan, 25 were in the low probability and 12 in the intermediate group for RAS, and in both groups none was positive for RAS. Ten were in high-probability group, out of which 4 were positive for RAS by CT/MR angiography which was confirmed by catheter angiography.
Conclusion: In patients suspected of RAS, 99m Tc DTPA ACEI scan is the investigation of choice to know the probability of RAS so as to prevent unnecessary high radiation exposure by CT angiography. By renal scintigraphy, we can assess the scarring and function of small kidney. The parameters like kidney size, uptake, glomerular filtration rate (GFR), and differential function can be assessed by renal scintigraphy.
Role of Lymphoscintigraphy in Differential Diagnosis of Lower Limb Swelling
J. Mandarapu, J. Rao, K. N. Reddy, S. Moon, Mansoor, Prathyusha
Department of Nuclear Medicine, Apollo Gleneagles Hospital, Hyderabad, India
Aims and Objectives: To evaluate the etiology of lower limb swelling.
Study Design: This was a retrospective study involving 10 cases who presented with lower limb swelling. Scintigraphy was performed using Siemens e-cam gamma camera. Planar images were acquired and data were interpreted accordingly.
Results and Conclusions: Of the 10 cases, 6 presented with unilateral and 4 with bilateral lower limb swelling. Eight cases were found to be positive on lymphoscintigraphy. Three of the eight were diagnosed as primary lymphedema and five as secondary lymphedema. Lymphoscintigraphy using Tc99m sulfur colloid helped the clinician in the management of lower limb swelling through proper diagnosis.
Relevance to Clinical Nuclear Medicine: Lymphedema (edema that results from chronic lymphatic insufficiency) is a chronic debilitating disease that is frequently misdiagnosed, treated too late, or not treated at all. There are, however, effective therapies for lymphedema that can be implemented, particularly after the disorder is properly diagnosed and characterized with lymphoscintigraphy.
Conclusion: On the basis of the lymphoscintigraphy image pattern, it is often possible to determine whether the limb swelling is due to lymphedema and, if so, whether compression garments, massage, or surgery is indicated. Effective use of lymphoscintigraphy to plan therapy requires an understanding of the pathophysiology of lymphedema and the influence of technical factors such as selection of the radiopharmaceutical, imaging times after injection, and patient activity after injection on the images. In addition to reviewing the anatomy and physiology of the lymphatic system, we review physiologic principles of lymphatic imaging with lymphoscintigraphy, discuss different qualitative and quantitative lymphoscintigraphy techniques and their clinical applications, and present clinical cases depicting typical lymphoscintigraphy findings.
Utility of SPECT-CT in Sentinel Lymph Node Detection
K. Y. Gupta, N. Singh, A. Kalshetty, R. Parab
Department of Nuclear Medicine, P. D. Hinduja Hospital, Mahim, Mumbai, India
Aims and Objectives: In the era of minimal invasive surgery, sentinel lymph node (SLN) identification plays an important role for the decision making in surgical extent. The method for SLN detection [like methylene blue (MB) dye method and Sentinel Node Lymphoscintigraphy] should enable identification and precise anatomical localization of sentinel node. The fusion imaging of SPECT-CT has a potential advantage of dual nature of structural and functional imaging. We summarize our institutional experience with this modality.
Study Design: Fifteen patients with biopsy-proven primary breast cancer (11 patients) and head and neck cancers (4 patients: 3 With squamous cell carcinoma of tongue and 1 cancer of buccal mucosa) underwent SLN 12-24 h before surgery. Intradermal injection of 5-20 MBq was given in peri-tumoral region and sequential images were acquired till the sentinel node was visualized. SPECT-CT imaging was performed in all these patients at 45-60 min of injection. Pre-operatively, MB dye was used in 14 / 15 patients. The results were validated comparing the intraoperative gamma probe-guided SLN biopsy and histological evaluation.
Results: Multiple nodes were identified in most of the patients (9 / 15). The total number of nodes biopsied by gamma probe identification method and MB dye method was 28. The total number of nodes visualized on MB dye was 18 / 27 (MB was not used in one patient), on planar images was 19 / 28, and on SPECT-CT was 27 / 28. The node not identified on SPECT-CT was identified by MB dye method; however, in the same patient, two other nodes were detected by SPECT-CT and by gamma probe intraoperatively. Histologically six patients (three breast carcinoma and three head and neck carcinoma) had metastases in SLN. Out of the above, two patients had axillary node metastases and two had neck node metastases. All six were identified on SPECT-CT, hence demonstrating good sensitivity, whereas planar images could identify only 4 / 6 (66.6%) patients and MB dye method could identify 3 / 6 (50%) patients.
Conclusion: SPECT-CT readily identifies the nodes not visualized on planar images, and therefore reduces the false-negative rate. It also has an additional value in enhancing topographic orientation and detecting more number of sentinel nodes. Hence, SPECT-CT has valuable contribution in SLN detection technique, and therefore in patient management.
Relevance: Unnecessary neck and axillary dissection in low-grade carcinomas of head and neck and breast (respectively) may be avoided, hence reducing the morbidities like lymphedema. Precise localization of sentinel node is utmost important for minimal invasive surgeries, hence the role of SPECT-CT holds significance.
Retrospective Analysis of Outcome with PET-CT Imaging used for Various Clinical Situations
Department of Nuclear Medicine, Samved Hospital, Ahmedabad, India
Aim: To retrospectively analyze the outcome with PET-CT imaging used for various clinical situations.
Materials and Methods: Whole body PET-CT scan of 29 patients was evaluated. In the first group, PET-CT was used for response evaluation after curative radio-chemotherapy. In the second group, PET-CT was used as an additional diagnostic tool. In the third group, PET-CT was used for delineating target volume. For the first and second groups, uptake was recorded with respect to primary, regional, and distant site of involvement, and confirmed through PET-CT guided biopsies whenever required. For the third group, hypermetabolic volume delineated on PET image was compared with gross target volume delineated on CT image.
Results: In the first group, 50% (6 / 12) of the patients had distant systemic disease, 33% (4 / 12) had residual regional disease, and 58% (7 / 12) had residual/recurrent local disease. In the second group, 30% (3 / 10) patients had distant systemic disease on PET-CT where CT was inconclusive. 25% (4 / 10) had variable extent of disease involvement on PET-CT that changed the technique of radiotherapy treatment. In 20% (2 / 10) patients, PET-CT changed the sequence of treatment. In the third group (n = 7), PET delineated volume was significantly higher (10-50%) than CT delineated volume for local site, but for regional targets the difference was <10%.
Conclusions: With the initial use of FDG18 PET-CT imaging, we realized that rate of distant metastasis is much higher which usually remains unnoticed because of conventional approach of investigation. PET-CT imaging has the potential to improve the method of conventional IMRT planning.
Establishment of Clean Room Facility for Tc-99m Cold Kit Production
M. Z. Abedin, M. A. Haque, M. M. Rahman, M. A. Hossain, M. R. Ali, R. Akhter, A. Razia, R. Roy
Radioisotope Production Division, INST, AERE, Savar, Dhaka, Bangladesh
A GMP-compliant clean room facility has been established at RIPD, INST, AERE, Savar, Dhaka, Bangladesh, under a government project with technical help from IAEA for local production of Tc-99m cold kit production. The facility is provided with supply air filtered through H14 HEPA filter of minimum 99.97% efficiency for 0.3 μm particles. The clean room walls are constructed with sandwich-type panels to confirm the elements, air and particle tightness. Average air exchange rate at Class 1000(B), Class 10,000(C), and Class 100,000(D) areas are 120-150, 45-60, and 20-30 air changes/hour, respectively. Positive air pressures in the gowning room, formulation room, and dispensing room are 12.5 Pa, 25 Pa, and 35 Pa, respectively. Temperature and humidity of the clean room are maintained at 22 ± 2°C and 55 ± 5%, respectively. According to GMP, the personnel flow, material flow, and product flow are different. Pass boxes are installed between rooms of different grades. Air shower is installed between class C and class B areas. The presence of air-borne particles was found to be well below the minimum class limit (Federal Standard 209D). The monitoring of microbial load (settle plate method) showed that only a single colony was formed in class C area, which is far below the allowed level. The parameters of the clean room and the equipment have been validated and the facility has been awarded with ISO 14644 Certificate. Test production of MDP, DTPA, and DMSA kits has been carried out in the new facility. Regular kit production will be started soon.
PET-CT Findings of Extranodal Lymphoma
J. Das, S. Sen, M. Chowdhury, A. Chandra, A. Chakrapani, A. Ray
Department of Radiology and Nuclear Medicine, Tata Medical Center, New Town, Rajarhat, Kolkata, India
Extranodal lymphoma refers to lymphomatous infiltration of anatomic sites other than the lymph nodes. It is an increasingly common identity in hematological oncology practice. Both Hodgkin's as well as non-Hodgkin's lymphoma can involve extranodal site at different stages of disease or can present as primary extranodal disease. The imaging characteristics of extranodal involvement can be subtle or absent at conventional computed tomography (CT). Imaging of tumor metabolism with 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) by hybrid PET-CT has become the standard imaging modality for initial staging, follow-up, and treatment response assessment in patients with lymphoma and has proved superior to CT in these settings. Familiarity with the certain PET-CT pattern with different extranodal manifestations in various locations is critical for correct image interpretation. In this retrospective study of 70 cases of extranodal lymphomas of various subtypes, we illustrate the spectrum of PET-CT features of extranodal lymphoma of commonly involved organs in different stages of the disease.
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