|Year : 2013 | Volume
| Issue : 5 | Page : 14-15
|Date of Web Publication||29-Nov-2013|
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
. Scintigraphy Oncology. Indian J Nucl Med 2013;28, Suppl S1:14-5
Imaging appearance of neurofibromas on 99MTC methylene diphosphonate and 99MTC dimercaptosuccinic acid (V): High negative predictive value
Sunita Sonavane, Archi Agarwal 1 , Sneha Shah 1 , Nilendu Purandare 1 , Mehjaben 1 , Venkatesh Rangarajan 1
Department of Nuclear Medicine and PET/CT, Radiation medicine centre, Bhabha Atomic research Centre, 1 Department of Nuclear Medicine and PET/CT, Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India
Objective: We report a case of extensive cutaneous neurofibromatosis with newly diagnosed leftt breast carcinoma, referred for 99mTc methylene diphosphonate (MDP) bone scan for staging. Materials and Methods: Wholebody bone scintigraphy was performed 2-3 h post intravenous injection 20 mCi of 99mTc- MDP. 99mTc- DMSA (V) scan was performed 2 h post intravenous injection of 8 mCi of 99mTc- DMSA (V). High-resolution 256 Χ 256 delayed whole-body image were acquired in both the scans. Results: 99mTc- MDP bone scan revealed no definite osteoblastic skeletal metastases. Mildly increased extraosseous activity accumulation in the multiple cutaneous neurofibromas of varing sizes was also noted. In view of gaint neurofibromas a 99mTc- DMSA (V) scan was performed to rule out malignant transformation, revealed mild to moderate diffusely increased radiotracer uptake in the multiple neurofibromas, however, none of the subcutaneous neurofibromas showed abnormal intense radiotracer concentration. Thus, 99mTc- DMSA (V) whole-body scintigraphy didnot suggest malignant transformation in any of the peripheral neurofibromas. Conclusion: Comparing 99mTc MDP bone and 99mTc DMSA (V) scans, more number of neurofibromas noted in 99mTc DMSA (V) scan. This case highlights high negative predictive value of 99mTc DMSA (V) scan in evaluating malignant transformation in gaint neurofibromas in a case of extensive cutaneous neurofibromatosis.
Value of SPECT/CT in differentiating haemangioma from metastasis in suspicious vertebral lesions detected on planar bone scan
K Sreenivasa Reddy, L Peethamber, Madhur K Srivastava, Madhusudhanan Ponnusamy, H Dhanapathi, Nandini Pandit
Department of Nuclear Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
Objective: Bone scan is the modality of choice in the staging work up of cancer patients to rule out skeletal metastasis. It has high sensitivity and provides information on the extent of skeletal metastatic lesions. However, bone scan is non-specific and many a times benign lesions are also detected that are difficult to differentiate from metastases. SPECT/CT increases the specificity over planar bone scan. Here, we are presenting a series of 6 cases with known primary malignancy in whom SPECT/CT was helpful in diagnosing vertebral haemangioma and thus, ruling out metastasis. Materials and Methods: Five female patients with known carcinoma of breast and one male with history of left lobe hepatectomy for HCC underwent bone scan to rule out skeletal metastases. Planar bone scan was performed after administration of 20 mCi of 99m Tc-MDP (methylene diphosphonate) I.V and images were acquired after 3 h. Regional SPECT/CT was perfomed corresponding to the sites of lesions seen on planar bone scan. SPECT/CT was evaluated for lesion charecterisation. Results: Planar bone scan showed vertebral lesions that were equivocal for metastasis in all these patients (5 patients had lesions in thoracic vertebrae and one had lesions in lumbar vertebrae). SPECT/CT revealed typical features of vertebral haemangioma, like dense dots in a fatty background (polka dot appearance). Two of these patients also underwent MRI spine that confirmed haemangioma. Conclusion: SPECT/CT is a valuable tool in differentiating an unsuspected haemangioma from metastasis in patients with known primary and a vertebral lesion suspicious for skeletal metastasis detected on planar image.
Sentinel lymph node detection by intra operative gamma probe
R Krishna Kumar, K Vijayalakshmi, GK Rangarajan, MC Vinod Kumar, Sridevi, N Kadiresan
Cancer Institute (WIA) Adyar, Chennai, Tamil Nadu, India
Aim: Sentinel lymph node detection by intraoperative gamma probe and by lymphoscintigraphy have helped us in more accurate and less unnecessary surgery and probably better patient survival. Materials and Methods: The technique requires one or more interstitial injection into appropriate tissue plane. We have done sentinel node biopsy procedure on 46 patients (44 patients with cancer breast and 2 patients with malignant melanoma). Blue dye was used along with isotope technique and for the sentinel lymph node biopsy procedure technique to be accurate; a biopsy must be done for all sentinel true nodes in every patient. Tc-99m sulfur colloid was injected peritumorally and imaging done 45-90 min to look for axillary nodes in cancer breast and inguinal and popliteal nodes in melanoma of lower limb. The nodal areas with the tracer uptake were localized on the skin with marking pencil. Results: Out of 44 patients with cancer breast 12 patients showed metastases in the sentinel nodes and had routine axillary detection. However, in 4 patients sentinel node alone was positive (rest of the axillary nodes was negative). In 2 melanoma patients one had sentinel nodal metastases and had ilioinguinal block dissection. In the other patient sentinel node was negative for metastases and no further surgery was done. Conclusion: Pre-operative lymphoscintigraphy with a small particle radiocolloids allows lymphatic vessel to be visualized draining directly to the sentinel nodes.
Synthesis of 99m Tc analogue of 123/131 I-mIBG for possible use in neuroendocrine tumor imaging
Anupam Mathur, Abhishek Sharma, Navin Sakhare, G Prabhakar, VV Murhekar, SS Sachdev
Board of Radiation and Isotope Technology, Navi Mumbai, Maharashtra, India
Objective : 123/131 I-mIBG (meta-iodo-benzylguanidine) is a known radiopharmaceutical used in the diagnosis of neuroendocrine tumors in particular adrenal medullae related tumors. However, 123 I is cyclotron produced, with a relatively short half-life (t 1/2 ~ 13 h) which limits its availability in all parts of the world. Though, 131 I is a rationale substitute for 123 I in case of mIBG labeling, but the former radioisotope lacks the desired characteristics of a diagnostic radionuclide. Hence, molecules labeled with 99m Tc, which is a more widely available isotope and possesses ideal diagnostic radionuclide characteristics, is preferred. In this regard, an attempt is made to synthesize a 99m Tc analogue of mIBG and evaluate its efficacy for the aforementioned application. Materials and Methods : A bi-functional chelate (dithiocarbamate group) was introduced in benzylguanidine moiety at meta-position, which is known to efficiently complex with [ 99m Tc≡N] 2+ core. The synthesis of derived meta derivative is a two step procedure starting from (3-(aminomethyl)phenyl)methanamine (1). The first step is condensation of 1:1 equivalent of 1 and cyanamide in DMF at 140°C for 4 h to yield (3-(aminomethyl)benzyl)guanidine. The latter compound was further treated with carbon disulphide and NaOH in dioxane to give a white precipitate of sodium 3-(guanidinomethyl)benzylcarbamodithioate 2. The prepared derivative was characterized by 1 H-NMR. This was then radiolabeled with [ 99m TcN] 2+ core. The core was synthesized following a reported protocol. To the freshly prepared core, 2 dissolved in saline was added and the reaction mixture incubated at room temperature for 30 min. The formation of the complex was ascertained by HPLC. Results: The desired derivative 2 was synthesized in an overall yield of 60%. The radiolabeled product was obtained in 85% yield and purity as characterized by HPLC. Conclusion: Further steps are underway to carry out in vitro study of the radiolabeled preparation, to ascertain its efficacy for imaging neuroendocrine tumors.
Skeletal metastases in differentiated thyroid carcinoma: Experience in a tertiary care medical centre in India
Chinmoy Kumar Biswal, Mohammed Labeeb Abrar, Ashwani Sood, Anish Bhattacharya, BR Mittal
Department of Nuclear Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India
Objective : To evaluate incidence of skeletal metastases (SM) in post-operative cases of differentiated thyroid carcinoma (DTC) and role of nuclear medicine in diagnosis, treatment and follow up of these patients. Materials and Methods : A retrospective analysis of 256 patients of DTC (39/256 follicular [FTC; 15.2%] and 217/256 papillary [PTC, 84.8%]) referred after primary surgery to the department of nuclear medicine was done to determine the occurrence of SM. All patients underwent diagnostic iodine 131 whole body scan (I-WBS). A final diagnosis of SM was made with histopathological correlation and/or imaging follow-up with I-131 WBS. All patients with SM who underwent serial I-131 therapies were followed up by imaging and clinical data. Results : 18/256 patients demonstrated SM (7%). 5/217 patients with PTC had SM (2.3%) and 13/39 patients with FTC had SM (33.33%). 4/18 patients showed additional skeletal lesions on post therapy I-131 WBS. On follow-up after serial I-131 therapies (9/18); 3 patients showed progression of SM and 1 patient showed decrease in SM (after a median follow-up period of 16 months). In 3/18 patients, initial presentation was due to SM (pathological fracture) and they were subsequently referred for I-131 therapy after external beam radiation. In 2/3 of these patients there was no evidence of SM on the diagnostic and post therapy I-WBS. However, one of these patients showed additional unknown sites of skeletal metastases on I-WBS. 14/18 patients showed stable disease without evidence of disease progression on follow-up. Conclusion : In our study the incidence of skeletal metastases in DTC was 7%. SM were more common in FTC as compared to PTC. Although rare in occurrence SM in DTC is a significant cause of morbidity in these patients. Nuclear medicine plays an important role not only in the diagnosis but also in the treatment and follow-up of these patients.
Radioisotope sentinel lymph node mapping in early breast cancer-reliable?
Divya Naresh Shivdasani, Smita Krishnamurty Moodi, Sudhanva Hemant Kumar 1 , Biswanath Patita Gouda 1
Department of Nuclear Medicine, P D Hinduja Hospital and MRC, 1 Department of General Surgery, P D Hinduja Hospital and MRC, Mumbai, Maharashtra, India
Objective: To assess the role of radioisotope technique of sentinel lymph node mapping in early breast cancer. Materials and Methods: 30 patients (age 29-69 years) diagnosed with T1-T2 tumours and clinically N0 axilla underwent pre-op localisation of sentinel lymph node 1 day prior to surgery. An intradermal peritumoral injection of 200-500 μCi 99m Tc sulphur colloid was followed by dynamic imaging for 30 min and further static imaging till visualisation of the node. Once identified, the corresponding superficial location was marked on the skin in the axilla under image guidance and using surgical γ probe. All patients underwent axillary clearance with intra-operative identification of sentinel node using γ probe. Histology of all dissected nodes was analysed for evidence of cancer involvement. Results: In 29/30 (96.6%) patients the sentinel node was identified either pre-operative on imaging or intra-operative using the probe. 32 "hot" nodes were identified with 5 patients having more than one node. Total 585 lymph nodes were excised of which 11 (10 level I 1 level II) were positive for malignant cells. 10/11 (90.9%) sentinel lymph nodes were correctly identified using isotope technique. 1/11(0.09%) positive nodes was a "cold" node. The sensitivity, specificity, PPV and NPV was 91%, 100%, 100% and 95% respectively. Conclusion: Radioisotope technique for localisation of sentinel node is an excellent, easy and reliable method for predicting axillary status in early breast cancer.
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