Connecting the Dots: Exploring the Relationship between Optical Coherence Tomography and 99mTc-TRODAT-1 SPECT Parameters in Parkinson's Disease.

Background and Objective: While optical coherence tomography (OCT) is explored as a potential biomarker in Parkinson's disease (PD), technetium-99m-labeled tropane derivative (99mTc-TRODAT-1) single-photon emission computed tomography (SPECT) imaging has a proven role in diagnosing PD. Our objective was to compare the OCT parameters in PD patients and healthy controls (HCs) and correlate them with 99mTc-TRODAT-1 parameters in PD patients. Materials and Methods: This cross-sectional study included 30 PD patients and 30 age- and gender-matched HCs. Demographic data, PD details including Movement Disorders Society Unified Parkinson's Disease Rating Scale-III (MDS-UPDRS-III) and Hoehn-Yahr (HY) staging, and OCT parameters including macular and peripapillary retinal nerve fiber layer (RNFL) thickness in bilateral eyes were recorded. PD patients underwent 99mTc-TRODAT-1 SPECT imaging. The terms "ipsilateral" and "contralateral" were used with reference to more severely affected body side in PD patients and compared with corresponding sides in HCs. Results: PD patients showed significant ipsilateral superior parafoveal quadrant (mean ± standard deviation [SD] = 311.10 ± 15.90 vs. 297.57 ± 26.55, P = 0.02) and contralateral average perifoveal (mean ± SD = 278.75 ± 18.97 vs. 269.08 ± 16.91, P = 0.04) thinning compared to HCs. Peripapillary RNFL parameters were comparable between PD patients and HCs. MDS-UPDRS-III score and HY stage were inversely correlated to both ipsilateral (Spearman rho = -0.52, P = 0.003; Spearman rho = -0.47, P = 0.008) and contralateral (Spearman rho = -0.53, P = 0.002; Spearman rho = -0.58, P < 0.001) macular volumes, respectively. PD duration was inversely correlated with ipsilateral temporal parafoveal thickness (ρ = -0.41, P = 0.02). No correlation was observed between OCT and 99mTc-TRODAT-1 SPECT parameters in PD patients. Conclusion: Compared to HCs, a significant thinning was observed in the ipsilateral superior parafoveal quadrant and the contralateral average perifoveal region in PD patients. Macular volume and ipsilateral temporal parafoveal thickness were inversely correlated with disease severity and duration, respectively. OCT and 99mTc-TRODAT-1 SPECT parameters failed to correlate in PD patients.

Role of Sentinel Lymph Node Drainage Mapping for Localization of Contralateral Lymph Node Metastasis in Locally Advanced Oral Squamous Cell Carcinoma - A Prospective Pilot Study.

Aim/Background: Sentinel lymph node biopsy (SLNB) has become the standard of care for nodal staging in early-stage oral squamous cell carcinoma (OSCC) as an alternative to elective neck dissection. However, the role of sentinel lymph node (SLN) and lymphatic drainage mapping with image-guided surgery has not been studied in locally advanced OSCC. Therefore, this study was undertaken to evaluate the role of lymphatic drainage mapping in the identification of contralateral cervical lymph node metastasis in locally advanced OSCC (Stage III-IVb). Materials and Methods: We have prospectively analyzed treatment-naïve patients of locally advanced, lateralized OSCC (n = 20). All patients underwent SLN imaging using peritumoral injection 0.5-1.0 mCi of 99 mTc-Sulfur colloid (Filtered) and intraoperative identification of contralateral neck nodes using a handheld gamma probe (Crystal Photonics). Results: A total of 20 patients (18 males and 2 females) with a median age of 52.5 (33-70 years) were included. Ipsilateral SLN was localized in 18 (90%) patients. Bilateral cervical nodes were visualized only in 7 (35%) patients on lymphoscintigraphy (LSG). Out of the seven patients, 5 patients underwent bilateral neck dissection and 2 patients had unilateral neck dissection with LSG-guided exploration of contralateral cervical node and intraoperative frozen section examination. Six out of these seven patients had one or other risk factor for contralateral metastasis (patients had either primary in the tongue, involvement of floor of mouth, or tumor thickness >3.75 mm). On postoperative HPE, only 1/20 (5%) patient showed metastasis in the contralateral cervical lymph node. Conclusion: Correct identification of metastatic disease in contralateral neck directly influences clinical management, as it can reduce contralateral neck failure rate and limit the morbidity associated with unnecessary contralateral neck dissection, and it is also crucial in radiotherapy planning in locally advanced OSCC. In the current study, lymphatic drainage mapping showed a metastatic rate of 5% in the contralateral neck nodes in locally advanced, lateralized OSCC. However, the role of SLNB and lymphatic drainage mapping in this subgroup of OSCC needs to be studied in larger population to validate these findings.

Comparison of CT and MRI for contouring active bone marrow in bone marrow sparing IMRT of carcinoma cervix and its effects on functional outcomes.

OBJECTIVE: Intensity-modulated radiotherapy (IMRT) has been used to reduce dose to bone marrow (BM) irradiation during pelvic conformal radiotherapy by contouring bone marrow and sparing it during radiotherapy planning. The present study was done to compare CT & MRI for contouring bone marrow to spare functional bone marrow for Intensity-modulated radiotherapy (IMRT) in carcinoma cervix and to assess its effect on functional outcome. MATERIAL & METHODS: This prospective, observational study included newly diagnosed carcinoma cervix patients treated by radical chemoradiation. Patients were distributed in two arms i.e. CT arm and MRI for contouring bone marrow. Regions taken into consideration for bone marrow volumes contouring were 4th and 5th Lumbar vertebrae, whole pelvis and proximal femur upto lesser trochanter. In CT arm bone marrow regions were contoured using freehand method with window adjusted to bone range (Window - 2500/ Level - 400) and in MRI arm BM regions on the MR images that had pixel values similar to muscle or IDEAL IQ sequence based on fat fractions present in bone marrow (BM) was used to contour. RESULTS: 17 patients in CT arm and 19 patients in MRI arm were included. There was no significant difference between the groups in terms of Bone Marrow Volume (cm3) (W = 171.500, p = 0.763). The mean value of V10, V20, V30 and V40 all were lower in group II (MRI) but the differences in volume were not significant. Bone marrow V30 in CT arm was found to correlate with absolute neutrophil count drop which was statistically significant in univariate (Coefficient - 1.00 [0.14-2.01, p = 0.025] and multivariate analysis (Coefficient - [1.08 (0.14 to 2.01, p = 0.025]). Bone marrow V30 in MRI arm was found to correlate with total leucocyte count percentage drop, which on multivariate analysis was statistically significant (Coefficient - 1.29 [0.29-2.28, p = 0.013]). CONCLUSIONS: Dosimetric parameters of bone marrow V10 and V30 were found to be associated with absolute neutrophil and total leucocyte nadir respectively. Haematological toxicity was observed more in MRI arm but more propspective studies are required for further validation.

The Vital Role of 131 I-MIBG in Localization of Paraganglioma at Unusual Sites.

Paragangliomas (PGLs) are extra-adrenal neuroendocrine tumors. PGL of the urinary bladder are very rare and commonly present with features of hypertensive crisis, headache, syncope, and other symptoms of sympathetic excess. A few of these tumors are silent at the presentation. Here, we report a case of a urinary bladder PGL, presenting with lower abdominal pain.

Role of 99m Tc-Mebrofenin Hepatobiliary Scintigraphy in the Diagnosis of Post Cholecystectomy Syndrome.

Background Huge variation in the prevalence of post cholecystectomy syndrome (PCS) is because PCS can include a wide variety of disorders that can be both related and unrelated to cholecystectomy. Hepatobiliary scintigraphy (HBS) is a noninvasive nuclear medicine scan that can evaluate a delay in the transit of bile from the hepatic hilum to the duodenum using a radiotracer 99m Tc-Mebrofenin that can be associated with a functional ampullary obstruction. The aim of this study was to assess the role of 99m Tc-Mebrofenin HBS in the detection of the cause of PCS among the patients undergoing cholecystectomy. Methods Twenty-one patients who presented with PCS from September 2018 to February 2020 were included in the study. These patients were characterized based on history, examination, liver function test, and abdominal ultrasound. Sphincter of Oddi dysfunction (SOD) was diagnosed using the Rome 3 criteria and the Milwaukee classification. Magnetic resonance cholangiopancreatography (MRCP) and upper gastrointestinal endoscopy and biopsy were done when indicated, to establish the diagnosis. These patients were further subjected to 99m Tc-Mebrofenin HBS, and the findings were analyzed. Results The most common symptom in PCS was biliary pain occurring in 85.7% of the patients. The average time of presentation since surgery was 1.9 years. The most common cause of PCS was SOD, occurring in 52.3% of the patients, followed by benign biliary stricture occurring in 23.8% of the patients. The mean bile duct (common bile duct) visualization time in patients with PCS was 25.2 minutes, the mean duodenal visualization time was 38.2 minutes, and the mean jejunal visualization time was 60.5 minutes. The mean bile duct to duodenum transit time was 12.7 minutes, while the mean bile duct to jejunum transit time was 30.1 minutes. HBS showed consistent findings with the final diagnosis made by other diagnostic modalities (clinical criteria/MRCP/intraoperative findings) in 80.9% of the patients. Conclusion 99m Tc-Mebrofenin HBS has a significant role in the evaluation of PCS.

Utility of Axillary Reverse Mapping (ARM) and Incidence of Metastasis in Arm Draining Lymph Nodes in Patients with Breast Cancer.

Objective Lymphedema of the upper limb is the most common complication in patients with breast cancer, who require axillary lymph node (LN) dissection. Proposition of identifying upper limb draining LN and preserving it, during axillary dissection can reduce significant postoperative morbidity, but it has the risk of inadequate oncological resection. This study was planned to find out metastatic rate in axillary reverse mapping (ARM) nodes in our population. Materials and Methods Lymphoscintigraphy (LSG) was performed using intradermal injection of 99m Tc Sulfur Colloid into ipsilateral second and third interdigital web spaces of hand in patients with breast cancer. Planar, single-photon emission computed tomography-computed tomography images were acquired followed by intraoperative localization of arm draining LNs using Gamma Probe. All identified ARM nodes were dissected and sent for histopathological examination to confirm metastatic involvement. Results Twenty eligible patients were prospectively analyzed. The identification rate of arm draining LN with LSG was 90% (18/20). Among 14 eligible patients included in the study, ARM node metastasis was seen in two patients. A total of 64 ARM nodes were dissected from 14 patients, 4/64 nodes (2 patients) were positive for metastases (6.25%). Of the six patients excluded from the study, in 1 patient ARM node could not be identified on Gamma Probe, in two cases, it could not be retrieved surgically, in next two cases ARM could not be identified on LSG and remaining one case was removed because of previous surgical intervention. Conclusion In the current study, LSG showed the identification rate of 90% for ARM nodes in patients with carcinoma breast and metastatic involvement was seen in 6.25% (4/64) of these nodes in 2/14 (14.2%) patients, which is in agreement with previously published data. Oncological safety of preserving ARM nodes needs to be evaluated in the larger population.

Dual thyroid ectopia: A pictorial case series and review of literature.

Ectopic thyroid (ET) is a developmental anomaly of the thyroid gland with the presence of thyroid tissue at sites other than the normal cervical location anterior to second and third tracheal ring due to abnormal migration of the gland. It may be found along the path of descent of the developing thyroid primordium from the foramen caecum to the isthmus of the thyroid and up to the base of the diaphragm. Dual thyroid ectopia, where ET tissue is simultaneously present at two different abnormal locations, is a very rare developmental defect. Only a few cases have been reported worldwide. ET is predominantly seen in females and during puberty when the hormonal demand is high. Patients with ET may remain asymptomatic or present with swelling in the neck, symptoms such as dysphagia, dysphonia, dyspnea, and features of hypothyroidism. The diagnosis is usually made on clinical examination, laboratory tests, imaging studies, and cytology. Careful clinical evaluation is essential as ET may be the only functioning thyroid tissue. Thyroid scintigraphy is an important imaging tool and the gold standard for the diagnosis of ET tissue, as it has high sensitivity and specificity. Early and accurate diagnosis of ET is essential to start hormone replacement and avoid unnecessary surgery. The authors report here a series of four patients with dual ET tissue, diagnosed on thyroid scintigraphy.

Atypical Parathyroid Adenoma with Multiple Brown Tumors as Initial Presentation: A Rare Entity.

Brown tumors seen in hyperparathyroidism are rare, non-neoplastic lesions because of abnormal bone metabolism, and they can mimic benign bone tumors or malignancy. Although biopsy is considered as the gold standard for diagnosis, it can be inconclusive. As the diagnosis of brown tumors is often challenging, a high index of suspicion is essential for diagnosis. We present a case of 21-year-old woman who presented with multiple painful bony lesions, which were initially misdiagnosed as fibrous dysplasia. Due to persistent bone pain and deterioration in her physical mobility, she was referred to tertiary care centre. After thorough clinical workup, she underwent Tc-99m methylene diphosphonate bone scintigraphy that raised strong clinical suspicion of hyperparathyroidism and brown tumors. Subsequently, Tc-99m-methoxy isobutyl isonitrile (MIBI) parathyroid scintigraphy revealed a solitary MIBI avid focal lesion, suggestive of left inferior parathyroid adenoma. Later parathyroidectomy was performed and histopathological examination confirmed it as atypical parathyroid adenoma.