Factors predicting remission in hyperthyroid patients after low-dose I-131 therapy: 20 years retrospective study from a tertiary care hospital.

OBJECTIVE: To assess the therapeutic outcome and factors predicting remission in hyperthyroid patients treated with low-dose I-131 (radioactive iodine) from a tertiary care hospital in South India. METHODS: This 20-year single-institutional retrospective study was carried out on 3891 hyperthyroid adult patients. Only those patients with complete clinical records were audited. Selection criteria were based on patients with scintigraphic diagnosis of either Graves' disease (GD), toxic multinodular goitre (TMNG) or autonomous toxic nodule (ATN) and the records of those who received low-dose I-131 therapy (LDT) between March 2000 and 2020 at Amrita Institute, Cochin were analysed. SPSS 10 software was used for statistical analysis. RESULTS: The records of 3891 hyperthyroid predominantly female patients were analysed. 65% patients had GD, 33% had TMNG and 3% were ATN. High rates of remission as early as 12 weeks (in 61% patients) was observed with a single dose of LDT while on strict iodine-free diet for 3-4 weeks prior to LDT. Study reveals that those with lower free T4 (fT4), small goitre (thyroid volume < 25 cm3), < 15% thyroid trapping function, shorter time duration from onset of hyperthyroidism to LDT, and treatment-naïve patients were factors determining high remission rates. Mann Whitney U test and Chi-square test was used to correlate variables in the remission and relapse groups. We found a positive correlation between fT4, thyroid volume (r = 0.35, p < 0.01) and trapping function (r = 0.34, p < 0.01), which were independent of age, sex, body mass index and TSH levels in our study. CONCLUSION: High therapeutic outcome was observed with a single dose of LDT while on iodine-free diet. Remission with single dose of LDT occurred in 90% patients by 5th month. Of them 56% patients were treatment naive prior to LDT. LDT is thus a safe and effective therapy in hyperthyroid patients and can be recommended as a primary modality of management.

In primary lymph nodal staging of patients with high-risk and intermediate-risk prostate cancer, how critical is the role of Gallium-68 prostate-specific membrane antigen positron emission tomography-computed tomography?

OBJECTIVE: To assess the diagnostic performance of Gallium-68 prostate-specific membrane antigen positron emission tomography-computed tomography (Ga-PSMA PET-CT) in primary lymphnodal staging of patients with intermediate-risk and high-risk prostate cancer and to compare it with multiparametric MRI (mp-MRI) whenever available. MATERIALS AND METHODS: Ga-PSMA PET-CT scans of 51 patients (average age 66.0 ± 7.0 years) with biopsy-proven intermediate-risk and high-risk prostatic cancer who were managed by radical prostatectomy and extended pelvic lymph nodal dissection were retrospectively analyzed. Diagnostic performance of Ga-PSMA PET-CT in primary lymph nodal staging was analyzed using histopathology as reference. Diagnostic performance of mp-MRI, which was available in 35/51 patients was compared with that of Ga-PSMA PET-CT. RESULTS: Univariate analysis of patient characteristics showed significant influence of the pathological T-stage and maximum standard uptake value (SUV)max of the primary lesion on presence of nodal metastasis. In 51 patients, for patient-based analysis, the sensitivity, specificity and accuracy of Ga-PSMA PET-CT in detecting lymphnodal metastases were 80, 90.3 and 86.3%, respectively, and for lesion-based analysis 69.2, 99.6 and 98.4%, respectively. In 35/51 patients (who also had undergone mp-MRI), the patient-based and lesion-based sensitivity, specificity, and accuracy of Ga-PSMA PET-CT were 81.3, 84.2, 82.8% and 70.9, 99.5, 98.2%, respectively, and that of mp-MRI were 43.7, 78.9, 62.8% and 32.2, 98.5, 95.5%, respectively. For lesion-based analysis, Ga-PSMA PET-CT performed better than mp-MRI (P value = 0.04). CONCLUSION: Ga-PSMA PET-CT allows accurate detection of lymphnodal metastases in patients with intermediate-risk and high-risk prostate cancer prior to definitive surgical treatment. It performed better than mp-MRI in a subset of patients.

Effectiveness of sentinel lymph node scintigraphy and intraoperative gamma probing with gold standard elective neck dissection in patients with N0 oral squamous cell cancers.

OBJECTIVE: Oral cancer ranks in the top three of all cancers in India, accounting for over 30% of all cancers reported. Elective neck dissection (END) is the mainstay of treatment in early disease. Performing ENDs for node negative (N0) patients can result in significant morbidity with questionable benefit and impair the patients' quality of life. Sentinel Lymph Node Biopsy (SLNB), is an emerging investigation helping in risk stratification of patients with early oral cancer and node negative disease. SLNB is a simple, easy to perform investigation with a high sensitivity and plays a major role in avoiding neck dissection. Studies have compared SLNB-based neck dissection with END in early oral cancers, and also on survival benefit with prophylactic neck dissection at the time of primary surgery as compared to watchful waiting followed by therapeutic neck dissection for nodal relapse, in patients with clinical N0 (cN0) oral squamous cell carcinoma (OSCC) on literature search. AIM: Our primary aim was to determine the effectiveness of lymphoscintigraphy in OSCC in clinically neck node negative (cN0) patients in comparison to gold standard END for nodal metastases identification and secondly to assess the utility of gamma probe in guiding SLNB in this group of patients. MATERIALS AND METHODS: Fifty-eight patients (M:F = 42:16) with histologically confirmed OSCC of T1-3 stage with cN0 and planned for curative intent primary surgical treatment were divided into two arms. All patients underwent sentinel lymph node (SLN) imaging and biopsy. Arm 1 underwent nodal dissection based on SLNB positivity, while all patients in arm 2 had wide neck dissection irrespective of SLNB findings. RESULTS: SLN was detected in all 58 patients, 96.4% patients showed SLN immediately postinjection. More than one SLN was found in 94.3% patients and 6.8% patients showed contralateral SLN also. Higher proportion of nodal metastasis were observed in tongue cancers than in remaining floor of mouth and buccal mucosa cancers (38% vs 12%, P< 0.01). We also found significant association between T size and nodal metastasis in our series. Sensitivity of SLNB was 88.23% with a specificity of 100%, both for SLN imaging and gamma probing localization reflecting the reliability of this technique. Serial step sectioning at 150 micrometre is recommended. SLNB showed positive nodes in 29.3 % patients with cN0 neck. We found that the association between the outcome in both arms was not statistically significant. On follow-up, three patients with T3N0 OSCC of arm 2 had nodal recurrence/lung metastases. One patient of arm 1 had nodal recurrence. Two patients expired within one year. As high as 73% patients (22 negative necks out of 30) had unwarranted neck dissection in arm 2. CONCLUSION: SLNB is an effective method to circumvent unwarranted neck dissection in early OSCC and prevent complications. Gamma probing is a robust and easy tool to identify SLN in T1-3 stages with N0 necks clinically. A positive SLNB is found to be reliable in guiding neck dissection in this small study. Larger studies are warranted to establish its recommendation in routine clinical practice.

PET/CT in paediatric malignancies - An update.

(18)F-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.

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.

Unusual presentation of Warthin variant of Papillary thyroid carcinoma with lymph nodal metastases in a patient of Graves' disease.

Warthin-like Papillary thyroid carcinoma (WPTC) is a rare variant of papillary carcinoma of thyroid, PTC which derives its name by closely resembling Warthin's tumor of salivary gland. Hallmark histological feature of this variant is papillary folding lined by oncocytic neoplastic cells with clear nuclei and nuclear pseudoinclusions, accompanied by prominent lymphocytic infiltrate in the papillary stalks. It is thought to be one of those differentiated thyroid cancers with favorable prognosis. We report a case of Graves' disease with a cold nodule harboring WPTC with initial presentation of lymph nodal metastases. It is important to identify this peculiar variant of PTC as 5 to 10% of them undergo dedifferentiation and 30% have the lymph nodal metastases and extra thyroidal extension.

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.

(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.(99m)Tc-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.

Myocardial perfusion SPECT in a case of retropulmonary looping of left coronary artery in a baby after arterial switch surgery.

Pediatric myocardial perfusion imaging (MPI) is not a routine investigation in an Indian setting due to under referrals and logistic problems. However, MPI is a frequently performed and established modality of investigation in adults for the identification of myocardial ischemia and viability. We report myocardial perfusion scintigraphy in a case of retropulmonary looping of left coronary artery in a baby after arterial switch surgery. Adenosine stress MPI revealed a large infarct involving anterior segment with moderate reversible ischemia of the lateral left ventricular segment. Coronary angiogram later confirmed left main coronary artery ostial occlusion with retrograde collateral supply from dilated right coronary artery.

Parathyroid scintigraphy, histopathology correlation in patients with tropical pancreatitis and coexisting primary hyperparathyroidism.

PURPOSE: Tropical pancreatitis (TP) is a juvenile, non-alcoholic type of chronic pancreatitis and is highly prevalent in Kerala, India. Increasing prevalence of TP and its varied manifestations prompted us to undertake this retrospective analysis. We attempted to study the incidence of TP in patients with primary hyperparathyroidism (PHPT) and correlate with calcium levels, scintigraphy and histopathology findings. MATERIALS AND METHODS: Records of 44 hypercalcemic patients with raised parathormone (PTH) were analyzed. Clinical, biochemical and imaging findings were noted to look for diabetes mellitus and pancreatitis. All patients underwent dual phase (99m) Technetium methoxy isobutyl isonitrile parathyroid scintigraphy in our department between January 2007 and 2010. Gamma probe assisted minimally invasive parathyroidectomy was performed. Histopathological correlation was obtained in all patients. RESULTS: Our study shows 18% (8/44 patients) incidence of TP in patients with PHPT (compared to 7% reported in 1970's) in Kerala. Results show involvement of middle aged, non-alcoholic males. No direct association between severity of diabetes, pancreatitis and PHPT was noted in our series. Parathyroid adenoma was the most common underlying pathology. All TP patients' clinical outcome improved post parathyroidectomy. TP patients with PHPT demonstrated adenomas, mainly composed of oxyphilic cells. Non pancreatitis group interestingly showed a varied picture of adenoma, hyperplasia with predominance of chief cells histologically. CONCLUSION: There is a 2.6 fold increase in the incidence of TP (18%) in patients with PHPT. Hypercalcemia may be the causative factor leading to TP in PHPT patients in our limited series. The data suggests a causal association between pancreatitis and PHPT. Patients presenting with either one or a combination of hypercalcemia, pancreatic dysfunction or raised PTH need to be thoroughly evaluated as their management is interlinked.

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.