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.

Are Semiquantitative Methods Superior to Deauville Scoring in the Monitoring Therapy Response for Pediatric Hodgkin Lymphoma?

Tailoring treatment in patients with Hodgkin lymphoma (HL) is paramount to maximize outcomes while avoiding unnecessary toxicity. We aimed to compare the performance of SUVmax reduction (ΔSUVmax%) and the PET ratio (rPET) versus the Deauville score (DS) for assessing the chemotherapy response in pediatric HL patients undergoing 18F-FDG PET-CT. Fifty-two patients with biopsy-proven HL (aged 8-16 years) were enrolled at baseline, interim (after the second or third chemotherapy round) and post-therapy (on completion of first-line chemotherapy). Interim and post-therapy DS, ΔSUVmax% and rPET were compared as response predictors. Patients were classified as responders or non-responders based on a 24-month clinical follow-up. Interim DS showed a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of 100%, 80.4%, 100%, 40% and 82.7%, respectively, in predicting the therapy response. Post-therapy DS showed a sensitivity, specificity, PPV, NPV and accuracy of 66.7%, 97.8%, 95.7%, 80% and 94.2%, repsectively. Interim ΔSUVmax% showed a sensitivity, specificity, PPV, NPV and accuracy of 83.3%, 82.6%, 97.4%, 38.5% and 82.7%, respectively, with a 56.3% cutoff. Post-therapy ΔSUVmax% showed a sensitivity, specificity, PPV, NPV and accuracy of 83.3%, 84.8%, 97.5%, 41.7% and 84.6%, respectively, with a 76.8% cutoff. Compared to ΔSUVmax%, DS showed a significantly higher sensitivity, specificity (p < 0.05) and NPV (p < 0.01). The sensitivity, specificity, PPV, NPV and accuracy of rPET in predicting the therapy response at 24 months were 76.1%, 100%, 100%, 35.3% and 78.8%, respectively, with a cut-off of 1.31. DS and rPET showed comparable predictive performance (p > 0.58). In conclusion, DS is an easier method with better performance than ΔSUVmax% and rPET in predicting the chemotherapy response in pediatric HL patients.

Extrahepatic metastases of hepatocellular carcinoma on 18F FDG PET CT.

BACKGROUND: To determine locations, relative frequencies, imaging features, and pattern of distribution of extrahepatic metastasis from hepatocellular carcinoma (HCC) on 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG) PET CT. METHODS: FDG PET CT scans of 224 consecutive patients of HCC acquired between 2010 and 2018 were reviewed. Fifty-six patients detected with extrahepatic metastasis on FDG PET CT were retrospectively analyzed. Findings were correlated with prior/follow-up imaging studies, clinical findings, FNAC, or biopsy findings whenever available. Descriptive analysis of location, relative frequencies, imaging features, and pattern of distribution of extrahepatic metastasis was done. RESULTS: Commonest were metastatic pulmonary nodules (55.3% patients), most of them being well-defined solid lesions (53.5%) with bilateral involvement in 44.6% patients and lower lobes of lungs along with other lobes being more frequently involved (41.0% patients). While in 7.14% patients lung nodules were FDG avid, 23.2% patients had both FDG avid and non-avid pulmonary nodules. Second most common were regional metastatic lymph nodes in 44.65% of patients seen at aortocaval (25%), paraaortic (23.21%), portocaval (21.4%), and left gastric nodal (17.8% of patients) stations. Twenty-five percent of patients had FDG avid lymph nodes and 5.36% patients had both FDG avid and FDG non-avid lymph nodes. Distant metastatic lymph nodes were third most common in 39.2% of patients seen at paratracheal (2.5%), juxtaphrenic (8.9%), and mesenteric lymphnodal (7.1%) stations. Twenty-five percent of patients had FDG avid lymph nodes while 5.36% patients had both FDG avid and FDG non-avid lymph nodes. Skeletal involvement was seen in 32.1% of patients. Commonest sites are vertebrae (16.7%), pelvis (14.2%), and ribs (10.7% patients). Six out of 7 patients had unilateral adrenal gland involvement. Bilateral adrenal gland involvement was seen in 1 patient. FDG non-avid peritoneal/omental metastases was seen in 2 patients. Brain, spleen, and muscle metastatic lesions were seen in 1 patient each out of 56 patients (1.79%). CONCLUSIONS: Lungs, regional and distant lymph nodes and skeleton are the most frequently involved sites of extrahepatic metastatic hepatocellular carcinoma. Adrenal glands, muscles, brain and peritoneum are also involved but to a lesser extent.

In the evaluation of patients with skull base osteomyelitis, does 18F-FDG PET CT have a role?

PURPOSE: To evaluate the diagnostic performance of regional fluorine-18 fluorodeoxyglucose (F-FDG) positron emission tomography-computed tomography (PET-CT) in patients with skull base osteomyelitis (SBO) and to compare with magnetic resonance imaging (MRI) whenever available. MATERIALS AND METHODS: A total of 77 patients (male:female = 56:21; mean age 66.4 ± 9.4 years) with clinically suspected SBO, who underwent regional F-FDG PET-CT were included in this retrospective study. F-FDG PET-CT images were analyzed for presence, localization and intensity of FDG uptake. Diagnostic performance of F-FDG PET-CT was analyzed based on histopathology, culture, and clinical/imaging follow-up. The agreement analysis between F-FDG PET-CT and MRI findings was performed in 56 patients. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of F-FDG PET-CT for diagnosing SBO were 96.7, 93.3, 98.3, 87.5, and 96.1%, respectively. The average SUVmax of the lesions was 5.9 ± 3.5. The SUVmax of the fungal lesions was lower than that of bacterial lesions with P-value of <0.001. On comparing variables like C-reactive protein, erythrocyte sedimentation rate, and SUVmax for prediction of recurrence/progression, by plotting an ROC curve, the SUVmax was found to be an independent prognostic marker. 56 out of 77 patients had undergone both F-FDG PET-CT and MRI. The agreement analysis between the modalities showed almost perfect agreement for delineation of soft tissue and bony involvement with κ values of 0.82 and 0.81, respectively. CONCLUSION: F-FDG PET-CT is a sensitive tool in evaluation of patients with SBO. It shows a very good agreement with the MRI. It plays a critical role in treatment response evaluation.

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.

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.

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.

18-F flourodeoxy glucose positron emission tomography-computed tomography imaging: A viable alternative to three phase bone scan in evaluating diabetic foot complications?

BACKGROUND: This paper is based on the initial findings from a prospective ongoing study to evaluate the efficacy of flourodeoxy glucose positron emission tomography-computed tomography (FDG-PET CT) in diabetic foot evaluation. OBJECTIVE: The aim was to compare the diagnostic accuracies of three phase bone scan (TPBS) and FDG PET-CT (FDG-PET) in diabetic foot evaluation. METHODS: Seventy-nine patients with complicated diabetic foot (osteomyelitis/cellulitis, Charcot's neuropathy) were prospectively investigated. TPBS (15 mci methylene di phosphonate [MDP] intravenous [IV]), followed by FDG-PET (5 mci IV) within 5 days were performed in all patients. Based on referral indication, patients grouped into Group I, n = 36, (?osteomyelitis/cellulitis) and Group II, n = 43 (?Charcot's neuropathy). Interpretation was based on intensity, extent, pattern of MDP and FDG uptake (standardized uptake value) along with CT correlation. Findings were compared with final diagnostic outcome based on bone/soft tissue culture in Group I and clinical, radiological or scintigraphic followup in Group II. RESULTS: Group I: For diagnosing osteomyelitis, TP: TN: FP: FN were 14:5:2:2 by FDG PET and 13:02:05:03 by TPBS respectively. Sensitivity, specificity, positive predictive value and negative predictive value (NPV) of FDG-PET were 87.5%, 71%, 87.5% and 71% and 81.25%, 28.5%, 72% and 40% for TPBS, respectively. Group II: charcot's: cellulitis: Normal were 22:14:7 by FDG PET and 32:5:6 by TPBS, respectively. CONCLUSION: Flourodeoxy glucose PET-CT has a higher specificity and NPV than TPBS in diagnosing pedal osteomyelitis. TPBS, being highly sensitive is more useful than FDG-PET in detecting Charcot's neuropathy.

Dual Time Point 18F-FDG PET/CT Imaging Identifies Bilateral Renal Tuberculosis in an Immunocompromised Patient with an Unknown Primary Malignancy / 감염과화학요법

18F-FDG PET/CT imaging is an established imaging modality for cancer staging and response assessment. Its role in identifying infective and inflammatory pathologies from malignancy is debated. Dual time - point imaging is a refined technique used to overcome this interpretational dilemma. We present a 59 year old male with an unknown primary malignancy who was referred for a 18F-FDG PET/CT imaging. Images revealed primary lung malignancy with co existing bilateral renal tuberculosis which otherwise would have gone amiss or would have been considered as metastases.

(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.

Current practice and recommendation for presurgical cardiac evaluation in patients undergoing noncardiac surgeries.

The increasing number of patients with coronary artery disease (CAD) undergoing major noncardiac surgery justifies guidelines concerning preoperative cardiac evaluation. This is compounded by increasing chances for a volatile perioperative period if the underlying cardiac problems are left uncorrected prior to major noncardiac surgeries. Preoperative cardiac evaluation requires the clinician to assess the patient's probability to have CAD, severity and stability of CAD, placing these in perspective regarding the likelihood of a perioperative cardiac complication based on the planned surgical procedure. Coronary events like new onset ischemia, infarction, or revascularization, induce a high-risk period of 6 weeks, and an intermediate-risk period of 3 months before performing noncardiac surgery. This delay is unwarranted in cases where surgery is the mainstay of treatment. The objective of this review is to offer a comprehensive algorithm in the preoperative assessment of patients undergoing noncardiac surgery and highlight the importance of myocardial perfusion imaging in risk stratifying these patients.

Multilocular disseminated tarlov cysts: importance of imaging.

With technological advancements and wider availability of multimodality imaging, incidental lesions are frequently identified in patients undergoing various imaging studies. We report here a case of multiloculated disseminated perineural or Tarlov cysts (TCs). The primary aim of our study was to (1) provide a comprehensive review of the clinical, imaging and histopathological features of TCs (2) to draw attention to the fact that multiple lumbo-sacral and dorsal TCs can produce nerve injuries and serious movement disturbances (3) to document the usefulness of the magnetic resonance imaging (MRI) and bone scan in noninvasive diagnosis and guiding management in such cases. These cysts are clearly identified by MR and computerized tomography imaging of the lumbosacral spine. However, there are no reports on the scintigraphic findings of TCs in literature. TCs are typically benign, asymptomatic lesions that can simply be monitored. Until date, no consensus exists about the best surgical strategy to be followed for their management.

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.

Random Synchronous Malignancy in Male Breast: A Case Report / 한국유방암학회지

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.

Multilocular disseminated Tarlov cysts: Importance of imaging and management options.

With technological advancements and wider availability of multimodality imaging, incidental lesions are frequently identified in patients undergoing various imaging studies. We report here a case of multiloculated disseminated perineural or Tarlov cysts (TCs). The primary aim of this case study was to (1) provide a comprehensive review of the clinical, imaging, and histopathological features of TCs (2) to draw attention to the fact that multiple lumbosacral and dorsal TCs can produce nerve injuries and serious movement disturbances, and (3) to document the usefulness of the magnetic resonance imaging and bone scan in non-invasive diagnosis and guiding management in such cases. These cysts are clearly identified by magnetic resonance imaging (MRI) and computerized tomography imaging of the lumbosacral spine. However, there are no reports on the scintigraphic findings of multilocular disseminated TC in literature. TCs are typically benign, asymptomatic lesions that can simply be monitored. To date, no consensus exists about the best surgical strategy to use when indicated.