Pharmacopeia is the national collection of quality standards of pharmaceutical products. It is an important instrument for drug safety. The inclusion of radiopharmaceuticals (RPs) in the Indian Pharmacopeia is a step-in right direction as the adaptation of provision of pharmacopeia will reduce the unwanted adverse effects and ensure the effectiveness of RPs.

Background: Fluorine-18-fluorodeoxyglucose (¹⁸F-FDG)-positron emission tomography/computed tomography (PET/CT) is emerging as a useful imaging modality in suspected large-vessel vasculitis (LVV), owing to its ability to accumulate at the sites of inflammation within the arterial walls. However, there remains scope for standardization of reporting criteria to ensure reproducibility. Recently, a semiquantitative scoring system called “total vascular score” (TVS) has been suggested as a method to standardize and harmonize FDG PET/CT evaluation in LVV patients. The purpose of this study was to assess the clinical utility of the proposed semiquantitative grading scale in LVV patients. Materials and Methods: Patients presenting with clinical symptoms of vasculitis, who had undergone a baseline FDG-PET/CT were evaluated.¹⁸F-FDG uptake in the major vessels was quantified with standardized uptake values (SUVs_max) using four-point scale by three independent nuclear physicians. TVS was calculated based on the calculation of the vascular uptake values with respect to mediastinal blood pool and liver uptake and the number of vessels involved. Results: A total of 106 PET-positive patients (74 males and 32 females) were evaluated. The most frequently involved vessels were thoracic aorta >abdominal aorta >subclavian arteries with mean SUV_maxvalues of 4.05, 3.12, and 2.70, respectively. Mean TVS was 13.18 ± 3.4 (range 03–19) among 276 involved vessels. TVS showed significant positive correlation with erythrocyte sedimentation rate (r = 0.82; P < 0.005). 18 patients showed periarticular FDG uptake, with shoulder joint being the most commonly involved joint. Conclusion: The simplified visual and semiquantitative grading scale for interpretation and reporting classification provides better objectivity in diagnosis, communication with referring clinicians, and planning in patients of LVV.

Introduction: In the present time, iodinated contrast agents are increasingly being used in the computed tomography (CT) component of positron-emission tomography (PET) study with the assumption that contrast-enhanced CT (CECT) will provide better diagnostic yield, although the utility of this procedure is still being debated. The aim of the study was to evaluate the effect of contrast CT on the diagnostic yield of PET-CT scan in patients with head-and-neck malignancies. Materials and Methods: In a prospective study, 204 patients (140 males and 64 females) of head-and-neck malignancies underwent contrast-enhanced and nonenhanced fluorodeoxyglucose (FDG)-PET-CT for various clinical indications following informed consent. After a plain CT scan, CECT was done using iodinated contrast iopromide-370 at a dose of 1 ml/kg intravenously. After CECT acquisition, FDG-PET acquisition was done and images were reconstructed to obtain whole-body PET/CT and PET-CECT images. Results: Both the modalities could detect similar number of primary lesions (n = 127), lymph nodal lesions (n = 118), and metastatic involvement (n = 55) with no significant difference between SUVmax. However, conspicuity of primary tumors and lymph nodal architecture was significantly better delineated with CECT, leading to better interpreter confidence. Conclusion: CECT data as part of the combined PET-CT examination provide precise anatomic localization and delineation of the primary tumor in comparison to nonenhanced PET-CT. However, no significant diagnostic changes are noted in the nodal and metastatic staging.

Purpose of the Study: Radioiodine (¹³¹I) therapy is approved and well-accepted modality for the treatment of hyperthyroidism. The dosage of¹³¹I for successful treatment is based on many factors; however, an objective tool to determine the dose was missing. In a retrospective study, we found that high¹³¹I uptake values required more dose to achieve desirable results contrary to the belief. Materials and Methods: Clinically and scintigraphically proven Graves' disease patients with high¹³¹I uptake (>50%) were accrued for this study and block randomized into low-dose (Group I) and high-dose (Group II) groups. Low activity (5 mCi) was administered in Group I and higher activity (10 mCi) in Group II. The patients were followed up after 3 months with thyroid function tests to determine the outcome. Results: A total of 344 patients were analyzed at the end of 3 months, with 174 in low-dose group and 170 in high-dose group. Euthyroidism/hypothyroidism was achieved in significantly higher number of patients as compared to the low-dose group. Conclusion: The higher dose of¹³¹I is required to achieve euthyroidism/hypothyroidism in patients with high¹³¹I uptake.

Introduction: Focal areas of high radiotracer uptake in a bone-scan image can result in dynamic range of the intensity value to exceed the dynamic range of the display, requiring multiple interactive contrast adjustments. This unnecessary burden on time of physician can be avoided using power law equation to brighten up the low-intensity areas in image. However, despite the widespread availability of this technique in commercial systems, for this clinical setting, the gamma-value needs to be standardized. Materials and Methods: Sixty dark bone scan images were selected. Ten randomly selected images from this set were evaluated qualitatively and quantitatively (perception-based image quality evaluator, absolute mean brightness error, structural similarity, and peak signal to noise ratio) to select a range of gamma values (from 0.1 to 0.9, increment of 0.1), where the results were acceptable. This range of gamma was then applied to rest of the 50 images to find the best value. Images were evaluated by two experienced nuclear medicine physicians. Although not ideal, but for the purpose of simplicity, we tried reaching a single best value. For this, the physicians were asked to reach consensus on the acceptable images. Results: In the first part of the study, after evaluation of 100 images (1 original and 9 processed images with 0.1–0.9 gammas), range of gamma values from 0.3 to 0.8 was found to be optimum. This range was then applied to rest of the 50 images. Evaluation of resultant 350 images (1 original and 6 processed for each input image) further narrowed this range to 0.4–0.7 (0.3 gamma selected only twice by one physician). The kappa for acceptable images was moderate at 0.482 (P <0.001). The single gamma value of 0.6 resulted in 72% of the images to be acceptable. Conclusion: Use of power law equation to brighten up the low intensity areas of dark bone scan images, without loss of clinically significant details, is feasible with single gamma value of 0.6 and range of 0.4–0.7 giving best results.

Background: Radiation absorbed dose to the red bone marrow, in the therapy of differentiated thyroid carcinoma (DTC) with 131I (radioiodine), cannot be measured directly. The absorbed dose to the blood seems to be a good first- order approximation of the radiation absorbed dose to the hematopoietic system and a better means to quantify exposure from therapy than the total amount of activity administered. Objective: The aim of this research was to determine the radiation absorbed dose to the blood, for patients suffering from differentiated thyroid cancer. Materials and Methods: Twenty seven patients, 22 women and 5 men, suffering from DTC were enrolled in this study. We applied four formulas and we compared between the estimated values of absorbed dose that were obtained by three formulas and those that obtained by fourth (standard one). Results: All the values of absorbed dose that obtained by one of the techniques were regularly highly estimated, even though they have an excellent correlation (99%) with the standard value. Conclusions: Highly overestimated or highly underestimated results that can be obtained by certain method or technique are not desirable, because they tend to exaggerate, by increasing or decreasing, the radiation protection procedures. Conversion radiation Units: To convert the values of absorbed dose from S.I unit (mGy/MBq) to traditional unit (rad/mCi), we can simply multiply the values that expressed in S.I units by a factor of 3.7, and we don't need to apply complicated formulas, which were applied by other researches.

Introduction: In lutetium-177 (Lu-177) single-photon emission computed tomography (SPECT) imaging, the accuracy of activity quantification is degraded by penetrated and scattered photons. We assessed the scattered photon fractions in order to determine the optimal situation and development of correction method. This study proposes to compare the image quality that can be achieved by three collimators. Materials and Methods: Siemens Medical System Symbia fitted with high-energy (HE), medium-energy (ME), and low-energy high-resolution collimators was simulated using the SIMIND Monte Carlo code simulation code. Counts were collected in three different main-energy window widths (20%, 15%, and 10%) for Lu-177 point source. Primary and scattered point spread functions and also geometric, penetration, scattering were drawn and analyzed. Results: In Lu-177 imaging, a 20% of main-energy window and ME collimator were found to be optimal. HE collimator can be used when the resolution is not required. Conclusion: These results provide the optimal energy window and collimator in Lu-177 SPECT imaging and will help the quantification of Lu-177.

Aim: Our aim of this study was to evaluate the diagnostic accuracy of staging positron emission tomography/computed tomography (PET/CT) in early breast cancers (EBCs) and to assess its impact on disease management. Patients and Methods: We retrospectively reviewed preoperative PET/CT scans of patients from January 2015 to December 2018 with Stage I/II, clinically T1–T2 N0–N1 breast cancers. The diagnostic performance of PET/CT for nodal (N) and distant metastases (M), its correlation with patient/tumor-specific factors, and its impact on disease management were analyzed using histopathology/clinical follow-up as standards of reference. Results: Of 158 patients evaluated, 14% of patients were Stage I (T1N0), 60% were Stage IIA (T1N1, T2N0), and 26% were Stage IIB (T2N1). Sensitivity, specificity, and the diagnostic accuracy of PET/CT for axillary staging were 76%, 97%, and 84% and for distant metastasis evaluation were 100%, 98%, and 99%, respectively. The diagnostic accuracy of PET/CT for axillary staging was lower for low-grade, T1 tumors, postmenopausal group, and luminal A pathological subtype (77%, 84%, 81%, and 73%, respectively) compared to high-grade, T2 tumors, premenopausal group, and nonluminal A subtype (88%, 88%, 94%, and 87%, respectively). Distant metastases were detected on PET/CT in overall 16% (n = 25) of the patients (9% in Stage IIA and 27% in Stage IIB). PET/CT also incidentally identified clinically occult internal mammary nodes in 5% (n = 8) and organ-confined synchronous second malignancies in 5% (n = 8) of the patients. Conclusion: Preoperative PET/CT should be considered in all EBCs> 2 cm as it upstages the disease and alters management in about 24% of these patients. Given its high specificity for axillary staging PET/CT, patients with PET-positive axilla can be subjected to axillary dissection and those with PET-negative axilla to sentinel lymph node biopsy. The yield and diagnostic accuracy of PET/CT is less for low-grade tumors <2 cm and with luminal A subtype.

Type 2 multiple endocrine neoplasia (MEN2A) is a variant of hereditary medullary thyroid carcinoma (MTC). MEN2A is characterized by the presence of the following: MTC, hyperparathyroidism, and pheochromocytoma (PHEO). The pathogenesis includes RET proto-oncogene mutation; the most frequently observed mutation is in exon 11 codon 634. We report pedigree of a large Indian family involving three generations including 21 members with MEN2A, in whom RET mutation status was determined. We then analyzed their clinical follow-up details, with a median duration of follow-up of 60 months (range: 9–276 months). Calcitonin (Ctn) levels were routinely checked during the follow-up. The index case was found to carry p.C634R mutation involving exon 11 of the RET gene. RET mutation was positive in 12 members in the family (12/21, i.e., 57%), was negative in 7 patients, and was not tested in 2 patients, as they were not available for the genetic test. Thirteen were clinically affected with MTC and 10 members had PHEO. At the last follow-up, the median Ctn level was 14.3 pg/mL (range: 2–12655 pg/mL). Four patients developed lymph nodal recurrence during follow-up, for which they underwent re-operations with median duration to recurrence being 48 months (range: 9–156 months). We highlight in this article that early diagnosis, adequate surgery, and appropriate genetic counseling with genetic screening are essential to improve the outcome of persons with MTC. Every case of MTC should be seen as familial or index case of hereditary MTC unless otherwise RET mutation excludes it.

Autoimmune limbic encephalitis (AE) is an autoimmune-mediated inflammation typically affecting the medial temporal lobes and other limbic structures (cingulate gyrus, orbital cortex, and hypothalamus). It can be associated with underlying malignancy as a paraneoplastic syndrome. Nonparaneoplastic AE is a difficult disease to diagnose and often requires the collaboration of multiple modalities for effective diagnosis and treatment. We describe an interesting case of contactin-associated protein-like 2 antibody-associated nonparaneoplastic limbic encephalitis on fluorine-18 fluorodeoxyglucose positron emission tomography and magnetic resonance imaging.

Prostate-specific membrane antigen (PSMA) is a glycosylated type-II transmembrane protein highly expressed in certain tumor cells. It has emerged as a novel radiotracer for evaluation of prostate cancer. Increased PSMA expression in isolated liver lesion is a diagnostic challenge. Solitary liver metastasis from prostate cancer is rare. On the other hand, PSMA avid primary hepatocellular carcinoma (HCC) has been reported in literature. We report a case of PSMA expressing atypical HCC with normal alphafeto protein (AFP) and raised prostate specific antigen (PSA).

We present a case of a 79-year-old man with prostate cancer with biochemical recurrence after radical prostatectomy and hormonal therapy.⁶⁸Ga-prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) was performed to look for recurrent disease, and a solitary metastasis to the left testicle was detected. This case report highlights the importance of⁶⁸Ga-PSMA PET/CT in detecting unusual metastatic lesions from prostate cancer in patients with biochemical recurrence.

We report here initial staging and follow-up imaging findings of a case of primary retroperitoneal transitional cell carcinoma, one of the rarest nonurological tumors of the retroperitoneal space, to highlight the importance of¹⁸F-fludeoxyglucose positron emission tomography/computed tomography in this infrequently encountered pathology.

Sister Mary Joseph's nodule (SMJN) refers to umbilical metastatic lesions and indicates widespread intra-abdominal malignancy. The most common primary sites are gastrointestinal and genital tract. Benign umbilical nodules are called pseudo-SMJN (PSMJN) and have been also reported in nonmalignant lesions such as endometriosis, fibroma, papillomas, myxoma, keloid, omphalith, nevi, foreign-body granulomas, and epidermoid cysts. We report a case with PSMJN as an extremely rare manifestation of intra-abdominal tuberculosis.

Scar site recurrence is a rare phenomenon and is even rarer in squamous cell carcinoma. We present a special case of isolated scar site recurrence in a patient with carcinoma cervix detected on fluorodeoxyglucose positron emission tomography-computed tomography, 2 years after hysterectomy and radiotherapy.

Richter's transformation (RT) is a rare complication of chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) with unfavorable prognosis. The clinical and laboratory findings of RT are nonspecific and requires histopathological confirmation for the diagnosis.¹⁸F-labeled fluoro-2-deoxyglucose positron-emission tomography/computed tomography (¹⁸F-FDG PET/CT) has shown higher diagnostic values for the detection of transformation of CLL/SLL to aggressive lymphoma. We present a case of CLL in remission for 6 years presenting with clinical features suggestive of RT.¹⁸F-FDG PET/CT done in our case showed liver and lung involvement with no lymphadenopathy, which is an unusual presentation of RT.

Posterior reversible encephalopathy syndrome (PRES) is characterized clinically by headache, seizures, vomiting, altered mental status, and blurred vision. However, with overlapping and atypical clinical symptoms, PRES becomes a diagnostic challenge. We describe the imaging findings of PRES in magnetic resonance imaging and¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography in an 11-year-old child who presented with features of hypertensive encephalopathy.

Treatment for tumor thrombus in multiple blood vessels can be a challenge for management and thus FDG PET CT is a potent tool in evaluation of such cases in differentiating between bland and tumor thrombus and commenting on the extent of the involvement.

Radioactive iodine ablation has long-lasting effects on remnant thyroid tissue and metastasis from well-differentiated thyroid cancer. After radioactive iodine treatment, scintigraphy is a major imaging modality for detecting metastasis and assessing its management. False-positive iodine uptake can be found in many aberrant locations, including cysts. This report describes iodine uptake in retroperitoneal cysts in a 62-year-old woman diagnosed with papillary thyroid carcinoma. Radioiodine scintigraphy was performed after iodine therapy. Abnormally increased iodine activity was noted in the left upper abdomen. Additional radiologic examinations helped in preventing invasive biopsy.

Rectal adenocarcinoma metastasizes most commonly to the lungs and liver. Metastasis to heart, although described in literature, is a very rare phenomenon. We describe the¹⁸F-fluorodeoxyglucose positron emission tomography–computed tomography (¹⁸F-FDG PET-CT) findings of a 45-year-old male who was a biopsy-proven case of adenocarcinoma rectum. Apart from metastatic disease involving liver, lungs, bone marrow, and lymph nodes, metastasis to right ventricle was also seen on PET-CT scan.

Primary lung lymphoma is one of the rarest forms of lymphoma and pulmonary space-occupying lesions. This case report represents the F-18 fluorodeoxyglucose positron emission tomography/computed tomography images of the most severe form of the primary pulmonary lymphoma reported in the literature.

Triple-negative breast cancer (TNBC) accounts for 20%–25% of breast cancer cases. Around 10%–15% of patients with breast cancer present with upfront metastasis. Lymph node, bone, and liver are common sites of metastasis in hormone-positive breast cancer while brain, lungs, and liver in TNBC. Although visceral metastasis is common in TNBC, metastasis to stomach is unusual. Morphological similarity of primary gastric carcinoma and lobular invasive breast carcinoma often leads to misdiagnosis. Meticulous review of histopathology and immunohistochemistry is essential for diagnosis. We present a case of carcinoma breast with unusual gastric nodular metastasis detected on¹⁸F-fluorodeoxyglucose positron emission tomography–computed tomography.

Situs ambiguous or heterotaxy syndrome is defined as the abnormal arrangement of organs and vessels within the body. Herein, we present an 8-year-old girl with growing right-sided suprarenal masses mimicking adrenal tumors. Technetium-99-m-radiolabeled red blood cells' planar images were inconclusive for the diagnosis of splenic tissue in the right side. Single-photon emission computed tomography/computed tomography imaging clearly identified right-sided functioning spleens and confirmed the diagnosis of situs ambiguous with polysplenia.

Adrenocortical carcinoma (ACC) is a rare and highly aggressive malignant neoplasm which can produce intravascular extension into the inferior vena cava (IVC) and can rarely extend into the right atrium. We describe the ¹⁸F Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography findings of a 57-year-old man diagnosed with ACC with IVC thrombus extending up to the right atrium.