Suhas Singla

Renal and Hematological Toxicity in Patients of Neuroendocrine Tumors After Peptide Receptor Radionuclide Therapy with 177Lu-DOTATATE

PURPOSE Peptide receptor radionuclide therapy (PRRT) with (177)Lu-DOTATATE is an efficient new treatment option in patients with neuroendocrine tumors (NETs), with low risk of toxicity. Since the kidneys are critical organs in PRRT, renal function is known to deteriorate after PRRT. We analyzed the decline in glomerular filtration rate (GFR), increase in serum creatinine (SCr), and changes in hemogram parameters between pretherapy and at least 6 months after last cycle post-therapy with (177)Lu-DOTATATE. METHODS Forty-seven patients with NETs received 2-6 cycles of (177)Lu-DOTATATE, leading to a total renal radiation absorbed dose of 12.5 ± 4.1 Gy. All renal dose estimates were calculated with the help of OLINDA/EXM software. All patients were infused with renal protective amino acids during the administration of the radiopharmaceuticals. In this study, we used GFR that was estimated by in vitro method using (99m)Tc-DTPA and SCr to assess renal toxicity. RESULTS The patients were administered a mean cumulative activity of 20.1 ± 6.74 GBq of (177)Lu-DOTATATE. There was a significant decrease in GFR from 86.8 ± 15.4 mL/1.73 m(2)/min to 66.1 ± 14.5 mL/1.73 m(2)/min and rise in SCr from 0.86 ± 0.19 mg/dL to 1.0 ± 0.2 mg/dL with treatment. Patients with WHO grade 1 renal toxicity (group 2) at baseline demonstrated an increase in SCr that was significantly higher compared with patients with normal baseline creatinine levels (group 1). No serious acute or remote adverse events were recorded. Self-limiting serious hematological toxicity was observed in 2 patients. CONCLUSIONS The decline in renal function as measured by in vitro GFR tends to be of greater magnitude in patients with baseline impaired renal function than in patients with preserved renal function after PRRT. Hematologic toxicity is relatively rare and can be managed conservatively when encountered.

Dosimetric analyses of kidneys, liver, spleen, pituitary gland, and neuroendocrine tumors of patients treated with 177Lu-DOTATATE.

Objectives The aim of this work was to calculate the radiation absorbed dose to kidneys, liver, spleen, pituitary gland, and neuroendocrine tumors (NETs) of patients treated with 177Lu-DOTATATE. Methods We enrolled 61 patients (male/female patients, 40/21) with mean age of 48.1 ± 15.3 years affected by different types of NETs diagnosed with 68Ga-DOTANOC PET-CT and biochemical markers. For radiation protection of kidneys, amino acid mixture (lysine and arginine) was coinfused; 3.7 to 7.4 GBq (100–200 mCi) of 177Lu-DOTATATE was infused to each patient over 30 minutes. Each patient underwent a series of 9 whole-body scans at 30 minutes (prevoid) and 4, 8, 12, 24, 48, 96, 144, and 168 h. The organs included in dosimetric calculation were kidney, liver, spleen, pituitary gland, and NETs. All dosimetric calculations were done using the OLINDA/EXM 1.0 software. Results Physiological uptake of 177Lu-DOTATATE was seen in all patients in kidneys, liver, spleen, and pituitary gland. Radiation absorbed doses were calculated: 0.57 ± 0.09 mGy/MBq for kidneys, 0.27 ± 0.05 mGy/MBq for liver, 1.17 ± 0.14 mGy/MBq for spleen, 0.058 ± 0.011 mGy/MBq for pituitary gland, and 3.41 ± 0.68 mGy/MBq for NETs. Conclusions The maximum cumulative activity of 177Lu-DOTATATE that can be safely administered to a patient within permissible renal threshold in our study was found to be 40 GBq (1100 mCi). However, there are considerable interpatient differences in absorbed doses of all organs requiring individualized dosimetry for optimizing tumor dose.

Prospective Comparison of 99mTc-GH SPECT/CT and 18F-FDOPA PET/CT for Detection of Recurrent Glioma: A Pilot Study

Objective This study aimed to evaluate and compare the role of 99mTc-GH SPECT/CT and 18F-FDOPA PET/CT for diagnosing recurrence in patients with glioma. Methods Thirty patients with histopathologically proven glioma (glioblastoma multiforme, 14; grade III, 6; grade II, 8; and grade I, 2), who presented with clinical and/or imaging suspicion of recurrence were prospectively evaluated. They were primarily treated with surgery and radiotherapy with or without chemotherapy. Each patient underwent 99mTc-GH SPECT/CT and 18F-FDOPA PET/CT within a span of 15 days. Images were evaluated qualitatively and quantitatively by 2 experienced nuclear medicine physicians in consensus. Histopathology and/or clinical/imaging follow-up were used as reference standard. Results Based on reference standard, 22 patients were positive and 8 were negative for recurrence. 99mTc-GH SPECT/CT was positive for recurrence in 22 and negative in 8 patients. 18F-FDOPA PET/CT scan was positive for recurrence in 23 and negative in 7 patients. Sensitivity, specificity, and accuracy were 86.4%, 62.5%, and 80% for 99mTc-GH SPECT/CT and 100%, 87.5%, and 96% for 18F-FDOPA PET/CT, respectively. No significant difference was found between 99mTc-GH SPECT/CT and 18F-FDOPA PET/CT overall (P = 1.00), as well as for low-grade (P = 0.250) or high-grade tumors (P = 0.50). Significant correlation was noted between tumor-brain of 99mTc-GH with both tumor-striatum (r = 0.371; P = 0.044) and tumor-cerebellum ratio of 18F-FDOPA (r = 0.369; P = 0.045). Conclusions For detection of recurrence in glioma patients, 99mTc-GH SPECT/CT is not inferior to 18F-FDOPA PET/CT and can be used as a low-cost alternative.

Effect of duration of fasting and diet on the myocardial uptake of F-18-2-fluoro-2-deoxyglucose (F-18 FDG) at rest

Context: Patterns of myocardial fluoro-2-deoxyglucose (FDG) uptake with respect to duration of fasting and dietary modifications. Aim: We observed the effect of duration of fasting and diet on the myocardial uptake pattern of F-18 FDG in patients routinely referred for oncological evaluation and no previous history of Coronary Artery Disease (CAD). Settings and Design: Prospective study. Subjects and Methods: A total of 153 patients (M: 81, F: 72; mean age: 47 ± 15 years; mean blood glucose level (mBG) 105 ± 23 mg/dl) were randomly divided in three groups. Group A: 4-6 h fasting; Group B: Overnight fasting (12–14 h); Group C: Low carbohydrate and fat rich diet for 2 days coupled with overnight fasting prior to the positron emission tomography (PET) scan. FDG uptake was classified as following: 1) homogeneous uptake, 2) heterogeneous uptake, and 3) ‘no uptake’ in the left ventricular (LV) myocardium. FDG PET study was performed as standard protocol for oncological conditions. Statistical Analysis Used: Descriptive statistics, Chi-square test or Fishers exact test, and Spearmans rank correlation tests were applied. Results: We observed the ‘no uptake’ pattern in five (10%), 28 (55%), and 39 (77%), ‘heterogeneous’ pattern in 20 (39%), 14 (28%), and seven (14%), and ‘homogeneous’ pattern in 26 (51%), nine (18%), and five (10%) patients in Group A, B, and C, respectively. There was statistically significant difference of myocardial uptake pattern between group A and B (P < 0.0001), between group A and C (P < 0.0001), and between Group B and C (P = 0.023). The mBG was 102, 105, and 111 mg/dl in ‘no uptake’, heterogeneous, and homogeneous uptake pattern, respectively, (P = 0.103). Also, within each group the mBG was not related to the uptake pattern. Conclusion: Both restricted diet and duration of fasting play an important role in determining the pattern and suppression of myocardial F-18 FDG uptake. Overnight fasting and restricted diet together suppress myocardial FDG uptake more than overnight fasting alone, which suppresses uptake more than 4-h fasting.

A Rare Case of Non–small Cell Lung Cancer Metastasizing to the Pituitary Gland: Detection With 18f-fdg Pet-ct

Metastases to the pituitary gland are rare. We here present a case of a 52-year-old man with non-small cell lung cancer where pituitary metastasis was detected on staging F-FDG PET-CT, characterized with MRI and confirmed at histopathology. By demonstrating such rare site of metastasis, F-FDG PET-CT can have significant impact on management of cancer patients.

Diagnosis of Men-I Syndrome on 68Ga-DOTANOC PET-CT and Role of Peptide Receptor Radionuclide Therapy With 177Lu-DOTATATE

Abstract MEN-I is a rare genetic disorder classically characterized by a predisposition to tumors of the parathyroid glands, anterior pituitary gland, and pancreatic islet cells. We present a case of MEN-I syndrome diagnosed using predominantly nuclear medicine imaging followed by radionuclide therapy, thus emphasizing the role of nuclear imaging in diagnosing and treating MEN-I.

68Ga DOTANOC PET/CT for accurate delineation of disease extent in a case of sinonasal small cell neuroendocrine carcinoma.

Neuroendocrine tumors constitute a heterogeneous group of neoplasms arising from the cells of the neural crest. We present a rare case of primary sinonasal neuroendocrine carcinoma in a 61-year-old male patient where somatostatin receptor PET/CT with 68Ga-DOTANOC correctly delineated the extent of primary tumor as compared to contrast-enhanced CT, thereby changing patient management.

Comparison of software programs for the assessment of left ventricular ejection fraction using 99mTc-tetrofosmin-gated SPECT/CT: correlation with equilibrium radionuclide ventriculography in the Indian population.

ObjectiveThe goal of this study was to compare Emory Cardiac Toolbox (ECTb), quantitative gated SPECT (QGS), four-dimensional single photon emission computed tomography (4D-MSPECT) and Myometrix cardiac software programs for the assessment of left ventricular ejection fraction (LVEF) using 99mTc-tetrofosmin-gated SPECT/CT [myocardial perfusion SPECT (MPS)] and correlate them with the LVEF values derived from equilibrium radionuclide ventriculography (ERNV) in patients with known/suspected coronary artery disease (CAD). Materials and methodsA total of 109 patients (80 men, 29 women) were recruited into the study. Fifty-five patients had known CAD and 54 were referred with suspicion of CAD. All the patients underwent ERNV and MPS as per the standard protocol. ERNV was processed using the vendor-provided ‘EF analysis’ and gated MPS was processed using individual software programs. ResultsThe mean LVEF on ERNV was 47.9±15.5%. The mean LVEF values for ECTb, QGS, 4D-MSPECT and Myometrix were 51.5±19.6, 51.0±18.6, 57.1±19.3 and 49.7±19%, respectively. On correlation analysis, a very strong positive correlation was observed between LVEF values derived by ERNV and those derived by the MPS software programs: ECTb (r=0.842, P<0.0001), QGS (r=0.835, P<0.0001), 4D-MSPECT (r=0.830, P<0.0001) and Myometrix (r=0.875, P<0.0001). Significant correlation was also seen for LVEFs among the four software programs. Normal cutoff values for ejection fraction on ECTb, QGS, 4D-MSPECT and Myometrix were 56, 52, 54 and 51%, respectively, using a 50% or more cutoff value on ERNV. ConclusionA strong correlation was observed among ECTb, QGS, 4D-MSPECT and Myometrix software programs when compared with ERNV and also between them for assessment of LVEF. However, there are subtle differences in the objective values of ejection fraction generated by individual software, which must be taken into account for clinical studies.

68ga Dotanoc Pet/ct in Primary Neuroendocrine Tumor of the Breast

Primary neuroendocrine tumor (NET) of the breast is very rare. We present a case of a pathologically confirmed, primary breast NET in a 49-year-old woman with 68Ga DOTANOC PET/CT imaging findings. 68Ga DOTANOC PET/CT revealed somatostatin receptors expressing active lesions in primary right breast NET with metastases to multiple bilateral axillary and right cervical lymph nodes, bilateral lungs, and multiple skeletal sites.

68Ga-DOTA-NOC PET and peptide receptor radionuclide therapy in management of bilateral ovarian metastases from gastrointestinal carcinoid.

The management of neuroendocrine tumours is challenging when curative surgery is ruled out because of distant metastases. We report a case of gastrointestinal carcinoid with bilateral ovarian metastases in a 50-year-old female who received octreotide therapy followed by peptide receptor radionuclide therapy and surgery thereafter. Somatostatin receptor expression on neuroendocrine tumours has implications in diagnosis and therapy. (68)Ga-DOTA-NOC PET is a recent advancement in the field of somatostatin receptor imaging. The lesions which demonstrate tracer uptake on positron emission tomographic studies can be further planned for treatment with octreotide and (177)Lu-DOTA-TATE. The case in discussion responded well to non-invasive treatment options before proceeding to definitive surgical management.