Indian Journal of Nuclear Medicine最新文献

Background: Another approach to improve the dose conformity is to use charged particles like protons instead of the conventional X- and γ-rays. Protons exhibit a specific depth-dose distribution which allows to achieve a more targeted dose deposition and a significant sparing of healthy tissue behind the tumor. In particular, proton therapy has, therefore, become a routinely prescribed treatment for tumors located close to sensitive structures. Moreover, the track structure and energy transfer of protons is different from those of photons which can provide advantages in terms of biological effectiveness. Furthermore, the application of nanotechnology in radiotherapy also offers interesting approaches to improve the therapeutic index.

Methods: Therefore, in this work, we first introduce the water phantom and simultaneously inject high-energy protons into it through a pencil beam and 50 nm nanoparticles (NPs) with different concentrations and investigate the increase in the absorbed dose. Then, we present a more realistic model of brain tumor and study the increase in the absorbed dose in the activated tumor in two cases with and without the injection of gold, silver, and platinum NPs into the brain phantom. The simulation software used in this article is GEANT4.

Results: As can be seen from this work, the absorbed dose with the injection of NPs at an energy of 150 MeV is, in order, from highest to lowest, related to platinum, gold, silver, and finally water without the injection of NPs, and this is due to the fact that the number of secondary electrons produced by platinum is more than gold, gold is more than silver and silver is more than water (Pt>Au>Ag>W).

Conclusion: This work shows that the optimum energy deposited in the Bragg curve at the end of the brain tumor is 110 MeV.

The patient, a 37-year-old male, initially presented with per rectal bleed. Colonoscopy revealed a circumferential lesion within the lower rectum, along with a few satellite lesions. At that time, we performed a biopsy, but the histopathological examination revealed consistent solitary rectal ulcer syndrome. Subsequent bone scan revealed increased radiotracer uptake at the left 6^th rib, resulting in a "banana-like appearance" and a ground glass appearance on the corresponding single-photon emission computed tomography (SPECT), in keeping with fibrous dysplasia. Given his asymptomatic state, the patient received reassurance and surveillance regarding his benign bone lesion.

Primary aldosteronism (PA) is one of the prevalent causes of secondary hypertension, characterized by the autonomous hypersecretion of aldosterone and concurrent renin inhibition. Clinical and biochemical remission rates for patients with PA achieved through surgery are far higher compared to those achieved through drug treatment; hence, subtyping PA is crucial for identifying patients who will benefit most from surgery. Computed tomography (CT) scan with adrenal protocol and adrenal venous sampling (AVS) is used conventionally for PA subtype classification. CT scans, being structural imaging, cannot provide functional information, while AVS is an invasive, technically challenging method with a limited success rate and a high risk of complications. The C-X-C chemokine receptor type 4 (CXCR4) is overexpressed in aldosterone-producing tissue but is almost negligibly expressed in nonfunctional adenoma. The positron emission tomography tracer 68Ga-pentixafor, a specific ligand for CXCR4, can detect aldosterone-producing adenoma noninvasively, which can guide surgical treatment. The image series below demonstrates the utility and patterns of findings on Ga-68-pentixafor for subtyping PA.

Diffuse large B-cell lymphoma (DLBCL) is a highly aggressive type of non-Hodgkin lymphoma. Accurate evaluation of treatment response is essential for effective management. This case report discusses the potential role of ⁶⁸Ga-Pentixafor positron emission tomography (PET)/computed tomography (CT) in comparison to ¹⁸F-fluorodeoxyglucose PET/CT for assessing treatment response in a patient with DLBCL.

Thyroglossal duct carcinoma is a rare clinical condition, accounting for only 1% of operated cases. It is characterized by ectopic thyroid adenocarcinoma developing within thyroglossal duct cysts (TGDCs). Among these, papillary thyroid carcinoma is the most frequently reported pathological type. The clinical presentation of thyroglossal duct malignancies is often nonspecific, with diagnosis typically confirmed postoperatively via the Sistrunk procedure. Due to the rarity of these cases and their generally favorable prognosis, standardized diagnostic and treatment guidelines have not yet been established. We report a rare case of a 31-year-old patient who underwent surgery for an anterior neck mass that had developed over the years. Histopathological examination revealed a Hürthle cell carcinoma occurring in a thyroglossal duct remnant. Following this diagnosis, the patient underwent a total thyroidectomy. The postoperative management plan included radioactive iodine therapy and thyroid hormone suppressive therapy.

Erdheim-Chester disease (ECD) is a rare systemic non-Langerhans cell histiocytosis with multiple organ involvement. Being a rare disease with variable clinical manifestations, it is often difficult to diagnose. ¹⁸F-2-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) plays a vital role in assessing disease extent and severity, diagnosis, treatment response and is a potential biomarker for BRAF mutation. We present here a rare case of ECD with FDG PET/CT showing extensive cutaneous lesions apart from skeletal involvement.

We present a unique case of a heart-shaped lesion identified on Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) imaging in a patient with metastatic adenocarcinoma of the left lung. The patient, initially diagnosed with a mass in the left upper lobe and a lytic lesion in the L3 vertebra, underwent chemoradiation therapy. Subsequent imaging revealed significant metabolic activity reduction in lung and vertebral lesions. This case emphasizes the occasional atypical and visually intriguing patterns encountered in PET/CT imaging.

Cyclotron technology plays a pivotal role in nuclear medicine, enabling the production of radiopharmaceuticals for diagnostics and therapies. Despite its benefits, its application entails significant ethical challenges, particularly regarding patient safety, environmental protection, and compliance with regulatory standards. This article provides a detailed comparative analysis of the ethical landscape surrounding cyclotron use, highlighting key differences and alignments between Indian and international regulatory frameworks. The article examines ethical issues such as radiation exposure risks to patients, emphasizing safeguards such as as low as reasonably achievable principles and informed consent. It also explores the responsible use of radioactive materials in clinical and research contexts, along with specific measures for mitigating environmental contamination, such as waste management protocols and emission controls. A comprehensive review of India's regulatory frameworks, including the Atomic Energy Regulatory Board and the Department of Atomic Energy, is juxtaposed with international standards set by the International Atomic Energy Agency and the World Health Organization. The roles of these regulatory bodies are clarified, focusing on their mandates, overlaps, and potential conflicts in guideline interpretation. The article also underscores the critical role of institutional ethics committees in implementing ethical guidelines, monitoring compliance, and ensuring adherence to both national and international standards. By comparing ethical norms, the analysis identifies gaps in oversight and provides actionable recommendations for harmonizing protocols across jurisdictions. This study emphasizes the need for robust ethical frameworks in cyclotron technology to enhance patient safety, protect the environment, and ensure regulatory compliance. Such integration fosters trust and accountability while advancing nuclear medicine research and clinical applications.

Intramedullary cauda equina metastases (ICEM) are rare lesions in patients with malignant tumors, accounting for <1% of all metastatic sites. We present a history of a 65-year-old female who achieved long disease-free survival (DFS) after local treatment of ICEM in the course of oligometastatic lung adenocarcinoma. More than 2 years after initial treatment (pneumonectomy and lymphadenectomy), the disease recurred with a single lesion in the contralateral lung. Stereotactic body radiation therapy (SBRT) guided by ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) resulted in a complete metabolic response of the lung metastasis. Soon thereafter, the patient was diagnosed with hypopituitarism, and the magnetic resonance imaging (MRI) and FDG PET/CT revealed the presence of a focal lesion in the sella turcica, highly suspicious for metastatic pituitary adenocarcinoma. Again, the lesion was successfully treated with SBRT. After another year of follow-up, the patient developed low back pain accompanied by urine incontinence. MRI revealed a focal lesion in S2, which was resected and confirmed as adenocarcinoma metastasis. The following FDG PET/CT guided the adjuvant radiotherapy of the residual disease in the S1/S2 region. The DFS has so far reached over 24 months.