Bone scintigraphy in testicular tumors

Tc-99m MDP Scan with Unusual and Isolated Skeletal Metastasis in Skull Bone in a Case of Testicular Seminoma

Seminomas are common germ cell tumors (GCT) that may arise in the testes as well as in extra testicular locations such as mediastinum with/without testicular tumor. Testicular tumors are usually detected early due to their location and presentation as testicular mass. The overall prognosis of the seminomatous GCTs is good with surgery as the mainstay of treatment in localized disease. Bone metastases, especially when present in isolation are exceedingly rare in seminoma. Here, we present a rare case of skull bone metastasis in a case of testicular seminoma which was detected on technetium-99m labeled methylene diphosphonate bone scintigraphy with single-photon emission computed tomography with computed tomography.

A Review on the Usage of Bone Single-Photon Emission Computed Tomography/Computed Tomography in Detecting Skeletal Metastases in the Post-COVID-19 Era: Is it Time to Ditch Planar and Single-Photon Emission Computed Tomography only Gamma Camera Systems?

Planar whole-body bone scanning (WBS) is widely used to evaluate skeletal lesions seen in cancer and noncancer cases. Frequently, degenerative, or other benign bony changes may give rise to indeterminate lesions that mimic bone metastases. In the post-COVID-19 era, there is an evolutionary phase that puts importance on global development and adaptability, which encompasses to include nuclear medicine practices worldwide. Single-photon emission computed tomography/computed tomography (SPECT/CT) can be used to improve the characterization of these lesions and help to resolve the diagnostic conundrum while reducing the need for patients to undergo multiple different examinations at various imaging departments. The fusion of SPECT and CT allows morphological characterization of functional abnormality detected by focal tracer uptake on planar scintigraphy, which provides a one-stop center imaging in nuclear medicine departments. The objective of this study was to review the diagnostic accuracy of SPECT/CT in diagnosing bone metastases in a variety of oncology and nononcology cases and to determine the feasibility of performing bone SPECT/CT in all suspected cancer cases, including cases of bone infection instead of planar imaging alone. The utilization of hybrid SPECT/CT in indeterminate bone lesions detected on planar WBS can significantly increase the diagnostic confidence and accuracy of image interpretation. Recognition of patterns of disease identified using hybrid imaging can improve the management of patients with potentially lower costs in the long term. Currently, hybrid SPECT/CT machines are becoming a norm in nuclear medicine departments, thus potentially making single planar application machines obsolete in the near future. We hypothesize that in the interest of providing a meaningful interpretation of isotope bone scans, the default protocol should involve the option of acquiring SPECT/CT images rather than relying on whole-body scans only. Departments choosing to upgrade existing equipment or those choosing to invest in only one gamma camera should proactively opt for hybrid SPECT/CT systems.

ACR Appropriateness Criteria® Staging and Surveillance of Testicular Cancer: 2021 Update

The staging and surveillance of testicular cancer is a complex topic, which integrates clinical, biochemical, and imaging components. The use of imaging for staging and surveillance of testicular cancer is individually tailored to each patient by considering tumor histology and prognosis. This document discusses the rationale for use of imaging by imaging modality during the initial staging of testicular seminoma and nonseminoma tumors and during the planned surveillance of stage IA and IB testicular cancer by histological subtype integrating clinical suspicion for disease recurrence in surveillance protocols. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Magnetic resonance imaging of bone metastases in patients with nonseminomatous germ cell tumors

OBJECTIVE

To investigate the role of magnetic resonance imaging (MRI) of bone metastases in nonseminomatous germ cell tumors.

METHODS AND MATERIALS

There were 5 consecutive patients with bone metastases from nonseminomatous germ cell tumors treated between 2003 and 2006 who underwent imaging studies, including MRI. The characteristic imaging findings are discussed in the light of the clinical course.

RESULTS

Of the 5 patients, 3 had symptoms related to bone involvement at diagnosis. All patients received conventional x-ray of their bony lesions, but only 1 of them was considered abnormal. Skeletal MRI was obtained in all patients. A bone scan was available in 3 cases with spinal involvement. It was normal in 1 case and detected only a minority of the lesions visible on MRI in the other 2 cases. Follow-up MRIs were available in all patients. A partial resolution of bone involvement during chemotherapy was observed in only 1 of them. In 2 cases, there was a slight progression of a diffuse alteration of the bone marrow during treatment. In 1 patient, severe spinal bone marrow changes were visible on MRI 2 years after cessation of treatment without evidence of disease recurrence.

CONCLUSIONS

MRI may disclose bone metastases in nonseminomatous germ cell tumors, which otherwise may be missed. MRI findings of bone lesions during treatment do not directly reflect the course of the disease and have to be interpreted with caution using clinical information.