Lymphoscintigraphic studies of lymphatic drainage from the testes

Nerve-sparing technique in RPLND for testicular cancer

PURPOSE OF REVIEW

The management of testicular cancer has evolved over time with multimodal therapy. Retroperitoneal lymph node dissection (RPLND), which is a complex and potentially morbid treatment option, remains the mainstay in surgical treatment. This article reviews the surgical template, approach and anatomical considerations with regards to nerve spare in RPLND.

RECENT FINDINGS

The standard full bilateral RPLND template has evolved over time to include the area between the renal hilum, bifurcation of the common iliac vessels, and the ureters. Morbidity with regards to ejaculatory dysfunction has led to further refinements in this procedure. Advancements in anatomical understanding of the retroperitoneal structures and their relationship to the sympathetic chain and hypogastric plexus has allowed for modification of surgical templates. Further refinements in surgical nerve sparing techniques have improved functional outcomes without sacrificing oncological outcomes. Finally, extraperitoneal access to the retroperitoneum and minimally invasive platforms have been implemented to further reduce morbidity.

SUMMARY

RPLND requires strict adherence to oncological surgical principles regardless of template, approach and technique. Contemporary evidence shows that outcomes are best for advanced testis cancer patients when managed at high volume tertiary care facilities with surgical expertise and access to multidisciplinary care.

Whole Body MRI in the Detection of Lymph Node Metastases in Patients with Testicular Germ Cell Cancer

Whole-Body Magnetic Resonance Imaging (WB-MRI) is increasingly used for metastatic screening in oncology. This prospective single center study assesses the diagnostic value of WB-MRI including diffusion weighted imaging (DWI) and identifies the sufficient protocol for metastatic lymph node detection in patients with testicular germ cell cancer (TGCC). Forty-three patients underwent contrast enhanced thoraco-abdominopelvic CT (TAP-CT) and WB-MRI with DWI for metastatic lymph node screening. Two independent readers reviewed CTs and WB-MRIs. The diagnostic performance of different imaging protocols (CT, complete WB-MRI, T1W + DWI, T2W + DWI), the agreement between these protocols and the reference standard, the reproducibility of findings and the image quality (Signal and contrast to Noise Ratios, Likert scale) were studied. Reproducibility was very good regardless of both lesion locations (retroperitoneal vs distant lymph nodes, other lesions) and the reader. Diagnostic accuracy of MRI was ≥95% (regardless of the locations and imaging protocol); accuracy of CT was ≥93%. There was a strict overlap of 95% CIs associated with this accuracy between complete WB-MRI, T1W + DWI and T2W + DWI, regardless of the reader. Higher Likert score and SNR were observed for DWI, followed by T2W and T1W sequences. In conclusion, a fast WB-MRI protocol including T2W and DWI is a sufficient, accurate, non-irradiating alternative to TAP-CT for metastatic lymph node screening in TGCC.

Intricacies of Radiographic Assessment in Testicular Germ Cell Tumors

Testicular germ cell tumors (GCTs) are malignancies with a unique biology, pathology, clinical appearance, and excellent outcomes. A correct radiographic assessment of GCTs is extremely important for the clinical management in several typical scenarios. Advancements in the field of diagnostic medicine bring an increasing number of sophisticated imaging methods to increase the performance of imaging studies. The conventional computed tomography (CT) remains the mainstay of diagnostic imaging in the management of GCTs. While certain improvements in the sensitivity and specificity are suggested with magnetic resonance (MR) imaging with lymphotrophic nanoparticles in evaluating retroperitoneal lymph nodes during the staging procedure, further exploration in larger prospective studies is needed. A common diagnostic dilemma is assessing the post-chemotherapy residual disease in GCTs. Several studies have consistently shown advantages in the utility of positron emission tomography (PET) scanning in post-chemotherapy residual retroperitoneal lymph nodes in patients with seminoma, but not with non-seminoma. Recommendations suggest that seminoma patients with a residual disease in the retroperitoneum larger than 3 cm should be subjected for PET scanning with 18-fluorodeoxyglucose. Relatively high sensitivity, specificity and a negative predictive value (80-95%) may guide clinical decision to spare these patients of high morbidity of an unnecessary surgery. However, a positive predictive value of around 50% renders PET scanning difficult to interpret in the case of positive finding. These patients often require extremely difficult surgical procedures with the high risk of post-operative morbidity. Therefore, seminoma patients with PET positive residual masses larger than 3 cm still remain a serious challenge in the decision making of nuclear medicine specialist, oncologists, and urologic surgeons. In this article, we aim to summarize data on controversial dilemmas in staging procedures, active surveillance, and post-chemotherapy assessment of GCTs based on the available published literature.

Lymph node imaging in testicular cancer

Testicular cancer is a rare malignancy mainly affecting young men. Survival for testicular cancer remains high due to the effectiveness of multimodal treatment options. Accurate imaging is imperative to both treatment and follow-up. Both computed tomography (CT) and magnetic resonance imaging (MRI) suffer from size cut-offs as the only distinguishing characteristic of benign vs. malignant lymph nodes and may miss up to 30% of micro-metastatic disease. While functional [positron emission tomography (PET)] imaging may rule out disease in patients with seminoma who have undergone chemotherapy, there is insufficient evidence to recommend its use in other settings. This review highlights the uses and pitfalls of conventional imaging during staging, active surveillance, and post-treatment phases of both seminomatous and non-seminomatous germ cell tumors (NSGCT).

Testicular scanning and other applications of radionuclide imaging of the genital tract

The major application of nuclear imaging techniques to the genital tract is pertechnetate scintigraphy for evaluation of the acute hemiscrotum. Within a few years of the first descriptions of scrotal imaging, this technique achieved recognition as a valuable, even indispensable, emergency diagnostic procedure in this context; its validity has since been well confirmed in hundreds of reported cases. Because it is an established procedure with widely recognized applications, its discussion will occupy most of this article. Other nuclear procedures, less widely used either because they are investigative or applicable to smaller patient populations, will be more briefly described.