Molecular Imaging for Evaluation of Viable Testicular Cancer Nodal Metastases

Nuclear medicine imaging in non-seminomatous germ cell tumors: lessons learned from the past failures

There is an unmet need for a more accurate molecular imaging radiotracer in the field of non-seminomatous germ cell tumors (NSGCT). The clinical problem is that no single imaging modality is able to differentiate teratoma from necrotic tissue in NSGCTs, which the nuclear medicine techniques are no exception. The exponential growth in the list of potentially promising radiotracers may hold promise in the future for imaging of NSGCTs. Here, we have reviewed the past efforts and potential future advances in this field.

Development and validation of a nomogram to predict lung metastasis in patients with testicular germ cell tumors

Background

Lung metastatic tumor (LM) is one of testicular germ cell tumors' most common metastatic sites. Our study aimed to develop a nomogram for predicting the risk of LM among patients with testicular germ cell tumors (TGCTs).

Methods

Clinicopathological information of 4078 patients with TGCT between 2010 and 2015 was obtained from SEER. Univariate and multivariate logistic regression analyses were performed to identify risk factors for LM, and a nomogram was developed based on these factors. Calibration curves, area under the receiver operating curve (AUC), and decision curve analysis (DCA) were used to evaluate the accuracy and discrimination of the model.

Results

Study participants included 4078 people with TGCTs, including 305 people with LM. They were randomly divided into two groups (training cohort = 2854 and validation cohort = 1224) at a ratio of 7:3. The following variables were incorporated in the nomogram: marital status, tumor histological type, T stage, brain metastasis, liver metastasis, lactate dehydrogenase (LDH), and chemotherapy. Besides, the AUC of it was 0.922 in the training cohort, while was 0.930 in the validation cohort. Training and validation cohort calibrations showed that the nomogram had excellent predictive abilities. DCA suggested it was more clinically relevant than the traditional TN staging.

Conclusion

We have established a nomogram to predict the risk of LM in patients with TGCTs. Doctors and patients can use this nomogram to monitor and identify lung metastasis of tumors through active monitoring and follow-up.

CT Rendering and Radiomic Analysis in Post-Chemotherapy Retroperitoneal Lymph Node Dissection for Testicular Cancer to Anticipate Difficulties for Young Surgeons

Post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) in non-seminomatous germ-cell tumor (NSTGCTs) is a complex procedure. We evaluated whether 3D computed tomography (CT) rendering and their radiomic analysis help predict resectability by junior surgeons. The ambispective analysis was performed between 2016-2021. A prospective group (A) of 30 patients undergoing CT was segmented using the 3D Slicer software while a retrospective group (B) of 30 patients was evaluated with conventional CT (without 3D reconstruction). CatFisher's exact test showed a p-value of 0.13 for group A and 1.0 for Group B. The difference between the proportion test showed a p-value of 0.009149 (IC 0.1-0.63). The proportion of the correct classification showed a p-value of 0.645 (IC 0.55-0.87) for A, and 0.275 (IC 0.11-0.43) for Group B. Furthermore, 13 shape features were extracted: elongation, flatness, volume, sphericity, and surface area, among others. Performing a logistic regression with the entire dataset, n = 60, the results were: Accuracy: 0.7 and Precision: 0.65. Using n = 30 randomly chosen, the best result obtained was Accuracy: 0.73 and Precision: 0.83, with a p-value: 0.025 for Fisher's exact test. In conclusion, the results showed a significant difference in the prediction of resectability with conventional CT versus 3D reconstruction by junior surgeons versus experienced surgeons. Radiomic features used to elaborate an artificial intelligence model improve the prediction of resectability. The proposed model could be of great support in a university hospital, allowing it to plan the surgery and to anticipate complications.

The Importance of Repeat Imaging Prior to Treatment Decision-making in Testicular Cancer: Commentary From the Inaugural Global Society of Rare Genitourinary Tumors Summit

Testicular cancer is a rare cancer that often affects young and otherwise healthy patients. Imaging plays a critical role in the staging and surveillance of patients with testicular cancer. Indeterminate findings on staging or surveillance imaging, can lead to challenging management decisions for clinicians and patients. In this article, we review the importance of short-interval, repeat imaging for several scenarios faced by patients with testicular cancer and their clinicians. The challenging scenarios and recommendations provided in this article summarize the discussion from the inaugural Global Society of Rare Genitourinary Tumors (GSRGT) Summit held on December 11-12, 2020.

Update on pediatric testicular germ cell tumors

BACKGROUND

Testicular germ cell tumors are uncommon tumors that are encountered by pediatric surgeons and urologists and require a knowledge of appropriate contemporary evaluation and surgical and medical management.

METHOD

A review of the recommended diagnostic evaluation and current surgical and medical management of children and adolescents with testicular germ cell tumors based upon recently completed clinical trials was performed and summarized in this article.

RESULTS

In this summary of childhood and adolescent testicular germ cell tumors, we review the initial clinical evaluation, surgical and medical management, risk stratification, results from recent prospective cooperative group studies, and clinical outcomes. A summary of recently completed clinical trials by pediatric oncology cooperative groups is provided, and best surgical practices are discussed.

CONCLUSIONS

Testicular germ cell tumors in children are rare tumors. International collaborations, data-sharing, and enrollment of patients at all stages and risk classifications into active clinical trials will enhance our knowledge of these rare tumors and most importantly improve outcomes of patients with testicular germ cell tumors.

LEVEL OF EVIDENCE

This is a review article of previously published and referenced level 1 and 2 studies, but also includes expert opinion level 5, represented by the American Pediatric Surgical Association Cancer Committee.

Pathologic concordance of resected metastatic nonseminomatous germ cell tumors in the chest

OBJECTIVE

Men with metastatic nonseminomatous germ cell tumors (NSGCTs) often present with residual chest tumors after chemotherapy. We examined the pathologic concordance of intrathoracic disease and outcomes based on the worst pathology of disease resected at first thoracic surgery.

METHODS

A retrospective analysis was performed of consecutive patients undergoing thoracic resection for metastatic NSGCT in our institution between 2005 and 2018.

RESULTS

Eighty-nine patients (all men) were included. The median age was 29 years (interquartile range [IQR], 23-35 years). Primary sites were testis (n = 84; 94.4%) and retroperitoneum (n = 5; 5.6%). Eighty-seven patients received chemotherapy before undergoing surgery. Nineteen patients (21.3%; group 1) had malignancy resected at first surgery (OR1), and the other 70 patients had benign disease at OR1 (78.7%; group 2). Concordant pathology between lungs was 85.2% in group 1 and 91% in group 2, and between lung and mediastinum was 50% in group 1 and 72.7% in group 2. Despite no teratoma at OR1, 3 patients (15.8%) in group 2 had resection of teratoma (n = 2) or malignancy (n = 1) at future surgery. After a mean follow-up of 65.5 months (IQR, 23.1-89.2 months) for group 1 and 47.7 months (IQR, 13.0-75.1 months) for group 2, overall survival was significantly worse for group 1 (68.4% vs 92.9%; P = .03).

CONCLUSIONS

The wide range of pathology resected in patients with intrathoracic NSGCT metastases requires careful decision making regarding treatment. Pathologic concordance between lungs is better than that between lung and mediastinum in patients with intrathoracic NSGCT metastases. Aggressive surgical management should be considered for all residual disease due to the low concordance between sites and the potential for excellent long-term survival even in patients with chemotherapy-refractory disease.

Defining risk of micrometastatic disease and tumor recurrence in patients with stage I testicular germ cell tumors

There is controversy in the management of patients with clinical stage I non-seminomatous germ cell tumor (NSGCT). Some experts recommend surveillance for all patients regardless of risk factors while others suggest a more risk-adapted approach by using lymphovascular invasion (LVI) and the embryonal component in the primary tumor to select patients most likely to benefit from primary treatment [retroperitoneal lymph node dissection (RPLND) or chemotherapy]. With the surveillance for all strategy, only patients who relapse are treated. While this minimizes the over treatment, problem associated with the risk adapted approach, this exposes young men to the effects of full induction cisplatin-based chemotherapy when these men could have received fewer cycles of bleomycin, etoposide, and cisplatin (BEP) or a curative primary RPLND. The challenge is identifying these men who are most likely to benefit from upfront treatment more precisely. This paper explores the currently risk adapted approaches as well as promising emerging biomarkers (microRNA) that, in early data, appear to more accurately predict the presence of microscopic disease in the retroperitoneum over conventional markers.

Genitourinary Tumors: Update on Molecular Biomarkers for Diagnosis, Prognosis and Prediction of Response to Therapy

BACKGROUND

Research of biomarkers in genitourinary tumors goes along with the development of complex emerging techniques ranging from next generation sequencing platforms, applied to archival pathology specimens, cytological samples, liquid biopsies, and to patient-derived tumor models.

METHODS

This contribution is an update on molecular biomarkers for diagnosis, prognosis and prediction of response to therapy in genitourinary tumors. The following major topics are dealt with: Immunological biomarkers, including the microbiome, and their potential role and caveats in renal cell carcinoma, bladder and prostate cancers and testicular germ cell tumors; Tissue biomarkers for imaging and therapy, with emphasis on Prostate-specific membrane antigen in prostate cancer; Liquid biomarkers in prostate cancer, including circulating tumor cell isolation and characterization in renal cell carcinoma, bladder cancer with emphasis on biomarkers detectable in the urine and testicular germ cell tumors; and Biomarkers and economic sustainability.

CONCLUSION

The identification of effective biomarkers has become a major focus in cancer research, mainly due to the necessity of selecting potentially responsive patients in order to improve their outcomes, as well as to reduce the toxicity and costs related to ineffective treatments.