2-¹⁸fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) for postchemotherapy seminoma residual lesions: a retrospective validation of the SEMPET trial

Complex treatment of residual metastatic germ cell cancer: A single center experience

BACKGROUND

Testicular cancer is the most common solid malignancy among men aged 15-35. Radical orchiectomy and platinum-based chemotherapy (BEP) are curative in the majority of patients, including advanced, metastatic cases. According to current urooncology guidelines all non-seminoma patients harbouring post-chemotherapy residual masses of ≥ 1 cm should undergo salvage retroperitoneal lymph node dissection (RPLND). However, only 10% of residual tumors contain viable disease.

OBJECTIVE

To assess patient outcomes and complications considering different treatment regimens and clinical characteristics.

MATERIALS AND METHODS

In a retrospective cross-sectional study patients (n=127) who underwent postchemotherapy RPLND between 2007 and 2023 at our referral center were evaluated. The patients received systemic treatment at various oncology centers. The number of BEP cycles received were occasionally different from standard. Only patients with normal postchemotherapy serum tumor markers and primary testicular or extragonadal germ cell neoplasms were included. Treatment groups were established according to the number of BEP cycles received, and the extent of RPLND (bilateral or modified template). Treatment outcomes and complications were assessed.

RESULTS

Standard 3-4 courses of BEP were received by 100 (78,7%) patients, while 11 (8,7%) patients underwent less, and 16 (12,6%) more courses than standard. On histopathologic evaluation viable germ cell tumor, teratoma, and necrosis/fibrosis was present in 26 (20,5%), 67 (52,7%) and 34 (26,8%) of specimen, respectively. In the 5-6 BEP series subgroup high rate of viable disease (37,5%) was found and significantly more nephrectomies were performed, than other chemotherapy subgroups. Extratesticular GCT, viable disease in residual mass or progression after RPLND indicated lower survival. Mild (Clavien-Dindo I-II) or no postoperative complications were reported in 93,7% of cases.

CONCLUSIONS

The study suggests no significant benefit from exceeding 3-4 courses of BEP. Timely salvage RPLND should be performed in high volume centers for optimal treatment outcomes with acceptable complication rates. Adherence to the Heidenreich criteria is advisable where practical.

The evolution of PET imaging in renal, bladder, upper urinary tract urothelial, testicular and penile carcinoma - Today's impact, tomorrow's potential

INTRODUCTION

The advancement of hybrid PET/CT or PET/MRI imaging for non-prostate genitourinary cancers has not experienced the rapid progress of prostate cancer. Nevertheless, these neoplasms are aggressive and reliable imaging plays a pivotal role in enhancing patients' quality of life and prognosis.

AREAS COVERED

the main evidence regarding [18F]FDG and non-[18F]FDG PET/CT or PET/MRI in non-prostate uro-oncological malignancies are summarized and discussed. Moreover, potential future directions concerning PET imaging in these neoplasms are debated, with the aim to stimulate future research projects covering these fields.

EXPERT OPINION

In Renal Cell Carcinoma (RCC), [18F]FDG PET/CT demonstrates varying efficacy in staging, restaging, and prognostic stratification, but PSMA PET/CT is emerging as a potential game-changer, particularly in advanced, high-grade aggressive clear cell RCC. [18F]FDG PET/CT may see an increased use in N and M-staging of bladder cancer, as well as for detecting recurrence and response to neoadjuvant chemotherapy. Preliminary data regarding [68Ga]-FAPI also looks promising in this context. [18F]FDG PET/MRI could be useful for the T-staging of bladder cancer, while upper tract urothelial carcinoma still lacks of molecular imaging literature reports. In testicular and penile cancer [18F]FDG PET/CT has demonstrated its usefulness in several clinical settings, although experiences with non-[18F]FDG radiotracers are lacking.

Testicular Tumors

BACKGROUND

Germ-cell tumors of the testes are the most common type of malignant tumor in men aged 20 to 40. Their incidence in Germany is 10 per 100 000 men per year, with an estimated 4200 new cases annually.

METHODS

This selective review is based on the recommendations of the German clinical practice guideline on the diagnosis, treatment and follow-up care of testicular germ-cell tumors, as well as on pertinent original articles and reviews.

RESULTS

The treatment of germ-cell tumors requires an interdisciplinary approach comprising resection of the affected testis followed by further steps that depend on the histological type and stage of the tumor, which may include active surveillance, chemotherapy, radiotherapy, further surgery, or some combination of these measures. Two-thirds of germ-cell tumors are diagnosed in clinical stage I, when they are still confined to the testis; one-third are already metastatic when diagnosed, with organ metastases in 10-15%. Stage-based multimodal treatment approaches are associated with cure rates of more than 99% for stage I tumors and 67-95% for advanced metastatic disease, depending on the degree of progression.

CONCLUSION

For patients with early-stage tumors, overtreatment should be avoided in order to minimize long-term sequelae. For those whose tumors are in advanced stages, it must be decided which patients should receive intensified treatment to optimize the outcome. Multimodal treatment approaches are associated with high cure rates even for patients with metastatic disease.

Evaluation of post-chemotherapy residual seminomatous masses by 18F-fluorodeoxyglucose PET/CT using tumor-to-liver ratio - conundrum or solution?

OBJECTIVE

Assessment of diagnostic accuracy of FDG-PET/CT in the detection of viable disease in post-chemotherapy seminomatous residual masses using visual interpretation, SUVmax, and T/L ratio.

METHODS

This is a retrospective study assessing the post-chemotherapy seminomatous residual masses of size >3 cm. The PET/CT scan findings were interpreted visually for presence of residual disease which were validated from histopathology reports or imaging follow-up for a maximum of 3 years. SUVmax and T/L ratios were also determined for all the residual lesions. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value NPV were calculated and compared for all three parameters along with ROC analysis to obtain an optimal cutoff value for SUVmax and T/L ratio, respectively.

RESULTS

Sample size was 49. Out of these 49 patients, 8 had validation of PET results with histopathology. Rest was validated with imaging follow-up. FDG-PET was positive in 30 patients and negative in 19 patients by visual interpretation. The sensitivity, specificity, PPV, and NPV by this method were 100%, 62.5%, 73%, and 100%, respectively. The SUVmax and T/L ratios were also calculated for these lesions. The cutoff for these two variables was 4.56 and 1.21, respectively. The sensitivity, specificity, PPV, and NPV at these cutoffs were 76%, 87.5%, 86%, 77.7%, and 92%, 87.5%, 88%, 91%, respectively.

CONCLUSION

FDG-PET has a favorable diagnostic value in predicting viable disease in post-chemotherapy seminomatous residual masses and using T/L ratio cutoff of 1.21 will increase the specificity of the test.

[Multimodal treatment of testicular cancer: chemotherapy, surgery or radiotherapy?]

BACKGROUND

Metastatic testicular germ cell tumors patients require histology- and stage-appropriate therapy to achieve optimal therapeutic outcomes.

OBJECTIVES

This work focuses on the interdisciplinary presentation of current recommendations for the treatment of metastatic germ cell tumor patients.

MATERIALS AND METHODS

The interdisciplinary recommendations were formulated based on the German S3 guideline and supplemented by recent literature.

RESULTS

Using a stage-specific and guideline-based treatment approach, interdisciplinary cooperation between urology, oncology, and radiotherapy is mandatory to successfully achieve a high rate of cure and, in the case of complex advanced tumors, also the most effective therapy possible. The question of optimal treatment approaches for seminoma in cSII A/B remains particularly challenging.

CONCLUSION

Since treatment of advanced or multiple relapsed germ cell tumor patients remains complex, patients should be referred for an online second opinion ( https://urologie.ekonsil.org ).

Advances in diagnosis and treatment of testicular cancer

Testicular cancer is a curable cancer. The success of physicians in curing the disease is underpinned by multidisciplinary advances. Cisplatin-based combination chemotherapy and the refinement of post-chemotherapy surgical procedures and diagnostic strategies have greatly improved long term survival in most patients. Despite such excellent outcomes, several controversial dilemmas exist in the approaches to clinical stage I disease, salvage chemotherapy, post-chemotherapy surgical procedures, and implementing innovative imaging studies. Relapse after salvage chemotherapy has a poor prognosis and the optimal treatment is not apparent. Recent research has provided insight into the molecular mechanisms underlying cisplatin resistance. Phase 2 studies with targeted agents have failed to show adequate efficacy; however, our understanding of cisplatin resistant disease is rapidly expanding. This review summarizes recent advances and discusses relevant issues in the biology and management of testicular cancer.

End-of-Treatment FDG PET-CT (EOT-PET) in Patients with Post-Chemotherapy Masses for Seminoma: Can We Avoid Further Intervention?

Anjana JoelContext  Patients with seminoma present with advanced disease. End-of-treatment (EOT) positron emission tomography-computed tomography (PET-CT) is done to assess response and direct management of post-chemotherapy residual masses. Purpose  This article assesses the utility of EOT PET-CT in the management of post-chemotherapy residual lymph nodal masses seminoma. Materials and Methods  We analyzed all patients with seminoma who underwent an EOT PET-CT from January 2015 to January 2020 at our center and calculated the positive predictive value (PPV) and negative predictive value (NPV) of EOT PET-CT in the entire cohort of patients and among subgroups. Results  A total of 34 male patients underwent EOT PET-CT. Fourteen (41.2%) were stratified as good risk and 20 (58.8%) as intermediate risk. The median follow-up was 23 months (interquartile range: 9.75-53 months). In 23 patients there were residual masses of size more than 3 cm at the EOT PET scan. EOT PET was positive as per the SEMPET criteria in 18 (78%) out of 23 patients. None underwent retroperitoneal lymph node dissection. All four who underwent image-guided biopsy, showed only necrosis on pathology. One patient with positive mediastinal node (standardized uptake value 13.6) had granulomatous inflammation. There was no relapse or progression during this period of follow-up. The NPV for EOT PET-CT for the entire cohort, > 3 cm, and > 6 weeks cutoff were 100%, respectively. The PPV for EOT PET-CT for the entire cohort, > 3 cm residual mass, and > 6 weeks cutoff were 8.7, 11.11, and 6.67%, respectively. Conclusion  EOT PET-CT has a low PPV and high NPV in predicting viable tumor in post-chemotherapy residual masses among patients with seminomatous germ cell tumors. If required, EOT PET positivity can be confirmed by a biopsy or reassessed with a repeat PET-CT imaging to document persistent disease prior to further intervention.

Serum Levels of MicroRNA-371a-3p (M371) Can Predict Absence or Presence of Vital Disease in Residual Masses After Chemotherapy of Metastatic Seminoma

Background

Radiological evaluation of postchemotherapy residual masses of metastatic seminoma is characterized by poor diagnostic accuracy. Serum levels of microRNA-371a-3p (M371) involve high specificity and sensitivity for the primary diagnosis of seminoma. We evaluated if M371 levels can indicate the presence of vital disease in postchemotherapy residual masses in patients with metastatic seminoma.

Methods

Twenty-three seminoma patients (median age 52 years) with residual masses had posttreatment measurements of serum M371 levels (group A), fourteen of whom had measurements also beforehand. The posttreatment results were compared with the clinical outcome during follow-up. Eleven patients with complete remission after treatment of metastatic seminoma (group B) and 33 men with non-malignant testicular diseases (group C) served as controls. M371 serum levels were measured by quantitative real-time PCR using miR-30b-5p as endogenous control. An evaluation was performed with descriptive statistical methods.

Results

Twenty-two patients of Group A had uneventful follow-up so far, twenty-one of whom had M371 level <5, and one other had a mildly elevated level below relative quantity (RQ) = 10. One patient with a level of RQ = 26.2 rapidly progressed. The median posttreatment M371 level of the non-progressing patients of group A is not significantly different from the median level of the control group with complete remission (B). Before treatment, the median M371 levels in groups A and B were 507.6 and 143.9, respectively. In both groups, significant drops in M371 levels resulted from treatment.

Conclusion

Normal M371 serum levels at the time of completion of treatment of metastatic seminoma indicate the absence of vital seminoma in residual masses, while elevated levels >RQ = 10 predict the presence of disease. The optimal timing of M371 measurement after chemotherapy and the appropriate cutoff level still need to be determined. Based on the present results, measuring serum M371 levels involves the potential of a novel tool for assessing postchemotherapy residual masses of metastatic seminoma.

Incidental Finding of Testicular Seminoma by 18F-Choline PET/CT in a Prostate Cancer Patient

ABSTRACT

An 80-year-old man with a history of prostate cancer, treated with radical prostatectomy and bilateral obturator nodal dissection, underwent an 18F-choline PET/CT because of biochemical recurrence. The scan revealed an intense focal uptake in the right testicle. A subsequent orchifunicumlectomy demonstrated the presence of a classic seminoma. At present, 18F-FDG PET/CT is useful for initial staging of testicular cancer and determining the viability of residual masses >3 cm after completion of treatment, especially in patients with seminoma.

Vigilance is key: Metastatic teratoma in an enlarging retroperitoneal mass after treatment of advanced seminoma – a case report

We present the case of a patient with pure seminoma in the orchiectomy specimen with retroperitoneal mass and a minimally elevated alpha fetoprotein (AFP). The patient received chemotherapy with positron emission tomography (PET) imaging demonstrating minimal fluorodeoxyglucose (FDG) uptake consistent with no viable tumour. Subsequent imaging revealed slow growth in the residual mass with a mildly elevated fluctuating AFP. A robotic-assisted laparoscopic retroperitoneal lymph node dissection was performed revealing metastatic teratoma. This case illustrates the potential for a missed or ‘burned out’ occult NSGCT in a patient with pure seminoma and the importance of post-treatment surveillance. In advanced seminoma, PET may be used to distinguish viable tumour from necrosis in post-chemotherapy residual masses. However, it is unable to distinguish between teratoma and necrosis in non-seminomatous germ cell tumours (NSGCT). Minimally elevated AFP could be a normal variant or signify a component of NSGCT in such cases.

Level of evidence: 4

Narrative review of developing new biomarkers for decision making in advanced testis cancer

Management of testicular germ cell tumor (GCT) patients is based on clinical determinants, mainly CT scan and serum tumor markers (alpha-fetoprotein, beta subunit of HCG and LDH). Treatment decisions are usually straightforward for patients with clear evidence of metastatic disease, confirmed either by imaging tests or by unequivocal elevated tumor markers. However, there are several clinical scenarios where the assessment of metastatic disease is complicated by the limited specificity of the current imaging tests and serum tumor markers. These include patients with clinical stage IIA GCT with negative tumor markers and patients with post-chemotherapy residual disease where, in absence of clear indicators of GCT, decision making and patient treatment allocation become challenging. Therefore, more accurate biomarkers are critical to reduce the risk of under-or over-treatment and to always deliver the most optimal therapy. The objectives of this narrative review are to review the available publications about micro-RNAs in GCT s and their potential clinical applications. Two clusters of micro-RNAs, miR-371a-3p and miR-302/367, specifically expressed by both seminoma and non-seminoma GCT and easily detectable in the peripheral blood, have demonstrated to be promising in this endeavor. Large prospective trials are ongoing to define the operating characteristics of these biomarkers and their clinical utility to improve GCT patient management and reduce the error rate deriving from clinical uncertainty, therefore reducing the risk of sub-optimal treatments.

Contemporary options and future perspectives: three examples highlighting the challenges in testicular cancer imaging

PURPOSE

One of the main issues in testicular germ cell tumors (TGCTs) management is to reduce the necessary amount of treatment to achieve cure. Excess treatment burden may arise from late diagnosis of the primary as well as from false positive or negative staging results. Correct imaging is of paramount importance for successful management of TGCT. The aim of this review is to point out the current state of the art as well as innovative developments in TGCT imaging on the basis of three common challenging clinical situations.

METHODS

A selective literature search was performed in PubMed, Medline as well as in recent conference proceedings.

RESULTS

Regarding small testicular lesions, recent studies using elastography, contrast-enhanced ultrasound or magnetic resonance imaging (MRI) showed promising data for differentiation between benign and malignant histology. For borderline enlarged lymph nodes FDG-PET-CT performance is unsatisfactory, promising new techniques as lymphotropic nanoparticle-enhanced MRI is the subject of research in this field. Regarding the assessment of postchemotherapeutic residual masses, the use of conventional computerized tomography (CT) together with serum tumor markers is still the standard of care. To avoid overtreatment in this setting, new imaging modalities like diffusion-weighted MRI and radiomics are currently under investigation. For follow-up of clinical stage I TGCTs, the use of MRI is non-inferior to CT while omitting radiation exposure.

CONCLUSION

Further efforts should be made to refine imaging for TGCT patients, which is of high relevance for the guidance of treatment decisions as well as the associated treatment burdens and oncological outcomes.

PET/CT limitations and pitfalls in urogenital cancers

Hybrid FDG PET/CT plays a vital role in oncologic imaging and has been widely adopted for the staging and restaging of a variety of malignancies. Its diagnostic value in urogenital malignancies is less well-known, not at least because of the variable FDG avidity of these tumor entities, the sites of these tumors, and technical challenges associated with sequential imaging of CT and PET. PET/CT interpretation thus can be especially challenging and is associated with many pitfalls, which can lead to both false-positive and false-negative diagnoses as well as incorrect assessment of metabolic change following therapy. Currently, FDG PET/CT is not the standard of care for the initial diagnosis or staging of early-stage or low-risk urogenital cancers; however, it can help evaluate distant metastatic disease, response to therapy, and disease recurrence in high-risk patients. Knowledge of imaging features of tumor metabolic avidity and pitfalls is essential for accurate interpretation.

Improving outcomes in germ cell cancers using miRNA

Owing to advances in treatment paradigms across the last five decades, testicular cancer is now eminently curable. However, current serum tumour and imaging biomarkers lack adequate sensitivity, specificity, and predictive value. Subsequently, their utility in detecting active malignancy and informing treatment decisions is minimal in a large proportion of men with testicular cancer. Micro-ribonucleic acids (miRNA), pertinently miR-371a-3p, offer a new tool, which based on early data, appears to fill many of the gaps that existing biomarkers leave. This paper reviews the evolution of the technology, potential limitations, and discusses the clinical relevance of miRNA as it moves towards the clinic.

Advanced germ cell tumor patients undergoing post-chemotherapy retroperitoneal lymph node dissection: Impact of residual teratoma on prognosis

OBJECTIVES

To evaluate the histologic findings and clinical outcomes of post-chemotherapy retroperitoneal lymph node dissection for advanced germ cell tumor.

METHODS

We analyzed the medical records of 66 patients who underwent post-chemotherapy retroperitoneal lymph node dissection between 2005 and 2019 at Tsukuba University Hospital.

RESULTS

The proportions of necrosis, teratoma, and viable germ cell tumor in the specimens were 62.1%, 36.4%, and 1.5%, respectively. The 5-year progression-free and overall survival rates were 82.3% and 91.3%, respectively. The 5-year overall survival rate of patients with residual teratoma was significantly worse than that of patients with necrosis only (74.1% vs 100%). Overall, three patients died: one from cancer and two from teratoma with somatic-type malignancy. Of these, two patients relapsed after incomplete resection of residual teratoma. When limited to patients with completely resected teratoma, the 5-year overall survival rate was 91.7%, which did not differ from that for patients with necrosis only. Multivariate analysis showed that presence of teratoma in the primary site and decrease in retroperitoneal lymph node mass to less than 50% of the initial tumor size were independent factors for residual teratoma. However, the absence of these factors could not reliably predict necrosis only in retroperitoneal lymph node dissection specimens.

CONCLUSIONS

In our series, 98% of post-chemotherapy retroperitoneal lymph node dissection pathology was either necrosis or teratoma, with viable germ cell tumor only found in 2% of patients. Residual teratoma was associated with poorer prognosis, especially in cases of incomplete resection.

A 25-year review of advances in testicular cancer: Perspectives on evaluation, treatment, and future directions/challenges

The year 2020 will be remembered for a number of different events, both good and bad. For the journal Urologic Oncology, Seminars and Original Investigations, this year represents the 25th anniversary of its inception and 1st publication. Under the encouragement of Editor-in-Chief Dr. Michael Droller, the collective editorial board has put together a reflection of the progresses made among the spectrum of genitourinary cancers across the entirety of therapeutic disciplines. In this review, we discuss the advances achieved in our knowledge and understanding of testicular germ cell tumors since 1995, and the challenges that lie ahead.

Radiotherapy for Post-Chemotherapy Residual Mass in Advanced Seminoma: A Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography-Based Risk-adapted Approach

AIMS

There is a lack of consensus regarding the management of post-chemotherapy residual mass in classical seminoma. The use of fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) may aid the detection of residual masses harbouring viable disease and help to tailor therapy. The aim of this study was to evaluate if PET-CT could identify patients who will benefit from locoregional radiotherapy.

MATERIALS AND METHODS

This ethics-approved study included patients with advanced classical seminoma primarily treated with standard platinum-based first-line chemotherapy. Patients were either observed or given adjuvant radiotherapy based on the clinician's preference and followed up. For this study, patients were stratified into two groups based on FDG PET-CT residual nodal maximum standardised uptake value (SUVmax): low risk (SUVmax <3) and high risk (SUVmax ≥3). Further subgroup analysis was carried out for patients with residual nodal size ≥3 cm and SUVmax ≥3, and this was considered as the very high risk group. The diagnostic accuracy of FDG PET-CT was assessed and survival was compared between the different groups.

RESULTS

Sixty-nine patients were included in the study: 48 patients were observed and 21 received radiotherapy. The low and high risk groups contained 50.7% and 49.3% of the patients, respectively. The very high risk subgroup had 24 patients. At a median follow-up of 44 months, locoregional failures in the radiotherapy and observation cohorts were 0% and 30% (P = 0.059) in the very high risk subgroup and 5.8% and 29.4% (P = 0.078) in the high risk group. The positive predictive value for the very high risk and high risk groups was 30% and 17.1%, respectively. The benefit of locoregional control failed to translate into overall survival benefit.

CONCLUSION

A tailored, FDG PET-based risk-adapted treatment approach can refine the management of post-chemotherapy residual masses in seminoma. In this study, with the largest cohort of advanced seminoma patients treated with radiotherapy reported to date, radiotherapy seems to benefit patients with post-chemotherapy residual mass SUVmax ≥3.

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.

PET imaging in testicular tumours

PURPOSE OF REVIEW

Testicular cancer is rare, but its incidence is expected to rise. [18F] fluorodeoxyglucose ([18F]FDG) PET/computed tomography (CT) added role in testicular cancer management has been defined in a set of specific clinical settings. The current review focuses on recent advances in the employment of PET/CT in testicular cancer patients.

RECENT FINDINGS

[18F]FDG PET/CT is not recommended for initial staging or for suspected testicular tumours. PET/CT role in testicular cancer management is mainly for the assessment of seminoma residual masses after therapy (>3 cm). Although [18F]FDG PET/CT has a very high negative predictive value, its positive predictive value varies across studies: appropriate PET/CT scheduling after therapy and a careful history are mandatory for accurate interpretation. Interim PET/CT could prove valuable to spare subsequent chemotherapy cycles in patients already in remission, reducing related toxicity. The role of [18F]FDG in nonseminoma tumours is hampered by the low sensitivity in teratoma.

SUMMARY

[18F]FDG PET/CT is currently used for the assessment of seminoma residual masses (>3 cm) after therapy. A negative PET could also spare unnecessary further chemotherapy cycles in responding patients, reducing toxicity. Although rare, testicular secondary lesions can be detected with non[18F]FDG tracers when PET/CT is performed for other primary tumours.

Surgical Management of Genitourinary Cancer Liver Metastases

Genitourinary cancers are common. Liver metastases from genitourinary cancers are uncommon; isolated liver metastasis is rare. Liver resection in select patients with metastatic renal cell carcinoma can lead to prolonged survival. Patients with metachronous and low-burden disease are most likely to benefit. Chemotherapy is first-line treatment of metastatic germ cell tumors. Liver resection is dependent on germ cell lineage and initial response to chemotherapy. Prognosis with liver metastases from prostate cancer is poor; liver-only lesions are rare. Liver resection generally is not indicated. Cumulative experience with liver resection for metastatic bladder cancer is limited. Liver metastases are poor prognostic indicators for metastasectomy.

Prognostic Role of Early Interim Fluorodeoxyglucose Positron Emission Tomography in Patients With Advanced Seminoma Undergoing Standard Treatment

BACKGROUND

Patients with advanced seminoma have an exceedingly favorable prognosis. Studies aiming to reduce the total treatment burden and side effects in patients with well-defined disease and very good prognosis are warranted.

PATIENTS AND METHODS

In a prospective observational study, patients with advanced stage seminoma were treated with bleomycin, etoposide, and cisplatin (BEP) or EP according to guidelines. Fluorodeoxyglucose with positron emission tomography and computed tomography (FDG-PET/CT) examinations were performed at baseline, after 2 cycles (PET/CT2) in all patients, and after chemotherapy at the physician's discretion. Disease response to treatment assessed by PET/CT was qualitatively evaluated by 2 independent nuclear medicine physicians. Contrast-enhanced CT scans were also performed according to guidelines (at baseline, after treatment, during follow-up). The study's primary endpoint was to evaluate the association between PET/CT2 findings and relapse-free survival.

RESULTS

From January 2009 to January 2017, a total of 75 consecutive patients were enrolled, of whom 70 were included for analysis. The clinical disease stage was IIA-B and IIC-III in 40% and 60%, respectively. By local assessment, 46 PET/CT2 scans (65.7%) were reported as negative, and 46% of these patients had stage IIC-III disease. Five-year relapse-free survival of PET/CT2-positive patients was 75% (95% confidence interval, 60-95) compared to 97.8% (95% confidence interval, 93.7-100) of PET/CT2-negative patients (P = .002). In univariate analyses, PET/CT2 was significantly associated with relapse-free survival (P = .02).

CONCLUSIONS

No residual FDG uptake after 2 cycles of conventional chemotherapy is prognostic in advanced seminoma, but it may be useful to optimize the standard prognostic risk groups and may be tested within larger prospective clinical trials of chemotherapy deescalation.

Significance of 18F-FDG PET/CT in Characterization of Equivocal Lesions in High-Risk Testicular Carcinoma in Restaging Setting

Objectives:

The present study aims to evaluate the role of Positron emission tomography (PET) -computed tomography (CT) with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) in the restaging of high-risk testicular cancer.

Methods:

Forty-five patients (mean age of 38.1±11.3 years and range 23-81 years) with testicular carcinoma, underwent ¹⁸F-FDG PET-CT during their clinical course were prospectively selected. PET positivity was defined as a site of abnormal ¹⁸F-FDG uptake in tissue histologically proven or clinically or radiographically suspected to represent tissue involvement. The sites of disease were characterized as either nodal or extranodal. All patients were followed-up for at least 12 months with a diagnostic and/or functional imaging modality.

Results:

Of the 45 patients 38 (84%) patient presented with seminoma and 7 (16%) were Non-seminomatous germ cell tumors. Analysis of secondary disease spectrum showed nodal involvement in 65%, osseous involvement in 23% and mixed visceral/soft tissue lesions in 12% of patients. Nineteen (42%) were negative for any metastatic disease. All negative patients remain disease free in the follow-up of one year. Out of the positive 26/45 patients, PET-CT showed progressive disease in 3/26, stable disease 1/26 and partial response in 2/26 and complete metabolic resolution in 20/26 patients. ¹⁸F-FDG PET-CT was able to characterize all patients leading to significant change of primary decision of wait and watch to go for treatment and vice versa.

Conclusion:

¹⁸F-FDG PET-CT scan is potentially an excellent tool for characterization of equivocal lesions on CT scan in the restaging settings and follow up of high-risk testicular cancer patients.

Surgical strategies for postchemotherapy testis cancer

The surgical management of disseminated disease has long been an essential component in the management of patients with testis cancer. While the indications for surgery have been narrowed since the advent of cisplatin based chemotherapy, resection remains essential to provide long-term survival. The indications for surgery vary by histology and rely on adequate preoperative imaging to evaluate for residual disease. Surgery for postchemotherapy testis cancer is challenging and requires that surgeons be prepared for extraretroperitoneal resections and adjunctive procedures as necessary. Herein, we review the imaging options that are essential for surgical planning and the various surgical techniques that are often necessary in this challenging situation.

Prognostic value of primary tumor surgery in seminoma patients with distant metastasis at diagnosis: a population-based study

The aims of this study were to determine the prognostic value of primary tumor surgery and identify optimal candidates for such surgery among patients with seminoma and distant metastasis at diagnosis. We identified 521 patients with seminoma and distant metastasis at diagnosis between 2004 and 2014 from the Surveillance, Epidemiology, and End Results database. Among these patients, 434 had undergone surgery, whereas 87 had not. The prognostic value of primary tumor surgery was assessed by Kaplan–Meier methods, log-rank analyses, and multivariate Cox's proportional hazards model. Survival curves and forest plots were also plotted. Survival analysis indicated that patients who underwent surgery had a better 5-year overall survival and cancer-specific survival than those who did not. Multivariate analyses demonstrated that primary tumor surgery is an independent prognostic factor for overall survival and cancer-specific survival, along with age at diagnosis, M stage, and marital status. In addition, primary tumor surgery still had considerable prognostic value in the subgroup of patients with lymph node metastasis. Further, forest plots demonstrated that patients with M1a stage, N1 or N2–3 stage, and a younger age at diagnosis (<60 years) may benefit from primary tumor surgery. In conclusion, our findings indicate that primary tumor surgery is correlated with improved survival in patients with seminoma and distant metastasis. Furthermore, primary tumor surgery is an independent prognostic indicator for patients with seminoma and distant metastasis.

[Management of residual masses of testis germ cell tumors]

A residual mass (RM) is an abnormal image with a transverse axis of more than 1cm trans that remains visible on the CT scan performed after chemotherapy for metastatic germ cell tumors. Their management depends on the histology of the initial tumor. In the case of a non-seminomatous germ cell tumor, all residual lesions must be resected if the tumor markers are negative. The surgery usually begins with a retroperitoneal lymphadenectomy. This lymphadenectomy is a programed regional surgery and not the only resection of visible masses. All RM must be resected, regardless of their location, and may require successive actions. In order to limit its morbidity, modifications on the extent of the lymphadenectomy and the use of minimally invasive approaches are proposed by some center. When the initial tumor is a pure seminoma the attitude is different: the decay of the masses in post chemotherapy is often postponed. If lesions less than 3cm can be monitored, the others benefit from 18FDG PET at the end of chemotherapy: a positive attachment to PET is suspected of the presence of residual active tissue. The surgery of these RM is curative. If its extent is precise in the case of non-seminomatous tumor, it is more controversial in the case of seminoma. In the case of residual markers, surgery has a place in very specific situations.

ESMO Consensus Conference on testicular germ cell cancer: diagnosis, treatment and follow-up

The European Society for Medical Oncology (ESMO) consensus conference on testicular cancer was held on 3-5 November 2016 in Paris, France. The conference included a multidisciplinary panel of 36 leading experts in the diagnosis and treatment of testicular cancer (34 panel members attended the conference; an additional two panel members [CB and K-PD] participated in all preparatory work and subsequent manuscript development). The aim of the conference was to develop detailed recommendations on topics relating to testicular cancer that are not covered in detail in the current ESMO Clinical Practice Guidelines (CPGs) and where the available level of evidence is insufficient. The main topics identified for discussion related to: (1) diagnostic work-up and patient assessment; (2) stage I disease; (3) stage II-III disease; (4) post-chemotherapy surgery, salvage chemotherapy, salvage and desperation surgery and special topics; and (5) survivorship and follow-up schemes. The experts addressed questions relating to one of the five topics within five working groups. Relevant scientific literature was reviewed in advance. Recommendations were developed by the working groups and then presented to the entire panel. A consensus vote was obtained following whole-panel discussions, and the consensus recommendations were then further developed in post-meeting discussions in written form. This manuscript presents the results of the expert panel discussions, including the consensus recommendations and a summary of evidence supporting each recommendation. All participants approved the final manuscript.

Imaging of Metastatic Germ Cell Tumors in Male Patients From Initial Diagnosis to Treatment-Related Toxicities: A Primer for Radiologists

OBJECTIVE. This review describes the influence of histology and metastatic sites on prognosis in male patients with metastatic germ cell tumors (GCTs) and explains the role imaging in assessing therapeutic response, residual disease, recurrence, sand treatment-related toxicities. CONCLUSION. Seminomatous and nonseminomatous GCTs differ in imaging appearance, pattern of spread, and prognosis, and an organ-based approach is helpful in prognostication. Multimodality imaging aids in accurate staging, prognostication, characterization of treatment response, and identification of therapy-related toxicity.

Management of Stage II Germ Cell Tumors

There are several treatment approaches for stage II germ cell tumors (GCTs), and a thorough understanding of the staging classification and histologic differences in tumor biology and therapeutic responsiveness is critical to determine an effective, multimodal management strategy that involves urologists, medical oncologists, and radiation oncologists. This article discusses contemporary management strategies for stage II GCTs, including chemotherapy, radiotherapy, retroperitoneal lymph node dissection (RPLND), and surveillance. Patient selection, histology, and extent of lymphadenopathy drive management, and, as both treatment and detection strategies continue to emerge and be refined, the management of patients with stage II GCT continues to evolve.

Management of Residual Mass in Germ Cell Tumors After Chemotherapy

PURPOSE OF REVIEW

The purpose of this review is to educate medical oncologists on the management of patients with residual germ cell tumors and the role of surgical resection after platinum-based chemotherapy.

RECENT FINDINGS

Patients with non-seminomatous testicular cancer and residual enlarged retroperitoneal lymph nodes > 1 cm following induction chemotherapy with normal tumor markers should undergo a post-chemotherapy retroperitoneal lymph node dissection. All patients with primary mediastinal non-seminoma should undergo surgical resection of the mediastinal mass post-chemotherapy. These are complex surgeries and require expert surgeons in high-volume centers. Patients with advanced testicular seminoma who have residual masses less than 3 cm after chemotherapy can be observed without further intervention. Patients with a residual mass > 3 cm should be evaluated with PET scan after 6 weeks of chemotherapy. Residual mass with negative PET scan can be followed by surveillance while a positive PET scan requires further work up to rule out active disease.

Current controversies on the role of lymphadenectomy for testicular cancer for the journal: Urologic Oncology: Seminars and Original Investigations for the special seminars section on the role of lymphadenectomy for urologic cancers

The role of surgery in the locoregional management of many solid tumors has long been established. For testicular cancer, the incorporation of lymphadenectomy has played an important part in generating long-term survival outcomes in excess of 90% for germ cell tumor patients. In this review, we address several clinical scenarios in which lymphadenectomy at times is underutilized, and others ill advised.

The Warburg Effect Is Associated With Tumor Aggressiveness in Testicular Germ Cell Tumors

Testicular Germ Cell Tumors (TGCTs) are a rare group of neoplasms and the most common solid malignancy arising in young male adults. Despite the good response of these tumors to platinum-based chemotherapy, some patients are refractory to treatment and present poor clinical outcomes. During carcinogenesis and tumor development, cancer cells reprogram energy metabolism toward a hyper-glycolytic phenotype, an emerging hallmark of cancer. This phenomenon, known as the Warburg effect or aerobic glycolysis, involves overexpression of metabolism-related proteins, like glucose and monocarboxylate transporters, pH regulators and intracellular glycolytic enzymes. The metabolic profile of TGCTs is very little explored and, recently, this metabolic rewiring of cancer cells has been associated with aggressive clinicopathological characteristics of these tumors. The overexpression of monocarboxylate transporter 4 (MCT4) in TGCTs has been pointed out as a poor prognostic factor, as well as a promising therapeutic target. As a result, the main aim of the present study was to evaluate the prognostic value of key metabolism-related proteins in TGCTs. The immunohistochemical expressions of CD44 (as a monocarboxylate transporter chaperone), glucose transporter 1 (GLUT1), carbonic anhydrase IX (CAIX), hexokinase II (HKII) and lactate dehydrogenase V (LDHV) were evaluated in a series of 148 adult male patients with TGCTs and associated with clinicopathological parameters. In addition, paired normal tissues were also evaluated. The sample included 75 seminoma and 73 non-seminoma tumors. GLUT1 and CD44 expression was significantly increased in malignant samples when compared to paired normal samples. Conversely, HKII and LDHV expressions were significantly decreased in malignant samples. Concerning the clinicopathological values, CAIX expression was significantly associated with disease recurrence, while HKII expression was significantly associated with aggressive characteristics of TGCTs, including higher staging and non-seminoma histology. In conclusion, this study brings new insights on the metabolic characteristics of TGCTs, showing alterations in the expression of proteins related with the Warburg effect, as well as associations of the hyper-glycolytic and acid-resistant phenotype with aggressive clinicopathological parameters.

State-of-the-Art Management of Germ Cell Tumors

The state of the art management of germ cell tumors (GCT) in 2018 does not include novel agents targeting genomic alterations or exciting immunologic-based approaches but rather the avoidance of pitfalls in everyday practice. The relative rarity of GCT and high curability with correct management create the "perfect storm" for high-stakes errors to occur. This review focuses on several common pitfalls that should be avoided in staging and management of early-stage and advanced GCT in order to maximize patient outcomes. A particularly frequent misstep is to base treatment decisions on pre- rather than postorchiectomy tumor markers that, depending on marker directionality, can lead to either undertreatment with potentially inferior outcomes or overtreatment with excess toxicity. Another common mistake is the failure to consider the unique ability of GCT to differentiate and the distinct biology of teratoma (chemoresistance and lack of increased glucose uptake compared with normal tissue), which exerts a pervasive influence on nonseminoma management. This may lead to inappropriate use of PET scan to evaluate the postchemotherapy residual mass and, if negative, the conclusion that surgery is not needed whereas (FDG-negative) teratoma should be removed. It could also result in administration of additional unnecessary chemotherapy to patients with marker normalization but without robust radiographic response after 3 to 4 cycles of BEP. Finally, oncologists should strive to maintain standard chemotherapy doses, not substitute carboplatin for cisplatin, and refer to expert centers when expertise (e.g., RPLND) is not available locally in order to achieve optimal cure rates in advanced disease.

[Positron emission tomography in germ cell tumors in men : Possibilities and limitations]

BACKGROUND

Conventional radiographic imaging may fail to safely distinguish clinical stage I from stage IIA germ cell cancer, to localize isolated tumor marker relapses, and to equivocally identify the viability of postchemotherapy residual masses.

OBJECTIVES

To provide an overview of the diagnostic value and limitations of functional imaging by positron emission tomography with 2‑deoxy-2-[fluorine-18]fluoro-D-glucose with computed tomography (¹⁸F-FDG-PET-CT) in male germ cell cancer.

MATERIALS AND METHODS

A narrative review based on a literature search of PubMed/MEDLINE for original articles published from 1990-2018 and conference proceedings of ASCO (American Society of Clinical Oncology) and EAU (European Association of Urology) annual meetings 2014-2017 is presented.

RESULTS

¹⁸F-FDG-PET-CT does not improve diagnostic accuracy compared to conventional CT imaging clinical stage (CS) I disease. Particularly PET-negativity of postchemotherapy residual masses of seminomas >3 cm in size guide decision-making against further additional treatment. Even PET-positive residues must not result in relapse. For nonseminoma, the value of PET imaging is reduced by potential mature teratoma components, which are commonly PET negative.

CONCLUSIONS

Current guidelines recommend ¹⁸F-FDG-PET-CT 6-8 weeks postchemotherapy for viability assessment of seminoma residues >3 cm in size. Exceptional circumstances, in which ¹⁸F-FDG-PET-CT may be helpful, include: (1) detection of active disease in CS IS, (2) viability assessment of residual masses >1 cm where complete secondary resection is impossible, (3) staging at marker relapse with unconspicuous conventional CT scan, (4) early response assessment during chemotherapy.

Questioning the Value of Fluorodeoxyglucose Positron Emission Tomography for Residual Lesions After Chemotherapy for Metastatic Seminoma: Results of an International Global Germ Cell Cancer Group Registry

PURPOSE

Residual lesions after chemotherapy are frequent in metastatic seminoma. Watchful waiting is recommended for lesions < 3 cm as well as for fluorodeoxyglucose (FDG) positron emission tomography (PET)-negative lesions ≥ 3 cm. Information on the optimal management of PET-positive residual lesions ≥ 3 cm is lacking.

PATIENTS AND METHODS

We retrospectively identified 90 patients with metastatic seminoma with PET-positive residual lesions after chemotherapy. Patients with elevated α-fetoprotein or nonseminomatous histology were excluded. We analyzed the post-PET management and its impact on relapse and survival and calculated the positive predictive value (PPV) for PET.

RESULTS

Median follow-up time was 29 months (interquartile range [IQR], 10 to 62 months). Median diameter of the largest residual mass was 4.9 cm (range, 1.1 to 14 cm), with masses located in the retroperitoneum (77%), pelvis (16%), mediastinum (17%), and/or lung (3%). Median time from the last day of chemotherapy to PET was 6.9 weeks (IQR, 4.4 to 9.9 weeks). Post-PET management included repeated imaging in 51 patients (57%), resection in 26 patients (29%), biopsy in nine patients (10%) and radiotherapy in four patients (4%). Histology of the resected specimen was necrosis in 21 patients (81%) and vital seminoma in five patients (19%). No biopsy revealed vital seminoma. Relapse or progression occurred in 15 patients (17%) after a median of 3.7 months (IQR, 2.5 to 4.9 months) and was found in 11 (22%) of 51 patients on repeated imaging, in two (8%) of 26 patients after resection, and in two (22%) of nine patients after biopsy. All but one patient who experienced relapse were successfully treated with salvage therapy. The PPV for FDG-PET was 23%.

CONCLUSION

FDG-PET has a low PPV for vital tumor in residual lesions after chemotherapy in patients with metastatic seminoma. This cautions against clinical decisions based on PET positivity alone.

The use of F-FDG PET/CT in testicular cancer

Testicular germ cell tumors are one of the most common neoplasms in young men. After inguinal orchiectomy is performed, treatment options range from active surveillance to chemotherapy, radiation therapy or retroperitoneal lymphadenectomy. For the accurate use of the different treatment options, precise imaging techniques are necessary to reduce side effects of the aggressive therapies but also to avoid undertreatment exposing the patient to the risk of recurrence. F-FDG PET/CT is already recommended in the European guidelines for the follow up of seminomas under certain conditions but conventional primary staging or restaging is still performed with CT or MRI. Recently, the importance of F-FDG PET/CT in this context has become an interesting topic of academic discussion and subject of various clinical trials which are reviewed in the following.

Minimally Invasive Retroperitoneal Lymphadenectomy

The feasibility of laparoscopic retroperitoneal lymphadenectomy (RLA) for testicular cancer was shown >25 years ago. Initially the indication was clinical stage I (CS I) nonseminomatous germ cell tumor (NSGCT). Compared with that of open surgery, the morbidity was much decreased. However, in Europe, surgery for CS I is now replaced by chemotherapy. A relatively new indication is laparoscopic retroperitonal lymphadenectomy for small unilateral residual tumor after chemotherapy. The technique of unilateral lymphadenectomy for both indications is described in detail and with a video. The most recent development is bilateral laparoscopic RLA for residual tumors larger than 5 cm.

Clinical Stage IIA-IIC Seminoma: Radiation Therapy versus Systemic Chemotherapy versus Retroperitoneal Lymph Node Dissection

BACKGROUND

Clinical stage II (CSII) seminoma is defined by the presence of pure seminoma accompanied by retroperitoneal lymph node metastases. In patients with bulky disease (lymph nodes > 5 cm in diameter), platinum-based chemotherapy is the widely accepted standard of care. However, the optimal choice of treatment for CSIIA and IIB is more controversial.

METHODS

We performed a PubMed search using the key words stage II seminoma, BEP (cisplatin, etoposide, and bleomycin), hockey-stick radiotherapy, dog-leg radiotherapy and retroperitoneal lymph node dissection. Most relevant publications were summarized for this review.

RESULTS

To date, no randomized trials have prospectively compared radiotherapy (RT), chemotherapy (CT) and retroperitoneal lymph node dissection (RLND) for CSII seminoma. Because of the predominantly retrospective analyses and only few prospective trials data interpretation is complex. In CSIIA with lymph nodes of < 2 cm, RT and CT seem to be equally effective, while in CSIIB, a decreased number of relapses were observed in CT-treated patients. In addition, RT seems to be associated with a higher incidence of long-term sequelae when compared with CT.

CONCLUSION

Prospective clinical trials are needed to systematically compare the different treatment modalities. De-escalation of treatment intensity without loss of efficacy is required to improve long-term outcome for this young patient population.