Staging of testicular germ cell tumours

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.

CT of the chest can hinder the management of seminoma of the testis; it detects irrelevant abnormalities

To evaluate the role of chest CT in the initial staging of testicular seminomatous germ cell tumours. All patients referred to Addenbrooke's Hospital with testicular seminoma from 1 January 2000 to 31 December 2005 were included and case notes retrospectively reviewed. One hundred and eighty-two patients with testicular seminoma were identified, with a median age of 37 years (range 19–74). Most patients had stage I disease (86%). Twenty-four patients had abnormal abdominal CT findings. One hundred and fifty-eight had normal abdominal CT findings but, on initial staging, chest CT reported abnormalities in 13 patients, which, on further follow-up CT were deemed to be irrelevant to the diagnosis of seminoma. There was a further patient with a normal CT abdomen in whom chest CT detected obvious metastatic disease, which was seen on chest x-ray. Overall 18 cases required additional investigations and follow-up for abnormalities subsequently found to be benign. There was a false-positive rate of 10% for initial staging with chest CT. This is the largest reported series of staging CT chest in testicular seminoma. In all patients with normal abdominal CT, normal chest x-ray and abnormal chest CT, subsequent follow-up investigations demonstrated that the lung lesions were incidental findings.

Late relapse of metastatic non-seminomatous testicular germ cell tumours

Although the majority of men presenting with non-seminomatous germ cell tumours (NSGCT) are cured, late relapse (occurring more than 2 years after obtaining a complete response to treatment) is increasingly recognized. The typical patterns of disease spread have been well-documented, but the findings at late relapse are more variable and less well-described. We discuss the phenomenon of late relapse, the characteristics of teratoma differentiated (TD), and the issue of long-term imaging surveillance of patients with NSGCT. The potential sites of late relapse of NSGCT and the associated spectrum of imaging appearances are illustrated.

Imaging of intrathoracic metastases of nonseminomatous germ cell tumors

Radiologic imaging is crucial in the evaluation of intrathoracic metastatic nonseminomatous germ cell tumors. Helical CT is the workhorse of radiologic staging and is sensitive in the detection of parenchymal nodules and mediastinal lymphadenopathy. CT may also demonstrate other less common sites of metastatic disease. Although, currently, no radiologic procedure is effective in distinguishing viable tumor or teratoma from residual fibrosis and necrosis, cross-sectional imaging remains essential in the presurgical evaluation of potential metastatic disease. FDG PET and CT-guided needle biopsy may be useful in select, high-risk patients.

Staging and prognostic factors in testicular cancer

Germ cell cancers of the testis are rare malignancies that occur most commonly in young adult male life. These malignancies are highly curable, and adoption of sophisticated treatment strategies, related to known prognostic-based variables, has resulted in overall cure rates of approximately 95% with acceptable morbidity. These treatment approaches require a thorough knowledge of the underlying pathology and patterns of tumour spread. In recent years a number of prognostic factor-based staging classifications have evolved, each of which can accurately predict prognosis. However, in 1997, an internationally agreed-upon consensus classification applicable to both seminoma and non-seminoma was published. This classification was well validated and has now been incorporated into the TNM and American Joint Committee on Cancer (AJCC) staging systems.

Imaging of the thorax in the management of germ cell testicular tumours

AIM

To evaluate role of chest computed tomography (CTC) and chest radiography (CXR) in management of patients with testicular germ cell tumours (GCT).

PATIENTS AND METHODS

An analysis was undertaken of staging and re-assessment CTC and CXR examinations performed on patients with GCT over a 4.5-year period. Data were obtained on clinical presentation, tumour histology, tumour marker levels and clinical course. Consensus review interpretation was combined with these data to obtain a 'standard of reference'. Sensitivity, specificity and predictive values were derived by comparison of original imaging reports to 'standard of reference'.

RESULTS

Six hundred and twenty-three CTC examinations on 207 patients with GCT were included. Intrathoracic metastases were identified in 1% of seminoma patients compared with 20% of non-seminoma (NSGCT) patients. CTC was more accurate than CXR in the detection of intrathoracic metastases at 0.97, 0.96-0.98 (95% CI) compared with 0.91, 0.89-0.93. The agreement between imaging techniques and the standard of reference (determined by Kappa statistic) was respectively 0.96 for CTC and 0.65 for CXR. In GCT patients undergoing re-assessment with both CXR and CTC, CXR never detected unknown intrathoracic metastatic disease. Abdominopelvic lymphadenopathy was associated with intrathoracic metastases (P < 0.001), however re-assessment CTC did identify intrathoracic metastases in 27 cases without concurrent abdominopelvic disease. CXR was negative in 19 of these.

CONCLUSION

Routine interval CXRs are unnecessary in NSGCT patients undergoing regular re-assessment CTC due to the low additional yield and limited effect on management. Re-assessment should still include CTC. In low risk, pure seminoma patients (abdominal CT and marker negative) re-assessment CTC can be safely avoided. Baseline CTC is advocated with CXR alone for re-assessment.

Evidence-based diagnostic radiology

The radiological community has a long track record of self-examination, starting well before evidence-based medicine came of age. It had to produce such evidence to prove the need for and win funds for its expensive gadgets. The assessment of new tests is easier than proving the value of well-established ones, and in scrutinising the evidence base for an imaging technique a balance must be struck between apparent (eg, diagnostic) benefit and real benefit to the patient. And even when there is a wealth of good evidence healthy debate continues. So radiology may be ahead of some other disciplines in considering the evidence for its daily practice. For example, where is the evidence for the routine clinical examination-and might the radiologist with a chest X-ray and abdominal ultrasound do better?

The role of computed tomographic examination of the pelvis in the management of testicular germ cell tumours

AIM

To clarify the role of pelvic CT in the imaging of patients with germ cell testicular tumours (GCTT).

PATIENTS AND METHODS

A retrospective analysis was undertaken of all CT examinations performed on patients with GCTT at a regional oncological centre over a 3-year-period. Patient notes were reviewed and data on histology, tumour marker levels, therapy and clinical course obtained. The review interpretation was combined with the original radiological report and clinical data to arrive at a consensus result.

RESULTS

Four hundred and forty-three examinations on 167 patients were included. One hundred and nineteen examinations (27%) demonstrated abdominal and/or pelvic lymph node enlargement. Nodal metastasis was entirely or predominantly ipsilateral in 73/77 examinations from left-sided primary tumours (95%) and 35/42 examinations from right-sided tumours (83%). Pelvic nodal enlargement was identified in 37 examinations from 16 patients. Thirteen of these sixteen patients possessed an identifiable risk factor for pelvic nodal metastasis; the remaining three had unequivocal nodal metastases in the abdomen. Combined abdominopelvic CT increased the effective dose equivalent (EDE) by 2.6 mSv (74%) compared with abdominal examination alone. Three hundred pelvic CT examinations were performed on 117 patients without risk factors for pelvic nodal metastasis. For this cohort the radiation burden from pelvic CT was 0.78 manSv, giving a risk of induction of a single fatal cancer of 3.9%.

CONCLUSION

We advocate pelvic CT only at the time of staging, except in patients with a risk factor for pelvic nodal metastasis. Any unequivocal abdominal lymph node enlargement should be regarded as a risk factor. Implementation of this policy would safely reduce pelvic CT examinations in patients with testicular tumours by nearly 50%, with a consequent reduction in patient radiation exposures and a resource saving.

Patterns of supradiaphragmatic metastases in testicular germ cell tumours

The imaging and clinical findings of 31 patients with supradiaphragmatic nodal metastases from primary testicular germ cell cancers were reviewed. In 11 patients the primary testicular tumor was a seminoma, and in 20 a non-seminomatous germ cell tumour (NSGCT). The patterns of spread of these tumour types were compared. All patients had chest radiographs (CXR): 27 had chest computed tomography (CT). One patient with seminoma and eight with NSGCT (40%) had lung metastases. Mediastinal lymphadenopathy was seen on CT in seven patients with seminoma (64%) and in nine patients with NSGCT (45%). Neck lymphadenopathy was present in 10 of 11 (91%) patients with seminoma, and 13 of 20 (65%) patients with NSGCT. Neck disease co-existed with mediastinal disease in six of 11 (55%) patients with seminoma, but in only two of 20 (10%) patients with NSGCT (P=0.012). This study gives further supporting evidence for the relative importance of haematogenous spread in teratoma, and lymphatic spread in seminoma. The contiguous nature of disease spread from abdomen to chest and neck in seminoma is confirmed. In NSGCT, supradiaphragmatic spread is more random but tends to occur in the paraoesophageal and subcarinal groups.

Has lymphography a role in early stage testicular germ cell tumours?

A retrospective study was performed of 183 newly diagnosed seminoma cases and 73 newly diagnosed non-seminomatous germ cell tumours (NSGCT) presenting from 1985 to 1989 to a tertiary referral cancer hospital. The purpose was to assess the contribution of bipedal lymphography (LG) to the management of these patients. As the main value of LG is in detecting small retroperitoneal lymph node (LN) metastases, analysis concentrated upon early stage disease, specifically N0 and N1a LN disease. Comparison between LG results, abdominopelvic computed tomography (APCT), final clinical stage and treatment outcome was performed. We found that with the LG and APCT criteria used (filling defects > 2 mm and LN diameter > 20 mm, respectively), LG was much more sensitive in disease detection. However, with modern techniques APCT can reliably detect disease 10 mm or greater. In addition, tumour marker status, primary tumour vascular invasion status and initial clinical examination were each more important in staging NSGCT disease than LG alone. Thus, LG is now rarely used in our institution but we will have to monitor our excellent survival data to confirm that this change in policy is warranted.