Diagnostic and prognostic value of 18F-FDG PET/CT in recurrent germinal tumor carcinoma

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.

Lymph Node Dissection in Testicular Cancer: The State of the Art and Future Perspectives

PURPOSE OF REVIEW

This narrative review provides a comprehensive overview of the evolving role of retroperitoneal lymph node dissection (RPLND) in the management of testicular cancer (TC). It explores the significance of RPLND as both a diagnostic and therapeutic tool, highlighting its contribution to accurate staging, its impact on oncological outcomes, and its influence on subsequent treatment decisions.

RECENT FINDINGS

RPLND serves as an essential diagnostic procedure, aiding in the precise assessment of lymph node involvement and guiding personalized treatment strategies. It has demonstrated therapeutic value, particularly in patients with specific risk factors and disease stages, contributing to improved oncological outcomes and survival rates. Recent studies have emphasized the importance of meticulous patient selection and nerve-sparing techniques to mitigate complications while optimizing outcomes. Additionally, modern imaging and surgical approaches have expanded the potential applications of RPLND. In the context of TC management, RPLND remains a valuable and evolving tool. Its dual role in staging and therapy underscores its relevance in contemporary urological practice. This review highlights the critical role of RPLND in enhancing patient care and shaping treatment strategies, emphasizing the need for further research to refine patient selection and surgical techniques.

The Japanese breast cancer society clinical practice guidelines for breast cancer screening and diagnosis, 2022 edition

This article provides updates to readers based on the newly published Japanese Breast Cancer Society Clinical Practice Guidelines for Breast Cancer Screening and Diagnosis, 2022 Edition. These guidelines incorporate the latest evaluation of evidence from studies of diagnostic accuracy. For each clinical question, outcomes for benefits and harms were established, and qualitative or quantitative systematic reviews were conducted. Recommendations were determined through voting by a multidisciplinary group, and guidelines were documented to facilitate shared decision-making among patients and medical professionals. The guidelines address screening, surveillance, and pre- and postoperative diagnosis of breast cancer. In an environment that demands an integrated approach, decisions are needed on how to utilize modalities, such as mammography, ultrasound, MRI, and PET/CT. Additionally, it is vital to understand the appropriate use of new technologies, such as tomosynthesis, elastography, and contrast-enhanced ultrasound, and to consider how best to adapt these methods for individual patients.

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.

[18F]fluorodeoxyglucose positron emission tomography/computed tomography characteristics of primary mediastinal germ cell tumors

Primary mediastinal germ cell tumor (MGCT) is an uncommon tumor. Although it has histology similar to that of gonadal germ cell tumor (GCT), the prognosis for MGCT is generally worse than that for gonadal GCT. We performed visual assessment and quantitative analysis of [18F]fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT) for MGCTs. A total of 35 MGCT patients (age = 33.1 ± 16.8 years, F:M = 16:19) who underwent preoperative PET/CT were retrospectively reviewed. The pathologic diagnosis of MGCTs identified 24 mature teratomas, 4 seminomas, 5 yolk sac tumors, and 2 mixed germ cell tumors. Visual assessment was performed by categorizing the uptake intensity, distribution, and contour of primary MGCTs. Quantitative parameters including the maximum standardized uptake value (SUVmax), tumor-to-background ratio (TBR), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and maximum diameter were compared between benign and malignant MGCTs. On visual assessment, the uptake intensity was the only significant parameter for differentiating between benign and malignant MGCTs (p = 0.040). In quantitative analysis, the SUVmax (p < 0.001), TBR (p < 0.001), MTV (p = 0.033), and TLG (p < 0.001) showed significantly higher values for malignant MGCTs compared with benign MGCTs. In receiver operating characteristic (ROC) curve analysis of these quantitative parameters, the SUVmax had the highest area under the curve (AUC) (AUC = 0.947, p < 0.001). Furthermore, the SUVmax could differentiate between seminomas and nonseminomatous germ cell tumors (p = 0.042) and reflect serum alpha fetoprotein (AFP) levels (p = 0.012). The visual uptake intensity and SUVmax on [18F]FDG PET/CT showed discriminative ability for benign and malignant MGCTs. Moreover, the SUVmax may associate with AFP levels.

Late relapsing testicular cancer detected with 18F-FDG PET preceded by long-term alpha-fetoprotein elevation

Late relapse (LR) of testicular cancer is often associated with chemoresistance, and thus the first choice of therapy is surgery if complete resection is possible. In some LR cases (including our patient, a 31-year-old Japanese man), elevation of alpha-fetoprotein (AFP) may precede the radiologic detection of LR. Approximately 500 days after the start of our patient's AFP elevation, 18F-fluordeoxyglucose positron emission tomography (FDG-PET) revealed strong FDG uptake in an equivocally enlarged external iliac lymph node. The lymphadenectomy as salvage surgery resulted in long-term complete remission without further treatment. Using FDG-PET made it possible to perform effective salvage surgery.

Tumor markers and 18F-FDG PET/CT after orchiectomy in seminoma: Is there any correlation?

OBJECTIVE

The aim of our study was to analyze the potential relationship between tumor markers and ¹⁸F-fluorodoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) results in patients affected by seminoma.

MATERIAL AND METHODS

65 ¹⁸F-FDG PET/CT scans of 41 patients with diagnosis of seminoma were analyzed and compared to alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG). PET/CT studies were analyzed qualitatively and measuring the maximum and mean standardized uptake value body weight max (SUVbwmax, SUVbwmean), maximum SUV lean body mass (SUVlbm), maximum SUV body surface area (SUVbsa), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of hypermetabolic lesions. All values were compared with serum markers.

RESULTS

31 PET/CT studies were true negative, 28 true positive, 6 false positive and 0 false negative with sensitivity of 100%, specificity of 84%, negative predictive value of 100%, positive predictive value of 82% and accuracy of 91%. No correlation between PET results and tumor marker levels was found and also between AFP and PET/CT semiquantitive parameters. All semiquantitative PET parameters were significantly related to hCG level.

CONCLUSIONS

¹⁸F-FDG PET/CT has good accuracy in evaluating patients with relapsed seminoma. HCG levels were significantly correlated with metabolic PET/CT parameters.

18F-FDG PET/CT for primary staging of patients with testicular germ cell tumors: the predictors of 18F-FDG PET positivity and prognostic value of PET derived metabolic parameters

PURPOSE

The aim of this study was to investigate the role of histopathologic and biochemical parameters for predicting F-FDG PET positivity for primary staging in patients with newly diagnosed testicular germ cell tumors (TGCT). It was also aimed to evaluate the prognostic value of PET derived metabolic features in this patient group.

MATERIALS AND METHODS

The imaging findings of 51 patients who were diagnosed as TGCT and underwent F-FDG PET/CT for primary staging after surgery between 2009 and 2019 were evaluated retrospectively. In terms of the presence of F-FDG uptake consistent with metastasis, the patients were divided into two groups as 'PET-positive' and 'PET-negative'. In 'PET-positive' patients, highest maximum standardized uptake values of metastatic lesions, whole-body total metabolic tumor volumes (wb-TMTV) and total lesion glycolysis (wb-TLG) were extracted. Pathological tumor types, pathological T stages (pT), tumor marker (TM) levels (AFP, hCG, LDH) after orchiectomy and overall survival (OS) times in months were also recorded. The predictive value of variables for OS was evaluated using the Kaplan-Meier survival analysis.

RESULTS

PET positivity was observed in 28% of pT1 and in 83.3% in pT2-T3 tumors (P < 0.001). In the logistic regression analysis to predict 'PET positivity', pT stage and ≥2 elevated TMs were found as independent significant predictors. Survival analysis demonstrated that wb-TMTV, wb-TLG and TMs were significantly associated with prognosis for OS.

CONCLUSION

The likelihood of PET positivity was significantly higher in patients with elevated TMs and pT2-T3 stages compared to those with normal TMs and pT1 tumors. PET derived quantitative metabolic-volumetric parameters can be used as biomarkers to identify patients with poor prognosis in TGCT.

Tumor markers and18F-FDG PET/CT after orchiectomy in seminoma:Is there any correlation?

OBJECTIVE

The aim of our study was to analyze the potential relationship between tumor markers and ¹⁸F-fluorodoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) results in patients affected by seminoma.

MATERIAL AND METHODS

65 ¹⁸F-FDG PET/CT scans of 41 patients with diagnosis of seminoma were analyzed and compared to alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG). PET/CT studies were analyzed qualitatively and measuring the maximum and mean standardized uptake value body weight max (SUV_bwmax, SUV_bwmean), maximum SUV lean body mass (SUV_lbm), maximum SUV body surface area (SUV_bsa), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of hypermetabolic lesions. All values were compared with serum markers.

RESULTS

31 PET/CT studies were true negative, 28 true positive, 6 false positive and 0 false negative with sensitivity of 100%, specificity of 84%, negative predictive value of 100%, positive predictive value of 82% and accuracy of 91%. No correlation between PET results and tumor marker levels was found and also between AFP and PET/CT semiquantitive parameters. All semiquantitative PET parameters were significantly related to hCG level.

CONCLUSIONS

¹⁸F-FDG PET/CT has good accuracy in evaluating patients with relapsed seminoma. hCG levels were significantly correlated with metabolic PET/CT parameters.

Prognostic Value of Positive Presurgical FDG PET/CT in the Evaluation of Tumor-Induced Osteomalacia

METHODS

Seventy-six patients who had surgically removed tumors that caused osteomalacia were included in this retrospective investigation. All patients underwent both 18F-FDG and 68Ga-DOTATATE PET/CT prior to surgery. The prognostic value of presurgical FDG PET/CT study was determined with 5-year follow-up.

RESULTS

In the presurgical evaluation, 68Ga-DOTATATE detected lesions in all 76 patients. However, FDG PET/CT was positive in only 25 among all 76 patients. Following surgical removal of the causative tumor, all 76 patients had symptomatic relief and normalization of the serum phosphate level initially. However, 15 of 76 cases (19.7%) had recurrent hypophosphatemia and became symptomatic again during the follow-up. Among these 15 patients with recurrence, 11 (73.3%) had recurrent lesions at the original location of the resected causative tumors, whereas 4 were in other locations due to malignant nature of the primary tumor. Interestingly, 14 of these 15 patients with recurrent disease had positive presurgical FDG PET/CT findings with an incident ratio of 56.0% (14 of 25). In contrast, only 1 patient with recurrent disease had negative presurgical FDG PET/CT scan with an incident ratio of 1.9% (1 of 51), significantly less than the positive presurgical FDG PET/CT group (P < 0.05).

CONCLUSIONS

A positive presurgical FDG PET/CT suggests increased likelihood for possible recurrence of TIO after surgical resection. In contrast, when a causative tumor detected by 68Ga-DOTATATE PET/CT does not have elevated activity on FDG PET/CT, the chance of recurrence is very small.

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.

Clinical and Prognostic Value of 18F-FDG-PET/CT in the Restaging Process of Recurrent Cutaneous Melanoma

BACKGROUND

Several studies on 18F-FDG-PET/CT have investigated the prognostic role of this imaging modality in different tumors after treatment. Nevertheless, its role in restaging patients with recurrent CM still needs to be defined.

OBJECTIVE

The aim of this retrospective multicenter study was to evaluate the clinical and prognostic impact of 18F-FDG-PET/CT on the restaging process of cutaneous melanoma (CM) after surgery in patients with suspected distant recurrent disease or suspected metastatic progression disease.

MATERIALS AND METHODS

74 patients surgically treated for CM underwent 18F-FDG-PET/CT for suspected distant recurrent disease or suspected metastatic progression disease. The diagnostic accuracy of visually interpreted 18F-FDG-PET/CT was obtained by considering histology (n=21 patients), other diagnostic imaging modalities performed within 2 months of PET/CT (CT in 52/74 patients and Whole-Body MRI in 18/74 patients) and clinical follow-up (n=74 patients) for at least 24 months containing all the clinical and diagnostic information useful for the PET performance assessment and outcome. Progression-free survival (PFS) and overall survival (OS) were assessed by using the Kaplan- Meier method. The risk of progression (Hazard Ratio-HR) was computed by the Cox regression analysis.

RESULTS

Suspicion of recurrent CM was confirmed in 24/27 patients with a positive 18F-FDG-PET/CT scan. Overall, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-FDG-PET/CT were 82%, 93%, 88%, 89%, and 89%, respectively, with area under the curve being 0.87 (95%IC 0.78-0.97; p<0.05). 18F-FDG-PET/CT findings significantly influenced the therapeutic management in 18 patients (modifying therapy in 10 patients; guiding surgery in 8 patients). After 2 years of follow-up, PFS was significantly longer in patients with a negative vs. a positive 18F-FDG-PET/CT scan (90% vs 46%, p<0.05; Fig. 1). Moreover, a negative scan was associated with a significantly longer OS than a positive one (76% vs 39% after 2 years, p<0.05; Fig. 2). In addition, a positive 18F-FDG-PET/CT scan was associated with an increased risk of disease progression (HR=8.2; p<0,05).

CONCLUSION

18F-FDG-PET/CT showed a valuable diagnostic performance in patients with suspicion of recurrent CM. This imaging modality might have an important prognostic value in predicting the survival outcomes, assessing the risk of disease progression, and guiding treatment decision making.

Clinical and prognostic value of 18F-FDG-PET/CT in restaging of pancreatic cancer

AIM

The aim of this retrospective multicentre study was to evaluate the clinical and prognostic effect of fluorine-18-fluorodeoxyglucose (F-FDG)-PET/computed tomography (CT) in the restaging process of pancreatic cancer (PC).

MATERIALS AND METHODS

Data from patients treated for primary PC, who underwent F-FDG-PET/CT for suspicious of disease progression, were collected. Accuracy was assessed employing conventional diagnostic procedures, multidisciplinary team case notes, further F-FDG-PET/CT scans and/or follow-up. Receiver operating characteristic curve and likelihood ratio (LR+/-) analyses were used for completion of accuracy definition. Progression-free survival (PFS) and overall survival were assessed by using Kaplan-Meier method. The Cox proportional hazards model was used to identify predictors of outcome.

RESULTS

Fifty-two patients (33 males and 19 females, with mean age of 59 years and range: 42-78 years) with PC were finally included in our study. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of F-FDG-PET were 85, 84, 90, 76, and 84%, respectively. Area under the curve was 0.84 (95% confidence intervals: 0.72-0.96; P<0.05). LR+ and LR- were 5.3 and 0.17, respectively. F-FDG-PET/CT revealed new metastatic foci in 5/52 patients (10%) and excluded suspicious lesions in 11/52 (21%). Analysis of PFS revealed F-FDG-PET/CT positivity to be associated with a worse cumulative survival rate over a 6 and 12-month period in comparison with F-FDG-PET/CT negativity (6-month PFS 95 vs. 67%, P<0.05; 12-month PFS 81 vs. 29%, P<0.05). A negative F-FDG-PET/CT result was associated with a significantly longer overall survival than a positive one (70 vs. 26% after 2 years, P<0.05). In addition, a positive F-FDG-PET/CT scan result and an maximum standardized uptake value (SUVmax) value more than 6 were significantly associated with an increased risk of disease progression (PET positivity hazard ratio=3.9, P=0.01; SUVmax>6 h=4.2, P=0.02) and death (PET positivity hazard ratio=3.5, P=0.02; SUVmax>6 h=3.7, P=0.01).

CONCLUSION

F-FDG-PET/CT showed high diagnostic accuracy for restaging process of PC, proving also its potential value in predicting clinical outcome after primary treatment.