[18f]fluorodeoxyglucose positron emission tomography as a useful indicator of metastatic gestational trophoblastic tumor: preliminary results in three patients

A poor prognostic male choriocarcinoma with multiple systemic metastases: a case report and the literature review

Background

Non-gestational choriocarcinoma, also known as primary choriocarcinoma, is extremely rare in men, manifesting with specific signs such as breast feminization, testicular atrophy, and loss of libido. The presentation typically includes elevated serum β-hCG levels, widespread metastatic disease, and a rapid progression of the condition.

Case report

We present a rare case of a 41-year-old man diagnosed with choriocarcinoma, exhibiting a unique combination of multiple metastases, including lung, brain, bone, and retroperitoneal lymph node metastases, as confirmed by 18F-FDG PET/CT imaging. The patient was treated with aggressive chemotherapy and pembrolizumab, and the prognosis remained poor. The patient's overall survival was a mere 5 months following diagnosis.

Conclusion

Non-gestational choriocarcinoma represents a rare entity in clinical practice and should be considered in young men presenting with gynaecomastia and elevated β-hCG levels alongside normal gonads. Thus, we advocate for a more comprehensive inquiry into medical history and a systematic examination. The 18F-FDG PET/CT examination not only visually delineates the lesion's location and extent but also serves as a cornerstone for clinical tumor staging, providing valuable support for treatment monitoring and subsequent follow-up.

18F-FDG PET/CT May Predict Tumor Type and Risk Score in Gestational Trophoblastic Disease

PURPOSE

The aim of this study was to investigate the role of 18F-FDG PET/CT in predicting pathological prognostic factors, including tumor type and International Federation of Gynecology and Obstetrics (FIGO) score, in gestational trophoblastic disease (GTD).

METHODS

Retrospective monocentric study including 24 consecutive patients who underwent to 18F-FDG PET/CT from May 2005 to March 2021 for GTD staging purpose. The following semiquantitative PET parameters were measured from the primary tumor and used for the analysis: maximum standardized uptake value (SUVmax), SUVmean, metabolic tumor volume (MTV) and total lesion glycolisis (TLG). Statistical analysis included Spearman correlation coefficient to evaluate the correlations between imaging parameters and tumor type (nonmolar trophoblastic vs postmolar trophoblastic tumors) and risk groups (high vs low, defined according to the FIGO score), whereas area under the curve (AUC) of the receiver operating characteristic (ROC) curve was used to assess the predictive value of the PET parameters. Mann-Whitney U test was used to further describe the parameter's potential in differentiating the populations.

RESULTS

SUVmax and SUVmean resulted fair (AUC, 0.783; 95% confidence interval [CI], 0.56-0.95) and good (AUC, 0.811; 95% CI, 0.59-0.97) predictors of tumor type, respectively, showing a low (ρ = 0.489, adjusted P = 0.030) and moderate (ρ = 0.538, adjusted P = 0.027) correlation. According to FIGO score, TLG was instead a fair predictor (AUC, 0.770; 95% CI, 0.50-0.99) for patient risk stratification.

CONCLUSIONS

18F-FDG PET parameters have a role in predicting GTD pathological prognostic factors, with SUVmax and SUVmean being predictive for tumor type and TLG for risk stratification.

Case Report: 18F-FDG PET/CT and Laparoscopic Nephron Sparing Surgery in the Management of Bleeding From Renal Metastases of Choriocarcinoma

Choriocarcinoma is a cancer that usually occurs in the uterus during pregnancy. Although choriocarcinoma with renal metastasis and spontaneous renal hemorrhage is very rare, it can occur. We describe a rare case of metastatic choriocarcinoma, wherein the patient presented with acute abdominal pain due to a subcapsular hematoma secondary to a bleeding renal metastasis. We performed a laparoscopic nephron sparing surgery to remove the tumor and control the bleeding. A retrospective analysis revealed that metastasis was detected on ¹⁸F-fluorodeoxyglucose PET/CT, but not on CT alone. To our knowledge, a case of choriocarcinoma with such symptoms and treatment has not been described in recent literature. Our case illustrates that acute bleeding from a renal metastasis can be effectively managed by laparoscopic nephron sparing surgery. It also demonstrates the advantage ¹⁸F-FDG PET/CT may have in the evaluation of metastatic choriocarcinoma.

[Clinical and radiological features of gestational trophoblastic tumors]

Gestational trophoblastic disease incorporates a group of diseases which differ from each other by their regressive evolution, their evolution to metastasis and to recurrence. It is a severe disease that affects women of childbearing age. Gestational trophoblastic tumors (GTT) are the malignant forms of gestational trophoblastic diseases. They are always a result of pregnancy, more often molar pregnancy (hydatidiform mole). The most common type of gestational trophoblastic tumors (GTT) is the invasive mole because, in most cases, the diagnosis is made when cancer is still confined to the uterus. Choriocarcinoma is a more rare type of tumor, often developing distant metastases. When there is a progression to a trophoblastic tumor, the assessment of locoregional extension and distant metastases is essential to establish an appropriate treatment protocol. We here report three clinical cases of GTT by describing their clinical presentations and the use of imaging techniques in the diagnosis and management of these disorders.

Historical, morphological and clinical overview of placental site trophoblastic tumors: from bench to bedside

INTRODUCTION

Placental site trophoblastic tumor (PSTT) is a form of gestational trophoblastic disease that originates from the implantation of an intermediate trophoblast. It was described for the first time by Von F. Marchand in 1895 as belonging to chorioepithelioma sui generis, a pathological condition with many variations and a progressive degree of malignancy.

METHODS

We have conducted a literature review in MEDLINE about epidemiology, etiopathogenesis and clinical features of PSTT. Moreover, a case that occurred in our institution was reported.

RESULTS

Our research has highlighted that existing published data about PSTT are not uniform. The number of cases described in the literature has updated and the clinical features of selected "case series" of patients diagnosed with PSTT were showed. The etiopathogenesis was discussed. It was noted that current prognostic factors still allow important information regarding PSTT to be obtained, albeit fragmentary.

CONCLUSIONS

The lack of uniformity in data collection seen so far has limited full knowledge of PSTT. For this reason, we suggest a model (PSTT model) that collects and unifies PSTT evidence as this would be useful to identify worldwide precise prognostic factors, which are still lacking. When PSTT is diagnosed, the proper procedure seems to be total hysterectomy, with sampling of pelvic lymph nodes and ovarian conservation. For advanced-stage diseases, (stage III and IV) a combination of surgery and polychemotherapy is suggested.

Role of PET-CT Scan in Gynaeconcology

THE PURPOSE OF THIS STUDY

This study was undertaken to evaluate the role of positron emission tomography-CT (PET-CT) in diagnosis and management of gynecological malignancies in primary and recurrent settings and also to investigate its role in inappropriately treated patients, for pretreatment evaluation (staging) to help in proper therapeutic management.

METHOD

This is a retrospective study of 56 patients of gynecological malignancy registered in Gujarat Cancer Research Institute from June 2011 to December 2013.

RESULTS

Out of 56 cases where PET was done, the results were as follows: carcinoma cervix-23, carcinoma ovary-20, carcinoma endometrium-9, carcinoma vulva-1, carcinoma vagina-2, and GTN-1. PET scan was negative in 37 % of patients where CT scan was suspicious, which changed the therapeutic modality and prevented further unnecessary interventions. In cases where clinical suspicion of recurrence was high based on rising tumor marker and CT scan was negative, subsequent PET-CT was able to pick up malignancy in 75 % cases. Eleven patients (25 %) with suspected recurrence with inconclusive CT scan and negative PET-CT scan were kept on follow-up, thus reducing further morbidity and cost.

CONCLUSION

Addition of PET-CT, a noninvasive method to the oncologist's imaging armamentarium may ultimately improve both outcomes and costs by altering management strategies in primary and recurrent settings. The potential use of PET-CT appears promising in several decision-making steps in the management of patients with gynecological malignancy. It defines the extent of metastatic disease which enables the clinician to decide regarding salvageable surgical intervention or palliative measures.

Imaging Features of Uncommon Gynecologic Cancers

OBJECTIVE

The role of imaging in patients with suspected gynecologic malignancies is to provide an accurate diagnosis to achieve the best and most tailored treatment plan. Uncommon cancers pose a distinct challenge, because current knowledge of these diseases is still limited. Our purpose is to highlight the role of cross-sectional imaging techniques, including ultrasound, CT, MRI, and PET/CT, in the diagnosis and pretreatment stratification of patients with rare gynecologic cancers.

CONCLUSION

This review shows the relevance of imaging findings for diagnosis, staging, and treatment planning in patients with uncommon uterine, cervical, vaginal, vulvar, and ovarian cancers.

Role of 18F-FDG PET in the management of gestational trophoblastic neoplasia

PURPOSE

Gestational trophoblastic neoplasia (GTN) is a rare and aggressive tumour that is usually sensitive to chemotherapy. The usefulness of conventional imaging modalities in evaluating treatment response is limited, mainly due to the difficulty in differentiating between residual tumour tissue and necrosis. The aim of the present study was to evaluate the role of FDG PET or PET/CT in primary staging and in monitoring treatment efficacy. The effect of FDG PET and combined PET/CT on the management of patients with GTN was also evaluated comparing the differences between standard treatments based on conventional imaging and alternative treatments based on PET.

METHODS

This retrospective study included 41 patients with GTN referred to San Raffaele Hospital between 2002 and 2010. All patients were studied by either PET or PET/CT in addition to conventional imaging. Of the 41 patients, 38 were evaluated for primary staging of GTN and 3 patients for chemotherapy resistance after first-line chemotherapy performed in other Institutions. To validate the PET data, PET and PET/CT findings were compared with those from conventional imaging, including transvaginal ultrasonography (TV-US) in those with uterine disease, CT and chest plain radiography in those with lung disease and whole-body CT in those with systemic metastases. Conventional imaging was considered positive for the presence of uterine disease and/or metastases when abnormal findings relating to GTN were reported. PET and PET/CT were considered concordant with conventional imaging when metabolic active disease was detected at the sites corresponding to the pathological findings on conventional imaging. In addition, in 12 of the 41 patients showing extrauterine disease, FDG PET/CT was repeated to monitor treatment efficacy, in 8 after normalization of beta human chorionic gonadotropin (βHCG) and in 4 with βHCG resistance. In some patients, PET or PET/CT findings led to an alternative nonconventional treatment, and this was considered a change in patient management for the study analysis.

RESULTS

When compared to TV-US, chest radiography and CT for staging, PET showed a concordance in 91 %, 84 % and 81 % of patients, respectively. In 8 of the 41 patients with extrauterine disease during staging, PET/CT showed a complete response to therapy after βHCG normalization. PET and PET/CT identified the sites of persistent disease in all seven high-risk patients with βHCG resistance, of whom four underwent second-line chemotherapy, two surgical removal of resistant disease instead of additional chemotherapy, and one surgical removal of resistant disease and second-line chemotherapy with subsequent negative βHCG.

CONCLUSION

In staging, PET cannot replace conventional imaging and does not show any information in addition to that shown by conventional imaging. The additional value of PET/CT in GTN with respect to conventional imaging is found in patients with high-risk disease. PET can identify the sites of primary and/or metastatic disease in patients with persistent high levels of βHCG after first-line chemotherapy and may be of additional value in patient management for guiding alternative treatment.

Gestatational trophoblastic disease: multimodality imaging assessment with special emphasis on spectrum of abnormalities and value of imaging in staging and management of disease

Gestational trophoblastic disease is a spectrum of disorders of varying malignant potential arising from trophoblastic cells and encompassing hydatidiform moles and persistent trophoblastic neoplasia. Ultrasound is the initial imaging investigation of choice when gestational trophoblastic disease is suspected. Complete hydatiform mole, the most common form of molar pregnancy, usually has a characteristic "cluster of grapes" appearance, especially on second-trimester ultrasounds. Persistent trophobastic neoplasia usually appears as a focal, hypervascular myometrial mass on pelvic ultrasound. Pelvic magnetic resonance imaging is often used as a problem-solving tool in equivocal or complicated cases of gestational trophoblastic disease to assess the degree of invasion into the myometrium and surrounding tissues. Chest x-ray, brain magnetic resonance imaging, and body computed tomography scans are primarily used for the evaluation of metastatic disease, which usually occurs in the context of choriocarcinomas. Choriocarcinoma metastases are usually hypervascular and have a tendency to bleed, features that are reflected in their imaging appearance.

Detection of primary choriocarcinoma in the mediastinum by F-18 FDG positron emission tomography

A 31-year-old woman with a history of infection with human papilloma virus was found to have an elevated human chorionic gonadotropin level (beta-HCG) of more than 9000 IU/L in January 2006. The patient reported an irregular menstrual cycle. Extensive clinical work-up including gynecologic examinations with laparoscopy, hysteroscopy, and curettage were performed but no pathologic explanation of this elevated beta-HCG could be found. In the initial computed tomography (CT) of the abdomen and the thorax, a tumor could not be detected. Based on a clinical decision, chemotherapy with methotrexate in a dose of 1 mg/kg body weight was started. Four months after beginning of the chemotherapy the beta-HCG level dropped to 3048 IU/L. At this time a first F-18 FDG PET was performed and the findings were negative. After completion of 7 cycles of chemotherapy the beta-HCG level rose again. In a second F-18 FDG PET in August 2006 focal, intense and pathologic F-18 FDG accumulation with a SUV max. of 5.4 was seen in the mediastinum in the region of the thymus. At this time the beta-HCG level was 7000 IU/L. In a subsequent CT of the chest a retrosternal mass of 4 x 1.7 cm was detected with contrast enhancement. Resection of the tumor and thymus gland demonstrated a choriocarcinoma in part adjacent to the thymus and in part in the thymus. Postoperative beta-HCG levels dropped to 105 IU/L.

Positron emission tomography imaging for gynecologic malignancy

PURPOSE OF REVIEW

The utility of positron emission tomography (PET) in gynecologic malignancy has increased rapidly in recent years. This review examines publications in this area.

RECENT FINDINGS

PET scans are mostly performed using 18-fluorodeoxyglucose (FDG-PET). It is valuable in primary staging of untreated advanced cervical cancer, for posttreatment unexplained tumor marker elevation and restaging of potentially curable recurrent cervical cancer. Its value in early-stage cervical cancer is limited. In ovarian cancer, sequential imaging predicts response to neoadjuvant chemotherapy and survival. It also provides benefits when increases in serum CA 125 or computed tomography/magnetic resonance imaging defined recurrence is noted but biopsy deemed infeasible. A few studies have shown that FDG-PET may facilitate optimal management of endometrial cancer, especially for posttherapy surveillance and after salvage therapy. FDG-PET is potentially useful in selected gestational trophoblastic neoplasia by monitoring response and localizing viable tumors after chemotherapy. Scanty studies have been reported in vulvar and vaginal cancer. The methodology and prospects of using integrated PET/computed tomography in the management of gynecological cancer are discussed. Other PET compounds are briefly introduced.

SUMMARY

The role of PET or PET/computed tomography has evolved from a diagnostic tool into a potential indicator of response to treatment and prognosis. Evaluating this tool by clinical impact is an attractive end point.

Radiology of gestational trophoblastic neoplasia

Gestational trophoblastic neoplasia (GTN) encompasses a broad spectrum of placental lesions from the pre-malignant hydatidiform mole (complete and partial) through to the malignant invasive mole, choriocarcinoma and rare placental site trophoblastic tumour (PSTT). Ultrasound remains the radiological investigation of choice for initial diagnosis, and it can also predict invasive and recurrent disease. Magnetic resonance imaging is of invaluable use in assessing extra-uterine tumour spread, tumour vascularity, and overall staging. Positron emission tomography and computed tomography undoubtedly have a role in recurrent and metastatic disease, while angiography has a place in disease and complication management. This review will describe the relevant pathophysiology and natural history of GTN, and the use of imaging techniques in the diagnosis and management of these conditions.

Positron emission tomography in gynecologic cancer

Most positron emission tomography (PET) imaging studies in gynecologic cancer are performed using (18)F-fluorodeoxyglucose (FDG). It contributes valuable information in primary staging of untreated advanced cervical cancer, in the post-treatment surveillance with unexplained tumor marker (such as squamous cell carcinoma antigen [SCC-Ag]) elevation or suspicious of recurrence, and restaging of potentially curable recurrent cervical cancer. Its value in early-stage resectable cervical cancer is questionable. In ovarian cancer, FDG-PET provides benefits for those with plateaued or increasing abnormal serum CA 125 (>35 U/mL), computed tomography and/or magnetic resonance imaging (CT-MRI) defined localized recurrence feasible for local destructive procedures (such as surgery, radiotherapy, or radiofrequency ablation), and clinically suspected recurrent or persistent cancer for which CT-guide biopsy cannot be performed. The role of FDG-PET in endometrial cancer is relatively less defined because of the lack of data in the literature. In our prospective study, FDG-PET coupled with MRI-CT may facilitate optimal management of endometrial cancer in well-selected cases. The clinical impact was positive in 29 (48.3%) of the 60 scans, 22.2% for primary staging, 73.1% for post-therapy surveillance, and 57.1% after salvage therapy, respectively. Scant studies have been reported in the management of vulvar cancer using FDG-PET. More data are needed. Gestational trophoblastic neoplasia is quite unique in biological behavior and clinical management. Our preliminary results suggest that FDG-PET is potentially useful in selected gestational trophoblastic neoplasia by providing a precise metastatic mapping of tumor extent up front, monitoring response, and localizing viable tumors after chemotherapy. The evaluation of a diagnostic tool, such as PET, is usually via comparing the diagnostic efficacy (sensitivity, specificity, etc), by using a more sophisticated receiver operating curve method, or the proportion of treatment been modified. Evaluating PET by clinical benefit is specific to the individual tumor and an attractive new endpoint.

Exclusion of lung metastases in placental site trophoblastic tumor using [18F]fluorodeoxyglucose positron emission tomography: a case report

BACKGROUND

We present the first case using [18F]fluorodeoxyglucose positron emission tomography (PET) for the evaluation of multiple lung nodules in a woman with placental site trophoblastic tumor (PSTT) and history of pulmonary tuberculosis.

CASE

PSTT was diagnosed by endometrial biopsy in a 38-year-old female, 11 months after an abortion. She had received medical treatment for pulmonary tuberculosis 8 years ago. Nodular lung lesions in upper and lower lung fields were noted on the chest X-ray and computed tomography, which was not shown on PET. She then received hysterectomy and complete remission of serum beta-hCG titer with stationary lung lesions in follow-up images were noticed thereafter.

CONCLUSION

PET, as adjuvant study to conventional images, may help in the differentiation of chest lesions in PSTT.

The role of 18F-fluorodeoxyglucose positron emission tomography in gestational trophoblastic tumours: a pilot study

PURPOSE

We conducted a pilot trial to evaluate the value of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in gestational trophoblastic tumours (GTTs).

METHODS

Patients with placental site trophoblastic tumour (PSTT), high-risk GTT (World Health Organisation score > or =8, disease onset at postpartum or greater than 6 months after antecedent pregnancy), metastatic GTT, recurrent/resistant GTT after chemotherapy, or post-molar GTT with unexplained abnormal beta-hCG regression and patients undergoing re-evaluation after salvage treatment were enrolled. PET was undertaken within 1 week after computed tomography (CT). Clinical impacts of additional PET were determined on a scan basis.

RESULTS

A total of 14 patients were recruited. Sixteen PET scans were performed, with one patient having three serial studies. Benefits of additional PET were seen in 7 of 16 (43.8%) scans; these benefits included disclosure of chemotherapy-resistant lesions (n = 2), exclusion of false-positive CT lesions (n = 1), detection of an additional lesion not found by conventional imaging (n = 1) in high-risk GTT at the start of primary chemotherapy, and confirmation of complete response to treatment for PSTT or to salvage therapy for recurrent/resistant GTT (n = 3). On the other hand, in two instances there were false-negative PET findings, six scans yielded no benefit, and one showed an indeterminate lesion.

CONCLUSION

Our preliminary results suggest that 18F-FDG PET is potentially useful in selected patients with GTT by providing precise mapping of metastases and tumour extent upfront, by monitoring treatment response and by localising viable tumours after chemotherapy. A larger study is necessary to further define the role of 18F-FDG PET in GTT.

Occult choriocarcinoma discovered by positron emission tomography/computed tomography imaging following a successful pregnancy

BACKGROUND

Positron emission tomography (PET) is commonly used to detect occult or recurrent malignancy, including tumors of the female genital tract. Recently, there have been reports of PET scans used in patients with Gestational Trophoblastic Disease (GTD).

CASE

A 22-year-old female presented with vaginal bleeding and elevated beta-hCG 7 months after a spontaneous vaginal delivery of a healthy infant. She had a history of molar pregnancy and persistent GTD requiring multi-agent chemotherapy. Metastatic evaluation with computed tomography and magnetic resonance imaging showed no evidence of GTD. A positron emission tomography/computed tomography (PET/CT) scan revealed a focus of metabolic activity in the left pelvis. The patient underwent an exploratory laparotomy that revealed metastatic choriocarcinoma in the left broad ligament.

CONCLUSION

PET/CT may be useful in the evaluation of occult choriocarcinoma when conventional imaging fails to identify metastatic disease.