Posttreatment FDG PET/CT in predicting survival of patients with ovarian carcinoma

Predicting epithelial ovarian cancer prognosis: correlation of posttreatment 18F-fluorodeoxyglucose positron emission tomography-computed tomography metabolic parameters, serum carbohydrate antigen, and human epididymis protein levels with overall survival

Background

Identifying reliable prognostic indicators can aid in improving patient care. The aim of this study was to establish the association of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) whole-body metabolic parameters, serum carbohydrate antigen 125 (CA125), and human epididymis protein 4 (HE4) with overall survival (OS) in patients with epithelial ovarian cancer (EOC) after surgery combined with platinum-based chemotherapy.

Methods

From May 2014 to May 2019, a total of 79 patients with EOC who underwent posttreatment 18F-FDG PET/CT in the First Affiliated Hospital of Chongqing Medical University were included. Clinical data and laboratory indicators were obtained. The whole-body maximum standardized uptake value (WBSUVmax), whole-body metabolic tumor volume (WBMTV), and whole-body total lesion glycolysis (WBTLG) were measured and calculated on 18F-FDG PET/CT. The follow-up was conducted until February 2023, and the endpoint was death from any cause. Pearson correlation analysis, Kaplan-Meier, and Cox proportional regression were used in this study.

Results

The PET-positive (PET-P) patients had significantly decreased OS based on either Kaplan-Meier survival analysis (P<0.001) or univariate Cox regression analysis [hazard ratio (HR) =40.177, 95% confidence interval (CI): 2.690-600.134; P=0.007]. "Ln" is a logarithmic transformation with a base of "e" (natural logarithm). LnWBMTV, lnWBTLG, and therapy after PET were independent predictors of OS in a cohort of 63 PET-P patients. The difference in OS between groups sorted by the median WBMTV (4.16; P<0.001) and WBTLG (14.71; P<0.001) was statistically significant. There were statistically significant differences in CA125 and HE4 levels between patients in the PET-P and PET-negative (PET-N) groups (P<0.001). In the PET-P patient cohort, serum HE4 levels were substantially correlated with WBMTV and WBTLG. Kaplan-Meier survival analysis suggested a reduction in OS after treatment in patients with EOC positive for CA125, HE4, and PET (P<0.001).

Conclusions

Post-PET/CT treatment strategy, WBMTV, and WBTLG demonstrated significant prognostic utility in predicting posttreatment OS in patients with EOC. Patients who tested positive for both tumor markers CA125 and HE4 and had a positive PET scan demonstrated a significantly poorer prognosis in terms of posttreatment OS.

18F-FDG PET/MRI and 18F-FDG PET/CT for the Management of Gynecological Malignancies: A Comprehensive Review of the Literature

OBJECTIVE

Positron emission tomography with 2-deoxy-2-[fluorine-18] fluoro- D-glucose integrated with computed tomography (18F-FDG PET/CT) or magnetic resonance imaging (18F-FDG PET/MRI) has emerged as a promising tool for managing various types of cancer. This review study was conducted to investigate the role of 18F- FDG PET/CT and FDG PET/MRI in the management of gynecological malignancies.

SEARCH STRATEGY

We searched for relevant articles in the three databases PubMed/MEDLINE, Scopus, and Web of Science.

SELECTION CRITERIA

All studies reporting data on the FDG PET/CT and FDG PET MRI in the management of gynecological cancer, performed anywhere in the world and published exclusively in the English language, were included in the present study.

DATA COLLECTION AND ANALYSIS

We used the EndNote software (EndNote X8.1, Thomson Reuters) to list the studies and screen them on the basis of the inclusion criteria. Data, including first author, publication year, sample size, clinical application, imaging type, and main result, were extracted and tabulated in Excel. The sensitivity, specificity, and diagnostic accuracy of the modalities were extracted and summarized.

MAIN RESULTS

After screening 988 records, 166 studies published between 2004 and 2022 were included, covering various methodologies. Studies were divided into the following five categories: the role of FDG PET/CT and FDG-PET/MRI in the management of: (a) endometrial cancer (n = 30); (b) ovarian cancer (n = 60); (c) cervical cancer (n = 50); (d) vulvar and vagina cancers (n = 12); and (e) gynecological cancers (n = 14).

CONCLUSIONS

FDG PET/CT and FDG PET/MRI have demonstrated potential as non-invasive imaging tools for enhancing the management of gynecological malignancies. Nevertheless, certain associated challenges warrant attention.

Role of 18F FDG PET/CT in evaluation of post-operative ovarian carcinoma

Background

We evaluated the sensitivity, specificity and accuracy of fluorine-18-fluorodeoxyglucose with positron emission tomography/computed tomography (18F-FDG-PET/CT) in a group of patients with suspicion of ovarian cancer recurrence. It is considered a diagnostic dilemma, particularly in the 2 years following first-line therapy. CA125 serum levels computed tomography (CT) and other modalities are used during routine follow-up. These traditional modalities could provide a significant number of false-negative or equivocal results even in the presence of elevated CA125 levels. So the performance of 18F-FDG-PET/CT is essential for the optimal diagnosis of recurrence and treatment planning.

Results

Studying PET/CT behaviour in the detection of ovarian cancer recurrence, 18F-FDG-PET/CT had an accuracy of 98% with sensitivity and specificity of 98% and 100%, respectively. 18F-FDG-PET/CT had a PPV of 100% and NPV of 83%. While studying the CA125 level (> 35 U/ml) to detect the ovarian cancer recurrence during patient follow-up, the CA125 level had an accuracy of 50% with a sensitivity ratio and specificity ratio of 47% and 80%, respectively. CA-125 level had a PPV of 95% and NPV of 14%. In comparison between conventional CT and PET/CT studies, the PET/CT diagnosed local tumor recurrence in 16 patients (32%), while CT scan diagnosed local tumor recurrence in only 3 patients (6%), and PET/CT detected peritoneal recurrence in 34 patients (68%). CT scan found peritoneal deposits in 11 patients (22%), also the PET/CT showed suspicious abdominal LNS in 22 patients (44%) while, CT scan showed suspicious abdominal LNS in 4 patients (8%), and PET/CT showed suspicious pelvic LNS in 16 patients (32%). CT scan showed suspicious pelvic LNS in 7 patients (14%). PET/CT detected distant organ metastases in 18 patients (36%). CT scan detected distant organ metastasis in only 8 patients (16%). Comparison between CT and PET/CT in 32 follow-up cases for the detection of local tumor recurrence, peritoneal deposits, suspicious abdominal/pelvic LNs and distant organ metastasis. There was a statistically significant difference between CT and PET/CT the end results (p < 0.0001, p = 0.0047, p = 0.001, p = 0.03).

Conclusions

18F-FDG-PET/CT is more sensitive in detection and localization of ovarian cancer recurrence and more superior than the other imaging modalities.

A Comparative Study between 18F-FDG PET/CT and Conventional Imaging in the Evaluation of Progressive Disease and Recurrence in Ovarian Carcinoma

The aim of this study is to compare the efficiency of conventional imaging and 18F-FDG PET-CT in detecting progressive disease and recurrences over a period of one year (2018), in the case of ovarian cancer, and also to assess the importance of 18F-FDG PET/CT in changing the course of the treatment for these patients. This study included 29 patients diagnosed in various stages with ovarian carcinoma, most of them of epithelial origin. All patients were evaluated throughout their treatment using 18F-FDG PET/CT and various conventional techniques (computed tomography (CT), magnetic resonance imaging (MRI), abdominal and intravaginal ultrasound, chest X-ray). PET/CT was more useful and effective in our group of patients in detecting progressive disease compared with conventional imaging (37.93% vs. 17.24%) and also in establishing the recurrences (24.14% vs. 6.90%). Moreover, F18-FDG PET-CT led to a therapeutic change in 55.17% of the patients of our group, compared with only 17.24% after conventional imaging. This underlines the crucial aspect of the metabolic changes of tumors that should be assessed alongside the morphological ones, with PET-CT imaging remaining the only viable tool for achieving that at present. PET/CT with 18F-FDG represents one of the most important imaging techniques used in the diagnosis and management of ovarian carcinoma. Our results seem to fall in line with what other authors reported, indicating that 18F-FDG PET-CT is potentially gaining more ground in the management of ovarian carcinoma, by influencing therapeutic strategies and by being able to detect relapse and progression accurately.

Comparison of different images in gross target volume delineating on VX2 nasopharyngeal transplantation tumor models

Background: To determine the optimum conditions for diagnosis of nasopharyngeal carcinoma, we established VX2 rabbit model to delineate gross target volume (GTV) in different imaging methods. Methods: The orthotopic nasopharyngeal carcinoma (NPC) was established in sixteen New Zealand rabbits. After 7-days inoculation, the rabbits were examined by CT scanning and then sacrificed for pathological examination. To achieve the best delineation, different GTVs of CT, MRI, ¹⁸F-FDG PET/CT, and ¹⁸F-FLT PET/CT images were correlated with pathological GTV (GTVp). Results: We found 45% and 60% of the maximum standardized uptake value (SUV_max) as the optimal SUV threshold for the target volume of NPC in ¹⁸F-FDG PET/CT and ¹⁸F-FLT PET/CT images, respectively (GTV_FDG45% and GTV_FLT60%). Moreover, the GTV_MRI and GTV_CT were significantly higher than the GTVp (P ≤ 0.05), while the GTV_FDG45% and especially GTV_FLT60% were similar to the GTVp (R = 0.892 and R = 0.902, respectively; P ≤ 0.001). Conclusions: Notably, the results suggested that ¹⁸F-FLT PET/CT could reflect the tumor boundaries more accurately than ¹⁸F-FDG PET/CT, MRI and CT, which makes ¹⁸F-FLT PET-CT more advantageous for the clinical delineation of the target volume in NPC.

F-18 FDG PET/CT metabolic tumor volume predicts overall survival in patients with disseminated epithelial ovarian cancer

OBJECTIVE

We evaluated the prognostic impact of quantitative assessment by maximum standardized uptake value (SUVmax), metabolic tumour volume (MTV) and tumour lesion glycolysis (TLG) on [F-18] FDG PET/CT for patients with peritoneal carcinomatosis from epithelial ovarian cancer (EOC).

METHODS

Thirty-one patients with EOC underwent PET/CT for an early restaging after cytoreductive surgery, having been diagnosed with carcinomatosis (before chemotherapy). The SUVmax, MTV (cm³; 42% threshold) and TLG (g) were registered on residual peritoneal lesions. The patients were followed up 20±12months thereafter. The PET/CT results were compared to overall survival (OS).

RESULTS

The Kaplan-Meier survival analysis for the SUVmax did not reveal significant differences in OS (p=0.48). The MTV survival analysis showed a significant higher OS in patients presenting with a higher tumour burden than those with less tumour burden (p=0.01; 26 vs. 14 months), whereas TLG exhibited a similar trend though not significant (p=0.06). Apart from chemo-resistance, the higher the MTV, the better will be the response to chemotherapy.

CONCLUSIONS

Quantitative assessment by MTV rather than by SUVmax and TLG on PET/CT may be helpful for stratifying patients who present with peritoneal carcinomatosis from EOC, in order to implement the appropriate therapeutic regimen.