Clinical impact of FDG PET-CT on the management of patients with locally advanced cervical carcinoma

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.

Radiation oncology management of stage III and IVA cervical carcinoma

Worldwide, stage III-IVA carcinomas of the uterine cervix comprise a significant proportion of cases at presentation, and have a higher rate of recurrence and worse overall survival. This review will discuss the epidemiology, prevention strategies, clinical presentation, and treatment recommendations for stage III-IVA cervical cancer. The focus will be on the role of radiation therapy, concurrent chemoradiotherapy, and brachytherapy, including the potential benefits and anticipated toxicities. The unique challenges and considerations of fistula formation and approaches to management will be highlighted, and follow-up care and future directions discussed. As low and middle income countries bear the highest burden of advanced stage carcinoma of the uterine cervix, this review will address the unique needs of global communities.

Assessment of retroperitoneal lymph node status in locally advanced cervical cancer

Background

The assessment of retroperitoneal lymph node status in patients with locally advanced cervical cancer is still a problem. This study aimed to explore the choice of these assessment methods.

Methods

Laparoscopic retroperitoneal lymphadenectomy was performed in 96 patients with advanced cervical cancer. The positive rates of lymph node metastasis were analyzed. The values of computed tomography lymph node minimum axial diameter (MAD) and squamous cell carcinoma antigen (SCC-Ag), and their combination in predicting retroperitoneal lymph node metastasis were compared. High-risk factors for common iliac lymph node (CILN) and/or para-aortic lymph node (PALN) metastasis were analyzed.

Results

The lymph node metastasis rate was 62.50% and the CILN and/or PALN metastasis rate was 31.25%. Overall, 96 patients had 172 visible lymph nodes. The positive rate of lymph node metastasis was significantly higher in the MAD ≥1.0 cm group (83.33%) than in the 0.5 cm ≤ MAD < 1.0 cm group (26.82%). The critical values of MAD and SCC-Ag in determining lymph node metastasis were 1.0 cm and 5.2 ng/mL, respectively. The accuracy, specificity, and Youden index of MAD ≥1.0 cm combined with SCC-Ag ≥ 5.2 ng/mL for evaluating lymph node metastasis were 75.71%, 100%, and 0.59, respectively, and were significantly different from the values for the MAD ≥1.0 cm (72.09%, 80.56%, and 0.47, respectively) and SCC-Ag ≥ 5.2 ng/mL (71.43%, 68.97%, and 0.42, respectively) groups. Correlation analysis showed that non-squamous cell carcinoma, pelvic lymph node (PLN) MAD ≥1.0 cm plus number ≥ 2, and 1 PLN MAD ≥1.0 cm with CILN and/or PALN MAD 0.5–1.0 cm were risk factors for CILN and/or PALN metastasis.

Conclusion

Patients with MAD ≥1.0 cm and SCC-Ag ≥ 5.2 ng/mL, as well as high risk factors for CILN and/or PALN metastasis, should undergo resection of enlarged lymph nodes below the common iliac gland and lymphadenectomy of CILN/PALN to reduce tumor burden and to clarify lymph node metastasis status for accurate guidance in follow-up treatment. Patients with MAD < 1.0 cm and SCC-Ag < 5.2 ng/mL may be treated with chemoradiotherapy directly based on imaging, given the low lymph node metastasis rate.

2018 FIGO Staging Classification for Cervical Cancer: Added Benefits of Imaging

Cervical cancer is the fourth most common cancer in women of all ages worldwide. The disease is staged using the International Federation of Gynecology and Obstetrics (FIGO) system, which was updated in 2018. The authors explain the key changes from the 2009 version and the rationale behind them. The changes have been made to reflect common clinical practice, differentiate prognostic outcomes, and guide treatment stratification. Treatment options are dependent on the stage of disease and include fertility-sparing and non-fertility-sparing surgical options as well as chemoradiotherapy for locally advanced disease. The updated FIGO staging gives added importance to MRI as a method of accurately measuring tumor size and depicting the presence of parametrial involvement. With the inclusion of lymph node involvement in the updated 2018 FIGO staging, cross-sectional imaging-and in particular, fluorodeoxyglucose PET/CT-has an increasing role in the depiction of nodal disease. Understanding the radiologic techniques used, the literature supporting them, and common imaging pitfalls ensures accurate staging of disease and optimization of treatment. ^©RSNA, 2020 See discussion on this article by Javitt (pp 1823-1824).

FDG-PET Imaging in Cervical Cancer

FDG-PET/CT has an established role in the initial staging of locally advanced cervical cancers, particularly in evaluation of nodal disease and distant metastases. It is common practice to perform FDG-PET/CT 3 months postcompletion of chemoradiotherapy as it can predict outcome and be used to tailor management, including adjuvant therapy and follow-up. It is also routinely used prior to pelvic exenterative surgery to ensure there is no disease outside the pelvis. There is growing evidence that FDG-PET-derived parameters are prognostic and could potentially be used to tailor therapy. This review outlines the use of FDG-PET/CT imaging in cervical cancer.

18F-FDG PET/CT in locally advanced cervical cancer: A review

Cervical cancer is the second most common gynecological cancer worldwide. In locally advanced cervical cancer, ¹⁸F-FDG PET/CT has become important in the initial staging, particularly in the detection of nodal and distant metastasis, aspects with treatment implications and prognostic value. The aims of this study were to review the role of ¹⁸F-FDG PET/CT in uterine cervical cancer, according to the guidelines of the main scientific institutions (FIGO, NCCN, SEGO, SEOM, ESGO, and ESMO) and its diagnostic accuracy compared to conventional radiological techniques, as well as to review the acquisition protocol and its utility in radiotherapy planning, response assessment and detection of recurrence.

18F-FDG-PET/CT guided external beam radiotherapy volumes in inoperable uterine cervical cancer

BACKGROUND

In patients with advanced stage cancer of the uterine cervix who undergo irradiation with curative intent, there is the necessity to treat all suspicious nodes on imaging. Our hypothesis was that adding fluorodeoxyglucose positron emission computer tomography/computer tomography (FDG-PET/CT) to the imaging workup would alter the external beam radiotherapy (EBRT) treatment plan, either resulting in an extended external beam radiotherapy (EBRT) field to the para-aortal region or an additional boost to suspicious nodes. Since extended field radiotherapy or additional boost can cause toxicity, our secondary aim was to assess the incidence of severe late bowel toxicity in patients treated with extended para-aortal EBRT-field and boost compared to elective pelvic radiotherapy.

METHODS

Eighty-eight patients were enrolled. First, the optimal radiation treatment plan (EBRT and boost) was retrospectively determined based on magnetic resonance imaging (MRI) or FDG-PET/CT. Second, the severe bowel toxicity caused by the extended para-aortal field was assessed, based on the executed radiotherapy.

RESULTS

Based on MRI 8/88 patients would receive EBRT with para-aortic extension, this was 21/88 for FDG-PET/CT. Based on MRI 47/704 lymph node regions would receive additional boost, while based on PET/CT 91/704. Late severe bowel toxicity was seen in 12/84 patients, 6/65 in the group who received elective pelvic irradiation and 6/19 with para-aortal EBRT and boost at common iliac and/or para-aortal lymph nodes. Significant worse overall survival was seen of patients who needed para-aortal irradiation.

CONCLUSIONS

Addition of FDG-PET/CT leads to an extension of the elective EBRT volume and more suspicious lymph nodes receive a boost. However, when deciding to intensify radiation therapy, late severe bowel toxicity has to be taken into account.

Molecular Imaging Using PET/CT for Radiation Therapy Planning for Adult Cancers: Current Status and Expanding Applications

Accurate tumor delineation is a priority in radiation therapy (RT). Metabolic imaging has a key and evolving role in target volume selection and delineation. This is especially so for non-small cell lung cancer, squamous cell cancer of the head and neck, and lymphoma, for which positron emission tomography/computed tomography (PET/CT) is complimentary to structural imaging modalities, not only in delineating primary tumors, but also often in revealing previously undiagnosed regional nodal disease. At some sites, PET/CT has been confirmed to enable target size reduction compared with structural imaging alone, with enhanced normal tissue sparing and potentially allowing for dose escalation. These contributions often dramatically affect RT strategies. However, some limitations exist to the use of fluorodeoxyglucose-PET in RT planning, including its relatively poor spatial resolution and partial voluming effects for small tumors. A role is developing for contributions from metabolic imaging to RT planning at other tumor sites and exciting new applications for the use of non-fluorodeoxyglucose metabolic markers for RT planning.

Application of magnetic resonance imaging in diagnosis of Uterus Cervical Carcinoma

BACKGROUND AND OBJECTIVE

Effective treatment of Uterus Cervical Carcinoma (UCC) rely heavily on the precise pre-surgical staging. The conventional International Federation of Gynecology and Obstetrics (FIGO) system based on clinical examination is being applied worldwide for UCC staging. Yet its performance just appears passable. Thus, this study aims to investigate the value of applying Magnetic Resonance Imaging (MRI) with clinical examination in staging of UCC.

MATERIALS AND METHODS

A retrospective dataset involving 164 patients diagnosed with UCC was enrolled in this study. The mean age of this study population was 46.1 years (range, 28-#x2013;75 years). All patients underwent operations and UCC types were confirmed by pathological examinations. The tumor stages were determined by two experienced Gynecologist independently based on FIGO examinations and MRI. The diagnostic results were also compared with the post-operative pathologic reports. Statistical data analysis on diagnostic performance was then done and reported.

RESULTS

The study results showed that the overall accuracy of applying MRI in UCC staging was 82.32%, while using FIGO staging method, the staging accuracy was 59.15%.

CONCLUSIONS

MRI is suitable to evaluate tumor extent with high accuracy, and it can offer more objective information for the diagnosis and staging of UCC. Compared with clinical examinations based on FIGO, MRI illustrated relatively high accuracy in evaluating UCC staging, and is worthwhile to be recommended in future clinical practice.

Multiparametric [18F]Fluorodeoxyglucose/ [18F]Fluoromisonidazole Positron Emission Tomography/ Magnetic Resonance Imaging of Locally Advanced Cervical Cancer for the Non-Invasive Detection of Tumor Heterogeneity: A Pilot Study

Objectives

To investigate fused multiparametric positron emission tomography/magnetic resonance imaging (MP PET/MRI) at 3T in patients with locally advanced cervical cancer, using high-resolution T2-weighted, contrast-enhanced MRI (CE-MRI), diffusion-weighted imaging (DWI), and the radiotracers [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) and [¹⁸F]fluoromisonidazol ([¹⁸F]FMISO) for the non-invasive detection of tumor heterogeneity for an improved planning of chemo-radiation therapy (CRT).

Materials and Methods

Sixteen patients with locally advanced cervix were enrolled in this IRB approved and were examined with fused MP [¹⁸F]FDG/ [¹⁸F]FMISO PET/MRI and in eleven patients complete data sets were acquired. MP PET/MRI was assessed for tumor volume, enhancement (EH)-kinetics, diffusivity, and [¹⁸F]FDG/ [¹⁸F]FMISO-avidity. Descriptive statistics and voxel-by-voxel analysis of MRI and PET parameters were performed. Correlations were assessed using multiple correlation analysis.

Results

All tumors displayed imaging parameters concordant with cervix cancer, i.e. type II/III EH-kinetics, restricted diffusivity (median ADC 0.80x10^-3mm²/sec), [¹⁸F]FDG- (median SUV_max16.2) and [¹⁸F]FMISO-avidity (median SUV_max3.1). In all patients, [¹⁸F]FMISO PET identified the hypoxic tumor subvolume, which was independent of tumor volume. A voxel-by-voxel analysis revealed only weak correlations between the MRI and PET parameters (0.05–0.22), indicating that each individual parameter yields independent information and the presence of tumor heterogeneity.

Conclusion

MP [¹⁸F]FDG/ [¹⁸F]FMISO PET/MRI in patients with cervical cancer facilitates the acquisition of independent predictive and prognostic imaging parameters. MP [¹⁸F]FDG/ [¹⁸F]FMISO PET/MRI enables insights into tumor biology on multiple levels and provides information on tumor heterogeneity, which has the potential to improve the planning of CRT.