Magnetic resonance imaging/positron emission tomography provides a roadmap for surgical planning and serves as a predictive biomarker in patients with recurrent gynecological cancers undergoing pelvic exenteration

Clinical and prognostic 18F-FDG PET/CT role in recurrent vulvar cancer: a multicentric experience

PURPOSE

The aim of this retrospective multicentric study was to investigate the diagnostic performance, the prognostic value and the impact of 18F-FDG PET/CT on treatment decision-making in patients with suspected recurrent vulvar cancer (VC).

MATERIALS AND METHODS

Sixty-three patients affected by VC performed 18F-FDG-PET/CT for restaging purposes in case of suspected clinical and/or radiological recurrence. Histopatology results if available and/or clinical-imaging follow-up for at least 12 months were considered as reference standard. The diagnostic accuracy and the clinical impact of 18F-FDG PET/CT were investigated. Progression free survival (PFS) and overall survival (OS) were calculated using Kaplan-Meier curves.

RESULTS

Fifty-two (82.5%) PET/CT showed the presence of recurrence, while the remaining 11 (17.5%) were negative. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT were 100% (95%CI 93-100%), 92% (95%CI 62-100%), 98% (95%CI 89-99%), 100% and 98% (95%CI 92-100%). A relevant impact of 18F-FDG PET/CT imaging was registered in 28 cases: in 12 cases moving from local therapy to chemotherapy due to the recognition of disseminate localizations; in 10 showing the site of recurrence in presence of negative conventional imaging, and in 6 cases confirming to be true negative and avoiding unnecessary therapies. Beside advanced age and HPV status, a positive restaging 18F-FDG PET/CT scan was significantly correlated with shorter PFS and OS compared to negative scan (p < 0.001).

CONCLUSIONS

18F-FDG PET/CT demonstrated to be an accurate tool in the assessing of recurrent VC with high sensitivity and specificity and with a significant impact on clinical decision-making. Restaging 18F-FDG PET/CT findings were associated with survival.

Opportunities and Limitations of Pelvic Exenteration Surgery

PURPOSE

The practice of exenterative surgery is sometimes controversial and has garnered a certain scepticism. Surgical studies are difficult to conduct due to insufficient data. The aim of this review is to present the current standing of pelvic exenteration from a surgical, gynaecological and urological point of view.

METHODS

This review is based upon a literature review (MEDLINE (PubMed), CENTRAL (Cochrane) and EMBASE (Elsevier)) of retrospective studies on exenterative surgery from 1993-2020. Using MeSH (Medical Subject Headings) search terms, 1572 publications were found. These were evaluated and screened with respect to their eligibility using algorithms and well-defined inclusion and exclusion criteria. Therefore, the guidelines for systematic reviews (PRISMA) were used.

RESULTS

A complete tumour resection (R0) often represents the only curative option for advanced pelvic carcinomas and their recurrences. A recent systematic review showed significant symptom relief in 80% of palliative patients after pelvic exenteration. Surgical limitations (distant metastases, involvement of the pelvic wall, etc.) are diminished by adequate surgical expertise and close interdisciplinary cooperation. While the mortality rate is low (2-5%), the still relatively high morbidity rate (32-84%) can be minimized by optimizing the perioperative setting. Following exenterations, roughly 79-82% of patients report satisfying results according to PROs (patient-reported outcomes).

CONCLUSION

Due to multimodality treatment strategies combined with extended surgical expertise and patients' preferences, pelvic exenteration can be offered nowadays with low mortality and acceptable postoperative quality of life. The possibilities of surgical treatment are often underestimated. A multi-centre database (PelvEx Collaborative) was established to collect data and experiences to optimize the research in this field.

Preoperative assessment and optimisation for pelvic exenteration in locally advanced and recurrent rectal cancer: A review

The pre-operative phase in planning a pelvic exenteration or extended resections is critical to optimising patient outcomes. This review summarises the key components of preoperative assessment and planning in patients with locally advanced rectal cancer (LARC) and locally recurrent rectal cancer (LLRC) being considered for potential curative resection. The preoperative period can be considered in 5 key phases: 1) Multidisciplinary meeting (MDT) review and recommendation for neoadjuvant therapy and surgery, 2) Anaesthetic preoperative assessment of fitness for surgery and quantification of risk, 3) Shared decision making with the patient and the process of informed consent, 4) Prehabilitation and physiological optimisation 5) Technical aspects of surgical planning. This review will focus on patients who have been recommended for surgery by the MDT and have completed neoadjuvant therapy. Other important considerations beyond the scope of this review are the various neoadjuvant strategies employed which in this patient group include Total Neo-adjuvant Therapy and reirradiation. Critical to improving perioperative outcomes is the dual aim of achieving a negative resection margin in a patient fit enough for extended surgery. Advanced, realistic communication is required pre-operatively and should be maintained throughout recovery. Optimising patient's physiological and psychological reserve with a preoperative prehabilitation programme is important, with physiotherapy, psychological and nutritional input. From a surgical perspective, image based technical preoperative planning is important to identify risk points and ensure correct surgical strategy. Careful attention to the entire patient journey through these 5 preoperative phases can optimise outcomes with the accumulation of marginal gains at multiple timepoints.

The role of imaging in pelvic exenteration for gynecological cancers

Pelvic exenteration (PE) is one of the most challenging gynecologic oncologic surgeries and is an overriding term for different procedures that entail radical en bloc resection of the female reproductive organs and removal of additional adjacent affected pelvic organs (bladder, rectum, anus, etc.) with concomitant surgical reconstruction to restore bodily functions. Multimodality cross-sectional imaging with MRI, PET/CT, and CT plays an integral part in treatment decision-making, not only for the appropriate patient selection but also for surveillance after surgery. The purpose of this review is to provide a brief background on pelvic exenteration in gynecologic cancers and to familiarize the reader with the critical radiological aspects in the evaluation of patients for this complex procedure. The focus of this review will be on how imaging can aid in treatment planning and guide management.

ACR Appropriateness Criteria® Staging and Follow-up of Vulvar Cancer

Vulvar cancer is an uncommon gynecologic tumor and one of several human papillomavirus-associated malignancies. Squamous cell carcinoma is the most prevalent histologic subtype of vulvar cancer, accounting for the majority of cases. Imaging plays an important role in managing vulvar cancer. At initial diagnosis, imaging is useful to assess the size and extent of primary tumor and to evaluate the status of inguinofemoral lymph nodes. If recurrent disease is suspected, imaging is essential to demonstrate local extent of tumor and to identify lymph node and distant metastases. In this publication, we summarize the recent literature and describe the panel's recommendations about the appropriate use of imaging for various phases of patient management including initial staging, surveillance, and restaging of vulvar cancer. 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.

Staging, recurrence and follow-up of uterine cervical cancer using MRI: Updated Guidelines of the European Society of Urogenital Radiology after revised FIGO staging 2018

OBJECTIVES

The recommendations cover indications for MRI examination including acquisition planes, patient preparation, imaging protocol including multi-parametric approaches such as diffusion-weighted imaging (DWI-MR),  dynamic contrast-enhanced imaging (DCE-MR) and standardised reporting. The document also underscores the value of whole-body 18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG-PET/CT) and highlights potential future methods.

METHODS

In 2019, the ESUR female pelvic imaging working group reviewed the revised 2018 FIGO staging system, the up-to-date clinical management guidelines, and the recent imaging literature. The RAND-UCLA Appropriateness Method (RAM) was followed to develop the current ESUR consensus guidelines following methodological steps: literature research, questionnaire developments, panel selection, survey, data extraction and analysis.

RESULTS

The updated ESUR guidelines are recommendations based on ≥ 80% consensus among experts. If ≥ 80% agreement was not reached, the action was indicated as optional.

CONCLUSIONS

The present ESUR guidelines focus on the main role of MRI in the initial staging, response monitoring and evaluation of disease recurrence. Whole-body FDG-PET plays an important role in the detection of lymph nodes (LNs) and distant metastases.

KEY POINTS

• T2WI and DWI-MR are now recommended for initial staging, monitoring of response and evaluation of recurrence. • DCE-MR is optional; its primary role remains in the research setting. • T2WI, DWI-MRI and whole-body FDG-PET/CT enable comprehensive assessment of treatment response and recurrence.

Laparoscopic assessment improves case selection for exenterative surgery in recurrent cervical and endometrial cancer

The objective of this study is to evaluate the role of laparoscopy in the case selection of patients for pelvic exenteration to treat recurrent cervical or endometrial cancer. Pelvic exenteration is a rare surgical procedure performed by specialised multidisciplinary surgical teams. We performed a review of 55 consecutive laparoscopies for patients being evaluated for possible exenterative surgery for recurrent cervical or endometrial cancer at a single centre in the UK with a significant exenterative surgical practice. All patients had no evidence of metastatic disease on imaging prior to the laparoscopy. Despite thorough radiological assessment laparoscopy detected peritoneal, nodal or extrapelvic metastases in 20.8% of cases. 5.6% of the patients who underwent exenterative surgery were found to have unresectable pelvic disease intraoperatively. In these cases, the extent of disease was not determined radiologically or during the initial exploratory laparotomy. In our view, laparoscopic assessment is an essential component of the pre-operative work up of patients with recurrent cervical or endometrial cancer being considered for exenterative surgery.Impact statementWhat is already known on this subject? Pelvic exenteration is potentially curative in cases of recurrent pelvic malignancy. Case selection is essential to determine those patients without metastases and with resectable pelvic disease - this will improve patient outcomes, avoid the unnecessary morbidity of major surgery, as well as the psychological consequences of abandoned procedures. The only two previous studies, published in 1998 (Plante and Roy 1998) and 2002 (Köhler et al. 2002) have shown laparoscopic assessment to be safe and improve case selection.What do the results of this study add? This study provides evidence that in the context of modern imaging modalities, including PET-CT scans, laparoscopic assessment continues to improve case selection for exenterative surgery.What are the implications of these findings for clinical practice and/or further research? This study provides further evidence of the benefit of laparoscopy in the assessment of patients being considered for exenterative surgery for recurrent pelvic cancer. Routine laparoscopy improves case selection and will enhance patient experiences and outcomes.

The Role of Exenterative Surgery in Advanced Urological Neoplasms

Pelvic exenterative surgery is both complex and challenging, especially in the setting of locally recurrent disease. In recent decades, improved surgical techniques have facilitated more extensive resection of both locally advanced and recurrent pelvic malignancies, but its role in urological cancer surgery is highly selective. However, it remains an important part of the armamentarium for the management of bladder and prostate cancer cases where there is local invasion into adjacent organs or localized recurrence. Better diagnostics, reconstructive options and centralized care have reduced associated morbidity considerably, and it is still used rarely in palliative settings. Despite this, there is sparse prospective evidence reporting on long-term oncological or quality of life outcomes.

Utility of 18F-FDG-PET/CT imaging in patients with recurrent gynecological malignancies prior to pelvic exenteration

BACKGROUND

In patients with recurrent gynecologic malignancies isolated to the pelvis, pelvic exenteration is a potential option. 18F-Fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT), is often used to confirm no evidence of metastatic disease.

OBJECTIVE

To assess the impact of PET/CT on clinical management of patients with recurrent gynecologic malignancies being considered for pelvic exenteration.

METHODS

Patients with recurrent gynecological malignancies who underwent PET/CT imaging between 2011 and 2014 were identified. All were considered for pelvic exenteration and underwent conventional imaging with CT +/- pelvic MRI. Patient anthropometric data, disease sites, histology, stage, treatment received, and treatment plan based on PET/CT findings were extracted.

RESULTS

A total of 40 patients met inclusion criteria. In 15 (37.5%) of these patients, results of PET/CT changed the original plan of pelvic exenteration owing to metastatic disease/unresectability (11/15) or no evidence of disease on PET/CT imaging (4/15). Twenty-five (62.5%) patients had their planned surgery after PET/CT with 19 (76%) patients undergoing a completed exenteration procedure. Six (24%) patients with PET/CT indicating isolated pelvic recurrence ultimately had intra-operative findings of extra-pelvic metastasis or nodal disease and therefore the planned surgery was aborted.

CONCLUSION

In nearly 40% of patients with recurrent gynecologic malignancies being considered for radical salvage surgery, PET/CT can significantly alter the originally intended treatment and hence may reduce the number of futile surgical procedures.

[Resection of recurrent rectal cancer]

A curative treatment of locally recurrent rectal cancer (LRRC) can only be achieved with a complete resection and microscopically tumor-free surgical margins (R0). Imaging techniques are the most important investigations for the preoperative staging of local and systemic diseases. Due to substantial improvements in surgical strategies and techniques, previously unresectable tumors can now be excised. Several publications have demonstrated the oncological benefits of high sacral resection for LRRC. High subcortical sacrectomy (HiSS), extended lateral resection and extended lateral pelvic sidewall excision (ELSiE) belong to the newer surgical options. Biological meshes, various myocutaneous flaps, titanium and bone allografts can be used for reconstruction. Specialized centers provide an efficient management of complications and postoperative treatment.

Advances in surgical management for locally recurrent rectal cancer: How far have we come?

Locally recurrent rectal cancer (LRRC) is a complex disease with far-reaching implications for the patient. Until recently, research was limited regarding surgical techniques that can increase the ability to perform an en bloc resection with negative margins. This has changed in recent years and therefore outcomes for these patients have improved. Novel radical techniques and adjuncts allow for more radical resections thereby improving the chance of negative resection margins and outcomes. In the past contraindications to surgery included anterior involvement of the pubic bone, sacral invasions above the level of S2/S3 and lateral pelvic wall involvement. However, current data suggests that previously unresectable cases may now be feasible with novel techniques, surgical approaches and reconstructive surgery. The publications to date have only reported small patient pools with the research conducted by highly specialised units. Moreover, the short and long-term oncological outcomes are currently under review. Therefore although surgical options for LRRC have expanded significantly, one should balance the treatment choices available against the morbidity associated with the procedure and select the right patient for it.

Diagnostic Performance of Whole-Body PET/MRI for Detecting Malignancies in Cancer Patients: A Meta-Analysis

Background

As an evolving imaging modality, PET/MRI is preliminarily applied in clinical practice. The aim of this study was to assess the diagnostic performance of PET/MRI for tumor staging in patients with various types of cancer.

Methods

Relevant articles about PET/MRI for cancer staging were systematically searched in PubMed, EMBASE, EBSCO and the Cochrane Library. Two researchers independently selected studies, extracted data and assessed the methodological quality using the QUADAS tool. The pooled sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were calculated per patient and per lesion. The summary receiver-operating characteristic (SROC) curves were also constructed, and the area under the curve (AUC) and Q* estimates were obtained.

Results

A total of 38 studies that involved 753 patients and 4234 lesions met the inclusion criteria. On a per-patient level, the pooled sensitivity and specificity with 95% confidence intervals (CIs) were 0.93 (0.90–0.95) and 0.92 (0.89–0.95), respectively. On a per-lesion level, the corresponding estimates were 0.90 (0.88–0.92) and 0.95 (0.94–0.96), respectively. The pooled PLR, NLR and DOR estimates were 6.67 (4.83–9.19), 0.12 (0.07–0.21) and 75.08 (42.10–133.91) per patient and 10.91 (6.79–17.54), 0.13 (0.08–0.19) and 102.53 (59.74–175.97) per lesion, respectively.

Conclusion

According to our results, PET/MRI has excellent diagnostic potential for the overall detection of malignancies in cancer patients. Large, multicenter and prospective studies with standard scanning protocols are required to evaluate the diagnostic value of PET/MRI for individual cancer types.

Role of MR Imaging and FDG PET/CT in Selection and Follow-up of Patients Treated with Pelvic Exenteration for Gynecologic Malignancies

Pelvic exenteration (PE) is a radical surgical procedure used for the past 6 decades to treat locally advanced malignant diseases confined to the pelvis, particularly persistent or recurrent gynecologic cancers in the irradiated pelvis. The traditional surgical technique known as total PE consists of resection of all pelvic viscera followed by reconstruction. Depending on the tumor extent, the procedure can be tailored to remove only anterior or posterior structures, including the bladder (anterior exenteration) or rectum (posterior exenteration). Conversely, more extended pelvic resection can be performed if the pelvic sidewall is invaded by cancer. Preoperative imaging evaluation with magnetic resonance (MR) imaging and fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is central to establishing tumor resectability and therefore patient eligibility for the procedure. These imaging modalities complement each other in diagnosis of tumor recurrence and differentiation of persistent disease from posttreatment changes. MR imaging can accurately demonstrate local tumor extent and show adjacent organ invasion. FDG PET/CT is useful in excluding nodal and distant metastases. In addition, FDG PET/CT metrics may serve as predictive biomarkers for overall and disease-free survival. This pictorial review describes different types of exenterative surgical procedures and illustrates the central role of imaging in accurate patient selection, treatment planning, and postsurgical surveillance.

Image registration accuracy of an in-house developed patient transport system for PET/CT+MR and SPECT+CT imaging

OBJECTIVE

The aim of this study was to investigate the registration accuracy of a newly developed patient shuttle system that can integrate different scanners by patient transfer without repositioning for 'hardware'-based image fusion. We aimed to assess the registration accuracy of image fusion in two different settings: a trimodality PET/CT+MR system and a SPECT+CT system.

MATERIALS AND METHODS

In this prospective study, 43 patients underwent either sequential PET/CT and MR (n=31) or sequential SPECT and diagnostic CT (D-CT) (n=12). A side-loading patient shuttle system was used for patient transport. For PET/CT+MR, hardware-only coregistration was performed and then validated with anatomical landmarks on CT and MR. SPECT+D-CT image fusion was performed with external cobalt-57 markers and manual fusion. Registration accuracy was analysed by anatomical landmarks on the attenuation correction CT and the D-CT.

RESULTS

For the PET/CT+MR system, the mean offset between original CT and MR images in all 31 patients was 8.1±5.7 mm in the X-axis, 5±4 mm in the Y-axis and 4.9±5.6 mm in the Z-axis. The validation of the cobalt-57 marker-assisted SPECT+D-CT fusion yielded offsets of 0.7±1.7 mm in the X-axis, 2.1±1.7 mm in the Y-axis and 0.8±1.8 mm in the Z-axis.

CONCLUSION

Sequential PET/CT+MR and SPECT+D-CT imaging using a dedicated patient shuttle system is feasible, resulting in mean offsets between data sets of 10.7 mm using the gantry laser system and 2.4 mm with fiducial markers.

PET/MRI and PET/CT in advanced gynaecological tumours: initial experience and comparison

PURPOSE

To compare the diagnostic accuracy of PET/MRI and PET/CT for staging and re-staging advanced gynaecological cancer patients as well as identify the potential benefits of each method in such a population.

MATERIAL AND METHODS

Twenty-six patients with suspicious or proven advanced gynaecological cancer (12 ovarian, seven cervical, one vulvar and four endometrial tumours, one uterine metastasis, and one primary peritoneal cancer) underwent whole-body imaging with a sequential trimodality PET/CT/MR system. Images were analysed regarding primary tumour detection and delineation, loco-regional lymph node staging, and abdominal/extra-abdominal distant metastasis detection (last only by PET/CT).

RESULTS

Eighteen (69.2 %) patients underwent PET/MRI for primary staging and eight patients (30.8 %) for re-staging their gynaecological malignancies. For primary tumour delineation, PET/MRI accuracy was statistically superior to PET/CT (p < 0.001). Among the different types of cancer, PET/MRI presented better tumour delineation mainly for cervical (6/7) and endometrial (2/3) cancers. PET/MRI for local evaluation as well as PET/CT for extra-abdominal metastases had therapeutic consequences in three and one patients, respectively. PET/CT detected 12 extra-abdominal distant metastases in 26 patients.

CONCLUSION

PET/MRI is superior to PET/CT for primary tumour delineation. No differences were found in detection of regional lymph node involvement and abdominal metastases detection.

KEY POINTS

• PET/MRI is superior to PET/CT for primary tumour delineation • PET/CT represents a reliable tool to detect extra-abdominal distant metastasis • PET/MRI might be the preferred imaging modality for staging cervical and endometrial tumours • Whole-body staging for detection and evaluation of extra-abdominal metastases is mandatory.

Which imaging technique should we use in the follow up of gynaecological cancer?

Follow-up routines after gynaecological cancer vary. The optimal approach is unknown, and no randomised-controlled trials comparing surveillance protocols have been published. In this chapter, we summarise the diagnostic performance of ultrasound, computed tomography, and magnetic resonance imaging in the follow up of women treated for ovarian or uterine cancers. Computed tomography is today the standard imaging method for the follow up of women treated for endometrial, cervical, or ovarian cancer. Six-monthly or annual follow-up examinations have not been shown to positively affect survival. Instead, a combination of transvaginal and transabdominal ultrasound examination with clinical examination might be a more cost-effective strategy for early detection of recurrence. Positron-emission tomography might play a role in women with clinical or serological suspicion of recurrence but without evidence of disease at conventional diagnostic imaging. To create guidelines, more studies, preferably randomised-controlled trials, on follow-up strategies are needed.