Clinical value of fluorine-18 2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography in penile cancer

Targeting Oncometabolites in Peritoneal Cancers: Preclinical Insights and Therapeutic Strategies

Peritoneal cancers present significant clinical challenges with poor prognosis. Understanding the role of cancer cell metabolism and cancer-promoting metabolites in peritoneal cancers can provide new insights into the mechanisms that drive tumor progression and can identify novel therapeutic targets and biomarkers for early detection, prognosis, and treatment response. Cancer cells dynamically reprogram their metabolism to facilitate tumor growth and overcome metabolic stress, with cancer-promoting metabolites such as kynurenines, lactate, and sphingosine-1-phosphate promoting cell proliferation, angiogenesis, and immune evasion. Targeting cancer-promoting metabolites could also lead to the development of effective combinatorial and adjuvant therapies involving metabolic inhibitors for the treatment of peritoneal cancers. With the observed metabolomic heterogeneity in cancer patients, defining peritoneal cancer metabolome and cancer-promoting metabolites holds great promise for improving outcomes for patients with peritoneal tumors and advancing the field of precision cancer medicine. This review provides an overview of the metabolic signatures of peritoneal cancer cells, explores the role of cancer-promoting metabolites as potential therapeutic targets, and discusses the implications for advancing precision cancer medicine in peritoneal cancers.

Diagnostic Performance of 18F-FDG PET/CT for Lymph Node Staging in Penile Cancer

OBJECTIVE

The purpose of the current study was to evaluate the diagnostic accuracies of 18F-FDG PET/CT for detection of lymph node (LN) metastasis in penile cancer (PeCA) patients through a systematic review and meta-analysis.

PATIENTS AND METHODS

The PubMed, Cochrane database, and Embase database, from the earliest available date of indexing through August 31, 2021, were searched for studies evaluating diagnostic performance of 18F-FDG PET/CT for detection of metastatic LN in PeCA patients. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR-, respectively), and constructed summary receiver operating characteristic curves.

RESULTS

Across 12 studies (479 patients), the pooled sensitivity of 18F-FDG PET/CT was 0.87 (95% confidence interval [CI], 0.79-0.92) and the pooled specificity was 0.88 (95% CI, 0.79-0.93). Likelihood ratio syntheses gave an overall LR+ of 7.2 (95% CI, 3.9-13.1) and LR- of 0.15 (95% CI, 0.1-0.24). The pooled diagnostic odds ratio was 47 (95% CI, 19-116). In meta-regression analysis, no variable was the source of the study heterogeneity.

CONCLUSIONS

18F-FDG PET/CT showed a good diagnostic performances for detection of metastatic LN in PeCA patients. Also, 18F-FDG PET/CT revealed similar diagnostic accuracy for detection of inguinal and pelvic LN metastasis in PeCA patients.

Carcinoma Penis Manifesting as Upfront Supraclavicular Lymph Node Metastases Detected by 18F-Fluorodeoxyglucose Positron Emission Tomography Scan: Report of an Extremely Rare and Aggressive Case

Carcinoma penis is a rare malignancy accounting 0.5 to 1% cases in the developed countries with a slightly higher incidence in the developing nations. Slow locoregional progression is characteristic of penile carcinoma and distant metastases are very uncommon. We hereby report a case of highly aggressive squamous cell penile carcinoma in a 46-year-old male with fulminant upfront distant dissemination to left supraclavicular lymph nodes without involving the inguinal and pelvic nodes detected by whole-body ¹⁸ F-fluorodeoxyglucose positron emission tomography scan. The scan also detected lytic destructive lesion involving the pelvic and adjacent bones with infiltration of skeletal muscles. He was treated with palliative radiotherapy to the weight-bearing sites followed by systemic chemotherapy. A thorough review of literature reveals that our case may be one of the rarest cases ever reported in world literature where an asymptomatic penile carcinoma presents with upfront supraclavicular lymph node metastasis bypassing the inguinal, pelvic, and retroperitoneal lymph node chains.

Carcinoma penis manifesting as upfront supraclavicular lymph node metastases detected by 18F-fluorodeoxyglucose positron emission tomography scan: Report of an extremely rare and aggressive case

Carcinoma penis is a rare malignancy accounting 0.5%-1% of cases in the developed countries with a slightly higher incidence in the developing nations. Slow locoregional progression is characteristic of penile carcinoma (PC) and distant metastases are very uncommon. We hereby report a case of highly aggressive squamous cell PC in a 46-year-old male with fulminant upfront distant dissemination to left supraclavicular lymph nodes (LNs) without involving the inguinal and pelvic nodes detected by whole-body ¹⁸F-fluorodeoxyglucose positron-emission tomography scan. The scan also detected lytic destructive lesion involving the pelvic and adjacent bones with infiltration of skeletal muscles. He was treated with palliative radiotherapy to the wight-bearing sites followed by systemic chemotherapy. A thorough review of literature reveals that our case may be one of the rarest cases ever reported in world literature where an asymptomatic PC presents with upfront supraclavicular LN metastasis bypassing the inguinal, pelvic, and retroperitoneal LN chains.

A 25-year perspective on advances in an understanding of the biology, evaluation, treatment and future directions/challenges of penile cancer

Squamous cell carcinoma of the penis (SCCP) is uncommon in some countries (including the U.S.), but is an important malignancy elsewhere. As a rare disease, progress has been slow compared to more common tumor types discussed in this anniversary issue and most often limited to single-center or retrospective datasets.  In this section we describe developments leading to the current standard approach with current research questions.

F-18 Fluorodeoxyglucose Positron Emission Tomography with Computed Tomography Has High Diagnostic Value for Pelvic and Distant Staging in Patients with High-risk Penile Carcinoma

BACKGROUND

For penile cancer patients with pelvic metastases, multimodal treatment is advised, but pelvic lymph node metastases are often found upon surgical resection only. Early selection for multimodal treatment requires reliable noninvasive staging.

OBJECTIVE

To evaluate the diagnostic value of ¹⁸F-fluorodeoxyglucose positron emission tomography with computed tomography (FDG-PET/CT) for staging pelvic lymph nodes and distant metastases in high-risk penile cancer patients.

DESIGN, SETTING, AND PARTICIPANTS

FDG-PET/CT scans performed in patients with clinically overt inguinal lymph node metastases and/or high-risk primary tumors (bulky T3 or T4) were retrospectively analyzed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

All scans were reviewed by two independent nuclear medicine physicians staging the pelvic nodes and distant metastases. FDG-PET/CT findings were compared with histology after node dissection if available, or with positive imaging or follow-up of at least 1 yr.

RESULTS AND LIMITATIONS

Between 2006 and 2016, 61 patients met the inclusion criteria. For staging of pelvic nodes, sensitivity was 85% (specificity 75%, negative predictive value [NPV] 90%, and positive predictive value [PPV] 65%). For the detection of distant metastases, FDG-PET/CT had a PPV of 93%. Results are limited by the retrospective design and the lack of direct comparison with CT scanning alone.

CONCLUSIONS

FDG-PET/CT has high sensitivity and a high NPV for staging of pelvic lymph nodes in high-risk penile cancer. It also has a high PPV for the detection of distant metastases, which were found in 23% of patients. Therefore, FDG-PET/CT enables early selection for multimodal treatment of patients with pelvic metastases and may help avoid futile treatment of patients with distant metastases.

PATIENT SUMMARY

We studied whether positron emission tomography with computed tomography (PET/CT) scans in patients with advanced penile cancer can detect metastases before lymph node surgery is done. PET/CT scans can detect or rule out pelvic lymph node metastases, and can detect distant metastases. This helps in making timely treatment decisions (before surgery).

Management of the penile squamous cell carcinoma patient after node positive radical inguinal lymph node dissection: current evidence and future prospects

PURPOSE OF REVIEW

The level of evidence for current (adjuvant) treatment strategies after node positive inguinal lymphadenectomy is relatively low because of a paucity of prospective studies and controversy exist between the two major guidelines. The present review aims to provide a review of current literature on the available treatment options of patients after a tumor positive inguinal lymph node dissection.

RECENT FINDINGS

Patients without inguinal extranodal extension or less than two tumor positive inguinal nodes are at low risk of ipsilateral pelvic nodal disease. Patients with pN1 disease are unlikely to benefit from adjuvant treatment, whereas patients with pN2 disease might benefit from adjuvant radiotherapy. For patients with high risk of pelvic nodal disease, prophylactic pelvic lymph node dissection (PLND) is advised by current guidelines. The InPACT study investigates whether adjuvant chemoradiotherapy could be used instead of prophylactic PLND. Subgroup analyses of retrospective cohorts suggest that patients with pN3 disease based on tumor positive pelvic nodes may benefit from adjuvant radiotherapy or chemotherapy. Given the weak level of evidence and substantial toxicity associated with current regimens, adjuvant chemotherapy cannot be generally recommended.

SUMMARY

Despite current treatment strategies, patients with pN2-pN3 disease still have a poor prognosis. Prospective international multicenter studies are necessary to identify the best treatment options for patients with advanced node positive penile squamous cell carcinoma.

FDG PET Hybrid Imaging

Molecular imaging with positron emission tomography (PET) using tumour-seeking radiopharmaceuticals has gained wide acceptance in oncology with many clinical applications. The hybrid imaging modality PET/CT (computed tomography) allows assessing molecular as well as morphologic information at the same time. Therefore, PET/CT represents an efficient tool for whole-body staging and re-staging within one imaging modality. In oncology, the glucose analogue 18-F-fluorodeoxyglucose (FDG) is the most widely used PET/CT radiopharmaceutical in clinical routine. FDG PET and FDG PET/CT have been used for staging and re-staging of tumour patients in numerous studies. This chapter will discuss the use and the main indications of FDG PET/CT in oncology with special emphasis on lung cancer, lymphoma, head and neck cancer, melanoma and breast cancer (among other tumour entities). A review of the current literature is given with respect to primary diagnosis, staging and diagnosis of recurrent disease. Besides its integral role in diagnosis, staging and re-staging of disease in oncology, there is increasing evidence that FDG PET/CT can be used for therapy response assessment (possibly influencing therapeutic management and treatment planning) by evaluating tumour control, which will also be discussed in this chapter.

Detection of lymph node metastases in penile cancer

Penile cancer (PC) is a relatively rare malignancy in the United States (US) but a greater concern in developing nations. Lymph node imaging remains critical to the staging and treatment of this disease as metastases develop in a predictable, anatomic fashion. Early surgical intervention remains a mainstay in treatment and imaging often aids in decision making. This review highlights the indications for imaging in both low-stage and advanced disease. Furthermore, we discuss the benefits and limitations of currently available imaging for staging of inguinal and pelvic lymph nodes in PC and novel modalities in development.

Advancements in staging and imaging for penile cancer

PURPOSE OF REVIEW

We review recent advancements in staging and imaging of penile cancer, including surveillance after therapy.

RECENT FINDINGS

For cN0 patients, the sentinel lymph node biopsy is currently considered the preferred way for invasive staging. It has largely replaced other modalities such as staging inguinal lymphadenectomy. Its diagnostic value increases when combined with other staging modalities such as ultrasound with fine-needle aspiration cytology (US-FNAC) or fluorodeoxyglucose-PET with computed tomography (PET/CT). In patients with palpably suspicious nodes (cN+), imaging is more useful. PET/CT has shown good accuracy in a limited number of small studies. US-FNAC can confirm nodal metastatic disease. A staging inguinal lymphadenectomy is of therapeutic value but is associated with significant morbidity. Omitting staging inguinal lymphadenectomy was recently described; one study showed well tolerated use of sentinel lymph node biopsy combined with intraoperative ultrasound-guided resection of suspicious nodes in cN+ patients. Therapeutic inguinal lymphadenectomy was only performed in the 42% of groins with metastases confirmed by disorder. For M-staging, PET/CT has shown good sensitivity, and its role should be further evaluated. Follow-up and surveillance rely on physical examination and US-FNAC.

SUMMARY

Over the past decade, staging and treatment of penile cancer have become less invasive, while survival tends to improve.

PET-CT and PET-MR in urological cancers other than prostate cancer: An update on state of the art

Hybrid positron emission tomography with computed tomography (PET/CT) and magnetic resonance imaging (PET/MRI) have enabled the combination of morphologic and functional imaging with the promise of providing better information in guiding therapy. Further advance has been made in the past decade with the development of newer radiotracers and optimization of the technical aspects. We performed a search in PubMed, Scopus, and Google Scholar for peer-reviewed literature concerning the advances and newer developments in the imaging of nonprostate urologic cancers between 2005 and 2017. This review aims at summarizing the current evidence on PET imaging in nonprostate urologic cancers and their impact on the diagnosis, staging, prognostication, response assessment, and restaging of these malignancies. However, much of the evidence is still in infancy and has not been incorporated into routine management or the practice guidelines of National Comprehensive Cancer Network or European Society for Medical Oncology (ESMO).

The role of PET/CT imaging in penile cancer

Positron emission tomography (PET) imaging with ¹⁸F-fluorodeoxyglucose (FDG) combined with computed tomography (CT) provides functional imaging combined with anatomic information, improving diagnostic accuracy and confidence. Although virtually all primary penile tumors are FDG-avid, PET/CT is not recommended for primary tumor staging as it has limited spatial resolution and is hampered by urinary FDG excretion. The accuracy of PET/CT for lymph node staging seems to improve with the pretest likelihood of metastatic nodes. In groins with normal physical examination, sensitivity is only 57%. In groins with palpably enlarged lymph nodes, sensitivity of PET/CT reaches 96%. For pelvic lymph nodes and distant metastases, PET/CT is more accurate if inguinal metastases are present. However, these results are based on a very limited number of studies. Overall, the role of PET/CT imaging in penile cancer remains ambiguous, especially in inguinal lymph nodes. During staging and follow-up, it may be particularly useful in detecting pelvic lymph node metastases and occult distant metastases prior to systemic chemotherapy and/or extensive surgery, improving selection of patients that are most likely to benefit from such therapies.

Applications of PET/MR Imaging in Urogynecologic and Genitourinary Cancers

Positron emission tomograph (PET)-magnetic resonance (MR) is a new modality combining PET and MR. In gynecologic cancers it can be used for staging of cervical and endometrial cancer, planning of radiation therapy in cervical cancer, assessing response to chemotherapy in ovarian cancer, and detection of recurrence in most gynecologic cancers. It is being explored for prostate cancer and other genitourinary cancers, but is still in experimental stages.