Post-therapeutic Surveillance Research Articles

Presurgical Perspective and Posttreatment Evaluation of Soft Tissue Tumors of the Ankle and Foot in Adults.

This article discusses soft tissue tumors of the ankle and foot region in adults, including tumors of the joints, and also briefly addresses tumor-simulating lesions. We offer general recommendations and describe specific aspects of common entities in that region, such as typical imaging appearance, therapeutic strategies, and posttherapeutic considerations. Focal masses and diffuse swelling are common in the foot and ankle region; most of them are non-neoplastic. Some of the tumors, such as plantar fibromatosis, tenosynovial giant cell tumor, synovial chondromatosis, or schwannoma, have a very typical appearance on magnetic resonance imaging. Sarcomas are rare among true soft tissue tumors; however, they can be small and well demarcated, may grow slowly, and are often misinterpreted as benign. This is especially true for synovial sarcoma, one of the most common sarcomas in this region. Densely packed tissues in the foot and ankle may hamper determining the tissue of origin. Adherence to diagnostic guidelines and cooperation with tumor centers is crucial including for posttherapeutic surveillance. We also describe typical posttherapeutic changes and complications after surgery, radiation therapy, and chemotherapy, as well as parameters for the detection and exclusion of recurrence of soft tissue tumors of the ankle and foot.

Shining Damaged Hearts: Immunotherapy-Related Cardiotoxicity in the Spotlight of Nuclear Cardiology.

The emerging use of immunotherapies in cancer treatment increases the risk of immunotherapy-related cardiotoxicity. In contrast to conventional chemotherapy, these novel therapies have expanded the forms and presentations of cardiovascular damage to a broad spectrum from asymptomatic changes to fulminant short- and long-term complications in terms of cardiomyopathy, arrythmia, and vascular disease. In cancer patients and, particularly, cancer patients undergoing (immune-)therapy, cardio-oncological monitoring is a complex interplay between pretherapeutic risk assessment, identification of impending cardiotoxicity, and post-therapeutic surveillance. For these purposes, the cardio-oncologist can revert to a broad spectrum of nuclear cardiological diagnostic workup. The most promising commonly used nuclear medicine imaging techniques in relation to immunotherapy will be discussed in this review article with a special focus on the continuous development of highly specific molecular markers and steadily improving methods of image generation. The review closes with an outlook on possible new developments of molecular imaging and advanced image evaluation techniques in this exciting and increasingly growing field of immunotherapy-related cardiotoxicity.

Thoracic Imaging Manifestations of Treated Lymphomas: Response Evaluation, Posttherapeutic Sequelae, and Complications.

Lymphoma is the most common hematologic malignancy comprising a diverse group of neoplasms arising from multiple blood cell lineages. Any structure of the thorax may be involved at any stage of disease. Imaging has a central role in the initial staging, response assessment, and surveillance of lymphoma, and updated standardized assessment criteria are available to assist with imaging interpretation and reporting. Radiologists should be aware of the modern approaches to lymphoma treatment, the role of imaging in posttherapeutic surveillance, and manifestations of therapy-related complications.

The Role of Ki67 and p16INK4a Biomarkers on Conventional Cell Blocks to Differentiate Post Radiation Dysplasia from Cervical Cancer in Post Therapeutic Surveillance Cytology

Aim and objectives: Diagnostic accuracy of post therapy Papanicolaou (pap) tests is low, as it is difficult to differentiate benign from malignant lesions due to post radiation cellular changes. Here we have evaluated the role of biomarker p16INK4a and Ki67on conventional cell blocks (CCBs) in post therapeutic surveillance of cervical cancer to detect residual disease and site recurrence. We have also evaluated CCBs as a primary screening test. Material and Methods: In this cross-sectional study, patients who were diagnosed as cervical cancer before one year were followed between periods of April 2018-April 2019. We collected conventional pap smears and samples in 10% neutral buffered formalin for CCBs. The immunohistochemistry was performed on all cell blocks using Ki67 and p16INK4a as primary antibodies.Results: Out of total 35 cases, recurrences and residual disease were diagnosed in 8 cases. Sensitivity, specificity, diagnostic accuracy for pap, cell blocks and p16INK4a for detecting cervical cancer were 75%, 74.07%, 88.57%; 100%, 88.89%, 91.43% and 37.50%, 96.30% and 82.86% respectively. We observed that Ki67 labeling index ≥ 20% had a diagnostic accuracy of 100%. Conclusion: Our findings suggest that Ki67 labeling index ≥20% on CCBs can differentiate residual and recurrent cancer from post radiation dysplasia in post therapy surveillance cytology (p value <0.001). We also observed that CCBs has better diagnostic accuracy than pap test (Mac Nemar p value, 0.027). We did not found p16INK4A much useful as a biomarker in evaluation recurrence/residual disease.

FDG-PETCT versus contrast-enhanced computed tomography in diagnosis of post-therapeutic colorectal cancer recurrence and metastases

BackgroundThis study was designed to assess the role of 18F-FDG CT was able to detect additional/CT in post-therapeutic surveillance of colorectal cancer patients as compared with contrast-enhanced CT to allow early detection of recurrent and metastatic cases amenable for curative surgery and thus improve the overall survival of patients.ResultsOf the total 100 patients, 70 proved to have metastasis or local recurrent disease by the standard reference modalities. One hundred eighty-two diseased regions were detected in these 70 patients. PET/CT was positive in 174 regions (95.6%) whereas CECT was positive in 118 regions (64.8%). PET/CT was superior to CECT in detection of hepatic focal lesions, metastatic lymph nodes, pulmonary metastases, and peritoneal and suprarenal metastases whereas both were equal in detection of osseous deposits. CECT detected four lesions that were missed by PET/CT, and these were hepatic metastases from mucinous adenocarcinoma.ConclusionPET/CT is a better method to evaluate post-therapeutic colorectal cancer patients. It detected viable residual tumor cells in operative bed scar, small LNs, hepatic focal lesions, peritoneal deposits, pulmonary masses, bone deposits, and suprarenal deposits with significantly higher specificity and sensitivity than CECT avoiding unnecessary surgeries.

The role of a post therapeutic surveillance program for sinonasal malignancies: Analysis of 417 patients.

Post therapeutic surveillance of head and neck neoplasms is a still debated issue in the current literature: although different works tried to establish frequency, modality, and efficacy of a routine follow-up, little evidence has been produced, in particular considering only sinonasal malignancies. A retrospective review of patients treated for sinonasal malignancies in a single tertiary center and followed through a regular program of follow-up was carried out. Rate of recurrence, location, timing, diagnosis, and salvage treatment were the main data analyzed. Of note, 417 patients were included in the study and 117 experienced at least one relapse. Staging, histological type, and previous treatment represent the main clinical factors to be considered to stratify patient's risk of recurrence. A regular post therapeutic surveillance can provide an early recurrence detection for patients treated for sinonasal malignancies, offering opportunity for salvage treatment in a high percentage of patients.

Onchocerciasis in Burkina Faso: a Re-Emerging Vector-Borne Endemic Disease

Burkina Faso, like other countries, reported a focal interruption of onchocerciasis transmission and was thus placed under post-therapeutic surveillance. However, the country seems to be experiencing a resurgence of the disease according to recent surveys at certain sentinel sites and data from various surveys. The aim of our study is to take stock of the evolution of the current epidemiological situation of onchocerciasis in Burkina Faso. For data collection, in addition to the scientific articles, we have used data from different epidemiological and entomological surveys conducted by the National Program for the Control of Neglected Tropical Diseases (PNLMTN) through its onchocerciasis elimination unit in Burkina Faso. Prior to implementation of the Onchocerciasis Control Program in West Africa (OCP), Burkina Faso had onchocerciasis prevalence between 60% and 80%. In 2002, the maximum prevalence dropped to 15%. However, in 2010 and 2011, epidemiological surveys indicated that some villages in the Comoé River basin had prevalence rate ranging from 0.7% to 71%. Thirteen (13) villages had prevalence rates above the tolerable threshold of 5%. Despite the implementation of the community-directed treatment with ivermectin (CDTI) since 2011, recent surveys show a tendency for a recrudescence of the disease in some sites, yet covered by the TIDC. This suggests that the elimination of onchocerciasis requires the integration of new control strategies. Thus, an essential condition for the elimination of onchocerciasis is the analysis of the situation in each focus in order to define the most cost-effective strategy for permanently interrupting the transmission of the parasite. National onchocerciasis elimination committees put in place will play a key role in determining the best strategy.

Free-Circulating Methylated DNA in Blood for Diagnosis, Staging, Prognosis, and Monitoring of Head and Neck Squamous Cell Carcinoma Patients: An Observational Prospective Cohort Study.

Circulating cell-free DNA methylation testing in blood has recently received regulatory approval for screening of colorectal cancer. Its application in other clinical settings, including staging, prognosis, prediction, and recurrence monitoring is highly promising, and of particular interest in head and neck squamous cell carcinomas (HNSCCs) that represent a heterogeneous group of cancers with unsatisfactory treatment guidelines. Short stature homeobox 2 (SHOX2) and septin 9 (SEPT9) DNA methylation in plasma from 649 prospectively enrolled patients (training study: 284 HNSCC/122 control patients; testing study: 141 HNSCC/102 control patients) was quantified before treatment and longitudinally during surveillance. In the training study, 59% of HNSCC patients were methylation-positive at 96% specificity. Methylation levels correlated with tumor and nodal category (P < 0.001). Initially increased methylation levels were associated with a higher risk of death [SEPT9: hazard ratio (HR) = 5.27, P = 0.001; SHOX2: HR = 2.32, P = 0.024]. Disease recurrence/metastases were detected in 47% of patients up to 377 days earlier compared to current clinical practice. The onset of second cancers was detected up to 343 days earlier. In the testing study, sensitivity (52%), specificity (95%), prediction of overall survival (SEPT9: HR = 2.78, P = 0.022; SHOX2: HR = 2.50, P = 0.026), and correlation with tumor and nodal category (P <0.001) were successfully validated. Methylation testing in plasma is a powerful diagnostic tool for molecular disease staging, risk stratification, and disease monitoring. Patients with initially high biomarker levels might benefit from intensified treatment and posttherapeutic surveillance. The early detection of a recurrent/metastatic disease or a second malignancy could lead to an earlier consecutive treatment, thereby improving patients' outcomes.

Telomeres and telomerase in head and neck squamous cell carcinoma: from pathogenesis to clinical implications.

Strongly associated with tobacco use, heavy alcohol consumption, and with high-risk human papillomavirus (HPV) infection, head and neck squamous cell carcinoma (HNSCC) is a frequently lethal, heterogeneous disease whose pathogenesis is a multistep and multifactorial process involving genetic and epigenetic events. The majority of HNSCC patients present with locoregional advanced stage disease and are treated with combined modality strategies that can markedly impair quality of life and elicit unpredictable results. A large fraction of those who undergo locoregional treatment and achieve a complete response later develop locoregional recurrences or second field tumors. Biomarkers that are thus able to stratify risk and enable clinicians to tailor treatment plans and to personalize post-therapeutic surveillance strategies are highly desirable. To date, only HPV status is considered a reliable independent predictor of treatment response and survival in patients with HNSCC arising from the oropharyngeal site. Recent studies suggest that telomere attrition, which may be an early event in human carcinogenesis, and telomerase activation, which is detected in up to 90 % of malignancies, could be potential markers of cancer risk and disease outcome. This review examines the current state of knowledge on and discusses the implications linked to telomere dysfunction and telomerase activation in the development and clinical outcome of HNSCC.

Abstract 456: Identification of circulating tumor-derived microRNA signatures in osteosarcoma

Abstract Introduction: The lack of useful biomarkers is one of the most important clinical problems of bone and soft tissue sarcomas, although early detection of recurrent or metastatic disease and early decision making according to tumor response to chemotherapy is important to improve patient prognosis. The recent discovery of circulating cell-free microRNAs (miRNAs) in human blood has represented a new approach for the diagnostic screening for malignant diseases. In this study, we investigated whether the serum miRNA levels could be used as novel biomarkers for osteosarcoma (OS) patients. Methods: Global miRNA profiling was performed using the serum samples collected from OS patients, age-matched non-OS patients and healthy volunteers. The expression levels of extracted miRNA were confirmed in human OS cell lines (SaOS2, U2OS, HOS, 143B), human mesenchymal stem cell (hMSC), and their culture media. The miRNA candidates were evaluated using the serum samples of the validation set. Results: The miRNA expression profile of the serum samples of 10 OS patients, 10 age-matched non-OS patients, and 10 healthy controls identified 236 serum miRNAs to be highly expressed in the OS compared to the non-OS patients and healthy controls. Among these miRNAs, 8 miRNAs were overlapped with the secretory miRNAs in the culture medium of 7 osteosarcoma cell lines. Quantitative RT-PCR revealed that two candidates were significantly upregulated in the OS cells and culture medium, compared to MSCs. The expression of these miRNAs in the culture media from all OS cell lines increased along with culture time and tumor cell numbers, indicating that it is an important secretory miRNA derived from OS cells. The serum concentration of these miRNAs in OS patients was significantly higher than those in healthy volunteers and non-OS patients. Our ROC analyses revealed that an AUC value based on the miRNA expression was 0.868 (95% confidence interval = 0.743 to 0.993), which was was higher than that of alkaline phosphatase (ALP). Finally, the detected serum miRNA expression levels markedly decreased at the postoperative status in operative cases, while gradually decreased during neoadjuvant chemotherapy, which revealed that serum miRNA expression levels correlated with the tumor burden and drug sensitivity. Conclusions: We identified circulating tumor-derived miRNA signatures in the serum obtained from the OS patients. Furthermore, the definitive miRNA reflected tumor burden in OS patients. Evaluating the serum miRNA expression may thus have important clinical implications for risk stratification and the planning of post-therapeutic surveillance. Citation Format: Tomohiro Fujiwara, Koji Uotani, Aki Yoshida, Takuya Morita, Tadashi Komatsubara, Kazuhisa Sugiu, Toshinori Omori, Ken Takeda, Toshiyuki Kunisada, Yutaka Nezu, Akira Kawai, Hirotaka Kanzaki, Takahiro Ochiya, Toshifumi Ozaki. Identification of circulating tumor-derived microRNA signatures in osteosarcoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 456.

Optimal scheduling of post-therapeutic follow-up of patients treated for cancer for early detection of relapses

Post-therapeutic surveillance is one important component of cancer care. However, there still is no evidence-based strategies to schedule patients' follow-up examinations. Our approach is based on the modeling of the probability of the onset of relapse at an early asymptotic or preclinical stage and its transition to a clinical stage. For that we consider a multistate homogeneous Markov model, which includes the natural history of relapse. The model also handles separately the different types of possible relapses. The optimal schedule is provided by the calendar visit that maximizes a utility function. The methodology has been applied to laryngeal cancer. The different follow-up strategies revealed to be more efficient than those proposed by different scientific societies.

DNA methylation in melanoma

Melanoma is a highly aggressive malignant cutaneous tumor that has been increasing in incidence and mortality. Effective therapeutic approaches are unavailable currently. With further insights into melanoma, epigenetic modification, especially DNA methylation, in melanoma has drawn extensive attention in recent years. Changes in DNA methylation are relatively common in tumor cells, including melanoma cells. Thus, DNA methylation-related genes may serve as biomarkers for early screening for, as well as diagnosis, prediction of prognosis, staging, treatment, and post-therapeutic surveillance of melanoma. Key words: Melanoma; DNA methylation; Epigenesis, genetic; Molecular targeted therapy; Genes

Loco-regional recurrence after surgical treatment of oral squamous cell carcinoma: Proposals for follow-up imaging based on literature, national guidelines and institutional experience.

The recurrence rate following the treatment of oral squamous cell carcinoma (OSCC) by primary surgery is about 10%-26%. The earliest possible diagnosis of residual tumour, recurrence of local tumour disease, and subsequent metastasis is essential for an improvement of the overall survival and of the survival period for affected patients. No international consensus exists for a post-therapeutic surveillance schedule for OSCCs. Based on a review of the literature, existing guidelines, and our institutional experience, we have established an algorithm for the follow-up of these patients regarding the timing and techniques of postoperative imaging. We recommend a follow-up interval of 6 weeks during the first half-year after discharge from hospital by single clinical and alternating clinical check-ups combined with computed tomography (CT) or magnetic resonance imaging (MRI), followed by an interval of 3 months in the second half-year, with clinical and radiological check-ups. In year 2, we recommend a follow-up interval of 3 months with single clinical and alternating clinical check-ups combined with CT or MRI. In year 3, we recommend screening every 6 months, both clinically and via imaging, because of the decreased risk of recurrence. From year 5 onwards, our recommendation is a clinical and imaging-based examination every 6-12 months, depending on patient risk factors and disease progression. Four standard imaging techniques, namely positron emission tomography (PET), CT, MRI, and ultrasound (US), are discussed concerning their range of application, sensitivity, and specificity. Furthermore, the technical aspects of our institutional protocols are described in detail. In highly frequented head and neck cancer centres, PET and US are of secondary importance, since CT and MRI are nowadays highly efficient tools in primary diagnostic and post-therapeutic surveillance.

Prognostic factors of young women (≤ 35 years) with node positive breast cancer: possible influence on post-therapeutic follow-up

PurposeAlthough young age at diagnosis is an independent prognostic factor of poor survival; no specific recommendation are provided concerning the timing and modalities of follow-up for this population. These patients are followed similarly to older women during post-therapeutic surveillance. The objective of this study is to examine patterns of recurrence in a large series of positive lymph node breast cancer women aged 35 years or below and treated within adjuvant chemotherapy trials. MethodsData of 200 patients (≤35 years) included in three UNICANCER adjuvant trials for node positive breast cancer were used. Competing risks methodology was used to identify prognostic factors associated with time to first failure according to type of event. ResultsAfter a median follow-up of 52.4 months, 84 pts had disease related events (17 loco-regional, five contralateral, and 62 distant metastasis). Variables associated with an increased rate of first event were the number of involved lymph nodes and the type of surgery. In univariate analysis, prognostic factors associated with high potential curative recurrence were number of positive lymph nodes and vascular invasion. Only number of positive lymph node remained significant in multivariate analysis. Concerning distant metastasis, only the number of lymph node involved was associated to an increased risk of metastasis. ConclusionUsing the number of positive nodes as important prognostic factors, it should be possible to identify patients at a higher risk of loco-regional relapse or contralateral breast cancer, in order to propose more individualized follow-up.

Determining the Length of Posttherapeutic Follow-up for Cancer Patients Using Competing Risks Modeling

After a curative treatment for cancer, patients enter into a posttherapeutic surveillance phase. This phase aims to detect relapses as soon as possible to improve the outcome. Mould and others predicted with a simple formula, using a parametric mixture cure model, how long early-stage breast cancer patients should be followed after treatment. However, patients in posttherapeutic surveillance phase are at risk of different events types with different responses according to their prognostic factors and different probabilities to be cured. This paper presents an adaptation of the method proposed by Mould and others, taking into account competing risks. Our loss function estimates, when follow-up is stopped at a given time, the proportion of patients who will fail after this time and who could have been treated successfully. We use the direct approach for cumulative incidence modeling in the presence of competing risks with an improper Gompertz probability distribution as proposed by Jeong and Fine. Prognostic factors can be taken into account, leading to a proportional hazards model. In a second step, the estimates of the Gompertz model are combined with the probability for a patient to be treated successfully in case of relapse for each event type. The method is applied to 2 examples, a numeric fictive example and a real data set on soft tissue sarcoma. and The model presented is a good tool for decision making to determine the total length of posttherapeutic surveillance. It can be applied to all cancers regardless of the localizations.

Patterns of recurrence and second primary lung cancer in early-stage lung cancer survivors followed with routine computed tomography surveillance

At present, there is no consensus on the optimal strategy for follow-up care after curative resection for lung cancer. We sought to understand the patterns of recurrence and second primary lung cancer, and their mode of detection, after resection for early-stage non-small cell lung cancer in patients who were followed by routine surveillance computed tomography scan. We reviewed the outcomes of consecutive patients who underwent resection for early-stage non-small cell lung cancer at Memorial Sloan-Kettering Cancer Center between 2004 and 2009. A total of 1294 consecutive patients with early-stage non-small cell lung cancer underwent resection. The median length of follow-up was 35 months. Recurrence was diagnosed in 257 patients (20%), and second primary lung cancer was diagnosed in 91 patients (7%). The majority of new primary cancers (85 [93%]) were identified by scheduled routine computed tomography scan, as were a smaller majority of recurrences (157 [61%]). During the first 4 years after surgery, the risk of recurrence ranged from 6% to 10% per person-year but decreased thereafter to 2%. Conversely, the risk of second primary lung cancer ranged from 3% to 6% per person-year and did not diminish over time. Additional testing after false-positive surveillance computed tomography scan results was performed for 329 patients (25%), but only 4 of these patients (0.3%) experienced complications as a result of subsequent invasive diagnostic procedures. Almost all second primary cancers and the majority of recurrences were detected by post-therapeutic surveillance computed tomography scan. The risk of recurrence for early-stage non-small cell lung cancer survivors persisted during the first 4 years after resection, and vigilance in surveillance should be maintained.

Post-therapeutic surveillance strategies in head and neck squamous cell carcinoma

The management of head and neck squamous cell carcinomas does not end with the completion of ablative therapy. The oncologic objectives of post-treatment follow-up are to detect recurrences and second primary tumors; beyond that, follow-up should evaluate acute and chronic treatment-related side effects, guide the rehabilitation process, alleviate functional loss, manage pain, restore nutritional status and assess psychosocial factors. In this structured review, we address the questions of timing and the tools required to achieve a complete and coherent routine surveillance. Several guidelines and consensus statements recommend clinical examination as the cornerstone of follow-up which should be performed for at least 5 years, although there are no data in favor of any one particular follow-up program, and only low-level evidence suggests an improvement in oncologic outcomes by close follow-up. Baseline imaging (computed tomography and magnetic resonance imaging) should be obtained within 2-6 months after definitive therapy if used for treatment response evaluation. Metabolic response, if indicated, should be assessed preferably after 3 months in patients who undergo curative-intent therapy with (chemo)-radiotherapy. Chest computed tomography is more sensitive than plain radiography, if used in follow-up, but the benefit and cost-effectiveness of routine chest computed tomography has not been demonstrated. There are no current data supporting modifications specific to the surveillance plan of patients with human papillomavirus-associated disease.

Post-therapeutic Surveillance Schedule for Oral Cancer: Is There Agreement?

Patients with oral cavity squamous cell carcinoma represent a diverse group, and the treatment these patients undergo also varies widely. Some patients undergo local excision alone while others require extensive surgery, often with adjuvant chemoradiotherapy. The post-therapeutic surveillance schedule for these patients tends to be a "one size fits all" formula for all head and neck squamous cell carcinoma patients, which has often been dictated by institutional doctrine or a senior surgeon's dogma. The post-therapeutic needs and risks of a T1 oral cancer patient treated with surgery alone differ from those of a patient with advanced laryngeal carcinoma, and the follow-up regimen should be tailored to the specific patient's risk of loco-regional recurrence, distant metastasis, and other related medical issues. A total of 65 papers were identified, 18 of which either focused on follow-up strategy for oral cavity squamous cell carcinoma or their tabular data allowed these cases to be extracted. Internationally recognized cancer entities were also queried. No international consensus was achieved about the follow-up strategies. The value of post-therapeutic surveillance schedule following oral cancer treatment is generally not in dispute, although patient-initiated symptom-driven visits can be effective in identifying tumor recurrence for oral cancer patients. The range of appointment interval schemes tends to identify a progressive escalation of visit intervals such that there are more visits in the first year than in the second, and fewer yet during the third. Patients may fail to comply with their clinic visit structure. Most references agree that follow-up beyond the third year is unnecessary and may waste medical resources as well as the time of both patient and surgeon. There is no agreement as to the need for or interval of imaging studies.

Imaging in laryngeal cancers

Imaging plays an important complementary role to clinical examination and endoscopic biopsy in the evaluation of laryngeal cancers. A vast majority of these cancers are squamous cell carcinomas (SCC). Cross-sectional imaging with contrast-enhanced computed tomography (CT) and magnetic resonance (MR) imaging allows excellent depiction of the intricate anatomy of the larynx and the characteristic patterns of submucosal tumor extension. CT, MRI and more recently PET-CT, also provide vital information about the status of cervical nodal disease, systemic metastases and any synchronous malignancies. Additionally, certain imaging-based parameters like tumor volume and cartilaginous abnormalities have been used to predict the success of primary radiotherapy or surgery in these patients. Integration of radiological findings with endoscopic evaluation greatly improves the pretherapeutic staging accuracy of laryngeal cancers, and significantly impacts the choice of management strategies in these patients. Imaging studies also help in the post-therapeutic surveillance and follow-up of patients with laryngeal cancers. In this article, we review the currently used laryngeal imaging techniques and protocols, the key anatomic structures relevant to tumor spread and the characteristic patterns of submucosal extension and invasion of laryngeal cancer. The role of CT, MRI and PET-CT in the evaluation of patients with laryngeal SCC and the impact of imaging findings on prognosis and clinical management is also discussed.

Roles and Limitations of FDG PET in Pediatric Non-Hodgkin Lymphoma

The usefulness of 18F fluorodeoxyglucose (FDG) positron emission tomography (PET) in pediatric Hodgkin lymphoma (p-HL) has been well demonstrated; however, pediatric non-Hodgkin lymphoma (p-NHL) has distinct characteristics from p-HL and adult NHL. We assessed roles of FDG PET in p-NHL. Nineteen patients with p-NHL underwent 80 scans. Scans for staging (group A, n=6) and response assessment (group B, n=42) were compared with conventional imaging modalities (CIMs). Scans within group B for end-chemotherapy assessment (subgroup B+, n=11) and for post-therapeutic surveillance (group C, n=32) were analyzed for diagnostic performance. In group A, PET and CIM demonstrated comparable results. In group B, PET diagnoses were concordant with CIM in 21 and discordant in 11 studies. Of the discordant cases, PET suggested remnant lesions in 5 cases, whereas CIM suggested lesions in 6 cases. PET modified therapeutic strategy in 4 cases by detecting new extranodal lesions. In subgroup B+, sensitivity, specificity, and accuracy for predicting relapse were 50%, 71%, and 64%, respectively. In group C, sensitivity, specificity, and accuracy were 100%, 87%, and 88%, respectively, but positive predictive value was 33%. The role of FDG PET in p-NHL may be limited, unlike with p-HL or adult NHL. Nevertheless, FDG PET may serve complementarily in detecting unexpected lesions that can emerge in p-NHL.