Quality and consistency of clinical practice guideline recommendations for PET/CT and PET: a systematic appraisal.

OBJECTIVES: To systematically appraise the methodologies used for guidelines for positron emission tomography (PET) imaging and to compare the consistency of these recommendations. METHODS: We searched PubMed, EMBASE, four guideline databases, and Google Scholar to identify evidence-based clinical practice guidelines pertaining to the use of PET, PET/computed tomography (CT), or PET/magnetic resonance in routine practice. We assessed the quality of each guideline using the Appraisal of Guidelines for Research and Evaluation II instrument and compared recommendations regarding indications for 18F-fluorodeoxyglucose (FDG) PET/CT. RESULTS: Thirty-five guidelines for PET imaging, published between 2008 and 2021, were included. These guidelines performed well in the domains of scope and purpose (median 80.6%, inter-quartile range [IQR] 77.8-83.3%) and clarity of presentation (median 75%, IQR 69.4-83.3%), but poorly in applicability (median 27.1%, IQR 22.9-37.5%). Recommendations for 48 indications in 13 cancers were compared. Considerable inconsistencies in the direction of whether to support the use of FDG PET/CT were observed in 10 (20.1%) indications pertaining to 8 cancer types: head and neck cancer (treatment response assessment), colorectal cancer (staging in patients with stages I-III disease), esophageal cancer (staging), breast cancer (restaging and treatment response assessment), cervical cancer (staging in patients with stage < IB2 disease and treatment response assessment), ovarian cancer (restaging), pancreatic cancer (diagnosis), and sarcoma (treatment response assessment). CONCLUSIONS: Current guidelines for PET imaging vary in methodological quality and provided considerably inconsistent recommendations. Efforts are needed to improve adherence to guideline development methodologies, to synthesis high-quality evidence, and to adopt standard terminologies. PROTOCOL REGISTRATION NUMBER: PROSPERO CRD42020184965. CLINICAL RELEVANCE STATEMENT: Guidelines for PET imaging provide considerably inconsistent recommendations and vary in methodological quality. It is suggested that clinicians be critical of these recommendations when applying them in practice, that guideline developers adopt more rigorous development methodologies, and that researchers prioritize research gaps identified by current guidelines. KEY POINTS: • PET guidelines vary in methodological quality and provided inconsistent recommendations. Efforts are needed to improve methodologies, synthesize high-quality evidence, and standardize terminologies. • Among six domains of methodological quality assessed by the AGREE II tool, guidelines for PET imaging performed well in scope and purpose (median 80.6%, inter-quartile range 77.8-83.3%) and clarity of presentation (75%, 69.4-83.3%), but poorly in applicability (27.1%, 22.9-37.5%). • Among the 48 recommendations (for 13 cancer types) compared, conflicts in the direction of whether to support FDG PET/CT use were observed in 10 (20.1%), for 8 cancer types (i.e., head and neck, colorectal, esophageal, breast, cervical, ovarian, pancreatic, and sarcoma).

Cavernous Sinus Metastasis From Laryngeal Cancer Identified by 18F-FDG PET/MR.

ABSTRACT: Cavernous sinus metastasis from head and neck cancers is rare. We report FDG PET/MRI findings of cavernous sinus metastases from laryngeal cancer in a 56-year-old woman. The images revealed isointense lesions in the bilateral cavernous sinus on T2-weighted MR, with slight enhancement, and intense FDG uptake. The lesions were confirmed as metastases to the cavernous sinus.

Comparison of Lugano Criteria Versus RECIL and PERCIST as Prognostic Factors in Diffuse Large B-Cell Lymphoma.

OBJECTIVE: This study aimed to compare the criteria of the Lugano, RECIL, and PERCIST for prognosis in patients with diffuse large B-cell lymphoma. PATIENTS AND METHODS: We retrospectively evaluated 335 patients with diffuse large B-cell lymphoma. All patients underwent baseline 18 F-FDG PET/CT. Among them, 252 and 213 patients underwent interim PET/CT (I-PET/CT) and end-of-treatment PET/CT (EoT-PET/CT), respectively. Scans were interpreted by 2 nuclear medicine physicians using Lugano, RECIL, and PERCIST. RECIL and PERCIST were compared with Lugano for predicting progression-free survival (PFS) and overall survival (OS). RESULTS: All 3 response criteria could be used to predict PFS and OS. In I-PET/CT, the concordance index of Lugano in predicting PFS and OS was higher than that of RECIL (both P = 0.043) or PERCIST ( P = 0.008 and P = 0.034, respectively). In EoT-PET/CT, the concordance index of Lugano for predicting PFS and OS was similar to RECIL and not significantly different from PERCIST ( P = 0.597 and P = 0.231, respectively). CONCLUSIONS: For I-PET/CT, using the Lugano criteria is more accurate than RECIL or PERCIST in predicting PFS and OS. However, for EoT-PET/CT, the PERCIST criteria are minimally better.

Bone Sequestration as a Consequence of Esophageal Carcinoma Metastasis Detected by 18F-FDG PET/CT.

A bony sequestrum is a single piece of bone present in an area of osteolysis. It is separated from the surrounding bone and is primarily observed in patients with bone infection. We present our radiographic findings on F-FDG PET/CT in a case of esophageal squamous cell carcinoma with a sequestrum in the skull metastasis.

Humeral metastasis of sacrococcygeal chordoma detected by fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography: A case report.

Chordomas are rare, slow-growing, locally aggressive bone tumors arising from embryonic remnants of the notochord. Distant metastases most commonly involve the lung, liver, axial skeleton, skin, and lymph nodes. Humeral metastases are extremely rare. We report the case of a recurrent chordoma with humeral metastasis, complicated with pathologic fracture. Fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography revealed multiple hypermetabolic skeletal lesions, corresponding to the symptoms. Our report suggests that positron emission tomography-computed tomography is useful for evaluation of recurrence and distant metastases of chordomas.

Prognostic value of baseline, interim and end-of-treatment 18F-FDG PET/CT parameters in extranodal natural killer/T-cell lymphoma: A meta-analysis.

METHODS: We searched the PubMed, EMBASE, Cochrane Library and Medline databases for eligible articles. SUVmax, MTV, and TLG on B-PET/CT, DS on I-PET/CT and DS on E-PET/CT were regarded as efficacy data. Combined hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS) were estimated using RevMan 5.3 software. RESULTS: Nine trials with a total of 535 ENKTL patients were included. SUVmax, MTV and TLG on B-PET/CT were significantly associated with PFS with HRs of 2.78 (95%CI 1.54-5.03), 3.61 (95%CI 1.96-6.65) and 5.62 (95%CI 1.94-16.33), respectively, and with OS with HRs of 4.78 (95%CI 2.29-9.96), 3.20 (95%CI 1.55-6.60) and 7.76 (95%CI 1.79-33.58), respectively. For the DS on I-PET/CT, the HRs for PFS and OS were 5.15 (95%CI 2.71-9.80) and 5.80 (95%CI 2.28-14.73), respectively. Similarly, the DS on E-PET/CT was a significant predictor of PFS and OS with HRs of 3.65 (95%CI 2.13-6.26) and 3.32 (95%CI 1.79-6.15), respectively. CONCLUSION: Our results suggest that SUVmax, MTV, TLG on B-PET/CT, DS on I-PET/CT and DS on E-PET/CT may be significant prognostic indicators for PFS and OS in ENKTL patients. Moreover, TLG tends to be superior to SUVmax and MTV on B-PET/CT for predicting survival of ENKTL patients. Therefore, response monitoring and prognostication assessments based on multiple PET/CT parameters should be considered in the management of ENKTL patients.

Uterine Corpus Metastasis From Rectal Adenocarcinoma Detected Using 18F-FDG PET/CT.

We report an unusual case of uterine corpus metastasis from rectal adenocarcinoma detected using F-FDG PET/CT. A 47-year-old woman was diagnosed with rectal adenocarcinoma and treated with surgery and radiochemotherapy 3 years ago. During follow-up, she presented with lower abdomen pain and elevated tumor markers, but ultrasonography findings were unremarkable. We performed an F-FDG PET/CT scan, which showed intense F-FDG avidity in the myometrium of the uterine corpus. Uterine corpus metastasis was suspected, and complementary MRI and diagnostic curettage histopathology confirmed uterine metastasis from rectal adenocarcinoma.

Graves disease following radioiodine therapy for toxic adenoma: Clinical case report.

RATIONALE: There is a low risk of developing Graves disease (GD) with elevated thyrotropin receptor antibodies (TRAbs) in patients undergoing radioiodine therapy for toxic adenoma. PATIENT CONCERNS: An old female patient with a history of Hashimoto thyroiditis was referred to our department due to thyrotoxic symptoms. After the administration of radioiodine, a significant remission was achieved. However, after 4 months, she was referred to our department again due to recurrence of hyperthyroid symptoms. DIAGNOSES: Based on the results of laboratory test, thyroid scan and ultrasound examination, she was diagnosed as thyrotoxicosis induced by toxic adenoma at the first visit. However, 4 months later, she was diagnosed as Graves' disease at the second visit. INTERVENTIONS: She received radioiodine therapy two times with different doses of 15 mCi and 12 mCi. OUTCOMES: After the administration of 15 mCi radioiodine, her thyroid hormones and clinical symptoms showed significant improvement. However, 4 months later, she presented thyrotoxicosis again. After the second radioiodine therapy with a lower dose, her clinical symptoms moved towards normalization during regular follow up. LESSONS: Toxic adenoma and GD are considered as 2 distinct disease entities; however, radioiodine therapy for toxic adenoma may induce GD. We should learn to differentiate these 2 disorders prior to radioiodine therapy because of different treatment strategies and goals.