18F‐Fluorodeoxyglucose positron emission tomography/computed tomography for the detection of recurrent bone and soft tissue sarcoma

BACKGROUND:

The clinical utility of modern hybrid imaging modalities for detecting recurrent bone or soft tissue sarcoma remains to be determined. In this report, the authors present a clinical study on the diagnostic accuracy and incremental value of integrated ¹⁸F‐fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F‐FDG PET/CT) in patients with a history of sarcoma who have clinically suspected disease recurrence.

METHODS:

Forty‐three patients who had a history of bone or soft tissue sarcoma and had documented complete remission underwent ¹⁸F‐FDG PET/CT. Image analysis was performed independently for ¹⁸F‐FDG PET (n = 43) and for contrast‐enhanced spiral CT (CE‐CT) (n = 30) by 2 separate readers, whereas combined ¹⁸F‐FDG PET/CT (n = 43) images were analyzed in consensus by both readers. Imaging findings were rated on a 5‐point scale and finally were reported as malignant, benign, or equivocal. Imaging findings were validated either by histopathology (n = 24) or by clinical follow‐up (n = 19).

RESULTS:

¹⁸F‐FDG PET/CT had greater sensitivity and specificity compared with CE‐CT alone (94% and 92% vs 78% and 67%, respectively), resulting in significantly greater accuracy (93% vs 73%; P = .03). ¹⁸F‐FDG PET/CT was particularly superior regarding detection of local recurrence or soft tissue lesions (sensitivity and specificity: 83% and 100% vs 50% and 100%, respectively) or bone metastases (100% and 100% vs 85% and 88%, respectively).

CONCLUSIONS:

¹⁸F‐FDG PET/CT had greater diagnostic accuracy in the detection of recurrent bone or soft tissue sarcoma compared with CE‐CT alone. The detection of local recurrence was the most evident advantage of ¹⁸F‐FDG PET/CT over CE‐CT. Cancer 2013. © 2012 American Cancer Society.     

High rates of tumor growth and disease progression detected on serial pretreatment fluorodeoxyglucose‐positron emission tomography/computed tomography scans in radical radiotherapy candidates with nonsmall cell lung cancer

BACKGROUND:

The authors studied growth and progression of untreated nonsmall cell lung cancer (NSCLC) by comparing diagnostic and radiotherapy (RT) planning fluorodeoxyglucose (FDG)‐positron emission tomography (PET)/computed tomography (CT) scans before proposed radical chemo‐RT.

METHODS:

Patients enrolled on a prospective clinical trial were eligible for this analysis if they underwent 2 pretreatment whole body FDG‐PET/CT scans, >7 days apart. Scan 1 was performed for diagnosis/disease staging and scan 2 for RT planning. Interscan comparisons included disease stage, metabolic characteristics, tumor doubling times, and change in treatment intent.

RESULTS:

Eighty‐two patients underwent planning PET/CT scans between October 2004 and February 2007. Of these, 28 patients (61% stage III, 18% stage II) had undergone prior staging PET/CT scans. The median interscan period was 24 days (range, 8‐176 days). Interscan disease progression (TNM stage) was detected in 11 (39%) patients. The probability of upstaging within 24 days was calculated to be 32% (95% confidence interval [CI], 18%‐49%). Treatment intent changed from curative to palliative in 8 (29%) cases, in 7 because of PET. For 17 patients who underwent serial PET/CT scans under standardized conditions, there was a mean relative interscan increase of 19% in tumor maximum standardized uptake value (SUV) (P = .022), 16% in average SUV (P = .004), and 116% in percentage injected dose (P = .002). Estimated doubling time of FDG avid tumor was 66 days (95% CI, 51‐95 days).

CONCLUSIONS:

Rapid tumor progression was detected in patients with untreated, predominantly stage III, NSCLC on serial FDG‐PET/CT imaging, highlighting the need for prompt diagnosis, staging, and initiation of therapy in patients who are candidates for potentially curative therapy. Cancer 2010. © 2010 American Cancer Society.     

A prospective evaluation of the utility of 2‐deoxy‐2‐[18F]fluoro‐D‐glucose positron emission tomography and computed tomography in staging locally advanced gastric cancer

BACKGROUND:

The aim of this study was to examine prospectively the utility of adding preoperative [¹⁸F]fluorodeoxyglucose positron emission tomography (FDG‐PET)/computed tomography (CT) to routine CT, endoscopic ultrasound (EUS), and laparoscopic staging of localized gastric cancer.

METHODS:

Patients with locally advanced gastric/gastroesophageal cancer were screened for 2 institutional review board–approved Memorial Sloan‐Kettering Cancer Center neoadjuvant chemotherapy protocols. Locally advanced disease was defined as T3 or T4, or lymph node–positive, based on EUS and high‐resolution CT scan. All patients underwent both standard FDG‐PET/CT and laparoscopy with cytological examination of washings. The sensitivity and specificity of FDG‐PET/CT for the identification of metastatic disease not seen on CT was determined. An economic model using Medicare/Medicaid reimbursement charges was developed to assess the cost‐effectiveness of these interventions.

RESULTS:

A total of 113 patients were enrolled from 2003 to 2010. All patients were assessed as having locally advanced disease by CT/EUS. FDG uptake in the primary tumor was associated with male sex, proximal tumors, and nondiffuse Lauren's subtype. 31 (27%) patients had occult metastatic disease detected by PET/CT (n = 11, 10%) and/or laparoscopy (n = 21, 19%), with a single overlap. Economic modeling suggests that the addition of FDG‐PET/CT to the standard staging evaluation of patients with locally advanced gastric cancer resulted in an estimated cost savings of ～US $13,000 per patient.

CONCLUSIONS:

FDG‐PET/CT identifies occult metastatic lesions in approximately 10% of patients with locally advanced gastric cancer. Because of reduced morbidity from fewer futile surgeries and lower patient care costs, PET/CT should be considered as a component of the standard staging algorithm for localized gastric cancer. Cancer 2012. © 2012 American Cancer Society.     

Ability of integrated positron emission and computed tomography to detect significant colonic pathology

BACKGROUND:

The ability of integrated positron emission tomography and computed axial tomography (PET‐CT) to detect colonic pathology is not fully defined. The purpose of this study was to assess the ability of PET‐CT to detect colonic pathology and to determine the significance of (¹⁸F)2‐fluoro‐2‐deoxyglucose (¹⁸F‐FDG) activity noted incidentally in the colon on PET‐CT.

METHODS:

Records for all patients who underwent PET‐CT and colonoscopy at our institution were reviewed. Patients with history of colonic malignancy or colon surgery were excluded.

RESULTS:

Fifty‐eight patients had incidental colonic ¹⁸F‐FDG activity on PET (Group A) and 272 had none (Group B). In Group A, 65% of patients had pathologic findings detected on colonoscopy that corresponded to the site of PET activity. Standardized uptake value (SUV) readings were not helpful in distinguishing true‐positives from false‐positives. In Group B, 11.8% of patients were found to have significant colonic findings. Lesions not detected by PET‐CT included 4 colon cancers, 7 advanced adenomas, and 10 patients with colonic lymphoma. Overall, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET‐CT for detecting significant pathology were 53%, 93%, 65%, 89%, and 85%, respectively. For detecting colon cancer and adenomas 10 mm or more, the sensitivity, specificity, PPV, NPV, and accuracy of PET‐CT were 72%, 90%, 45%, 96%, and 88%, respectively.

CONCLUSIONS:

Incidental colonic activity detected by PET‐CT warrants further evaluation with colonoscopy. However, negative PET‐CT does not rule out significant colonic pathology including colon cancer, advanced adenomas, or lymphoma. Cancer 2010. © 2010 American Cancer Society.     

18F‐fluorodeoxyglucose positron emission tomography/computed tomography (FDG‐PET/CT) imaging in the staging and prognosis of inflammatory breast cancer

BACKGROUND:

To prospectively assess fluorodeoxyglucose positron emission tomography/computed tomography (FDG‐PET/CT) staging and prognosis value in patients with suspected inflammatory breast cancer (IBC).

METHODS:

Sixty‐two women (mean age 50.7 ± 11.4 years) presenting with unilateral inflammatory breast tumors (59 invasive carcinomas; 3 mastitis) underwent a PET/CT scan before biopsy.

RESULTS:

PET/CT scan was positive for the primary malignant tumor in 100% and false positive in 2 of 3 benign mastitis. In 59 IBC patients, FDG nodal foci were detected in axillary (90%; n = 53) and extra‐axillary areas (56%; n = 33) ipsilateral to the cancer. Compared with clinical examination, the axillary lymph node status by PET/CT was upstaged and downstaged in 35 and 5 patients, respectively. In 7 of 9 N0 patients, the axillary lymph node positivity on PET/CT was correct, as revealed by pathological postsurgery assessment (not available in the 2 remaining patients). The nodal foci were compared with preoperative fine needle aspiration and/or pathological postchemotherapy findings available in 44 patients and corresponded to 38 true positive, 4 false‐negative, and 2 false‐positive cases. In 18 of 59 IBC patients (31%), distant lesions were found. On the basis of a univariate analysis of the first enrolled patients (n = 42), among 28 patients who showed intense tumoral uptake (standard uptake value_max>5), the 11 patients with distant lesions had a worse prognosis than the 17 patients without distant lesions (P = .04).

CONCLUSIONS:

FDG‐PET/CT imaging provides additional invaluable information regarding nodal status or distant metastases in IBC patients and should be considered in the initial staging. It seems also that some prognostic information can be derived from FDG uptake characteristics. Cancer 2009. © 2009 American Cancer Society.     

Role of fluorine‐18‐fluorodeoxyglucose positron emission tomography/computed tomography in evaluating breast mucosa‐associated lymphoid tissue lymphoma: A case series

Mucosa‐associated lymphatic tissue (MALT) lymphoma of the breast is an extremely rare disease; its pathogenesis is not clear because of the rarity of disease, and the best diagnostic method has yet to be established. The metabolic behavior of this lymphoma is not still clear because only a few case reports are present in literature describing the possible role of fluorine‐18‐fluorodeoxyglucose positron emission tomography/computed tomography (18F‐FDG PET/CT) in this field. This report presents 4 cases of women with histologically proven breast MALT lymphoma who underwent 7 18F‐FDG PET/CT throughout the course of disease. All patients underwent staging PET/CT showing in all cases an FDG avid lesion corresponding to breast lymphoma; 3 patients underwent 18F‐FDG PET/CT also after chemotherapy. Our results suggest that breast MALT lymphomas are 18F‐FDG‐avid lymphomas. Positron emission tomography/computed tomography showed heterogeneous but high FDG uptake (mean maximum standardized uptake value 7.9), suggesting that it could be part of diagnostic workup and restaging process.     

Detection rate of fluorine‐18‐fluorodeoxyglucose positron emission tomography in patients with marginal zone lymphoma of MALT type: a meta‐analysis

The aim of this article is to meta‐analyse published data about the detection rate (DR) of fluorine‐18‐fluorodeoxyglucose (¹⁸F‐FDG) positron emission tomography (PET) and PET/computed tomography (CT) in the evaluation of patients with marginal zone lymphoma of the mucosa‐associated lymphoid tissue (MALT). A comprehensive literature search of studies published through February 2014 was performed. Pooled DR of ¹⁸F‐FDG PET or PET/CT including 95% confidence intervals (95% CI) was calculated on a per‐patient‐based analysis. Twenty studies including 376 patients with MALT lymphoma were selected. The pooled DR of ¹⁸F‐FDG PET or PET/CT was 71% (95% CI: 61–80%). A significant difference between the DR of PET/CT (69%; 95% CI: 61–80%) and that of PET alone (73%; 95% CI: 60–84%) was not demonstrated. A better DR of ¹⁸F‐FDG PET or PET/CT in bronchial (94%; 95% CI: 85–99%) and head‐and‐neck (90%; 95% CI: 78–98%) MALT lymphomas compared with gastric (62%; 95% CI: 46–77%) and ocular (49%; 95% CI: 36–63%) MALT lymphomas was found. This meta‐analysis demonstrates that MALT lymphoma is an ¹⁸F‐FDG‐avid tumour in most of the cases, suggesting a potential clinical role of ¹⁸F‐FDG PET or PET/CT in the initial evaluation of these patients. In particular, the DR of ¹⁸F‐FDG PET or PET/CT is related to the primary site of the MALT lymphoma. Copyright © 2014 John Wiley & Sons, Ltd.     

The prevalence and clinical significance of 18F–2‐fluoro‐2‐deoxy‐D‐glucose (FDG) uptake in the thyroid gland on PET or PET‐CT in patients with lymphoma

F¹⁸–2‐fluoro‐2‐deoxy‐D‐glucose (FDG) positron emission tomography (PET) has become a well established tool in staging and assessing therapy response in lymphoma. Incidental thyroid uptake on PET is not uncommon and can pose a diagnostic and management challenge. We retrospectively evaluate the prevalence and clinical significance of incidental FDG uptake in the thyroid gland in patients with lymphoma. 1868 lymphoma patients underwent PET and PET‐CT between August 2002 and August 2008. 52 patients (2.8%) demonstrated FDG thyroid uptake (M = 17, F = 35; mean age 63 yr). Thyroid uptake was determined as focal or diffuse, maximum standardized uptake values (SUVmax) recorded as well as SUV max ratio compared to background mediastinum activity (SUVR). Corresponding CT findings on PET‐CT were evaluated independently. Results were correlated with clinical, histopathological and imaging follow‐up. 30 (1.6%) patients had focal thyroid uptake. 16 (53%) had histological confirmation either by surgery (n = 7) or FNA under USS (n = 9). The final diagnosis was benign in 12/30 patients and malignant in 9/30. The malignancy risk for focal thyroid uptake was 30%. Five patients had intercurrent thyroid cancer (four papillary, one microinvasive follicular) and four had lymphomatous involvement. There was no significant difference between the mean sizes of benign (23.7 mm, range 12–34) and malignant nodules (23.6 mm, range 8–48). The mean SUVmax of malignant and benign nodules was 4.4 (range 1.8–10.1) and 3.2 (range 1.8–6.9) respectively with no statistically significant difference. 22 (1.2%) patients had diffuse FDG uptake in thyroid and benign aetiology was found in all with adequate follow‐up (15/22). Focal FDG thyroid uptake on PET or PET‐CT in lymphoma patients warrants further investigations. The malignancy risk is 30% either due to intercurrent thyroid cancer or lymphomatous involvement. SUVmax, SUVR and CT attenuation characteristics are not helpful in distinguishing between benign and malignant aetiologies. Diffuse thyroid uptake has a benign aetiology. Copyright © 2010 John Wiley & Sons, Ltd.     

[F‐18]‐fluorodeoxy‐D‐glucose–positron emission tomography response is associated with outcome for extremity osteosarcoma in children and young adults

BACKGROUND:

Response to neoadjuvant chemotherapy is 1 of the most powerful prognostic factors for extremity osteosarcoma. [F‐18]‐fluorodeoxy‐D‐glucose–positron emission tomography (FDG‐PET) is a noninvasive imaging modality that is used to predict histopathologic response. To determine the prognostic value of FDG‐PET response for progression‐free survival (PFS) in osteosarcoma, the authors of this report reviewed the University of Washington Medical Center experience.

METHODS:

Forty patients with extremity osteosarcoma were evaluated by FDG‐PET. All patients received neoadjuvant and adjuvant chemotherapy. FDG‐PET standard uptake values (SUVs) before neoadjuvant chemotherapy (SUV1) and after neoadjuvant chemotherapy (SUV2) were analyzed and correlated with histopathologic response.

RESULTS:

The median SUV1 was 6.8 (range, 3.0‐24.1), the median SUV2 was 2.3 (range, 1.2‐12.8), and the median SUV2 to SUV1 ratio (SUV2:1), was 0.36 (range, 0.12‐1.10). A good FDG‐PET response was defined as anSUV2 <2.5 or an SUV2:1 ≤0.5. FDG‐PET responses according to SUV2 and SUV2:1 were concordant with histologic response in 58% and 68% of patients, respectively. SUV2 was associated with outcome (4‐year PFS, 73% for SUV2 <2.5 vs 39% for SUV2 ≥2.5; P = .021). Both the initial disease stage and the histologic response were associated with outcome.

CONCLUSIONS:

FDG‐PET imaging of extremity osteosarcoma was correlated only partially with a histologic response to neoadjuvant chemotherapy. An SUV2 <2.5 was associated with improved PFS. Future prospective studies are warranted to determine whether FDG‐PET imaging may be used as a predictor of outcome independent of initial disease stage. Cancer 2009. © 2009 American Cancer Society.     

Quantitative F18‐fluorodeoxyglucose positron emission tomography accurately characterizes peripheral nerve sheath tumors as malignant or benign

BACKGROUND:

Correct pretreatment classification is critical for optimizing diagnosis and treatment of patients with peripheral nerve sheath tumors (PNSTs). The aim of this study was to evaluate whether F18‐fluorodeoxyglucose positron emission tomography (FDG PET) can differentiate malignant (MPNST) from benign PNSTs.

METHODS:

Thirty‐four adult patients presenting with PNST who underwent a presurgical FDG PET/computed tomography (CT) scan between February 2005 and November 2008 were included in the study. Tumors were characterized histologically, by FDG maximum standardized uptake value (SUV_max [g/mL]), and by CT size (tumor maximal diameter [cm]). The accuracy of FDG PET for differentiating MPNSTs from benign PNSTs (neurofibroma and schwannoma) was evaluated by receiver operating characteristic (ROC) curve analysis.

RESULTS:

SUV_max was measured in 34 patients with 40 tumors (MPNSTs: n = 17; neurofibromas: n = 9; schwannomas: n = 14). SUV_max was significantly higher in MPNST compared with benign PNST (12.0 ± 7.1 vs 3.4 ± 1.8; P < .001). An SUV_max cutoff point of ≥6.1 separated MPNSTs from BPSNTs with a sensitivity of 94% and a specificity of 91% (P < .001). By ROC curve analysis, SUV_max reliably differentiated between benign and malignant PNSTs (area under the ROC curve of 0.97). Interestingly, the difference between MPNSTs and schwannomas was less prominent than that between MPNSTs and neurofibromas.

CONCLUSIONS:

Quantitative FDG PET imaging distinguished between MPNSTs and neurofibromas with high accuracy. In contrast, MPNSTs and schwannomas were less reliably distinguished. Given the difficulties in clinically evaluating PNST and in distinguishing benign PNST from MPNST, FDG PET imaging should be used for diagnostic intervention planning and for optimizing treatment strategies. Cancer 2010. © 2010 American Cancer Society.     

Diagnostic value of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography for the detection of metastases in non–small‐cell lung cancer patients

In the recent years, fluorine 18 fluorodeoxyglucose (¹⁸F‐FDG) positron emission tomography (PET)/computed tomography (CT) has emerged as a new modality for staging non–small‐cell lung cancer (NSCLC) patients. The aim of this meta‐analysis was to assess the diagnostic value of ¹⁸F‐FDG PET/CT in detecting metastatic lesions in NSCLC patients. Meta‐analysis methods were used to pool sensitivity, specificity, positive and negative likehood ratios, diagnostic odd ratios and to construct a summary receiver‐operating characteristic curve. Data from included studies were pooled to compare the diagnostic accuracy between PET/CT and PET or CT alone in nodal staging. Totally, 56 studies involving 8,699 patients met the inclusion criteria. The pooled sensitivities and specificities of ¹⁸F‐FDG PET/CT were 0.72 [95% confidence interval (CI): 0.65–0.78] and 0.91 (95% CI: 0.86–0.94) in determining mediastinal nodal staging; 0.71 (95% CI: 0.60–0.80) and 0.83 (95% CI: 0.77–0.88) in intrathoracic staging; 0.78 (95% CI: 0.64–0.87) and 0.90 (95% CI: 0.84–0.94) in intrathoracic staging on a per‐node basis. For detecting extrathoracic metastases, the pooled sensitivities and specificities of ¹⁸F‐FDG PET/CT were 0.77 (95% CI: 0.47–0.93) and 0.95 (95% CI: 0.92–0.97) for all extrathoracic metastases; 0.91 (95% CI: 0.80–0.97) and 0.98 (95% CI: 0.94–0.99) for bone metastases. ¹⁸F‐FDG PET/CT is beneficial in detecting lymph node metastases and extrathoracic metastases although PET/CT showed low sensitivity in detecting brain metastases. ¹⁸F‐FDG PET/CT confers significantly higher sensitivity and specificity than contrast‐enhanced CT (both p < 0.01) and higher sensitivity than ¹⁸F‐FDG PET in staging NSCLC (p < 0.05).     

¹⁸F-fluoro-deoxyglucose positron emission tomography in assessment of myeloma-related bone disease: a systematic review

BACKGROUND:

The goal of this study was to conduct a comparative analysis of whole body X‐ray (WBXR) and ¹⁸F‐fluoro‐deoxyglucose positron emission tomography (¹⁸FDG PET) in staging and response assessment of multiple myeloma.

METHODS:

We performed a systematic review of studies comparing ¹⁸FDG PET with WBXR and/or magnetic resonance imaging in terms of sensitivity for myeloma‐related bone disease at staging and during follow‐up.

RESULTS:

Eighteen studies involving 798 patients met the inclusion criteria. The mean Quality Assessment of Diagnostic Accuracy Studies (QUADAS) score, expressed as a percentage of the maximum score, was 61%. In 7 studies (n = 242 patients), concordance assessment between WBXR and ¹⁸FDG PET scan was possible, showing a higher sensitivity of the ¹⁸FDG PET in the detection of myeloma bone lesions in 6 studies. The only study reporting on the prognostic value of ¹⁸FDG PET at staging found that the number of FDG‐avid focal lesions was an independent prognostic parameter. In addition, the limited studies on response monitoring showed that normalization of ¹⁸FDG PET during treatment correlated with a superior clinical outcome.

CONCLUSIONS:

In general, ¹⁸FDG PET has a superior sensitivity for myeloma bone lesions compared with WBXR. Future studies have to validate the additive value of myeloma‐related bone disease detected on ¹⁸FDG PET–computed tomography (CT) in predicting outcome. Response monitoring with the use of ¹⁸FDG PET‐CT during treatment is promising, allowing more precise prediction of prognosis compared with the standard response monitoring. In view of the expanding treatment options for multiple myeloma, this may provide important information for treatment decisions in the future. Cancer 2012. © 2011 American Cancer Society.     

18F‐fluorodeoxyglucose and 11C‐acetate positron emission tomography are useful modalities for diagnosing the histologic type of thymoma

BACKGROUND:

The objective of this study was to clarify the usefulness of positron emission tomography (PET) using¹⁸F‐fluorodeoxyglucose (FDG) and carbon 11‐labeled acetate (AC) for predicting the histologic types and tumor invasiveness of thymoma in a multicenter study.

METHODS:

Forty thymomas were examined using both FDG‐PET and AC‐PET before surgery. The histologic types were type A in 1 thymoma, type AB in 12 thymomas, type B1 in 11 thymomas, type B2 in 7 thymomas, type B3 in 6 thymomas, and type C in 3 thymomas. Tumor invasiveness was assessed by pathologic tumor stage and was identified as stage I in 17 tumors, stage II in 17 tumors, stage III in 4 tumors, and stage IV in 2 tumors. FDG and AC uptake was measured as the maximum standard uptake value (SUV).

RESULTS:

The FDG‐SUV in type C thymomas was significantly higher than that in the other types (A‐B3; P = .001 – P = .048). The AC‐SUV in type A/AB thymomas was significantly higher than that in the other tumor types (B1‐C; P < .001 – P = .002). All 3 type C tumors had an FDG‐SUV ≥6.3, and all 13 type A/AB tumors had an FDG‐SUV <6.3 and an AC‐SUV ≥5.7. All 17 thymomas that had an FDG‐SUV <6.3 and an AC‐SUV <5.7 were type B1, B2, or B3. Neither the FDG‐SUV nor the AC‐SUV differed significantly between the stages I/II tumors and stage III/IV tumors.

CONCLUSIONS:

Although neither the FDG‐SUV nor the AC‐SUV can predict the invasiveness of thymomas assessed by tumor stage, they are useful for predicting histologic types of thymoma. Thymomas with an FDG‐SUV <6.3 and an AC‐SUV ≥5.7 almost certainly are types A/AB, which is of considerable prognostic and management significance. Cancer 2009. © 2009 American Cancer Society.     

Impact of positron emission tomography/computed tomography surveillance at 12 and 24 months for detecting head and neck cancer recurrence

BACKGROUND:

In head and neck cancer (HNC), 3‐month post‐treatment positron emission tomography (PET)/computed tomography (CT) reliably identifies persistent/recurrent disease. However, further PET/CT surveillance has unclear benefit. The impact of post‐treatment PET/CT surveillance on outcomes is assessed at 12 and 24 months.

METHODS:

A 10‐year retrospective analysis of HNC patients was carried out with long‐term serial imaging. Imaging at 3 months included either PET/CT or magnetic resonance imaging, with all subsequent imaging comprised of PET/CT. PET/CT scans at 12 and 24 months were evaluated only if preceding interval scans were negative. Of 1114 identified patients, 284 had 3‐month scans, 175 had 3‐ and 12‐month scans, and 77 had 3‐, 12‐, and 24‐month scans.

RESULTS:

PET/CT detection rates in clinically occult patients were 9% (15 of 175) at 12 months, and 4% (3 of 77) at 24 months. No difference in outcomes was identified between PET/CT‐detected and clinically detected recurrences, with similar 3‐year disease‐free survival (41% vs 46%, P = .91) and 3‐year overall survival (60% vs 54%, P = .70) rates. Compared with 3‐month PET/CT, 12‐month PET/CT demonstrated fewer equivocal reads (26% vs 10%, P < .001). Of scans deemed equivocal, 6% (5 of 89) were ultimately found to be positive.

CONCLUSIONS:

HNC patients with negative 3‐month imaging appear to derive limited benefit from subsequent PET/CT surveillance. No survival differences were observed between PET/CT‐detected and clinically detected recurrences, although larger prospective studies are needed for further investigation. Cancer 2013. © 2012 American Cancer Society.     

Positron emission tomography/ultrasound fusion technique in patients with malignant melanoma

¹⁸F‐fluorodeoxyglucose positron emission tomography (FDG‐PET)/CT is commonly used to assess tumour recurrence in high‐risk patients with malignant melanoma (MM). However, results can be ambiguous either because of the CT's insufficient soft‐tissue contrast or non‐specific FDG accumulation caused by inflammation. Ultrasound (US) can provide additional morphologic information that is superior to CT. For precisely combining PET and US findings, we used a real‐time fusion technique based on navigated US (PET/US fusion). Here, we describe our results from patients where PET/US fusion proved helpful in differentiating unclear PET/CT findings. This fusion technique is likely to be helpful for decision making in MM patients and biopsy guidance.     

Utility of PET-CT for Evaluation of Patients With Peripheral T-cell Lymphoma

Background

Fluorine-18 fluorodeoxyglucose (FDG) avidity varies in peripheral T-cell lymphoma (PTCL). We evaluated FDG avidity of pretreatment positron emission tomography/computed tomography (P-PET/CT), to appraise the prognostic significance of interim PET/CT (I-PET/CT) and end of treatment PET/CT (E-PET/CT) in PTCL.

Coregistered whole body magnetic resonance imaging‐positron emission tomography (MRI‐PET) versus PET‐computed tomography plus brain MRI in staging resectable lung cancer

BACKGROUND:

The objective of this study was to assess whether coregistered whole brain (WB) magnetic resonance imaging‐positron emission tomography (MRI‐PET) would increase the number of correctly upstaged patients compared with WB PET‐computed tomography (PET‐CT) plus dedicated brain MRI in patients with nonsmall cell lung cancer (NSCLC).

METHODS:

From January 2010 through November 2011, patients with NSCLC who had resectable disease based on conventional staging were assigned randomly either to coregistered MRI‐PET or WB PET‐CT plus brain MRI (ClinicalTrials.gov trial NCT01065415). The primary endpoint was correct upstaging (the identification of lesions with higher tumor, lymph node, or metastasis classification, verified with biopsy or other diagnostic test) to have the advantage of avoiding unnecessary thoracotomy, to determine appropriate treatment, and to accurately predict patient prognosis. The secondary endpoints were over staging and under staging compared with pathologic staging.

RESULTS:

Lung cancer was correctly upstaged in 37 of 143 patients (25.9%) in the MRI‐PET group and in 26 of 120 patients (21.7%) in the PET‐CT plus brain MRI group (4.2% difference; 95% confidence interval, ?6.1% to 14.5%; P = .426). Lung cancer was over staged in 26 of 143 patients (18.2%) in the MRI‐PET group and in 7 of 120 patients (5.8%) in the PET‐CT plus brain MRI group (12.4% difference; 95% confidence interval, 4.8%‐20%; P = .003), whereas lung cancer was under staged in 18 of 143 patients (12.6%) and in 28 of 120 patients (23.3%), respectively (?10.7% difference; 95% confidence interval, ?20.1% to ?1.4%; P = .022).

CONCLUSIONS:

Although both staging tools allowed greater than 20% correct upstaging compared with conventional staging methods, coregistered MRI‐PET did not appear to help identify significantly more correctly upstaged patients than PET‐CT plus brain MRI in patients with NSCLC. Cancer 2013. © 2013 American Cancer Society.     

The clinical application of 18F‐fluorodeoxyglucose positron emission tomography to predict survival in patients with operable esophageal cancer

BACKGROUND:

Metabolic tumor activity using ¹⁸F‐fluorodeoxyglucose positron emission tomography (FDG‐PET) was believed to have a predictive value for patient outcome in malignancies. The objective of the current study was to assess the prognostic effectiveness of the highest standardized uptake value (SUV) in the primary or regional area (peak SUV) and the number of PET‐positive lymph nodes in esophageal cancer.

METHODS:

The authors retrospectively reviewed their experience with 184 consecutive esophageal cancer patients imaged preoperatively using FDG‐PET scanning.

RESULTS:

The median peak SUV was 4.5 (range, 1.4‐21.9). The survival curve was analyzed using the median peak SUV as the cutoff value. Comparison of each group and clinicopathologic characteristics revealed significant associations between peak SUV and each of the following factors: tumor status (P < .001), lymph node status (P < .001), metastatic status (P < .05), stage of disease (P < .001), number of PET‐positive lymph nodes (P < .001), and the number of histologically positive lymph nodes (P < .001). The 5‐year overall survival (OS) rate for patients having FDG uptake with a peak SUV ≥4.5 was 47% and that for patients with a peak SUV <4.5 was 76% (P < .0001). On multivariate survival analysis using the Cox proportional hazards model, peak SUV and the number of PET‐positive lymph nodes were found to be independent predictive factors for OS. The number of PET‐positive lymph nodes was a single prognostic factor predicting both disease‐free survival and OS.

CONCLUSIONS:

Pretreatment PET cannot only potentially diagnose the extent of disease, but also may be predictive of patient survival after esophageal cancer resection. Cancer 2009. © 2009 American Cancer Society.     

Prognostic value of 18F‐fluoroazomycin arabinoside PET/CT in patients with advanced non‐small‐cell lung cancer

This study evaluated the prognostic value of positron emission tomography/computed tomography (PET/CT) using ¹⁸F‐fluoroazomycin arabinoside (FAZA) in patients with advanced non‐small‐cell lung cancer (NSCLC) compared with ¹⁸F‐fluorodeoxyglucose (FDG). Thirty‐eight patients with advanced NSCLC (stage III, 23 patients; stage IV, 15 patients) underwent FAZA and FDG PET/CT before treatment. The PET parameters (tumor‐to‐muscle ratio [T/M] at 1 and 2 h for FAZA, maximum standardized uptake value for FDG) in the primary lesion and lymph node (LN) metastasis and clinical parameters were compared concerning their effects on progression‐free survival (PFS) and overall survival (OS). In our univariate analysis of all patients, clinical stage and FAZA T/M in LNs at 1 and 2 h were predictive of PFS (P = 0.021, 0.028, and 0.002, respectively). Multivariate analysis also indicated that clinical stage and FAZA T/M in LNs at 1 and 2 h were independent predictors of PFS. Subgroup analysis of chemoradiotherapy‐treated stage III patients revealed that only FAZA T/M in LNs at 2 h was predictive of PFS (P = 0.025). The FDG PET/CT parameters were not predictive of PFS. No parameter was a significant predictor of OS. In patients with advanced NSCLC, FAZA uptake in LNs, but not in primary lesions, was predictive of treatment outcome. These results suggest the importance of characterization of LN metastases in advanced NSCLC patients.