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.     

The diagnostic and prognostic utility of positron emission tomography/computed tomography‐based follow‐up after radiotherapy for head and neck cancer

BACKGROUND:

The detection of subclinical head and neck cancer recurrence or a second primary tumor may improve survival. In the current study, the authors investigated the clinical value of a follow‐up program incorporating serial ¹⁸F?fluorodeoxyglucose?positron emission tomography integrated with computed tomography (PET/CT) in the detection of recurrent disease in patients with head and neck cancer.

METHODS:

A total of 240 PET/CT scans were reviewed in 80 patients with head and neck cancer who were treated with radiotherapy (RT) from July, 2005 through August, 2007. All patients were followed with clinical examination, PET/CT, and correlative imaging for a minimum of 11 months (median follow?up, 21 months).

RESULTS:

The sensitivity, specificity, and positive and negative predictive values of PET/CT‐based follow‐up for detecting locoregional recurrence were 92%, 82%, 42%, and 98%, respectively. Corresponding values for distant metastases or second primary tumors were 93%, 96%, 81%, and 98%, respectively. Eight patients (10%) developed disease recurrences or second primary tumors that were amenable to salvage surgery with negative surgical margins. The 2‐year progression‐free survival and 2‐year overall survival rates were significantly different between patients who had a negative and those with a positive PET/CT result within 6 months of the completion of RT (93% vs 30% [P<.001] and 100% vs 32% [P<.001], respectively).

CONCLUSIONS:

Although post‐therapy follow‐up using PET/CT is reportedly associated with a high false‐positive rate in the irradiated head and neck, PET/CT appears to be a highly sensitive technique for the detection of recurrent disease. Furthermore, negative PET/CT results within 6 months of the completion of RT offer significant prognostic value. Cancer 2009. © 2009 American Cancer Society.     

Optimal Interval for 18F-FDG-PET After Chemoradiotherapy for Rectal Cancer

Introduction

Although ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) has been increasingly used to evaluate the response to preoperative chemoradiotherapy (CRT) in patients with rectal cancer, the optimal intervals between completion of CRT, PET, and surgery have not been fully investigated.

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.     

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.     

The use of PET in assessing tumor response after neoadjuvant chemoradiation for rectal cancer

Purpose

To assess the correlation of 18F-FDG-PET (PET) response to pathological response after neoadjuvant chemoradiation (CRT) for locally advanced rectal cancer.

Methods and materials

Twenty patients with locally advanced rectal cancer were identified between 2001 and 2005. The median age was 57 years (range 37-72) with 14 males and 6 females. All patients were staged with endorectal ultrasound and/or MRI, CT, and PET. The clinical staging was T3N0M0 (16), T3N1M0 (2), and T3N0M1 (2). Restaging PET was performed after CRT, and prior to definitive surgery. The response on PET and pathology was assessed and correlated. Patient outcome according to PET response was also assessed.

Results

Following CRT, a complete PET response occurred in 7 patients, incomplete response in 10, and no response in 3 patients. At surgery, complete pathological response was recorded in 7 patients, incomplete response in 10 and no response in 3. There was a good correlation of PET and pathological responses in complete responders (5/7 cases) and non-responders (3/3 cases). After a median follow-up of 62 months (range 7-73), twelve patients were alive with no evidence of disease. All patients achieving complete metabolic response were alive with no evidence of disease, while as those who had no metabolic response, all died as a result of metastatic disease.

Conclusions

PET is a promising complementary assessment tool for assessing tumor response after CRT if there is a complete or no response. PET response may also predict for outcome.     

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.     

Value of integrated positron emission tomography revised using a phantom study to evaluate malignancy grade of lung adenocarcinoma

BACKGROUND:

The malignant biological behavior of small‐sized lung adenocarcinomas remains obscure, although understanding this feature is important for selecting appropriate treatment. In the current study, the authors evaluated malignancy grades of small adenocarcinomas using fluorodeoxyglucose‐positron emission tomography/computed tomography (PET/CT) in addition to high‐resolution CT (HRCT) and pathological analysis in a multicenter setting.

METHODS:

A total of 201 patients with clinical T1N0M0 adenocarcinoma underwent PET/CT and HRCT followed by complete surgical resection. Associations between components of bronchioloalveolar carcinoma (BAC) in specimens and maximum standardized uptake values (maxSUV) on PET/CT and ground‐glass opacity (GGO) ratios and tumor disappearance rate (TDR) on HRCT were analyzed, as well as associations between these findings and pathological features of the tumors. Variations in maxSUV among institutions and the underestimations derived from small tumors, which are limitations of PET performed in multicenter studies, were adjusted using a phantom study.

RESULTS:

The maxSUV, BAC ratio, TDR, and GGO ratio (in that order) reflected the grade of tumor invasiveness and lymph node metastasis. The maxSUV and BAC ratio were found to be significant prognostic predictors derived from disease‐free survival curves. Although the BAC ratio was found to be significantly associated with preoperative radiographic parameters, the maxSUV, GGO ratio, and TDR (all P < .0001), the degree of correlation with maxSUV (correlation coefficient [R²] = 0.1699) was much weaker than that reported with the GGO ratio (R² = 0.5860) or TDR (R² = 0.5082).

CONCLUSIONS:

Phantom studies can overcome the difficulties of multicenter studies using PET. A higher maxSUV appears to reflect aggressive malignant behavior in clinical T1N0M0 adenocarcinomas, independent of BAC components. Preoperative PET/CT assessment in addition to HRCT could be used to construct hypotheses for a future clinical study of strategies for the treatment of patients with small lung adenocarcinoma. Cancer 2010. © 2010 American Cancer Society.     

Impact of post-therapy positron emission tomography on prognostic stratification and surveillance after chemoradiotherapy for cervical cancer

BACKGROUND:

A study was undertaken to investigate the detection of relapse and survival outcomes in patients with cervical cancer treated with curative intent chemoradiotherapy, and evaluated with a post‐therapy ¹⁸F‐fluorodeoxyglucose positron emission tomography (FDG‐PET) scan.

METHODS:

Between January 2002 and June 2007, 105 consecutive patients were prospectively enrolled into a registry study designed to assess outcomes of chemoradiotherapy. A FDG‐PET scan was performed between 3 and 12 months (median, 4.9 months) post‐treatment at clinician discretion. Tumor response was graded as complete metabolic response, partial metabolic response, or progressive metabolic disease.

RESULTS:

Median follow‐up was 36 months. At post‐therapy FDG‐PET, 73 (70%) patients had complete metabolic response, 10 (9%) had partial metabolic response, and 22 (21%) had progressive metabolic disease. Overall survival at 3 years was 77% in all patients, and 95% for those with complete metabolic response. On multivariate analysis, complete metabolic response (P < .0001) and pretreatment tumor volume (P = .041) were strong predictors for overall survival. The number of involved lymph nodes (P < .005) and International Federation of Gynecology and Obstetrics stage (P = .04) were predictive of relapse‐free survival. In total, 18 patients relapsed at a single site, and 13 underwent salvage, with a 3‐year survival of 67%. Patients with complete metabolic response had a distant failure rate 36‐fold less than those with partial metabolic response (P < .0001). After complete metabolic response, only 1 patient (1.6%) relapsed without symptoms and was detected through physical examination.

CONCLUSIONS:

The presence of a complete metabolic response at post‐therapy FDG‐PET is a powerful predictor for survival after chemoradiation. The very low rate of recurrence in patients with a complete metabolic response justifies a conservative follow‐up approach for these patients, because relapse is usually symptomatic and not detected by routine clinical review. Cancer 2011. © 2011 American Cancer Society.     

Early prediction of response by F-FDG PET/CT during preoperative therapy in locally advanced rectal cancer: A systematic review

Aim

To assess the predictive value of fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) in early assessing response during neo-adjuvant chemoradiotherapy (CRT) in patients with locally advanced rectal cancer.

Materials and methods

A systematic review was performed by search of MEDLINE Library for the following terms: “rectal carcinoma OR rectal cancer”, “predictive OR prediction OR response assessment OR response OR assessment”, “early OR ad interim”, “therapy”, “FDG OR ¹⁸F-FDG”, “PET OR PET/CT”. Articles performed by the use of stand-alone PET scanners were excluded.

Results

10 studies met the inclusion criteria, including 302 patients. PET/CT demonstrated a good early predictive value in the global cohort (mean sensitivity = 79%; mean specificity = 78%). SUV and its percentage decrease (response index = RI) were calculated in all studies. A higher accuracy was demonstrated for RI (mean sensitivity = 82%; pooled specificity = 85%) with a mean cut-off of 42%. The mean time point to perform PET scan during CRT resulted to be at 1.85 weeks. Some PET parameters resulted to be both predictive and not statistical predictive of response, maybe due to the small population and few studies bias.

Conclusion

PET showed high accuracy in early prediction response during preoperative CRT, increased with the use of RI as parameter. In the era of tailored treatment, the precocious assessment of non-responder patients allows modification of the subsequent strategy especially the timing and the type of surgical approach.     

Laparoscopic extraperitoneal para-aortic lymphadenectomy in locally advanced cervical cancer: a prospective correlation of surgical findings with positron emission tomography/computed tomography findings

BACKGROUND:

Failure to detect metastasis to para‐aortic nodes in patients with locally advanced cervical cancer leads to suboptimal treatment. No previous studies have prospectively compared positron emission tomography (PET)/computed tomography (CT) with laparoscopic extraperitoneal staging in the evaluation of para‐aortic lymph nodes.

METHODS:

Sixty‐five patients were enrolled; 60 were available for analysis. Patients with stage IB2‐IVA cervical cancer without evidence of para‐aortic lymphadenopathy on preoperative CT or magnetic resonance imaging (MRI) were prospectively enrolled. All patients underwent preoperative PET/CT. Laparoscopic extraperitoneal lymphadenectomy was performed from the common iliac vessels to the left renal vein.

RESULTS:

The median age at diagnosis was 48 years (range, 23‐84). The median operative time was 140 minutes (range, 89‐252). The median blood loss was 22.5 mL (range, 5‐150). The median length of hospital stay was 1 day (range, 0‐4). The median number of lymph nodes retrieved was 11 (range, 1‐39). Fourteen (23%) patients had histopathologically positive para‐aortic nodes. Of the 26 patients with negative pelvic and para‐aortic nodes on PET/CT, 3 (12%) had histopathologically positive para‐aortic nodes. Of the 27 patients with positive pelvic but negative para‐aortic nodes on PET/CT, 6 (22%) had histopathologically positive para‐aortic nodes. The sensitivity and specificity of PET/CT in detecting positive para‐aortic nodes when nodes were negative on CT or MRI were 36% and 96%, respectively. Eleven (18.3%) patients had a treatment modification based on surgical findings.

CONCLUSIONS:

Laparoscopic extraperitoneal para‐aortic lymphadenectomy is safe and feasible. Surgical staging of patients with locally advanced cervical cancer should be considered before planned radiation and chemotherapy. Cancer 2011. © 2010 American Cancer Society.     

Post-treatment (not interim) positron emission tomography-computed tomography scan status is highly predictive of outcome in mantle cell lymphoma patients treated with R-HyperCVAD

BACKGROUND:

Although convincing data exist regarding the prognostic utility of positron emission tomographic (PET)‐computed tomographic (CT) imaging in Hodgkin lymphoma and diffuse large B‐cell lymphoma, its prognostic utility both during treatment and immediately after treatment have not been systematically evaluated in a large mantle cell lymphoma (MCL) patient cohort to support its use in clinical practice.

METHODS:

The authors conducted a retrospective cohort study to examine the prognostic utility of PET‐CT imaging in a uniform MCL patient cohort undergoing dose‐intensive chemotherapy (R‐HyCVAD) in the frontline setting. The primary study endpoints were progression‐free survival (PFS) and overall survival (OS). PET‐CT images were centrally reviewed for the purposes of this study using standardized response criteria.

RESULTS:

Fifty‐three patients with advanced stage MCL with PET‐CT data were identified. With median follow‐up of 32 months, 3‐year PFS and OS estimates were 76% (95% confidence interval [CI], 64%‐84%) and 84% (95% CI, 72%‐90%), respectively. Interim PET‐CT status was not associated with PFS (hazard ratio [HR], 0.9; 95% CI, 0.3‐2.7; P = .8) or OS (HR, 0.6; 95% CI, 0.1‐2.9; P = .5). Post‐treatment PET‐CT status was statistically significantly associated with PFS (HR, 5.2; 95% CI, 2.0‐13.6; P = .001) and trended toward significant for OS (HR, 2.8; 95% CI, 0.8‐9.6; P = .07).

CONCLUSIONS:

These data do not support the prognostic utility of PET‐CT in pretreatment and interim treatment settings. A positive PET‐CT after the completion of therapy identifies a patient subset with an inferior PFS and a trend toward inferior OS. Cancer 2012;3565–3570. © 2011 American Cancer Society.     

Breast cancer recurrence diagnosis suspected on tumor marker rising: value of whole-body 18FDG-PET/CT imaging and impact on patient management

BACKGROUND:

Breast cancer recurrence is often suspected on tumor marker rising in asymptomatic patients. The value of fluorine‐18 fluorodeoxyglucose (18FDG)–positron emission tomography/computed tomography (PET/CT) imaging to detect recurrence and its subsequent impact on patient management were retrospectively assessed.

METHODS:

PET/CT scans were performed on 228 asymptomatic patients (mean, 60.8 years; range, 30‐91 years) presenting with rising CA 15‐3 and/or CEA serum levels.

RESULTS:

PET/CT scans were positive in 181 patients (79.5%) and normal in 47 patients, whereas 187 true recurrences were diagnosed. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET/CT imaging for detection of breast cancer recurrence were 93.6%, 85.4%, 96.7%, 74.5%, and 92.1%, respectively. When compared with the standard workup available in 67 patients, PET/CT imaging had a higher sensitivity and accuracy (94.5% vs 33% and 94% vs 48%, respectively). Recurrences were confirmed by pathology, conventional imaging techniques, or radiological and clinical follow‐up beyond 1 year (mean, 34 months; range, 12‐67 years) in 32, 130, and 25 patients, respectively. The diagnosis of recurrence led to a treatment modification in 123 patients (54%).

CONCLUSIONS:

18FDG‐PET/CT imaging is an efficient technique to detect breast cancer recurrence suspected on tumor marker rising in asymptomatic patients. It may thus contribute to improve patient management, providing an earlier diagnosis with complete whole‐body staging as a “one‐stop shop” procedure. Cancer 2011. © 2010 American Cancer Society.     

Is neoadjuvant chemoradiation with dose-escalation and consolidation chemotherapy sufficient to increase surgery-free and distant metastases-free survival in baseline cT3 rectal cancer?

Patients with cT3 rectal cancer are less likely to develop complete response to neoadjuvant chemoradiation (nCRT) and still face significant risk for systemic relapse. In this setting, radiation (RT) dose-escalation and consolidation chemotherapy in “extended” nCRT regimens have been suggested to improve primary tumor response and decrease the risks of systemic recurrences. For these reasons we compared surgery-free and distant-metastases free survival among cT3 patients undergoing standard or extended nCRT.

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.     

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 Role of Qualitative and Quantitative Analysis of F18-FDG Positron Emission Tomography in Predicting Pathologic Response Following Chemoradiotherapy in Patients with Esophageal Carcinoma

Objective

The aim of this study was to determine if a qualitative and quantitative assessment of pre- and post-chemoradiotherapy (CRT) F18-FDG PET scans of esophageal cancer patients could predict for residual disease in esophagectomy specimens.

Methods

We retrospectively reviewed the records of esophageal cancer patients who had undergone CRT at a single institution. Analysis was limited to esophagectomy patients with both pre- and post-CRT F18-FDG PET scans. The maximum standardized uptake value (SUV), location, and measured length of esophagus with increased F18-FDG uptake were obtained from the PET scan before and 3–4 weeks following CRT (preoperatively). The pattern of F18-FDG uptake was qualitatively assigned a category of diffuse, focal, or diffuse with focal component.

Results

Fifty-seven patients with localized esophageal carcinoma underwent F18-FDG PET/CT scans as part of their initial staging and post-CRT restaging workup, followed by esophagectomy. The pathologic complete response (pCR) rate was 25 %. The presence of a focal component on post-CRT PET predicted residual disease on univariate analysis (86 % vs. 64 %), and achieved significance when controlling for SUV and presence of diabetes on MVA (OR?=?5.59, p?=?0.028). There was no significant relationship between pre- or post-CRT SUV, tumor histology, or length of increased F18-FDG uptake and presence of residual disease. SUV and focality did not interact significantly to predict residual disease.

Conclusions

Qualitative but not quantitative PET imaging can help predict increased likelihood of residual tumor in esophageal cancer patients following CRT; however, it is not sensitive enough to solely rule out the presence of residual disease. Additional investigation with a larger cohort of patients is warranted.     

Prognostic significance of metabolic tumor burden by positron emission tomography/computed tomography in patients with relapsed/refractory diffuse large B‐cell lymphoma

The aim of the present study was to investigate the feasibility of measuring metabolic tumor burden using [F‐18] fluorodeoxyglucose (¹⁸F‐FDG) positron emission tomography/computed tomography (PET/CT) in patients with relapsed or refractory diffuse large B‐cell lymphoma (DLBCL) treated with bendamustine–rituximab. Because the standardized uptake value is a critical parameter of tumor characterization, we carried out a phantom study of ¹⁸F‐FDG PET/CT to ensure quality control for 28 machines in the 24 institutions (Japan, 17 institutions; Korea, 7 institutions) participating in our clinical study. Fifty‐five patients with relapsed or refractory DLBCL were enrolled. The ¹⁸F‐FDG PET/CT was acquired before treatment, after two cycles, and after the last treatment cycle. Treatment response was assessed after two cycles and after the last cycle using the Lugano classification. Using this classification, remission was complete in 15 patients (27%) and incomplete in 40 patients (73%) after two cycles of therapy, and remission was complete in 32 patients (58%) and incomplete in 23 patients (42%) after the last treatment cycle. The percentage change in all PET/CT parameters except for the area under the curve of the cumulative standardized uptake value–volume histogram was significantly greater in complete response patients than in non‐complete response patients after two cycles and the last cycle. The Cox proportional hazard model and best subset selection method revealed that the percentage change of the sum of total lesion glycolysis after the last cycle (relative risk, 5.24; P = 0.003) was an independent predictor of progression‐free survival. The percent change of sum of total lesion glycolysis, calculated from PET/CT, can be used to quantify the response to treatment and can predict progression‐free survival after the last treatment cycle in patients with relapsed or refractory DLBCL treated with bendamustine–rituximab.     

Can radicality of surgery be safely modulated on the basis of MRI and PET/CT imaging in locally advanced cervical cancer patients administered preoperative treatment?

BACKGROUND:

The goal of this study was to prospectively analyze the diagnostic performances of magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT) in predicting pathologically assessed residual disease in a large, single‐institution series of locally advanced cervical cancer (LACC) patients triaged to neoadjuvant treatments followed by radical surgery.

METHODS:

Between April 2007 and March 2010, 96 patients with histologically documented cervical cancer (any histology) and FIGO stage IB2‐IVA were enrolled. MRI and PET/CT were recommended to be performed within 4‐6 weeks from the end of treatment, and histology was the reference standard. Sensitivity, specificity, and accuracy were compared using the McNemar test.

RESULTS:

For residual disease in the cervix, sensitivity was higher for MRI than for PET/CT (86.1% vs 63.1%; P = .002), while specificity was significantly higher for PET/CT compared with MRI (P = .002). There was no difference in accuracy values between the 2 imaging modalities. For MRI analysis of lymph node groups, sensitivity, specificity, and accuracy were 35.7%, 95.9%, and 88.0%, respectively. Conversely, sensitivity, specificity, and accuracy for PET/CT were 28.6%, 97.8%, and 88.7%, respectively. Absence of follicular structures replaced by prevalent sclerosis and/or sinus histiocytosis was the most frequently documented morphological pattern in false‐positive cases.

CONCLUSION:

Neither MRI nor PET/CT accurately detected residual disease in LACC patients triaged to radical surgery after neoadjuvant treatment, disallowing the option of avoiding or modulating completion surgery. Cancer 2011;. © 2011 American Cancer Society.     

FDG-PET/CT for Assessing the Response to Neoadjuvant Chemotherapy in Bladder Cancer Patients

Purpose

To determine the accuracy of ¹⁸F-fluorodeoxyglucose with positron emission tomography and computed tomography (FDG-PET/CT) scans in assessing the response to neoadjuvant chemotherapy (NAC) in patients with bladder cancer scheduled to undergo radical cystectomy (RC).