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.     

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.     

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.     

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.     

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.     

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.     

Comparison of CT and positron emission tomography/CT coregistered images in planning radical radiotherapy in patients with non‐small‐cell lung cancer

Imaging with F‐18 fluorodeoxyglucose positron emission tomography (PET) significantly improves lung cancer staging, especially when PET and CT information are combined. We describe a method for obtaining CT and PET images at separate acquisitions, which allows coregistration and incorporation of PET information into the radiotherapy (RT) planning process for non‐small‐cell lung cancer. The influence of PET information on RT planning was analysed for 10 consecutive patients. Computed tomography and PET images were acquired with the patient in an immobilization device, in the treatment position. Using specially written software, PET and CT data were coregistered using fiducial markers and imported into our RT planning system (Cadplan version 6). Treatment plans were prepared with and without access to PET/CT coregistered images and then compared. PET influenced the treatment plan in all cases. In three cases, geographic misses (gross tumour outside planning target volume) would have occurred had PET not been used. In a further three cases, better planning target volume marginal coverage was achieved with PET. In four patients, three with atelectasis, there were significant reductions in V20 (percentage of the total lung volume receiving 20 Gy or more). Use of coregistered PET/CT images significantly altered treatment plans in a majority of cases. This method could be used in routine practice at centres without access to a combined PET/CT scanner .     

Correlation of [18F]‐2‐fluoro‐deoxy‐D‐glucose positron emission tomography standard uptake values with the cellular composition of stage I nonsmall cell lung cancer

BACKGROUND:

The aim of the current study was to determine whether the [18F]‐2‐fluoro‐deoxy‐D‐glucose (FDG) positron emission tomography (PET) standardized uptake value (SUV) in patients with a new diagnosis of stage I lung cancer correlates with a specific cellular component in the primary tumor.

METHODS:

This study was Health Insurance Portability and Accountability Act compliant and approved by our Institutional Review Board with a waiver of informed consent. Forty patients with stage I nonsmall cell lung cancer (NSCLC) who underwent FDG‐PET imaging at the time of diagnosis followed by surgical resection were retrospectively identified. Histologic sections of the primary tumor were reviewed by a pathologist without any clinical data and scored according to the percentage of each cellular component (tumor cells, normal stroma, inflammatory cells, necrosis, fibrosis, and other). Each component was compared with maximal (SUV_max) and mean (SUV_mean) SUVs using Pearson correlation coefficient analysis.

RESULTS:

The mean SUV_max and SUV_mean values for 40 stage I NSCLC tumors were 8.8 and 5.4, respectively. The mean histologic composition of tumor specimens in order of frequency was as follows: tumor cells (38.9%), fibrosis (30.8%), inflammatory cells (14.8%), normal stroma (5.2%), necrosis (5.8%), and other components (4.5%); however, there was considerable variation noted among individual tumors. There was no statistically significant correlation between SUV_max (r = .19; P = .24) or SUV_mean (r = .017; P = .29) and the proportion of tumor cells in the tumor mass or any other cellular components.

CONCLUSIONS:

The cellular composition of stage I NSCLC appears to be highly variable, with no correlation noted between a specific tumor cellular component and FDG activity. Cancer 2010. © 2010 American Cancer Society.     

Imaging with F‐18 FDG PET is superior to Tl‐201 SPECT in the staging of non‐small cell lung cancer for radical radiation therapy*

Thallium‐201 (Tl‐201) single photon emission computed tomography (SPECT) is funded for evaluation of malignancy in Australia and may have utility for staging of non‐small cell lung cancer (NSCLC) if CT results are equivocal. Fluorine‐18 fluorodeoxyglucose (F‐18 FDG) positron emission tomography (PET) is superior to CT for staging NSCLC but is more expensive and less widely available than Tl‐201 SPECT. Therefore, these techniques were prospectively compared in 27 radical radiation therapy candidates. Patients were allocated a conventional, PET and Tl‐201 stage. Tumour to background ratios (TBR) were recorded for the primary on both techniques. Metastatic disease was confirmed by surgical pathology, serial imaging or clinical follow up. Tumour to background ratios were consistently higher for FDG PET than Tl‐201 SPECT (P < 0.0001). Positron emission tomography detected all known primary tumours but Tl‐201 failed to image four primary tumours (15%). In 10 of 18 cases of discordance between PET and Tl‐201 SPECT regarding stage, corroboration was available from pathology or disease progression. Positron emission tomography was shown to have a 100% positive predictive value, including all three patients with PET‐detected distant metastases (P = 0.002). Results indicate that PET is superior to Tl‐201 SPECT scanning in the staging of NSCLC for radical radiation therapy, and that the low sensitivity for detection of local and metastatic disease is likely to limit the clinical impact and cost‐effectiveness of this technique despite its lower cost.     

Diagnostic accuracy of diffusion‐weighted imaging‐ magnetic resonance imaging compared to positron emission tomography/computed tomography in evaluating and assessing pathological response to treatment in adult patients with lymphoma: A systematic review

The use of Positron emission tomography/computerised tomography (PET/CT) is well established in the staging and assessment of treatment response of lymphoma. Recent studies have suggested that whole body diffusion‐weighted imaging –magnetic resonance imaging (WB‐DW‐MRI) may be an alternative to PET/CT in both staging and assessment of treatment response. A systematic review was performed to assess the ability of DW‐MRI in the assessment of treatment response in lymphoma. Pubmed, Medline, Web of Science and Embase databases were queried for studies examining whole body DW‐MRI compared to PET/CT in adult patients using a protocol of search terms. We carried out an extensive assessment of titles, abstracts and full texts of relevant paper as well as quality assessment with the Quality Assessment of Diagnostic Accuracy (QUADAS‐2) tool. Eight studies were found to meet the criteria and were included in our review and analysis. Overall, the quality of studies was found to be moderate, with good inter‐rater agreement (K = 0.74). Data analysis showed that lesion‐based assessment in 5 studies with pooled results had a sensitivity and specificity of 94.7% and 99.3%. Assessment with Cohen's Kappa coefficient showed agreement to be excellent (K = 0.88). Three studies were included for qualitative analysis, two of which showed good equivalence between PET/CT and DW‐MRI. WB‐DWI‐MRI can be considered a sensitive and specific method for assessing treatment response in Lymphoma without the use of ionising radiation or administration of F‐18 Flurodeoxyglucose. Further studies are needed to evaluate the optimum b‐values in assessing treatment response.     

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.     

Pretransplantation [18‐F]fluorodeoxyglucose positron emission tomography scan predicts outcome in patients with recurrent Hodgkin lymphoma or aggressive non‐Hodgkin lymphoma undergoing reduced‐intensity conditioning followed by allogeneic stem cell transplantation

BACKGROUND:

The use of positron emission tomography (PET) scanning in Hodgkin lymphoma (HL) and aggressive non‐Hodgkin lymphoma (HG‐NHL) has recognized prognostic value in patients who are receiving chemotherapy or undergoing autologous stem cell transplantation (SCT). In contrast, the role of PET before reduced‐intensity conditioning (RIC) and followed by allogeneic SCT has not been investigated to date.

METHODS:

PET was used to assess 80 patients who had chemosensitive disease (34 patients with HG‐NHL and 46 patients with HL) before they underwent allogeneic SCT: 42 patients had negative PET studies, and 38 patients had positive PET studies. Patients underwent allograft from matched related siblings (n = 41) or alternative donors (n = 39).

RESULTS:

At the time of the last follow‐up, 48 patients were alive (60%), and 32 had died. The 3‐year cumulative incidence of nonrecurrence mortality and disease recurrence was 17% and 40%, respectively. The cumulative incidence of disease recurrence was significantly lower in the PET‐negative patients (25% vs 56%; P = .007), but there was no significant difference between the patients with or without chronic graft‐versus‐host disease (P = .400). The patients who had negative PET studies before undergoing allogenic SCT also had significantly better outcomes in terms of 3‐year overall survival (76% vs 33%; P = .001) and 3‐year progression‐free survival (73% vs 31%; P = .001). On multivariate analysis, overall survival was influenced by PET status (hazard ratio [HR], 3.35), performance status (HR, 5.15), and type of donor (HR, 6.26 for haploidentical vs sibling; HR, 1.94 for matched unrelated donor vs sibling).

CONCLUSIONS:

The current results indicated that PET scanning appears to be an accurate tool for assessing prognosis in patients who are eligible for RIC allografting. Cancer 2010. © 2010 American Cancer Society.     

[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.     

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).     

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.     

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.     

Detection of hematogenous bone metastasis in cervical cancer

BACKGROUND:

In this large‐scale, retrospective study, the authors evaluated the diagnostic performances of computed tomography (CT), magnetic resonance (MR) imaging, and ¹⁸F‐fluorodeoxyglucose‐positron emission tomography (¹⁸F‐FDG–PET) in detecting hematogenous bone metastasis in patients with cervical cancer. The associated risk factors also were analyzed.

METHODS:

Patients with invasive cervical cancer who had both ¹⁸F‐FDG–PET studies and CT or MR imaging studies were selected. Patients who had either International Federation of Gynecology and Obstetrics (FIGO) stage III/IV disease or positive lymph node metastasis at the time of primary staging and patients who had suspected recurrent disease were included in the analyses. The diagnostic performances of PET was compared with the performance of CT and MR imaging by using the area under the receiver‐operating‐characteristic curve (AUC). Both univariate and multivariate analyses were applied to assess the risk factors for hematogenous bone metastasis at primary staging.

RESULTS:

PET was more sensitive than CT (P = .004) and was more specific than MR imaging (P = .04). The diagnostic performance of PET was significantly superior to the performance CT (AUC, 0.964 vs 0.662; P < .001) and MR (AUC, 0.966 vs 0.833; P = .033). Both FIGO stage and the extent of lymph node metastases were associated with hematogenous bone metastasis in univariate analysis. However, the extent of lymph node metastases was the only significant risk factor in multivariate analysis (P = .025).

CONCLUSIONS:

The current study demonstrated the superiority of ¹⁸F‐FDG–PET over CT and MR imaging for detecting hematogenous bone metastasis in patients with advanced cervical cancer. Hematogenous bone metastasis in cervical cancer was associated with the extent of lymph node metastases rather than with FIGO stage. Cancer 2009. © 2009 American Cancer Society.     

Impact of 18F-fluorodeoxyglucose positron emission tomography in the staging and treatment response assessment of extra-pulmonary small-cell cancer

The aim of this study was to retrospectively evaluate the value of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in extrapulmonary small-cell cancer (EPSCC). Patients with EPSCC who underwent PET for staging or response assessment between 1996 and 2007 were identified from a database. Patient records were reviewed. PET-based, and conventional staging and restaging results were compared. The binary staging classification of limited disease (LD) versus extensive disease (ED) was used. Patients with LD had tumours that could be encompassed within a tolerable radiation therapy (RT) volume. Of 33 eligible patients, 12 had staging PET scans, 11 had restaging scans and 10 had both. All known gross disease sites were FDG-avid. PET and conventional stage groupings were concordant in 21 of 22 cases. One patient was appropriately upstaged from LD to ED by PET. PET detected additional disease sites, without causing upstaging in three further patients. Restaging PET scans identified previously unrecognised persistent or progressive disease in 4 of 21 cases. In four further cases, persistent FDG uptake after treatment was either false positive (n = 2) or of uncertain (n = 2) aetiology. PPV was 100% for staging and 82% for restaging. In 8 of 43 imaging episodes (19%), PET appropriately influenced management in five cases by changing treatment intent from radical to palliative, and in three cases by altering the RT volume. PET has incremental value compared to conventional imaging for staging EPSCC, and may also be useful for restaging after therapy. PET influenced patient management in 19% of 43 imaging episodes.     

Midtreatment 18F-fluorodeoxyglucose positron-emission tomography in aggressive non-Hodgkin lymphoma

BACKGROUND:

The use of ¹⁸F‐fluorodeoxyglucose positron‐emission tomography (PET) scan has increased considerably in the clinical management of non‐Hodgkin lymphoma patients, and its role as a prognostic factor during chemotherapy has been established recently.

METHODS:

Between May 2003 and May 2009, 91 newly diagnosed patients with primary mediastinal large B‐cell lymphoma (PMLBCL) and diffuse large B‐cell lymphoma (DLBCL) were treated with 12 weekly cycles of rituximab‐MACOP‐B (n = 12 patients with PMLBCL), 6 cycles of rituximab‐CHOP21 (n = 65 patients with DLBCL, aged < 60 years and 1 patient with PMLBCL), or 8 weekly cycles of rituximab‐VNCOP‐B (n = 13 DLBCL patients, aged ≥ 60 years). All patients underwent a staging PET examination at baseline and a midtreatment (interim) PET examination after 6 weeks of rituximab‐MACOP‐B treatment, 3 cycles of rituximab‐CHOP21 treatment, or 4 weeks of rituximab‐VNCOP‐B treatment and again at the end of the chemo‐immunotherapy regimen.

RESULTS:

At midtreatment evaluation, 35 patients showed a persistently positive PET scan; only 6 (17%) of these patients achieved a continuous complete response (CCR). However, 56 patients presented with a negative interim PET, and 50 (89%) of these patients achieved and maintained a CCR. Comparison between the 2 PET groups indicated a statistically significant association between PET findings and event‐free survival (P = .0001) and overall survival (P = .0001).

CONCLUSIONS:

The results of this study indicated that midtreatment PET may represent a significant step forward in helping physicians make crucial decisions on further treatment. Cancer 2011. © 2010 American Cancer Society.     

2-Fluorine-18-fluoro-2-deoxy-D glucose positron emission tomography in the pretreatment staging of Hodgkin's disease: Influence on patient management in a single institution

Purpose:Optimum therapy for patients with Hodgkin's disease (HD)is determined by a number of prognostic factors, one of which is an accuratedefinition of extent of disease (stage). Computerised tomography is widelyused in staging but cannot reliably evaluate normal sized lymph nodes and someextranodal sites, e.g., liver, spleen and bone marrow.2-Fluorine-18-fluoro-2-deoxy-D glucose (FDG) has been shown to concentratepreferentially in lymphoma sites (whether in nodal or extranodal tissue) andtherefore may have a useful role in staging patients with HD. This studycompares concurrent computerized tomography (CT) and FDG positron emissiontomography (PET) in the staging of Hodgkin's disease and assesses thefrequency of stage migration and possible changes in therapy related to theuse of PET scanning. Patients and methods:This was a single centre retrospective studyof 44 patients with Hodgkin's disease who underwent both staging CT and PETprior to treatment between September 1993 and August 1998 at St. Thomas'Hospital. The number and sites of disease were assessed for each patient,documenting any stage and therapy modification prompted by PET findings. Results:One hundred fifty-nine sites of disease were demonstratedin forty-four patients by FDG–PET compared with eighty-four by CT. Asa result, 18 (40.9%) patients were upstaged, nine of these byFDG-uptake in splenic or extranodal sites not visualised on CT. Only threepatients were downstaged by PET results. Eleven patients (25%) hadtreatment modified by PET scan findings. Conclusions:Significantly more sites of disease were identifiedby PET than CT resulting in stage changes and a modification of therapy in25% of patients. This has important implications not only for currentpatient management but also for the design of future clinical trials.