Accuracy of CT colonography for detection of large adenomas and cancers

BACKGROUND

Computed tomographic (CT) colonography is a noninvasive option in screening for colorectal cancer. However, its accuracy as a screening tool in asymptomatic adults has not been well defined.

METHODS

We recruited 2600 asymptomatic study participants, 50 years of age or older, at 15 study centers. CT colonographic images were acquired with the use of standard bowel preparation, stool and fluid tagging, mechanical insufflation, and multidetector-row CT scanners (with 16 or more rows). Radiologists trained in CT colonography reported all lesions measuring 5 mm or more in diameter. Optical colonoscopy and histologic review were performed according to established clinical protocols at each center and served as the reference standard. The primary end point was detection by CT colonography of histologically confirmed large adenomas and adenocarcinomas (10 mm in diameter or larger) that had been detected by colonoscopy; detection of smaller colorectal lesions (6 to 9 mm in diameter) was also evaluated.

RESULTS

Complete data were available for 2531 participants (97%). For large adenomas and cancers, the mean (+/-SE) per-patient estimates of the sensitivity, specificity, positive and negative predictive values, and area under the receiver-operating-characteristic curve for CT colonography were 0.90+/-0.03, 0.86+/-0.02, 0.23+/-0.02, 0.99+/-<0.01, and 0.89+/-0.02, respectively. The sensitivity of 0.90 (i.e., 90%) indicates that CT colonography failed to detect a lesion measuring 10 mm or more in diameter in 10% of patients. The per-polyp sensitivity for large adenomas or cancers was 0.84+/-0.04. The per-patient sensitivity for detecting adenomas that were 6 mm or more in diameter was 0.78.

CONCLUSIONS

In this study of asymptomatic adults, CT colonographic screening identified 90% of subjects with adenomas or cancers measuring 10 mm or more in diameter. These findings augment published data on the role of CT colonography in screening patients with an average risk of colorectal cancer. (ClinicalTrials.gov number, NCT00084929; American College of Radiology Imaging Network [ACRIN] number, 6664.)

Natural history of untreated colonic polyps

The natural history of untreated colonic polyps is uncertain. A retrospective review of Mayo Clinic records from a 6-yr period just before the advent of colonoscopy identified 226 patients with colonic polyps greater than or equal to 10 mm in diameter in whom periodic radiographic examination of the colon was elected over excisional therapy. In all patients, follow-up of polyps spanned at least 12 mo (mean, 68 mo; range, 12-229 mo) and included at least two barium enema examinations (mean, 5.2; range, 2-17). During the follow-up period, 83 polyps (37%) enlarged. Twenty-one invasive carcinomas were identified at the site of the index polyp at a mean follow-up of 108 mo (range, 24-225 mo). Actuarial analysis revealed that the cumulative risk of diagnosis of cancer at the polyp site at 5, 10, and 20 yr was 2.5%, 8%, and 24%, respectively. In addition, 11 invasive cancers were found at a site remote from the index polyp during the same follow-up period. These data further support the recommendation for excision of all colonic polyps greater than or equal to 10 mm in diameter. Periodic examination of the entire colon is recommended in this group of patients to identify neoplasms arising at a site remote from the index polyp. Although this study has limitations inherent to any retrospective analysis, comparable prospective data are unlikely to be available in the future because of the current widespread availability of colonoscopy.

PET to assess early metabolic response and to guide treatment of adenocarcinoma of the oesophagogastric junction: the MUNICON phase II trial

BACKGROUND

In patients with locally advanced adenocarcinoma of the oesophagogastric junction (AEG), early metabolic response defined by 18-fluorodeoxyglucose-PET ([(18)F]FDG-PET) during neoadjuvant chemotherapy is predictive of histopathological response and survival. We aimed to assess the feasibility of a PET-response-guided treatment algorithm and its potential effect on prognosis.

METHODS

Between May 27, 2002, and Aug 4, 2005, 119 patients with locally advanced adenocarcinoma of AEG type 1 (distal oesophageal adenocarcinoma) or type 2 (gastric cardia adenocarcinoma) were recruited into this prospective, single-centre study. All patients were assigned to 2 weeks of platinum and fluorouracil-based induction chemotherapy (evaluation period). Those with decreases in tumour glucose standard uptake values (SUVs), predefined as decreases of 35% or more at the end of the evaluation period and measured by PET, were defined as metabolic responders. Responders continued to receive neoadjuvant chemotherapy of folinic acid and fluorouracil plus cisplatin, or folinic acid and fluorouracil plus cisplatin and paclitaxel, or folinic acid and fluorouracil plus oxaliplatin for 12 weeks and then proceeded to surgery. Metabolic non-responders discontinued chemotherapy after the 2-week evaluation period and proceeded to surgery. The primary endpoint was median overall survival of metabolic responders and non-responders. Secondary endpoints were median event-free survival, postoperative complications and mortality, number of residual tumour-free (R0) resections, and histopathological responses. This study has been registered in the European Clinical Trials Database (EudraCT) as trial 2007-003356-11.

FINDINGS

110 patients were evaluable for metabolic responses. 54 of these patients had metabolic responses (ie, decrease of 35% or more in tumour glucose SUV) after 2 weeks of induction chemotherapy, corresponding to a response of 49% (95% CI 39-59). 104 patients had tumour resection (50 in the responder group and 54 in the non-responder group). After a median follow-up of 2.3 years (IQR 1.7-3.0), median overall survival was not reached in metabolic responders, whereas median overall survival was 25.8 months (19.4-32.2) in non-responders (HR 2.13 [1.14-3.99, p=0.015). Median event-free survival was 29.7 months (95% CI 23.6-35.7) in metabolic responders and 14.1 months (7.5-20.6) in non-responders (hazard ratio [HR] 2.18 [1.32-3.62], p=0.002). Major histological remissions (<10% residual tumour) were noted in 29 of 50 metabolic responders (58% [95% CI 48-67]), but no histological response was noted in metabolic non-responders.

INTERPRETATION

This study confirmed prospectively the usefulness of early metabolic response evaluation, and shows the feasibility of a PET-guided treatment algorithm. These findings might enable tailoring of multimodal treatment in accordance with individual tumour biology in future randomised trials.

Progress and prospects of early detection in lung cancer

Lung cancer is the leading cause of cancer-related death in the world. It is broadly divided into small cell (SCLC, approx. 15% cases) and non-small cell lung cancer (NSCLC, approx. 85% cases). The main histological subtypes of NSCLC are adenocarcinoma and squamous cell carcinoma, with the presence of specific DNA mutations allowing further molecular stratification. If identified at an early stage, surgical resection of NSCLC offers a favourable prognosis, with published case series reporting 5-year survival rates of up to 70% for small, localized tumours (stage I). However, most patients (approx. 75%) have advanced disease at the time of diagnosis (stage III/IV) and despite significant developments in the oncological management of late stage lung cancer over recent years, survival remains poor. In 2014, the UK Office for National Statistics reported that patients diagnosed with distant metastatic disease (stage IV) had a 1-year survival rate of just 15-19% compared with 81-85% for stage I.

CT-based radiomic signature predicts distant metastasis in lung adenocarcinoma

BACKGROUND AND PURPOSE

Radiomics provides opportunities to quantify the tumor phenotype non-invasively by applying a large number of quantitative imaging features. This study evaluates computed-tomography (CT) radiomic features for their capability to predict distant metastasis (DM) for lung adenocarcinoma patients.

MATERIAL AND METHODS

We included two datasets: 98 patients for discovery and 84 for validation. The phenotype of the primary tumor was quantified on pre-treatment CT-scans using 635 radiomic features. Univariate and multivariate analysis was performed to evaluate radiomics performance using the concordance index (CI).

RESULTS

Thirty-five radiomic features were found to be prognostic (CI>0.60, FDR<5%) for DM and twelve for survival. It is noteworthy that tumor volume was only moderately prognostic for DM (CI=0.55, p-value=2.77×10(-5)) in the discovery cohort. A radiomic-signature had strong power for predicting DM in the independent validation dataset (CI=0.61, p-value=1.79×10(-17)). Adding this radiomic-signature to a clinical model resulted in a significant improvement of predicting DM in the validation dataset (p-value=1.56×10(-11)).

CONCLUSIONS

Although only basic metrics are routinely quantified, this study shows that radiomic features capturing detailed information of the tumor phenotype can be used as a prognostic biomarker for clinically-relevant factors such as DM. Moreover, the radiomic-signature provided additional information to clinical data.

Prediction of response to preoperative chemotherapy in adenocarcinomas of the esophagogastric junction by metabolic imaging

PURPOSE

Preoperative chemotherapy in patients with gastroesophageal cancer is hampered by the lack of reliable predictors of tumor response. This study evaluates whether positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (FDG) may predict response early in the course of therapy.

PATIENTS AND METHODS

Forty consecutive patients with locally advanced adenocarcinomas of the esophagogastric junction were studied by FDG-PET at baseline and 14 days after initiation of cisplatin-based polychemotherapy. Clinical response (reduction of tumor length and wall thickness by > 50%) was evaluated after 3 months of therapy using endoscopy and standard imaging techniques. Patients with potentially resectable tumors underwent surgery, and tumor regression was assessed histopathologically.

RESULTS

The reduction of tumor FDG uptake (mean +/- 1 SD) after 14 days of therapy was significantly different between responding (-54% +/- 17%) and nonresponding tumors (-15% +/- 21%). Optimal differentiation was achieved by a cutoff value of 35% reduction of initial FDG uptake. Applying this cutoff value as a criterion for a metabolic response predicted clinical response with a sensitivity and specificity of 93% (14 of 15 patients) and 95% (21 of 22), respectively. Histopathologically complete or subtotal tumor regression was achieved in 53% (eight of 15) of the patients with a metabolic response but only in 5% (one of 22) of the patients without a metabolic response. Patients without a metabolic response were also characterized by significantly shorter time to progression/recurrence (P =.01) and shorter overall survival (P =.04).

CONCLUSION

PET imaging may differentiate responding and nonresponding tumors early in the course of therapy. By avoiding ineffective and potentially harmful treatment, this may markedly facilitate the use of preoperative therapy, especially in patients with potentially resectable tumors.

CT colonography versus colonoscopy for the detection of advanced neoplasia

BACKGROUND

Advanced neoplasia represents the primary target for colorectal-cancer screening and prevention. We compared the diagnostic yield from parallel computed tomographic colonography (CTC) and optical colonoscopy (OC) screening programs.

METHODS

We compared primary CTC screening in 3120 consecutive adults (mean [+/-SD] age, 57.0+/-7.2 years) with primary OC screening in 3163 consecutive adults (mean age, 58.1+/-7.8 years). The main outcome measures included the detection of advanced neoplasia (advanced adenomas and carcinomas) and the total number of harvested polyps. Referral for polypectomy during OC was offered for all CTC-detected polyps of at least 6 mm in size. Patients with one or two small polyps (6 to 9 mm) also were offered the option of CTC surveillance. During primary OC, nearly all detected polyps were removed, regardless of size, according to established practice guidelines.

RESULTS

During CTC and OC screening, 123 and 121 advanced neoplasms were found, including 14 and 4 invasive cancers, respectively. The referral rate for OC in the primary CTC screening group was 7.9% (246 of 3120 patients). Advanced neoplasia was confirmed in 100 of the 3120 patients in the CTC group (3.2%) and in 107 of the 3163 patients in the OC group (3.4%), not including 158 patients with 193 unresected CTC-detected polyps of 6 to 9 mm who were undergoing surveillance. The total numbers of polyps removed in the CTC and OC groups were 561 and 2434, respectively. There were seven colonic perforations in the OC group and none in the CTC group.

CONCLUSIONS

Primary CTC and OC screening strategies resulted in similar detection rates for advanced neoplasia, although the numbers of polypectomies and complications were considerably smaller in the CTC group. These findings support the use of CTC as a primary screening test before therapeutic OC.

Growth rate of small lung cancers detected on mass CT screening

CT has recently been used in mass screening for lung cancer. Small cancers have been identified but the growth characteristics of these lesions are not fully understood. We identified 82 primary cancers in our 3-year mass CT screening programme, of which 61 were examined in the present study. The volume doubling time (VDT) was calculated based on the exponential model using successive annual CT images or follow-up CT images. All cases were also examined in the hospital by high resolution CT (HRCT). Lesions were divided into three types based on HRCT characteristics: type G (n = 19), ground glass opacity (GGO); type GS (n = 19), focal GGO with a solid central component; and type S (n = 23), solid nodule. 18 (95%) lesions of type G, 18 (95%) of type GS and 7 (30%) of type S were invisible on conventional chest radiographs. The mean size of the tumour was 10 mm, 11 mm and 16 mm for type G, type GS and type S, respectively. Most tumours (80%) were adenocarcinomas; 78% of these were GGO (type G and GS). Mean VDT values were 813 days, 457 days and 149 days for type G, type GS and type S, respectively; these are significantly different from each other (p < 0.05). Our results show that annual mass screening CT for 3 successive years resulted in the identification of a large number of slowly growing adenocarcinomas that were not visible on chest radiographs.

Determination of prostate volume by transrectal ultrasound

Estimation of prostate gland volume with transrectal ultrasound may provide important information in the evaluation of benign and malignant prostatic diseases. To determine the most accurate means of volume estimation 150 patients underwent transrectal ultrasound with 15 separate methods of volume estimation. All patients underwent subsequent radical prostatectomy or cystoprostatectomy. Prostate specimen weights were compared with the results of each volume estimation method. Step-section planimetry, previously assumed to be the most accurate means of volume measurement, exhibited a Pearson correlation coefficient of 0.93. The elliptical volume, widely used as an alternative to planimetry, demonstrated a correlation coefficient of 0.90. The most accurate method to estimate prostate weight (r = 0.94) was a variation of the prolate spheroid formula, expressed as pi/6 (transverse dimension)2 (anteroposterior dimension). When different volume ranges were considered, this prolate spheroid formula provided the closest estimate of weight in glands of less than 40 gm. and those in the 40 to 80 gm. range. The most accurate method to estimate prostates weighing greater than 80 gm. was the formula pi/6 (transverse dimension)3.

Metabolic imaging predicts response, survival, and recurrence in adenocarcinomas of the esophagogastric junction

PURPOSE

A previous study suggested that measurement of therapy-induced changes in tumor glucose metabolism by positron emission tomography (PET) with the glucose analog [18F]fluorodeoxyglucose (FDG) allows to select patients most likely to benefit from preoperative chemotherapy in adenocarcinomas of the esophagogastric junction (AEG). The aim of this study was to prospectively validate these findings by using an a priori definition of metabolic response.

PATIENTS AND METHODS

Sixty-five patients with locally advanced AEGs were included. Tumor glucose utilization was quantitatively assessed by FDG-PET before chemotherapy and 14 days after initiation of therapy. Patients were classified as metabolic responders when the metabolic activity of the primary tumor had decreased by more than 35% at the time of the second PET.

RESULTS

Metabolic responders showed a high histopathologic response rate (44%) with a 3-year survival rate of 70%. In contrast, prognosis was poor for metabolic nonresponders with a histopathologic response rate of 5% (P = .001) and a 3-year survival rate of 35% (P = .01). A multivariate analysis (covariates: ypT-, ypN-category, histopathologic response) demonstrated that metabolic response was the only factor predicting recurrence (P = .018) in the subgroup of completely resected (R0) patients.

CONCLUSION

This study prospectively demonstrates that changes in tumor metabolic activity during chemotherapy predict response, prognosis, and recurrence. These data provide the basis for clinical trials in which preoperative treatment is changed for patients without a metabolic response early in the course of therapy. PET-guided induction therapy may even be applicable to earlier tumor stages because surgery is only minimally delayed in nonresponding patients.

Utility of positron emission tomography for the staging of patients with potentially operable esophageal carcinoma

PURPOSE

A prospective study of preoperative tumor-node-metastasis staging of patients with esophageal cancer (EC) was designed to compare the accuracy of 18-F-fluoro-deoxy-D-glucose (FDG) positron emission tomography (PET) with conventional noninvasive modalities.

PATIENTS AND METHODS

Seventy-four patients with carcinomas of the esophagus (n = 43) or gastroesophageal junction (n = 31) were studied. All patients underwent attenuation-corrected FDG-PET imaging, a spiral computed tomography (CT) scan, and an endoscopic ultrasound (EUS).

RESULTS

FDG-PET demonstrated increased activity in the primary tumor in 70 of 74 patients (sensitivity: 95%). False-negative PET images were found in four patients with T1 lesions. Thirty-four patients (46%) had stage IV disease. FDG-PET had a higher accuracy for diagnosing stage IV disease compared with the combination of CT and EUS (82% v 64%, respectively; P: =.004). FDG-PET had additional diagnostic value in 16 (22%) of 74 patients by upstaging 11 (15%) and downstaging five (7%) patients. Thirty-nine (53%) of the 74 patients underwent a 2- or 3-field lymphadenectomy in conjunction with primary curative esophagectomy. In these patients, tumoral involvement was found in 21 local and 35 regional or distant lymph nodes (LN). For local LN, the sensitivity of FDG-PET was lower than EUS (33% v 81%, respectively; P: =.027), but the specificity may have been higher (89% v 67%, respectively; P: = not significant [NS]). For the assessment of regional and distant LN involvement, compared with the combined use of CT and EUS, FDG-PET had a higher specificity (90% v 98%, respectively; P: =. 025) and a similar sensitivity (46% v 43%, respectively; P: = NS).

CONCLUSION

PET significantly improves the detection of stage IV disease in EC compared with the conventional staging modalities. PET improves diagnostic specificity for LN staging.

Curative endoscopic resection of early esophageal adenocarcinomas (Barrett's cancer)

BACKGROUND

In view of the increasing incidence of adenocarcinoma in Barrett's esophagus and the mortality and high morbidity rates associated with surgical therapy for this condition, safe and effective but less invasive methods of treatment are needed.

OBJECTIVE

To evaluate efficacy and safety of endoscopic resection in these patients.

DESIGN

Single-center prospective study.

SETTING

Teaching hospital, conducted between October 1996 and September 2003.

PATIENTS

A total of 100 consecutive patients (mean age, 62.1 +/- 10.9 years; range, 31-86 years) with low-risk adenocarcinoma of the esophagus (macroscopic types I, IIa, IIb, and IIc; lesion diameter up to 20 mm; mucosal lesion without invasion into lymph vessels and veins; and histologic grades G1 and G2) arising in Barrett's metaplasia.

INTERVENTIONS

Endoscopic resection with the suck-and-cut technique.

MAIN OUTCOME MEASUREMENTS

Complete local remission.

RESULTS

A total of 144 resections (1.47 per patient) were performed without technical problems. No major complications and only 11 minor ones (bleedings without decrease of Hb >2 g/dL; treated with injection therapy) occurred. Complete local remission was achieved in 99 of the 100 patients after 1.9 months (range, 1-18 months) and a maximum of 3 resections. During a mean follow-up period of 36.7 months, recurrent or metachronous carcinomas were found in 11% of the patients, but successful repeat treatment with endoscopic resection was possible in all of these cases. The calculated 5-year survival rate was 98%. Two patients died of other causes.

LIMITATIONS

Nonblinded, nonrandomized study.

CONCLUSIONS

Endoscopic resection is associated with favorable outcomes for low-risk patients with early esophageal adenocarcinoma (Barrett's carcinoma).

Computed tomography-guided frameless stereotactic radiotherapy for stage I non-small cell lung cancer: a 5-year experience

PURPOSE

Stereotactic radiotherapy (SRT) is highly effective for brain metastases from non-small-cell lung cancers (NSCLCs). As such, primary lesions of NSCLC may also be treated effectively by similar focal high-dose SRT.

METHODS AND MATERIALS

Between October 1994 and June 1999, 50 patients with pathologically proven T1-2N0 M0 NSCLC were treated by CT-guided frameless SRT. Of these, 21 patients were medically inoperable and the remainder were medically operable but refused surgery. In most patients, SRT was 50-60 Gy in 5-10 fractions for 1-2 weeks. Eighteen patients also received conventional radiotherapy of 40-60 Gy in 20-33 fractions before SRT.

RESULTS

With a median follow-up period of 36 months (range 22-66), 30 patients were alive and disease free, 3 were alive with disease, 6 had died of disease, and 11 had died intercurrently. Local progression was not observed on follow-up CT scans in 47 (94%) of 50 patients. The 3-year overall survival rate was 66% in all 50 patients and 86% in the 29 medically operable patients. The 3-year cause-specific survival rate of all 50 patients was 88%. No definite adverse effects related to SRT were noted, except for 2 patients with a minor bone fracture and 6 patients with temporary pleural pain.

CONCLUSIONS

SRT is a very safe and effective treatment for Stage I NSCLC. Additional studies involving a larger patient population and longer follow-up periods are warranted to assess this new treatment for early-stage lung cancer.

Role of preoperative ultrasonography in the surgical management of patients with thyroid cancer

BACKGROUND

Cervical recurrence occurs in up to 30% of patients with differentiated thyroid carcinoma. We retrospectively compared preoperative transcutaneous ultrasonography and physical examination (PE) results in the detection of local-regional metastases (lymph node and soft tissue) in patients with thyroid cancer.

METHODS

Data were collected retrospectively from the medical records of patients with thyroid carcinoma who underwent preoperative ultrasonography. Patients were divided into 3 groups: group 1, those undergoing primary thyroid/neck surgery; group 2, those undergoing reoperation for persistent disease; and group 3, those undergoing reoperation for recurrent thyroid carcinoma. For each group, we recorded the frequencies with which ultrasonography detected disease in a neck compartment (central or lateral) that was normal on PE.

RESULTS

Two hundred twelve patients underwent operation for primary, persistent, or recurrent papillary (n=130), medullary (n=61), or follicular/Hürthle cell (n=21) carcinoma. Ultrasonography detected additional sites of metastatic disease not appreciated on PE in 21 (20%) of 107 group 1 patients, 9 (32%) of 28 group 2 patients, and 52 (68%) of 77 group 3 patients. The surgical procedure performed was altered by the information obtained from preoperative ultrasonography in 82 (39%) of the 212 patients. Of the 107 group 1 patients, cervical recurrence has been detected in only 6 (6%) at a median follow-up of 36 months, in spite of 67 (63%) having tumors larger than 2 cm or lymph node metastases.

CONCLUSIONS

Preoperative high-quality ultrasonography detected lymph node or soft-tissue metastases in neck compartments believed to be uninvolved by PE in 39% of patients. Ultrasound findings altered the operative procedure in these patients, facilitating complete resection of disease and potentially minimizing local-regional recurrence.

Local staging of pancreatic cancer: criteria for unresectability of major vessels as revealed by pancreatic-phase, thin-section helical CT

OBJECTIVE

This study was conducted to determine the criteria for unresectability of major peripancreatic vessels in patients with pancreatic carcinoma as revealed by optimally enhanced, pancreatic-phase thin-section helical CT.

SUBJECTS AND METHODS

Twenty-five patients with pancreatic adenocarcinoma who underwent local dissection during curative or palliative surgery also underwent preoperative pancreatic-phase thin-section helical CT (40- to 70-sec delay, 2.5- to 3-mm collimation). Tumor involvement of the portal and superior mesenteric veins and the celiac, hepatic, and superior mesenteric arteries was prospectively graded on a 0-4 scale based on circumferential contiguity of tumor to vessel. Subsequent surgical results were then correlated with the CT grades.

RESULTS

At surgery, definitive evaluation was possible for 80 vessels. Forty-eight of 48 vessels graded 0 and three of three vessels graded 1 were resectable. Four of seven vessels graded 2, seven of eight vessels graded 3, and 14 of 14 vessels graded 4 were unresectable. A threshold of between grades 2 and 3, which corresponded to tumor involvement of one-half circumference of the vessel, yielded the lowest number of false-negatives and an acceptable number of false-positives for unresectability. Such a threshold would have yielded a sensitivity of 84%, a specificity of 98%, a positive predictive value of 95%, and a negative predictive value of 93% for unresectability of the vessels studied.

CONCLUSION

A grading system for tumor involvement of the major vessels in patients with pancreatic adenocarcinoma can be based on the degree of circumferential contiguity of tumor to vessel. Involvement of vessel to tumor that exceeds one-half circumference of the vessel is highly specific for unresectable tumor.

Comparison of endoscopic ultrasonography and multidetector computed tomography for detecting and staging pancreatic cancer

BACKGROUND

Accurate preoperative detection and staging of pancreatic cancer may identify patients with locoregional disease that is amenable to surgical resection.

OBJECTIVE

To compare endoscopic ultrasonography and multidetector computed tomography (CT) for the detection, staging, and resectability of known or suspected locoregional pancreatic cancer.

DESIGN

Prospective, observational, cohort study.

SETTING

Single, tertiary referral hospital in Indianapolis, Indiana.

PATIENTS

120 participants with known or suspected locoregional pancreatic cancer.

INTERVENTIONS

Endoscopic ultrasonography followed by multidetector CT was performed in all patients. Patients with known or suspected pancreatic cancer deemed potentially resectable by 1 or both tests were considered for surgery.

MEASUREMENTS

Detection, staging, and resectability of pancreatic cancer. Surgically resected pancreatic cancer with negative microscopic histologic margins was considered resectable.

RESULTS

Of 120 patients enrolled, 104 (87%) underwent endoscopic ultrasonography and CT. Of the 80 patients with pancreatic cancer, 27 (34%) were managed nonoperatively, and 53 (66%) treated surgically had resectable (n = 25) or unresectable (n = 28) cancer. For the 80 patients with cancer, the sensitivity of endoscopic ultrasonography (98% [95% CI, 91% to 100%]) for detecting a pancreatic mass was greater than that of CT (86% [CI, 77% to 93%]; P = 0.012). For the 53 surgical patients, endoscopic ultrasonography was superior to CT for tumor staging accuracy (67% vs. 41%; P < 0.001) but equivalent for nodal staging accuracy (44% vs. 47%; P > 0.2). Of the 25 resectable pancreatic tumors in patients recommended for surgery, endoscopic ultrasonography and CT correctly identified 88% and 92%, respectively, as resectable. Of the 28 unresectable pancreatic tumors in patients recommended for surgery, endoscopic ultrasonography and CT correctly identified 68% and 64%, respectively, as unresectable.

LIMITATIONS

Radiologists who read the scans and endosonographers were not blinded to previous radiographic information. Because of the modest sample size, CIs of the sensitivity estimates were sometimes wide.

CONCLUSION

Compared with multidetector CT, endoscopic ultrasonography is superior for tumor detection and staging but similar for nodal staging and resectability of preoperatively suspected nonmetastatic pancreatic cancer.

Targeting of iodine-123-labelled tumour-associated monoclonal antibodies to ovarian, breast, and gastrointestinal tumours

Two tumour-associated monoclonal antibodies, HMFG1 and HMFG2, were labelled with iodine-123 and used to detect primary and metastatic ovarian, breast, and gastrointestinal neoplasms by external body scintigraphy in twenty patients with advanced disease. Tumours became visible 3 min to 18 h after injection of labelled antibody. The presence of antibody in the tumours was confirmed by autoradiography and immunoperoxidase staining of surgically removed tissues. The mean tumour uptake of radiolabel was 0.6% of the injected amount. These antibodies can therefore localise specifically to tumours and successful imaging can thus be achieved. This method can complement existing diagnostic techniques and also provide a basis for a selective therapeutic approach to malignant disease.

Breast cancer: PET imaging of estrogen receptors

Thirteen patients with primary breast masses were studied with positron emission tomography (PET) and 16 alpha-[fluorine-18]-fluoroestradiol-17 beta. PET images demonstrated uptake of the labeled estrogen analog at sites of primary carcinomas and in several foci of axillary lymph node metastases, as well as in one distant metastatic site. There was excellent correlation between uptake within the primary tumor measured on the PET images and the tumor estrogen-receptor concentration measured in vitro after excision (r = .96). This technique may provide an in vivo method of assessing estrogen receptors in primary and metastatic breast cancers and thus guide management of this disease with antiestrogen chemotherapy.

Persistent Pulmonary Nodular Ground-Glass Opacity at Thin-Section CT: Histopathologic Comparisons

PURPOSE

To retrospectively compare pure pulmonary ground-glass opacity (GGO) nodules observed on thin-section computed tomography (CT) images with histopathologic findings.

MATERIALS AND METHODS

The institutional review board approved this study and waived informed consent. Histopathologic specimens were obtained from 53 GGO nodules in 49 patients. CT scans were assessed in terms of nodule size, shape, contour, internal characteristics, and the presence of a pleural tag. The findings obtained were compared with histopathologic results. Differences in thin-section CT findings according to histopathologic diagnoses were analyzed by using the Kruskal-Wallis test or Fisher exact test.

RESULTS

Of 53 nodules in 49 patients (20 men, 29 women; mean age, 54 years; range, 29-78 years), 40 (75%) proved to be broncholoalveolar cell carcinoma (BAC) (n=36) or adenocarcinoma with predominant BAC component (n=4), three (6%) atypical adenomatous hyperplasia, and 10 (19%) nonspecific fibrosis or organizing pneumonia. No significant differences in morphologic findings on thin-section CT scans were found among the three diseases (all P>0.05). A polygonal shape (25%, 10 of 40 nodules) and a lobulated or spiculated margin (45%, 18 of 40) in BAC or adenocarcinoma with predominant BAC component were caused by interstitial fibrosis or infiltrative tumor growth. A polygonal shape and a lobulated or spiculated margin were observed in two (20%) and three (30%) of 10 nodules, respectively, in organizing pneumonia/fibrosis were caused by granulation tissue aligned in a linear manner in perilobular regions with or without interlobular septal thickening.

CONCLUSION

About 75% of persistent pulmonary GGO nodules are attributed to BAC or adenocarcinoma with predominant BAC component, and at thin-section CT, these nodules do not manifest morphologic features that distinguish them from other GGO nodules with different histopathologic diagnoses.

Peripheral lung adenocarcinoma: correlation of thin-section CT findings with histologic prognostic factors and survival

PURPOSE

To evaluate the prognostic importance of thin-section computed tomographic (CT) findings of peripheral lung adenocarcinomas.

MATERIALS AND METHODS

The subjects were 127 patients with adenocarcinomas smaller than 3 cm in largest diameter who underwent at least a lobectomy with hilar and mediastinal lymphadenectomy. The margin characteristics of nodules and the extent of ground-glass opacity (GGO) within the nodules at preoperative thin-section CT were analyzed retrospectively. Regional lymph node metastasis (LNM) and vessel invasion (VI) were histologically examined in surgical specimens. Survival curves were calculated according to the Kaplan-Meier method.

RESULTS

The frequencies of LNM (4% [1 of 24]) and VI (13% [three of 24]) in adenocarcinomas with GGO components of more than 50% were significantly lower than those with GGO components of less than 10% (LNM, P <.05; VI, P <.01). The patients with GGO components of more than 50% showed a significantly better prognosis than those with GGO components less than 50% (P <.05). All 17 adenocarcinomas smaller than 2 cm with GGO components of more than 50% were free of LNM and VI, and all these patients are alive without recurrence. Coarse spiculation and thickening of bronchovascular bundles around the tumors were observed more frequently in tumors with LNM or VI than in those without LNM or VI (P <.01).

CONCLUSION

Thin-section CT findings of peripheral lung adenocarcinomas correlate well with histologic prognostic factors.

CT in differential diagnosis of diffuse pleural disease

The CT features of benign and malignant pleural diseases have been described. However, the accuracy of these features in the differential diagnosis of diffuse pleural disease has not been assessed before. Without knowledge of clinical or pathologic data, we reviewed the CT findings in 74 consecutive patients with proved diffuse pleural disease (39 malignant and 35 benign). The patients included 53 men and 21 women 23-78 years old. Features that were helpful in distinguishing malignant from benign pleural disease were (1) circumferential pleural thickening, (2) nodular pleural thickening, (3) parietal pleural thickening greater than 1 cm, and (4) mediastinal pleural involvement. The specificities of these findings were 100%, 94%, 94%, and 88%, respectively. The sensitivities were 41%, 51%, 36%, and 56%, respectively. Twenty-eight of 39 malignant cases (sensitivity, 72%; specificity, 83%) were identified correctly by the presence of one or more of these criteria. Malignant mesothelioma (n = 11) could not be reliably differentiated from pleural metastases (n = 24). We conclude that CT is helpful in the differential diagnosis of diffuse pleural disease, particularly in differentiation of malignant from benign conditions.

Papillary renal cell carcinoma: a clinical, radiologic, and pathologic study of 34 cases

Papillary renal cell carcinoma (RCC) is known by its tendency to avascularity by angiography; however, data concerning its clinicopathologic spectrum and prognosis are not available. In a review of 224 renal cell carcinomas accesioned in our files, 34 were found to be papillary and 190 of other histologic types. A comparative analysis of these two gropus revealed marked differences. The majority of papillary tumors (85.3%) were in pathologic stage I, whereas more than half of the nonpapillary tumors had extended beyond the limits of the kidney. Follow-up data revealed that the survival for papillary RCC was significantly higher than that for nonpapillary tumors. This difference held true even when tumors in the same pathologic stage were compared. Many papillary tumors, particularly those with a favorable course, were massively necrotic, densely infiltrated by macrophages, or both. In view of these findings, the possibility that host mechanisms are involved in destruction and confinement of the tumor is discussed. Examination of kidney tissue distant from the tumor disclosed, in some cases, atypical hyperplastic changes of collecting tubules; this raises the possibility that some papillary tumors arise from distal tubular epithelium. Hypo- or avascularity was present in all papillary RCC's studied by angiography.

Staging of primary colorectal carcinomas with fluorine-18 fluorodeoxyglucose whole-body PET: correlation with histopathologic and CT findings

PURPOSE

To evaluate the diagnostic usefulness of positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) in patients with primary colorectal carcinomas.

MATERIALS AND METHODS

Forty-eight patients with biopsy-proved (n = 44) or high clinical suspicion for (n = 4) colorectal cancer underwent whole-body PET after intravenous administration of 10 mCi (370 MBq) of FDG. FDG PET results were correlated with computed tomographic (CT), surgical, and histopathologic findings.

RESULTS

PET depicted all known intraluminal carcinomas in 37 patients (including two in situ carcinomas) (sensitivity, 100%), but findings were false-positive in four of seven patients without cancer (three with inflammatory bowel conditions, one who had undergone polypectomy). Specificity was 43% (three of seven patients); positive predictive value, 90% (37 of 41 patients); and negative predictive value, 100% (three of three patients). No FDG accumulation was noted in 35 hyperplastic polyps. FDG PET depicted lymph node metastases in four of 14 patients (sensitivity, 29%). Results were similar to those obtained with CT (true-positive, two of seven patients [sensitivity, 29%]; true-negative, 22 of 26 patients [specificity, 85%]). FDG PET depicted liver metastases in seven of eight patients and was superior to CT, which depicted liver metastases in three patients (sensitivity of 88% and 38%, respectively). FDG PET and CT, respectively, correctly depicted the absence of liver metastases in 35 and 32 patients (specificity, 100% and 97%; negative predictive value, 97% and 86%).

CONCLUSION

FDG PET has a high sensitivity and specificity for detection of colorectal carcinomas (primary and liver metastases) and appears to be superior to CT in the staging of primary colorectal carcinoma.

Evolution of peripheral lung adenocarcinomas: CT findings correlated with histology and tumor doubling time

OBJECTIVE

This study was performed to evaluate the evolution of peripheral lung adenocarcinomas using CT findings and histologic classification related to tumor doubling time.

MATERIALS AND METHODS

The subjects were 34 patients, each with an adenocarcinoma smaller than 3 cm. All patients underwent chest radiography and 10 of them had previously undergone CT more than 6 months before surgery. Tumor doubling time was estimated by examining sequential radiographs using the method originally described by Schwartz. Tumor growth was also observed by studying the changes on CT in the 10 patients who had previously undergone CT. The histologic classification (types A-F) was evaluated according to the criteria of Noguchi et al.

RESULTS

Five (83%) of the six adenocarcinomas with tumor types A or B showed localized ground-glass opacity on high-resolution CT. All six tumors had a tumor doubling time of more than 1 year. Fifteen (71%) of the 21 tumors with type C showed partial ground-glass opacity mixed with localized solid attenuation on high-resolution CT. Ten (48%) of these 21 type C tumors had a tumor doubling time of more than 1 year. In types B and C, the solid component or the development of pleural indentation and vascular convergence increased during observation before surgery. All seven tumors with types D, E, and F showed mostly solid attenuation, and the tumor doubling time was less than 1 year in six (87%) of the seven tumors.

CONCLUSION

Two main types of peripheral lung adenocarcinoma exist. The first type appears on CT as a localized ground-glass opacity with slow growth, and the other appears as a solid attenuation with rapid growth.