Predicting residual rectal adenocarcinoma in the surgical specimen after preoperative brachytherapy with endoscopic ultrasound

BACKGROUND AND STUDY AIMS

A novel brachytherapy (BT) protocol evaluated at McGill University has shown promise in terms of downstaging and achieving high tumour sterilization rates in rectal cancer. Endoscopic ultrasound (EUS) has emerged as the imaging modality of choice for local staging of rectal cancer. However, external beam radiotherapy appears to decrease the accuracy of EUS from 85% to 40%. The aim of the present study was to prospectively evaluate the accuracy of EUS in assessing the response of rectal cancer to BT.

PATIENTS AND METHODS

Thirty-three patients with locally advanced (stage T2 or T3) operable rectal carcinomas were included in an experimental protocol involving a novel conformal technique, using three-dimensional planning, to administer high-dose rate preoperative BT. The 18 patients who were able to have a post-BT EUS exam arranged within two weeks before surgery (eg, four to eight weeks post-BT) were included in this study. Tumour (T)- and lymph node (N)-staging on radial EUS, as well as interpretation of the residual tumour, were assessed prospectively. Pathologists were blinded to the post-BT EUS results.

RESULTS

The mean age was 70 years (SD +/- 11; range, 52 to 93 years) and 78% of the patients were male. Pre-BT EUS indicated that 16 patients (89%) were stage T3, and two were stage T2. Five patients (28%) had positive nodes (N1) by ultrasound. With BT, the mean maximal wall thickness on EUS decreased from 14 mm to 9.4 mm (P<0.001). At the time of surgery, seven of the 18 patients (39%) had no detectable tumour in the resected specimen; one had carcinoma in situ, one was stage T1, one was stage T2, and eight were stage T3. Eleven patients (61%) underwent an abdominoperineal resection, including four of the 11 (36%) with no ultimate evidence of residual carcinoma. Eight patients (44%) were node-positive. The sensitivity, specificity, and positive and negative predictive values of post-BT EUS in predicting residual tumour were 82%, 29%, 64% and 50%, respectively. The post-BT EUS accurately predicted the T-stage in eight (44%) patients; most errors were due to overstaging.

CONCLUSIONS

Rectal cancer T-staging by EUS post-BT is inaccurate, and although it appears sensitive in predicting the presence or absence of residual tumor in rectal adenocarcinoma after preoperative BT, the low predictive values in this setting limit its utility at this time.

Optimization of technetium-99m Sestamibi single-photon emission tomography to define multidrug resistance with confidence

BACKGROUND

The efflux rate of technetium-99m Sestamibi (99mTc-Sestamibi) is a kinetic phenomenon related to the response of cancer cells to chemotherapy, and may be used to determine drug resistance. Measurement of the efflux rate requires accurate quantitative single-photon emission tomography (SPET) imaging within the time constraints imposed by the kinetics of the process.

METHODS

A phantom study, at activity concentrations typically found with 99mTc-Sestamibi in vivo, was undertaken to optimize the SPET parameters and, in particular, to determine whether 180 degrees acquisition arcs with heads in 'L' configuration could be used for accurate quantification. Following the development of the most appropriate SPET protocol, a small patient pilot study was undertaken.

RESULTS

Studies designed to evaluate statistical uncertainty (noise), contrast restitution and spatial resolution of the data sets, using different acquisition and reconstruction parameters, showed that 180 degrees SPET using a 64 x 64 matrix, 6 degrees angular sampling and iterative reconstruction was optimal. Finer linear and/or angular sampling afforded negligible improvement in resolution, but markedly increased the statistical uncertainty. Comparison of 360 degrees and 180 degrees acquisitions, utilizing conventional filtered backprojection and iterative reconstruction algorithms, demonstrated that the statistical uncertainty was reduced to a greater extent for 180 degrees data collection. For 360 degrees (64 x 64) data acquisition, statistical uncertainty decreased from 15% to 11% using the iterative algorithm, whilst the 180 degrees (64 x 64) data showed a reduction from 20% to 7%, and approached values obtained by planar imaging. The efflux measurements obtained in the patient pilot study were consistent with the observed chemotherapy response.

CONCLUSION

Our study shows that 180 degrees acquisition arcs are a practical option for accurate quantitative SPET kinetic imaging for potential studies of chemotherapy response in patients with lung cancer.

[Value of 18F-FDG PET imaging in diagnosing tumor residue of intracranial glioma after surgery and radiotherapy]

BACKGROUND & OBJECTIVE

It is difficult to diagnose tumor residue by CT/MRI after treatment. The application of (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) to determine the suspected tumor residue after treatment has become a hot target in the study of radiotherapy. This study was designed to discuss the clinical value of (18)-FDG PET imaging in post-operative and post-radiotherapeutic intracranial glioma.

METHODS

(18)F-FDG PET imaging was performed in 23 patients with post-operative and post-radio-therapeutic intracranial glioma, and compared with CT/MRI. The final diagnosis of tumor residue was proved by pathology or clinical follow-up.

RESULTS

Of 23 patients, 12 showed (18)F-FDG PET positive, and 11 showed negative,among which 3 were false negative. The accuracy of (18)F-FDG PET was 87.0% (20/23), significantly higher than 60.9% (14/23) of CT/MRI scan (P< 0.05). The diagnosis of tumor residue in 9 patients cannot be determined by CT/MRI, while 4 of these patients showed (18)F-FDG PET positive, and the other 5 showed (18)F-FDG PET negative. Eight of 23 patients diagnosed tumor residues by CT/MRI, showed (18)F-FDG PET positive,too. Six patients,diagnosed by CT/MRI as radioactive-disease sufferers, and PET indicated with low or deficient FDG metabolism, were proved to have radioactive diseases by follow-up.

CONCLUSIONS

(18)F-FDG PET imaging has significant dominance in characterizing lesions,and differentiating tumor residue in post-operative and post-radiotherapeutic intracranial glioma. Combined with CT and MRI, it can provide both anatomical and functional information for treatment.

131I Therapeutic Efficacy Is Not Influenced by Stunning after Diagnostic Whole-Body Scanning

PURPOSE

To determine if stunning can be seen with a 185-MBq (5-mCi) dose of iodine 131 (131I) at diagnostic whole-body scanning and, if stunning is seen, determine if there is any 131I therapeutic efficacy.

MATERIALS AND METHODS

A retrospective review of findings involving 166 patients who underwent thyroidectomy for differentiated thyroid carcinoma was performed. Diagnostic 131I scans were compared with postablation scans for evidence of stunning. Stunning was defined when the diagnostic scan showed activity that was subsequently decreased on the postablation scan. The sample population was divided into two groups: group NS, patients with no stunning, and group S, patients with stunning. Patients were considered successfully treated if no functioning thyroid tissue and/or metastases were seen on follow-up diagnostic scans. Fisher exact and Student t tests were used to evaluate the statistical significance of therapy success rates, clinical characteristics, and scanning parameters between the two groups.

RESULTS

Group NS included 135 (81.3%) of 166 patients, with 36 (26.7%) of 135 lost to follow-up. Group S included 31 (18.7%) of 166 patients, with eight (26%) of 31 patients lost to follow-up. There was no significant difference (P =.61) in treatment success rates between group NS (87 of 99, 88%) and group S (21 of 23, 91%). The treatment success rates for thyroid remnants were 87% (48 of 55) for group NS and 91% (10 of 11) for group S (P =.63). Treatment success rates for metastases (mostly lymph nodes) were 89% (39 of 44) for group NS and 83% (10 of 12) for group S (P =.55).

CONCLUSION

Thyroid stunning can occur with 185 MBq of 131I in diagnostic imaging. However, data did not show any effect of stunning on the efficacy of 131I therapy for differentiated thyroid carcinoma.

Endoscopic ultrasound after preoperative chemoradiation can help identify patients who benefit maximally after surgical esophageal resection

BACKGROUND

We investigated whether differences in postoperative survival exist based on the presence and site of residual tumor (esophagus vs regional lymph nodes) after preoperative chemoXRT in patients with esophageal cancer. Based on these data, we reevaluated the role of EUS in identifying patients who maximally benefit from surgical esophageal resection after preoperative chemoXRT.

METHODS

We studied 97 consecutive esophageal cancer patients treated with preoperative chemoXRT and a potentially curative surgical procedure between 1998 to 2001. All patients had EUS examination prior to chemoXRT and 53 had a repeat EUS examination after chemoXRT but prior to surgery. Surgical resection specimens were analyzed for absence or presence of residual tumor and its location.

RESULTS

Patients with residual tumor in the esophagus (pathT1-3N0) and patients without residual tumor (pathT0N0) had similar cumulative survival (p= 0.92). Patients with residual cancer in lymph nodes showed a trend toward shorter cumulative survival compared to patients without residual tumor in lymph nodes (p= 0.086). The actuarial survival in pathN1 group was lower than pathN0 group at 1, 2, and 3 yr. Patients with significant residual lymphadenopathy detected by EUS after therapy had significantly worse postoperative survival compared to patients with no residual lymphadenopathy (p= 0.028). In eight patients, we found that reliable cytologic identification of residual malignancy was technically feasible by EUS-FNA after chemoradiation therapy.

CONCLUSIONS

Following preoperative chemoXRT and surgery, patients with residual tumor in the regional lymph nodes have lower actuarial survival at 1, 2, and 3 yr after surgery, compared to patients with path CR or with residual tumor only in the esophagus. EUS and EUS-guided FNA can be helpful in identifying residual tumor in the lymph nodes after preoperative chemoXRT to select patients who benefit maximally from surgery.

Cancer in the gastric remnant after gastric bypass: a case report

Gastric cancer in the gastric stump after a Bilroth II subtotal gastrectomy is a well-recognized entity. However, gastric cancer in the bypassed gastric remnant after a gastric bypass operation for morbid obesity has not been well described, and only 2 such cases have been reported in the English literature. This case report presents a patient who developed gastric cancer in the defunctionalized, bypassed stomach 22 years after undergoing an open gastric bypass with a Roux-en-Y gastro-jejunostomy for morbid obesity. The problems of monitoring the defunctionalized bypassed stomach after gastric stapling and gastro-jejunostomy are discussed.

Retained calcified fibroid fragments after uterine artery embolization for fibroids

OBJECTIVE

To document a case of retained calcified fibroid fragments after uterine artery embolization (UAE) for fibroids.

DESIGN

Case report.

SETTING

Teaching district general hospital.

PATIENT(S)

A woman with past history of UAE for fibroids.

INTERVENTION(S)

Bilateral UAE.

MAIN OUTCOME MEASURE(S)

Retained calcified fibroid fragments.

RESULT(S)

Retained calcified fibroid fragments can occur after UAE.

CONCLUSION(S)

Retained calcified fibroid fragments can occur after UAE and may be associated with infertility and menstrual disorders. Measures to detect this complication in women with these problems who have undergone UAE are appropriate.

The role of positron emission tomography in germ cell cancer

Positron emission tomography (PET) is a non-invasive tool for imaging regional metabolic processes, which adds another dimension to current anatomy-derived imaging techniques, i.e. metabolic imaging. To date, 2-(18)fluoro-2-deoxy-D-glucose (FDG) has been the only tracer used for imaging germ cell tumors (GCT), which can be distinguished from normal tissue by their different glucose utilization. However, FDG PET has several limitations: (1) inflammatory and granulomatous tissues also show extensive FDG uptake, (2) lesions <1 cm in size can often not be detected, and (3) mature teratoma is indistinguishable from normal and necrotic tissue. Studies assessing the clinical role of FDG PET in GCT suggest that the technique has a place as a standard tool in evaluating post chemotherapy seminoma residuals. Whether it also improves the assessment of the risks carried by clinical stage I non-seminoma patients and the early prediction of response to salvage chemotherapy is still under investigation, or at least needs to be confirmed by further trials. In relapsing patients with a mismatch between tumor markers and imaging data, FDG PET appears to be useful whenever salvage surgery is considered, although systematic trials are not yet available.

2-18fluoro-deoxy-D-glucose Positron Emission Tomography Is a Reliable Predictor for Viable Tumor in Postchemotherapy Seminoma: An Update of the Prospective Multicentric SEMPET Trial

Purpose

To define the clinical value of 2-18fluoro-deoxy-D-glucose positron emission tomography (FDG PET) as a predictor for viable residual tumor in postchemotherapy seminoma residuals in a prospective multicentric trial.

Patients and Methods

FDG PET studies in patients with metastatic pure seminoma who had radiographically defined postchemotherapy residual masses were correlated with either the histology of the resected lesion or the clinical outcome documented by computer tomography (CT), tumor markers, and/or physical examination during follow-up. The size of the residual lesions on CT, either > 3 cm or ≤ 3 cm, was correlated with the presence or absence of viable residual tumor.

Results

Fifty-six FDG PET scans of 51 patients were assessable. All 19 cases with residual lesions > 3 cm and 35 (95%) of 37 with residual lesions ≤ 3 cm were correctly predicted by FDG PET. The specificity, sensitivity, positive predictive value, and negative predictive value of FDG PET were 100% (95% CI, 92% to 100%), 80% (95% CI, 44% to 95%), 100%, and 96%, respectively, versus 74% (95% CI, 58% to 85%), 70% (95% CI, 34% to 90%), 37%, and 92%, respectively, for CT discrimination of the residual tumor by size (> 3 cm/≤ 3 cm).

Conclusion

This investigation confirms that FDG PET is the best predictor of viable residual tumor in postchemotherapy seminoma residuals and should be used as a standard tool for clinical decision making in this patient group.

Importance of F18-fluorodeoxy-D-2-glucose positron emission tomography (FDG-PET) for staging and therapy control of Hodgkin's lymphoma in childhood and adolescence - consequences for the GPOH-HD 2003 protocol

The prognosis for children and adolescents with Hodgkin's lymphoma is excellent. However, many patients will show secondary malignancies 15-30 years after the initial diagnosis, which appears to be connected with the intensity of treatment during primary disease. In the GPOH-HD 95 trial, the indication for radiotherapy was limited to patients who did not show a complete remission after chemotherapy, as determined radiographically. In the future protocol, the indication for radiotherapy in patients with early-stage Hodgkin's lymphoma should be further refined by using FDG-PET for evaluating the response to chemotherapy. Furthermore, in patients at an advanced stage of the disease, it should be determined if sequential FDG-PET research during chemotherapy can separate patients into subgroups with an excellent or a poor prognosis. This article gives a review of the current literature on FDG-PET in patients with Hodgkin's lymphoma and outlines the consequences for future protocols.

Radio-guided brain tumorectomy using a gamma detecting probe and a mobile solid-state gamma camera

BACKGROUND

We herein report a technique to distinguish brain tumors from normal brain tissue during surgery using a gamma probe and a solid-state mobile gamma camera after (99m)Tc-hexakis-2-methoxy-isobutyl-isonitrile ((99m)Tc-MIBI) is administered to patients immediately before operation.

METHODS

We examined 13 patients with brain tumors. Before the operation, (99m)Tc-MIBI single photon emission computed tomography (SPECT) was performed to assess accumulation in the tumors. On the day of the operation, (99m)Tc-MIBI was administered intravenously and craniotomy for tumor resection was performed. During the operation, the tumor was localized with a gamma probe and preremoval scintigraphy images were taken with a mobile gamma camera. After tumor resection was completed, residual tumors were confirmed using it again. We compared accumulation found in the preoperative SPECT images and intraoperative scintigraphy images, performed a histologic examination of adjacent tissues, and measured the dose the personnel was exposed to per operation.

RESULTS

In all patients, tumors were confirmed by a gamma probe and scintigraphy during the operation. Intraoperative accumulation in tumors was significantly related to accumulation found in the preoperative (99m)Tc-MIBI SPECT images. In 9 out of 13 patients, accumulation disappeared in the postremoval scintigraphy images, and no tumor tissue was found by histologic examination. Residual tumor tissue was found in 4 patients. Average exposure of the personnel per operation was 22.9 +/- 4.0 microSv.

CONCLUSION

Resection of brain tumors with a gamma probe and a mobile gamma camera was very useful since the area to be removed was easily identified and residual tumors could be detected.

Recurrent desmoplastic ameloblastoma of the maxilla: a case report

A case of desmoplastic ameloblastoma recurring within 2 months of curettage is presented. This tumour appeared in the premolar region of the left maxilla with involvement of the antrum. The 24-year-old female patient was initially treated by curettage with wide surgical margins. Later, partial maxillectomy was carried out followed immediately by iliac bone graft. The case was followed with periodic plain radiography and computed tomography. The presence of a pulpally infected premolar and the atypical radiographic appearance obscured the disease. The biologic profile of this tumour is not fully understood because of the limited number of reported cases, coupled with inadequate long-term follow-up. A review of the lesion with emphasis on the pathogenesis of recurrence is discussed.

Long-term follow up of children with meningiomas in Denmark: 1935 to 1984

OBJECT

Meningiomas in children are rare, infrequently described in the literature, and often associated with neurofibromatosis Type 2 (NF2). The authors report a series of 22 children treated for an intracranial meningioma in Denmark between 1935 and 1984.

METHODS

Of 1542 cases of pediatric intracranial tumors in children younger than 15 years of age, 22 harbored meningiomas. Three children suffered from NF. The male/female ratio was 8:14. The mean age at the time of diagnosis was 5 years for boys and 11.5 years for girls. At the time of diagnosis all tumors were large. All patients underwent surgery. In 20 cases, the final histological diagnoses were low-grade and in two cases high-grade tumors. The follow-up period ranged from I to 45 years (mean 16 years). Two patients were lost to follow up. Four of seven boys and three of 13 girls survived. Five of 13 children in whom the tumor was completely removed survived, whereas two of seven in whom the lesion was partially removed survived. The mean survival time in children who died during follow up was 10 years. Two children with anaplastic meningioma remain alive.

CONCLUSIONS

The long-term prognosis for surgically treated children with intracranial meningiomas was worse than expected. Some reasons for this may have been the late diagnosis and related large size of the tumor during a period of limited diagnostic capacity prior to the computerized tomography and magnetic resonance imaging eras, and the association of NF2 with multiple tumors of the central nervous system. Complete resection is not always possible and should be performed as an image-guided operation.

Re-appearance of power Doppler signals in the tumor nodules of hepatocellular carcinoma after transarterial embolization reflects residual viable tumor cells: histological confirmation

BACKGROUND/AIMS

A recent advance in ultrasonography is the use of power Doppler for detecting low-velocity angle-independent blood flow at the microvascular level. The present study was prospectively performed to elucidate the relationship between the power Doppler signals of hepatocellular carcinoma after transarterial embolization and histological confirmation of viable tumor cells.

METHODOLOGY

The observance of hepatocellular carcinoma-related Doppler signals in 48 patients with 67 nodules was examined after transarterial embolization, and its correlation with the presence of viable tumor cells using ultrasound-guided biopsy specimens was analyzed.

RESULTS

Power Doppler signals disappeared in 54 out of 67 nodules (80%) one day after transarterial embolization, but the signals re-appeared in 55-53% of the specimens at 4-7 days and 10-14 days after treatment. Viable tumor cells were histologically proven in 27 of 34 nodules (79%) presenting power Doppler signals, while only 5 of the 22 nodules (23%) negative for Doppler signals confined viable tumor cells (P<0.001). Univariate and multivariate analysis showed that the detection of power Doppler signals after transarterial embolization was related to the size of the tumor and the presence of viable tumor cells (both, P<0.001).

CONCLUSIONS

These results indicate that the presence of power Doppler signals may reflect the presence of viable tumor cells after transarterial embolization, leading to the need for further treatment of hepatocellular carcinoma nodules.

Detection of Recurrent or Residual Nasopharyngeal Carcinomas After Radiotherapy with Technetium-99m Tetrofosmin Single Photon Emission Computed Tomography and Comparison with Computed Tomography—A Preliminary Study

The effectiveness of technetium-99m tetrofosmin (Tc-TF) single photon emission computed tomography (SPECT) of the head and neck for detecting recurrence of nasopharyngeal carcinomas (NPC) was evaluated and compared with computed tomography (CT). Both Tc-TF SPECT and CT of the head and neck were performed in 36 NPC patients 4 months after radiotherapy. All 36 then underwent histopathological examinations of nasopharyngeal biopsies. Based on the histopathological results, the sensitivity, specificity, and accuracy of visually interpreted Tc-TF SPECT images, to differentiation of recurrent NPC from benign lesions, were 64%, 96%, and 86%, respectively. The sensitivity, specificity, and accuracy of CT for detecting recurrent NPC were 73%, 88%, and 83%, respectively. The Tc-TF SPECT has a better specificity but a lower sensitivity to differentiate benign lesions and recurrent/residual NPC when compared with CT. Combined Tc-TF SPECT and CT sensitivity and specificity were 100% and 88%, respectively. There are much better either test alone. However, further studies, including a larger NPC patient population, are warranted to determine the exact role and clinical usefulness of Tc-TF SPECT to differentiate benign lesions and recurrent/residual NPC.

Using thallium-201 SPECT to detect recurrent or residual nasopharyngeal carcinoma after radiotherapy in patients with indeterminate CT findings

BACKGROUND

The aim of this study is to evaluate the usefulness of thallium-201 (Tl-201) single-photon emission CT (SPECT) to detect recurrent or residual nasopharyngeal carcinomas (NPC) when CT findings are indeterminate.

METHODS

After radiotherapy, 30 NPC patients with indeterminate CT findings were included. CT, Tl-201, and biopsy were performed at least 4 months after radiotherapy and within 1 week of each other. The final results were based on histopathologic findings and clinical follow-up after at least 6 months.

RESULTS

The rates for sensitivity, specificity, and accuracy of Tl-201 SPECT in detecting recurrent or residual NPC when there were indeterminate CT findings, were 86.7%, 93.3%, and 90.0%, respectively.

CONCLUSIONS

These results suggest that Tl-201 SPECT is effective in detecting recurrent or residual NPC when CT findings are indeterminate.

Therapy evaluation of laryngeal carcinomas by tyrosine-pet

INTRODUCTION

One of the major problems in head and neck oncology is determination of tumor status after radiotherapy. Physical examination and conventional imaging by CT and MRI do not always accurately differentiate between residual or recurrent tumor and posttreatment inflammation, fibrosis, edema, or scarring. The feasibility of positron emission tomography (PET) with L-[1-(11)C]-tyrosine (TYR) for therapy evaluation of laryngeal squamous cell carcinomas by identification of residual or recurrent disease after radiotherapy was investigated.

PATIENTS AND METHODS

Nineteen patients with laryngeal carcinomas had standard workups with endoscopy and conventional imaging. All subjects underwent a TYR PET scan (PET1) before definitive treatment. For determination of tumor status, a second TYR PET scan (PET2) was performed 3 months after radiotherapy. At the time of scanning, seven patients were clinically suspected of having residual disease, and in these cases, additional CT imaging and biopsies during endoscopy were performed. During the minimal follow-up period of 29 months, six patients had clinical suspicion of recurrent disease. In these six cases, a third TYR PET (PET3), CT imaging, and biopsy were performed.

RESULTS

All pretreatment tumors were depicted by TYR PET (PET1). Three months after radiotherapy, sensitivity and specificity of TYR PET (PET2) for discrimination between residual tumor and benign posttreatment tissue changes were both 100%, and for CT, 50% and 67%, respectively. For detection of recurrent tumor during follow-up, sensitivity and specificity of TYR PET (PET3) were also 100%, and CT, 75% and 50%, respectively.

CONCLUSIONS

Dynamic TYR PET is an accurate imaging modality for therapy evaluation in detection of residual and recurrent disease with higher sensitivity (100%) and specificity (100%) for discrimination of tumor status by TYR PET compared with conventional imaging.

Prognostic value of PET using 18F-FDG in Hodgkin's disease for posttreatment evaluation

Detection of relapse after completion of therapy in patients with Hodgkin's disease (HD) and non-Hodgkin's lymphomas (NHL) constitutes an important challenge in modern medical imaging. An accurate assessment of the presence of residual disease is essential to determine which patients would benefit from additional therapy. The objective of this study was to assess the diagnostic accuracy of (18)F-FDG PET in detecting residual disease or relapse during the posttherapy period in patients with HD in comparison with CT. We also established different predictive values for (18)F-FDG PET according to the time interval between the end of therapy and the PET study.

METHODS

Forty-eight patients with HD underwent (18)F-FDG PET after the completion of chemotherapy (median, 58 d) between March 1999 and April 2002. Disease-free intervals and proportions were calculated using the Kaplan-Meier method. Standardized uptake values of the most active lesion in each patient with a positive study were also measured. PET and CT results were compared with clinical follow-up, with relapse being defined by a positive biopsy or the introduction of a second-line treatment.

RESULTS

Thirty-four patients were still disease-free during a mean follow-up of 605 d. Fourteen patients relapsed during a mean follow-up of 197 d. The sensitivity and specificity of (18)F-FDG PET to predict relapse were 79% and 97%, respectively. The positive predictive value and the negative predictive value were both equal to 92%. The diagnostic accuracy of (18)F-FDG PET (92%) was significantly higher than the accuracy of CT (56%) (P < 0.0005). Patients with positive (18)F-FDG PET also had a far shorter median disease-free interval (79 d) than those with positive CT (disease-free proportion of 52% at 1,143 d) (P = 0.0046). The 3 cases of false-negative (18)F-FDG PET studies that we observed occurred in patients who underwent their PET study within the first 49 d after the end of chemotherapy.

CONCLUSION

Positive (18)F-FDG PET after the end of therapy in HD patients is a strong predictor of relapse. A negative PET study is also an excellent predictor of good prognosis. The diagnostic accuracy of (18)F-FDG PET to assess the presence of residual disease after therapy is superior to that of CT.

Radiofrequency ablation for treatment of hepatocellular carcinoma with cirrhosis

BACKGROUND/AIMS

The majority of hepatocellular carcinoma patients with cirrhosis are not candidates for surgical resection, and local thermal therapy producing destruction of cancer cells was one of the ideal options for treatment. Heat from radiofrequency ablation is generated through agitation caused by an alternating electrical current. The heat of radiofrequency energy results in local cell coagulation and causes cellular ablation necrosis of tumor tissue.

METHODOLOGY

Eighteen cases of hepatocellular carcinoma were treated with radiofrequency ablation in our institute. We used a RFA 2000 generator (Boston Scientific Co, USA) with LeVeen needle with the maximum diameter of 3.5 cm when the array electrodes were fanned out. The indications for this method included; i) normal prothrombin profile, ii) no ascites, iii) tumor can be detected and approached by ultrasound, iv) tumor cannot be resected or patient is not willing to take the operation.

RESULTS

No specific complication was noted during or after the procedure. Only two cases needed more analgesics after the procedure. One case was found with burning of the stomach serosa proved by laparoscopic examination, in which radiofrequency ablation was performed to the tumor located in the left lobe of the segment 3. Impedance could not raise up completely in two cases with larger size tumor more than 5 cm. The decreased levels of alpha-fetoprotein were significant (P = 0.005) after radiofrequency ablation treatment. Residual tumor was found in four cases (20%) in the follow-up abdominal computed tomography scan.

CONCLUSIONS

Radiofrequency ablation resulted in a higher rate of complete necrosis of tumor tissue and the complication rate was low as well. Therefore, we believed that radiofrequency ablation is an ideal treatment modality for most liver tumors, which cannot tolerate the conventional surgical procedures.

Technetium-99m tetrofosmin uptake in insular thyroid carcinoma. A comparison with iodine-131

The authors describe a 42-year-old man with insular thyroid carcinoma. In this patient, iodine-131 (I-131) and technetium-99m (Tc-99m) tetrofosmin imaging were performed to investigate residual thyroid tissue and metastatic foci of tumor. Both I-131 and Tc-99m tetrofosmin images showed metastatic foci, but Tc-99m tetrofosmin imaging revealed the lesions better than did the I-131 scan. Tc-99m tetrofosmin imaging does not require withholding of thyroid hormone suppression and can be used for follow-up evaluation of patients with insular thyroid carcinoma.

Non-germ cell malignancy in residual or recurrent mass after chemotherapy for nonseminomatous testicular germ cell tumor

BACKGROUND

After chemotherapy for nonseminomatous testicular germ cell tumor (NSTGCT), residual masses or recurrent disease may contain a non-germ cell malignancy (NGCM).

METHODS

Over 20 years, 369 patients with disseminated NSTGCT were treated with cisplatin-based polychemotherapy at the University Medical Center Groningen. Residual tumor masses were resected in 244 patients and recurrent tumor masses in 37 patients. Histology was reviewed, focusing on the presence of NGCM.

RESULTS

Nine patients developed an NGCM. Four patients had an NGCM in the resected residual tumor mass after chemotherapy: three patients had a sarcoma, and one patient had both a sarcoma and an adenocarcinoma. Five patients developed a late recurrence with an NGCM after 39, 40, 72, 72, and 84 months. One patient had a primitive neuroectodermal tumor, one had a sarcoma, and three had an adenocarcinoma in the resected recurrent tumor mass. A complete surgical resection was achieved in five (56%) of the nine patients. After a median follow-up of 48 months (range, 3-271 months), five patients had no evidence of disease (56%), three patients were dead of disease (33%), and one patient was alive with disease (11%).

CONCLUSIONS

Sarcoma, adenocarcinoma, or both in residual or recurrent tumor masses after combined-modality NSTGCT treatment are rare. Complete surgical resection of the tumor mass is the only curative treatment option.

Factors associated with residual disease on re-excision in patients with ductal carcinoma in situ of the breast

PURPOSE

This study examines the factors associated with the presence of residual disease at re-excision in patients with ductal carcinoma in situ of the breast.

METHODS

Of 143 consecutive patients undergoing breast conservation treatment from 1990 to 1999, 90 patients (63%) underwent re-excision of the tumor bed. Grade was recorded in 70% (N = 63), size in 78% (N = 70), margin status in 96% (N = 86), volume of excision in 90% (N = 81), and extent of residual disease in 99% (N = 89).

RESULTS

There was no significant correlation between extent of residual disease on re-excision and method of detection, tumor size, histology, grade, or first margin status. Of patients undergoing re-excision, 56% (N = 50) had no residual disease, 38% (N = 34) had minimal microscopic residual disease, and only 6% (N = 5) had either extensive microscopic or gross residual disease. For these five patients, the median volume of first excision was similar to that of the other patients (26 vs 36 cc), but the median volume of second excision was smaller (33 vs 63 cc). The median age for these five patients was 41 years, compared with 55 years for the remaining patients. All five patients had comedo (N = 4) or solid tumor (N = 1) histology, with grade 3 (N = 3) or unknown grade (N = 2).

DISCUSSION

Patients with extensive microscopic disease or gross residual at the time of re-excision would be at increased risk for local recurrence after conventional radiation treatment if re-excision had not been performed. Only 6% of patients in this study had such pathology findings. No factor predicted for these adverse pathology findings, although these patients tended to be younger, with high-grade or comedo histology.

Early detection of relapse by whole-body positron emission tomography in the follow-up of patients with Hodgkin's disease

BACKGROUND

Relapse after treatment of Hodgkin's disease (HD) is usually identified as a result of the investigation of symptoms. We undertook this study to examine the value of whole-body positron emission tomography (PET) for the detection of preclinical relapse.

PATIENTS AND METHODS

Thirty-six patients underwent 2-[fluorine-18]fluoro-2-deoxy-D-glucose ((18)F-FDG) PET at the end of treatment and than every 4-6 months for 2-3 years after the end of polychemotherapy and/or radiotherapy. In those cases of abnormal (18)F-FDG accumulation a confirmatory study was performed 4-6 weeks later.

RESULTS

One patient had residual tumor and four patients relapsed during a follow-up of 5-24 months. All five events were correctly identified early by (18)F-FDG PET. Residual tumor or relapse was never first diagnosed based on clinical examination, laboratory findings or computed tomography (CT) studies. Two patients presented B symptoms and the three others were asymptomatic at the time of residual disease or relapse. Confirmation of residual disease or relapse was obtained by biopsy in four patients 1, 1, 5 and 9 months after PET and by unequivocal clinical symptoms and CT studies in one patient 3 months after PET. False-positive (18)F-FDG PET studies incorrectly suggested possible relapse in six other patients, but the confirmatory PET was always negative. Our study also provides important information about physiological (18)F-FDG uptake in the thymus.

CONCLUSIONS

Our data suggest the potential of (18)F-FDG PET to detect preclinical relapse in patients with HD. This could help identify patients requiring salvage chemotherapy at the time of minimal disease rather than at the time of clinically overt relapse. Further studies are warranted to determine the impact of PET on treatment management and outcome. In fact, the aim of follow-up procedures is not only to detect preclinical relapse but mainly to obtain better results by starting salvage treatment earlier. A cost-benefit analysis will also be necessary before (18)F-FDG PET can be used routinely in the follow-up of patients with HD.

Thyroid carcinoma: iodine-131-negative whole-body scan reverses to positive after a combination of thyrogen stimulation and withdrawal

PURPOSE

Reports state that scan results for as many as 25% of patients with differentiated thyroid carcinoma will convert to iodine-131 (I-131) negative over time with positive thyroglobulin levels. Tl-201, positron emission tomography (PET), and sestamibi or tetrofosmin have all helped to identify I-131-negative thyroid carcinomas. The authors have identified a case of reversal of I-131 findings from negative to positive after short-term thyroxine withdrawal combined with treatment with recombinant human thyroid-stimulating hormone (rhTSH).

MATERIALS AND METHODS

The authors obtained multiple I-131 whole-body scans with 4-week thyroid hormone withdrawal, post-I-131 therapy scans, nonthyroid withdrawal Tl-201 chloride whole-body tumor images, and finally combined 2.5-week thyroid hormone withdrawal and rhTSH-stimulation I-131 whole-body scans before and after therapy.

RESULTS

The authors examined one patient during a period of 9 years whose I-131 whole-body scan results were at first positive and then became negative. After a combination of rhTSH stimulation and thyroid hormone withdrawal, the results changed again to I-131 positive.

CONCLUSIONS

This is the first known case in which I-131 findings changed from negative to positive. A combination of rhTSH stimulation and nearly adequate withdrawal may help convert more I-131-negative whole-body scans to positive.

[F-18 fluorodeoxyglucose positron emission tomography in malignant lymphoma]

Non-invasive imaging methods are important diagnostic tools for initial staging and re-staging after radiochemotherapy in patients with malignant lymphomas. Conventional imaging is mainly based on CT although MRI and sonography also gain more and more importance in these indications. The F-18-Fluorodeoxyglucose-positron emission tomography (F-18-FDG-PET) imaging is based upon increased glucose metabolism in tumor tissue, a phenomenon also seen in lymphomas with the exeption of MALT type lymphomas. Comparative studies between conventional imaging methods and F-18-FDG-PET showed that F-18-FDG-PET is capable of visualizing the extent of lymphomas with high sensitivity and specificity at initial staging and at re-staging after therapy. Results of F-18-FDG-PET were better than those of conventional imaging. One of the major limitations of conventional imaging with CT is the lack of distinguishing residual lymphoma tissue and fibrotic scar tissue after therapy. However, F-18-FDG-PET is capable to resolve this problem as it is based on metabolism and it can distinguish with high sensitivity and specificity between residual lymphoma tissue and fibrotic scar tissue after therapy. Thus, in particular, in those patients with residual lymphoma bulks after therapy, the use of F-18-FDG-PET can give essential informations with regard to the planning of further therapeutic interventions. In conclusion, F-18-FDG-PET seems to open new dimensions in imaging of lymphoma both for initial staging and for restaging after therapy. Moreover, studies have shown that the use of F-18-FDG-PET in lymphoma patients is cost effective. Due to this background and the fact that the availability of F-18-FDG will be further facilitated, the F-18-FDG-PET will probably gain increasing importance in the management of patients with lymphomas in the close future.

[Differentiated thyroid gland carcinoma in a scintigraphically hot thyroid nodule: diagnosis and interdisciplinary therapeutic management]

A hyperfunctioning differentiated thyroid carcinoma is a rare occurrence. Nevertheless, this diagnosis must be considered in a scintigraphically hot nodule if there is a clinical or sonographic suggestion of malignancy. The case of a 57-year old patient with hyperthyreosis and a scintigraphically hot thyroid nodule is presented. Further evaluation led to the diagnosis of a differentiated thyroid carcinoma with extensive lymph node and pulmonary metastases (pT2b, pN1b, pM1). The scintigraphically hot nodule corresponded to the primary tumor, whereas scintigraphic detection of the lymph node metastases was only possible postoperatively. Extensive resection of the lymph node metastases was achieved by the intraoperative application of a gamma probe (2nd operation). This allowed sufficient uptake of radioiodine in the pulmonary metastases for their detection and subsequent devitalisation by radioiodine therapy. Complete elimination of all tumour tissue was documented at a control follow-up after six months. Gamma probe-guided surgery may allow for additional removement of non-palpable lymph node metastases. In selected cases this may optimize the surgical results and thereby facilitate the subsequent radioiodine elimination of advanced differentiated thyroid carcinomas.

Can pre-operative computed tomography predict resectability of ovarian carcinoma at primary laparotomy?

OBJECTIVE

To assess the ability of computed tomography in predicting whether suspected ovarian cancer could be fully excised at primary laparotomy.

DESIGN

Retrospective analysis of patient notes and pre-operative computed tomography scans. Setting A UK NHS cancer centre.

POPULATION

Seventy-seven women who underwent laparotomy for an ovarian tumour and who had had a pre-operative computed tomography scan.

METHODS

Women who had a computed tomography scan before laparotomy for an ovarian tumour were identified. Analysis was undertaken to determine the accuracy of computed tomography in predicting malignancy, stage and residual disease. The computed tomography parameters significantly associated with residual disease were determined by a chi2 analysis. These parameters, in addition to age and CA125, were used to generate a predictive model. This model was further refined by stepwise logistic regression and a clinical scoring index was generated.

MAIN OUTCOME MEASURES

To identify those computed tomography parameters significantly associated with residual disease and to use these with CA125 and age to generate a useful clinical scoring index to predict residual disease in suspected ovarian cancer.

RESULTS

Seventy-seven women underwent a laparotomy for an ovarian tumour and had a pre-operative computed tomography scan. Fifty-one of these women had malignant disease and twenty-five of these women had residual disease remaining. The sensitivity of computed tomography in predicting malignancy was 90% with a specificity of 85% and the overall accuracy of computed tomography for predicting stage of disease was 73% (37/51). The overall sensitivity of computed tomography in predicting residual disease was 88%, the specificity was 92% and the positive predictive value was 85%. The parameters on computed tomography that were significantly (P < 0.05) associated with residual disease were ascites, omental cake, mesenteric disease, paracolic gutter deposits, diaphragmatic deposits and pleural effusion. The predictive model generated was more accurate than computed tomography alone (sensitivity 88%, specificity 98%, positive predictive value 95%). Using stepwise logistic regression enabled the predictive model to be simplified to include mesenteric disease, omental cake, age and CA125 without any change in sensitivity or specificity and this model was used to generate a scoring index.

CONCLUSION

This study shows that prediction of resectability by computed tomography is excellent and is further improved by the generation of a predictive model, which can be used to generate a simple scoring index. This scoring system now needs to be tested prospectively to ensure that its performance remains as good in an independent sample population.

The use of recombinant human TSH in the follow-up of differentiated thyroid cancer: experience from a large patient cohort in a single centre

BACKGROUND

Periodic evaluation of serum thyroglobulin (Tg) and whole body 131I imaging (131I-WBS) are essential in the follow-up of differentiated thyroid carcinoma (DTC); both diagnostic modalities require stimulation by high levels of TSH. Administration of recombinant human TSH (rhTSH) is an alternative to the withdrawal of thyroid hormone therapy.

OBJECTIVE

The aim of this study was to report our experience in the use of rhTSH for the management of patients with DTC.

PATIENTS

One hundred and four patients were enrolled in the study. A dose of 10 U of rhTSH therapy was injected intramuscularly for 2 consecutive days; 24 h after the second dose of rhTSH the patients were administered 4--5 mCi of 131I and, 48 h later, WBS was performed.

RESULTS

In all patients, baseline mean serum Tg and TSH levels were 2.4 +/- 1.9 ng/ml and 0.0153 +/- 0.0232 mIU/l, respectively. Basal Tg levels were detectable in 58 out of 104 patients. After rhTSH injection, mean serum TSH levels rose to 122.67 +/- 47.36 mIU/l. Stimulated serum Tg levels increased to greater-than-or-equal 5 ng/ml and the 131I-WBS showed an uptake in 18 patients (17.4%). Among them there were three with bone metastases and one with brain metastases, who reported violent skeletal pain and a severe headache, respectively. These were caused by the growth of tumour mass of metastases induced by rhTSH administration.

CONCLUSIONS

The use of rhTSH avoids the debilitating effects of hypothyroidism and its use successfully promotes iodine uptake and increases the sensitivity of serum Tg testing. The risk of causing serious side-effects recommends performing skull magnetic resonance and radionuclide bone scan in cases of suspected brain or skeletal metastases.

[Difficulties in diagnosis and localization of recurrent medullary thyroid carcinoma]

Recurrent and residual medullary thyroid carcinoma (MTC) are common in patients following primary surgical resection. Difficulty arises in performing precise localization of the tumor because of anatomical distortion of the neck structures following surgery. To date, no modality has been shown superior to others in the diagnosis of recurrent or residual MTC, and the issue is currently under debate in the literature. We report a case in which secondary recurrence of MTC was detected and localized using a novel combination of preoperative and intraoperative radionuclide imaging, and a method of preventing intraoperative damage to the recurrent laryngeal nerve in the anatomically disrupted neck. To our knowledge, this is the first report of a combination of these three modalities in detection and localization of recurrent MTC, while minimizing the possibility for nerve injury during the operative procedure. Such a therapeutic strategy may prove useful in the management of patients who have previously undergone neck surgery and suffer from anatomical distortion of normal neck structures.

I-123 diagnostic thyroid tumor whole-body scanning with imaging at 6, 24, and 48 hours

PURPOSE

The use of I-123 in lieu of I-131 for diagnostic whole-body thyroid tumor scanning (DxRal) in patients with differentiated thyroid cancer obviates the risk for stunning and affords significantly improved image quality. Because of the shorter half-life (13 hours) of I-123, images have been acquired primarily 6 or 24 hours after injection, potentially decreasing the sensitivity for detecting weakly avid thyroid tumor or remnant.

MATERIALS AND METHODS

The authors evaluated the use of 111 to 185 MBq (3 to 5 mCi) I-123 for DxRal under withdrawal conditions, imaging at 6, 24, and, in most cases, 48 hours. DxRal with I-123 was compared in 13 evaluations performed in 10 patients, with post-I-131 treatment scans acquired early (2 to 3 days) and late (7 to 10 days) in all cases but one.

RESULTS

Of 37 sites of tumor or remnant identified in post-treatment scans, 26 were found in the DxRal I-123 scan (sensitivity, 70%). Of the 11 sites missed by I-123, 7 were seen only in the late post-treatment scans. Therefore, the sensitivity of I-123 imaging compared with the early post-I-131 treatment scans was 26 of 30, or 86.7%. In 10 cases, 48-hour I-123 imaging was attempted, yielding images of acceptable quality in eight of them. Lesion identification was improved on the 48-hour images; in one case, this allowed the identification of a site of tumor recurrence that was confirmed positive on the I-131 post-treatment scan.

CONCLUSIONS

I-123 doses of 111 to 185 MBq for DxRal provide acceptable levels of sensitivity overall and may permit 48-hour imaging for improved detection of weakly avid tumor or remnant without any risk for "stunning."

Comparison of 18FDG-PET with CT scans in the evaluation of patients with residual and recurrent Hodgkin's lymphoma

The reliable assessment of residual masses after treatment as well as of new lesions suspected for relapse remains a diagnostic problem in patients with Hodgkin's disease (HD). The current study compares the results obtained by CT scan to FDG-PET imaging in a blind analysis with respect to the viability of residual masses and in case of suspected relapse. Between 1/94 and 10/99, 47 comparisons of PET and corresponding CT scans - 26 comparisons in 24 patients with residual tumors and 21 comparisons in 20 patients with suspected relapse of HD - were evaluated by independent reviewers blinded to he results of each other. Patients with primary diagnosis had been treated within trials of the German HD Trial study group. Relapsed patients received intensified salvage chemotherapy regimens. PET was assessed visually and by quantifying glucose uptake (SUV). Changes in size of tumor lesions as well as contrast medium enhancement served as criteria for assessment by CT scans. Results were validated either by histologic examination of a resected mass or biopsy (n=17) or by a clinical follow-up over 6 months following treatment (n=30). In 26 cases with residual lesions FDG-PET showed an increased tracer uptake in 8, 7 of which were true positive (TP) and 1 false positive (FP). Eighteen cases were classified as being negative (no viable HD), 17 true negative (TN) and 1 FN. In the blinded reading of the corresponding CT scans, 10 cases with residual lesions were considered to contain vital lymphoma (2 TP, 8 FP). Sixteen CT scans were classified as negative (10 TP, 6 FN). The resulting sensitivity and specificity of PET were 87.5% and 94.4% in contrast to only 25% and 56% for CT scans. The positive and negative predictive values of PET and CT scans were 87.5% and 94.4% and 20% and 62.5%, respectively. In patients with suspected relapse, sensitivity and positive predictive value for the diagnosis of the relapse were 100% and 86%, respectively, yielding the same results for both methods. FDG-PET performed in HD patients with residual masses appears to offer important additional information regarding the presence of viable HD in these residual lesions. In patients with suspected relapse of HD, FDG-PET seems not to offer any information over CT scans. Using SUVs is not superior to visual assessment of PET alone.

Positron emission tomography and lymphoma therapy

FDG-PET is both able to provide information of lymphomatous organ involvement not available by conventional imaging techniques (US, CT, MRI) and to give reliable data otherwise obtainable only by using invasive procedures. As a whole body-screening technique, PET reduces diagnostic requirements and potential complications. Nevertheless the conventional imaging techniques are essential for the exact localisation and correct interpretation of PET findings. A number of factors that may produce false-positive results have to be taken into consideration, including post-treatment inflammatory changes and the sensitivity of the method in the setting of minimal residual disease. Despite its potential of a screening method being performed prior to other imaging procedures, PET is not yet established as a routine element for the primary staging of Hodgkin's disease and non-Hodgkin's lymphoma. Its value for re-staging is less doubtful due to the frequency of stage migration and possible changes in therapy related to the use of PET. Detailed cost-effectiveness studies are needed to assess the economic implications of an expanded use of PET in lymphoma therapy.

Predictive impact of 2-18fluoro-2-deoxy-D-glucose positron emission tomography for residual postchemotherapy masses in patients with bulky seminoma

PURPOSE

To establish the predictive potential of 2-18fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) for detecting viable tumor tissue in residual postchemotherapy masses of seminoma patients.

PATIENTS AND METHODS

In this prospective multicenter trial, results of FDG PET studies in seminoma patients with postchemotherapy masses > or = 1 cm were correlated with either the histology of the resected lesion or the clinical outcome on follow-up without resection. Negative PET scans of residual lesions that were devoid of viable tumor tissue on resection or disappeared, shrunk, or remained stable in size for at least 2 years were rated as true-negative (TN). Positive scans without histologic or clinical evidence of tumor tissue were classified as false-positive. In patients with histologically positive or progressive lesions, positive PET scans were defined as true-positive (TP) and negative scans, false-negative (FN).

RESULTS

Thirty-seven PET scans of 33 patients were assessable at a median follow-up time of 23 months (range, 2 to 46 months). Histologic data were available from nine patients who had undergone resection. Twenty-eight patients were followed-up clinically and radiologically. Twenty-eight scans were TN, eight were TP, and one was FN. All 14 residual lesions more than 3 cm and 22 (96%) of the 23 < or = 3 cm were correctly predicted by FDG PET. The specificity (100%; 95% confidence interval [CI], 87.7% to 100%), sensitivity (89%; 95% CI, 51.7% to 99.7%), positive predictive value (100%), and the negative predictive value (97%) of FDG PET were superior to data obtained by assessing residual tumor size (< or = or > 3 cm).

CONCLUSION

FDG PET is a clinically useful predictor of viable tumor in postchemotherapy residuals of pure seminoma, especially those greater than 3 cm.

Using contrast-enhanced sonography to assess the effectiveness of transcatheter arterial embolization for hepatocellular carcinoma

OBJECTIVE

We evaluated the usefulness of contrast-enhanced wideband harmonic gray-scale sonography in assessing the therapeutic effects of transcatheter arterial embolization for patients with hepatocellular carcinoma and compared the findings of this imaging modality with those of helical CT.

SUBJECTS AND METHODS

Twenty-nine patients with 39 hepatocellular carcinoma lesions were examined. We scanned lesions before and after therapy using contrast-enhanced wideband harmonic gray-scale sonography after injection of a galactose-palmitic acid contrast agent. All patients held their breath for 20--50 sec after injection while the vascularity of the tumor was observed. We then monitored tumor enhancement between 60 and 180 sec after injection with patients breath-holding for a few seconds. Lesions were considered to exhibit viable tumor residue if hypervascular enhancement was observed in the tumor. We compared this enhancement with helical CT findings.

RESULTS

After therapy, 36 of the 39 lesions showed viable tumor residue on contrast-enhanced wideband harmonic gray-scale sonography, with no artifacts from iodized oil. Helical CT revealed a high-attenuation area in 12 of the 36 lesions, whereas 24 of the 36 lesions could not be evaluated for tumor residue as a result of artifacts from iodized oil accumulation in the tumor. The remaining three lesions showed complete deposition of iodized oil and complete necrosis on contrast-enhanced wideband harmonic gray-scale sonography.

CONCLUSION

Contrast-enhanced wideband harmonic gray-scale sonography is useful in evaluating the therapeutic effects of transcatheter arterial embolization for hepatocellular carcinoma.

Detection of minimal residual disease in acute leukemia by Tc-99m MIBI femoral marrow imaging

To determine the potential of Tc-99m MIBI femoral marrow imaging for detecting minimal residual disease in acute leukemia, MIBI images of 68 patients with acute leukemia and 110 control patients were examined. MIBI accumulation was classified into three patterns: not detectable, mild accumulation, and clearly visualized accumulation. Clearly visualized accumulation was interpreted as abnormal. The mean uptake ratio of the femoral marrow to muscle was calculated. Forty-five patients who were in complete remission (CR) at the time of MIBI imaging had a follow-up study (mean interval, 23 months). Clearly visualized accumulation was demonstrated in 35 patients with acute leukemia: in 7 patients before starting induction chemotherapy, in 12 patients after relapse, and in 16 of the 49 patients in the CR group. Mild accumulation was demonstrated in 14 patients in the CR group and in 13 control group patients. No detectable accumulation was observed in 19 patients in the CR group and in 97 control patients. The marrow and muscle uptake ratio of patients before starting chemotherapy (2.29 +/- 0.26) was greater compared with that in patients after relapse (1.78 +/- 0.44, P < 0.02) and in patients with abnormal accumulation despite complete remission (1.84 +/- 0.36, P < 0.01). The uptake ratio in patients with abnormal accumulation despite CR was higher compared with patients with mild accumulation in CR (1.26 +/- 0.13, P < 0.001) and controls (1.23 +/- 0.10, P < 0.001) who had mild accumulation. Fifteen patients with abnormal accumulation despite CR had a markedly greater relapse rate (66.7% > 10.0%, P < 0.005), a higher mortality rate (46.7% > 6.7%, P < 0.01), and shorter remission time (8.7 +/- 10.2 months < 35.9 +/- 20.1 months, P < 0.001) compared with 30 patients without abnormal accumulation in CR. MIBI femoral marrow imaging may be a useful and simple method for monitoring levels of residual leukemic cells. Clearly visualized MIBI accumulation may be a marker for relapse.

Surgical strategy for cholesteatoma in children

OBJECTIVE

We reviewed our experience with childhood cholesteatoma in children under 15 years old. Based on cumulative postoperative data, we propose a modified canal-wall-up technique in conjunction with a planned, staged operation.

METHODS

From 1982 to 1997, 56 children with cholesteatoma (58 ears, total) underwent surgery in our department. In the early period (1982-1990), canal wall-down mastoidectomy was performed in 52% (21 of 40 ears), and canal wall-up mastoidectomy in 48% (the remaining 19 ears). In the late period (1991-1997), 18 ears with cholesteatoma underwent surgery. The canal-wall up mastoidectomy was performed in 89% (16 ears), and canal-wall-down mastoidectomy in the remaining 11% (two ears).

RESULTS

In the early period (1982-1990), cholesteatoma recurred more frequently in the canal-wall-up mastoidectomy group than in the canal-wall down mastoidectomy group (53 vs. 14%). Other postoperative complications, such as erosion of the mastoid cavity, otorrhea, and perforation of the eardrum, occurred more frequently in the canal-wall-down mastoidectomy group than in the canal-wall-up mastoidectomy group. In the late period (1991-1997), in the canal-wall-up mastoidectomy group, ten ears underwent one-stage surgery. Planned staged tympanoplasty was completed in six ears. After one-stage surgery, four of ten ears experienced residual cholesteatoma. Two of the recurrent ears had undergone planned staged tympanoplasty. As revealed by postoperative computed tomography (CT) images, 12 of 15 ears had aeration in the attic and antrum as well as in the tympanic cavity. In these cases, no attic retraction pocket formation was observed.

CONCLUSION

Our strategy for pediatric cholesteatoma in the future is to use canal-wall-up mastoidectomy when possible. If aeration in the attic and antrum is observed by preoperative CT-scan image and no erosion in the malleus and incus exists, the one-stage surgery will be chosen. If no aeration is observed by CT-scan and/or erosion exists in the surgical findings, planned staged tympanoplasty will be necessary. This strategy allows a high incidence of aeration of the attic and antrum, and prevents the formation of the attic retraction pocket while enabling the early detection of residual cholesteatoma by means of CT.

Somatostatin receptor scintigraphy in the management of cerebral malignant ectomesenchymoma: a case report

A 10-year-old girl presented with a cerebral malignant ectomesenchymoma (MEM), a very unusual tumour with undifferentiated mesenchymal as well as ectodermal elements. Somatostatin receptor scintigraphy (SRS) was performed during the diagnostic workup. The recurrent residual tumour mass was exactly visualized with SRS, and was negative after successful treatment of the patient. The potential application of SRS in initial staging, follow-up and therapy planning in MEM is discussed. This is the first application of SRS in MEM.

Preparation by recombinant human thyrotropin or thyroid hormone withdrawal are comparable for the detection of residual differentiated thyroid carcinoma

Clinical recurrences of differentiated thyroid carcinoma occur in 20% of patients after thyroid surgery. We performed a retrospective analysis of a cohort of patients undergoing routine follow-up testing to detect recurrent thyroid carcinoma over a 2-yr period. One group was prepared for testing by thyroid hormone withdrawal (THW), and the other group remained on thyroid hormone and received injections of recombinant human TSH (rhTSH) before diagnostic whole-body radioiodine scanning (DxWBS). We hypothesized that no differences in the ability to detect residual disease would exist between these 2 groups. Two hundred and eighty-nine patients were examined by both DxWBS and by measurement of the serum thyroglobulin (Tg) response to elevated TSH levels. THW was used for 161 patients, and rhTSH preparation was used for 128 patients. Based on all available testing results, we categorized patients as having metastatic disease, thyroid bed uptake only, or no evidence of disease. We examined the sensitivity, specificity, positive and negative predictive values of the DxWBS, and the stimulated Tg after preparation by THW or rhTSH. Patients with thyroid bed were not considered in accuracy testing. The sensitivity and specificity of the 2 tests were comparable between groups. No significant differences were present in the positive or negative predictive values between groups. The highest negative predictive value (97%) was in patients who had both a negative DxWBS and low stimulated Tg levels after rhTSH. In summary, we were unable to demonstrate a difference in the diagnostic accuracy of DxWBS and/or Tg between patients prepared by either THW or rhTSH. We conclude that preparing patients by rhTSH is diagnostically equivalent to preparing them by THW.

Prognostic value of positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose ([18F]FDG) after first-line chemotherapy in non-Hodgkin's lymphoma: is [18F]FDG-PET a valid alternative to conventional diagnostic methods?

PURPOSE

A complete remission (CR) after first-line therapy is associated with longer progression-free survival (PFS). However, defining CR is not always easy because of the presence of residual masses. Metabolic imaging with fluorine-18 fluorodeoxyglucose ([18F]FDG) positron emission tomography (PET) offers the ability to differentiate between viable and fibrotic inactive tissue. In this study, we evaluated the value of PET in detecting residual disease and, hence, predicting relapse after first-line treatment in patients with non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

Ninety-three patients with histologically proven NHL, who underwent a whole-body [18F]FDG-PET study after completion of first-line chemotherapy and who had follow-up of at least 1 year, were included. Persistence or absence of residual disease on PET was related to PFS using Kaplan-Meier survival analysis.

RESULTS

Sixty-seven patients showed a normal PET scan after first-line chemotherapy; 56 of 67 remained in CR, with a median follow-up of 653 days. Nine of these patients with a residual mass considered as unconfirmed CR received additional radiotherapy. Only 11 of 67 patients relapsed (median PFS, 404 days). Persistent abnormal [18F]FDG uptake was seen in 26 patients, and all of them relapsed (median PFS, 73 days). Because standard restaging also suggested residual disease, 12 patients received immediate secondary treatment. In 14 of 26 patients, only PET predicted persistent disease. From these patients, relapse was proven either by biopsy (n = 8) or by progressive disease on computed tomography or magnetic resonance imaging (n = 6).

CONCLUSION

Persistent abnormal [18F]FDG uptake after first-line chemotherapy in NHL is highly predictive for residual or recurrent disease. In relapsing patients, PFS was significantly shorter after a positive scan than after a negative scan.

[Clinical value of FDG PET using coincident gamma cameras in staging and restaging of malignant lymphoma--compared with convenitonal diagnostic methods]

AIM of the present retrospective study was to validate the clinical value of F-18-FDG PET imaging in lymphoma patients with a dual head camera modified for coincidence detection. Staging before and after oncological treatment was compared with a conservative diagnostic approach.

METHODS

48 patients (28 non-Hodgkin lymphoma, 20 Hodgkin's disease) received FDG-Hybrid-PET scans. Pretherapeutic staging was realized in 28 patients, 9 of them had control studies after they had completed therapy. Totally 29 persons were examined for post-therapeutic restaging. Computed tomography imaging and lymph node sonography was performed in all cases. Results were validated by clinical follow-up, in three cases a recidive was proven by biopsy.

RESULTS

CT and ultrasound detected 77 lesions in 28 patients compared with 100 visualized by PET, but this difference in pretherapeutic staging did not reach significance at p > 0.05 by Fisher's t-test. Hybrid-PET obtained a sensitivity of 93%, a specificity of 79%, a positive of 82% and a negative predictive value of 92% for detection of residual disease. The values for CT + US were 87%, 64%, 72% and 88% respectively.

CONCLUSION

FDG Hybrid-PET is as or even more accurate than standard morphologic diagnostic methods for prestaging in malignant lymphoma. Additionally, there is a substantial benefit for therapy monitoring of residual disease using coincidence detection PET with a 3/4-inch crystal gamma camera.

Positron emission tomography in imaging spinal cord tumors

The ability of positron emission tomography (PET) to detect spinal cord tumors was studied prospectively in 14 patients presenting over a 5-year period. Abnormal uptake by [18F]-fluorodeoxyglucose (FDG) or 11C-methionine was detected in all except one. These data were assessed in relation to magnetic resonance imaging (MRI) findings with regard to tumor type and extent preoperatively, findings at operation, and subsequent clinical course. The group consisted of six astrocytomas, five ependymomas, one mixed ependymoma and astrocytoma, one schwannoma, and one ganglioglioma, all confirmed histologically. This is the largest study comparing spinal PET to MRI. Accurate preoperative correlation between PET and MRI was found in all eight patients scanned at first presentation. The PET uptake was in keeping with the low-grade histology of the tumors. Postoperatively, PET and MRI findings were in agreement in nine patients. In eight of these the findings were in keeping with the subsequent clinical course. In three patients, however, the PET findings were at variance with the clinical course and MRI findings. In one, persistent FDG uptake after radiotherapy was seen where there was subsequent tumor resolution. In two patients with low-grade astrocytomas, scanned with FDG and 11C-methionine, respectively, tracer was not taken up by residual tumor. In this small group of patients, PET did not provide additional useful information. This could be because all tumors studied were low grade and the limited spatial resolution of PET does not lend itself to imaging small spinal cord tumors. The prospective study of larger numbers of patients with a wider range of tumor types is required, but this might be difficult to achieve given the rarity of spinal cord tumors.

[Value of positron emission tomography with 18-fluorodeoxyglucose (FDG-PET) in early detection of residual tumor in oro-pharyngeal-laryngeal carcinoma]

OBJECTIVE

To evaluate and compare the performances of FDG-PET imaging, MRI and clinical examination in the detection of residual tumour 3 months after treatment of patients with head and neck squamous cell carcinoma.

PATIENTS

A consecutive sample of 50 patients with squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx or larynx, or a cervical lymph node metastasis from an unknown primary site excluding T1 lip and T1 vocal cord tumours.

METHODS

Treatment outcome was assessed after 3 months by clinical examination, MRI, and FDG-PET scan. Sensitivity, specificity and accuracy were calculated relative to proven biopsy of residual tumour or a clinical follow-up of 4 months.

RESULTS

Residual cancer was confirmed in 8 patients (16%), while the clinical follow-up was unsuspicious in the remaining 42 patients. PET-FDG had a sensitivity of 100% as compared to MRI (88%) and clinical examination (63%). Specificity was higher for clinical examination (90%), intermediate for MRI (83%) and lowest for PET-FDG (74%).

CONCLUSIONS

This study finds very high sensitivity for PET-FDG in the detection of residual tumour. However, its lower specificity, lack of anatomical resolution, and high cost, require further studies to determine its role in routine screening.

Persistent mediastinal mass is not indicative of recurrence after chemotherapy only in paediatric Hodgkin's disease

Most patients with Hodgkin's disease are treated with chemotherapy in conjunction with radiotherapy, but at the end of treatment a residual mass is often present. After combined therapy, it has been assumed that no additional treatment is needed. However, for children treated without radiotherapy, no data exist on the relevance of a residual mediastinal mass to risk of relapse. We report on the findings of follow-up thorax radiographs of a group of 27 children with initial mediastinal involvement, who were treated with chemotherapy only. We conclude that the regression rate of the mediastinal mass was not related to a later recurrence. Regression after chemotherapy without radiotherapy is probably slower than after combined therapy. We consider chest radiograph examinations to be appropriate for the follow-up of tumour regression. When the data were compared with a group of children with Hodgkin's disease without mediastinal involvement, we found that survival was not related to initial mediastinal involvement.

18-FDG-PET for the assessment of residual masses on CT following treatment of lymphomas

BACKGROUND

The problem of residual masses on post-treatment CT scans is a continuing dilemma for the oncologist treating malignant lymphomas. These masses may contain active disease or represent only necrotic tumour which continues to shrink without further treatment or post-treatment fibrosis which remains stable on continued follow-up. 18-FDG-PET offers a novel metabolic imaging modality, which can differentiate malignant from benign tissue on the basis of increased glycolytic activity.

PATIENTS AND METHODS

Thirty-two patients (15 with Hodgkin's disease (HD) and 17 with aggressive histology non-Hodgkin's lymphoma (NHL)) who had residual masses on their post-treatment CT scans underwent 18-FDG-PET. The post-treatment CT and PET scans were compared and the accuracy of the 18-FDG-PET in assessing residual masses was evaluated using clinical and pathological follow-up data.

RESULTS

Nine patients had positive post-treatment 18-FDG-PET, eight (89%) of whom have relapsed. Twenty-three patients had negative post-treatment PET with only two relapses in this group. The 2 patients who relapsed had aggressive NHL while none of the 11 HD patients with negative PET relapsed. The median follow-up of patients in continued complete remission is 38 months.

CONCLUSIONS

18-FDG-PET can differentiate between residual masses containing viable lymphoma where further treatment will be required to achieve cure and those representing ablated disease, where unnecessary treatment and additional morbidity may be avoided.

Detection of colorectal carcinoma by anti-CEA monoclonal antibody (IOR-CEA1) labeled with 99mTc scintigraphy

BACKGROUND/AIMS

This study shows that a new monoclonal antibody (IOR-CEA1) labeled with technetium-99m has high diagnostic efficacy for colorectal adenocarcinoma. This immunoscintigraphy is helpful in clinical management especially for patients whose serum carcinoembryonic antigen and computed tomography are questionable for recurrent diseases. The study aims to evaluate the efficiency of a new monoclonal antibody (IOR-CEA1) labeled with technetium-99m in the detection of colorectal carcinoma.

METHODOLOGY

Forty colorectal carcinoma patients were examined. They were divided into 2 groups: Group I (9 patients) with untreated primary tumor; and Group II (31 patients) who were suspected of recurrent or residual diseases from 1) equivocal computed tomography or magnetic resonance imaging, or 2) rising serum carcinoembryonic antigen but normal imaging or clinical findings. One milligram of the antibody labeled with 25mCi of technetium-99m was slowly infused intravenously and images were obtained by nuclear medicine techniques. Sensitivity, specificity, accuracy, positive and negative predictive values were determined.

RESULTS

99mTc-IOR-CEA1 had 86% sensitivity, 71% specificity, 83% accuracy, 94% positive predictive value and 50% negative predictive value for the detection of colorectal cancer in 42 studies (2 patients had repeated studies). Serum carcinoembryonic antigen had only 33% sensitivity for detection of the primary cancer and 58% sensitivity in detection of recurrent diseases. Carcinoembryonic antigen had 100% positive predictive value but only 31.3% negative predictive value for diagnosis of the recurrence of tumor. Fifty-two percent of the antibody scans provided more information than computed tomography scans with clinical impact on further management in group II patients.

CONCLUSIONS

The 99mTc-IOR-CEA1 scintigraphy is a promising investigative method which is safe and has high accuracy in the detection of recurrent colorectal carcinoma, especially in the patients whose serum carcinoembryonic antigen and computed tomography findings are equivocal for recurrent diseases.

Percutaneous microwave coagulation therapy for hepatocellular carcinoma located on the surface of the liver

OBJECTIVE

Percutaneous microwave coagulation therapy was recently introduced as a new treatment for hepatocellular carcinoma in our country. We performed this study to evaluate the efficacy and safety of this therapy for treatment of hepatocellular carcinoma, especially for tumors located on the surface of the liver.

CONCLUSION

Percutaneous microwave coagulation therapy can be performed safely even in patients with cirrhosis and can achieve complete remission of small hepatocellular carcinomas (< or = 2.0 cm) located on the surface of the liver.

Gallium-67 scintigraphy in the management: Hodgkin's disease and non-Hodgkin's lymphoma

Gallium scintigraphy has an important role in the management of patients with lymphoma. It contributes to patient management by detecting residual disease or relapse after treatment, monitoring response during therapy, and providing prognostic information.