A single case of rosai-dorfman disease marked by pathologic fractures, kidney failure, and liver cirrhosis treated with single-agent cladribine

Rosai–Dorfman disease (RDD) is a proliferative histiocytic disorder of unknown etiology, which is characterized by sinus histiocytosis with massive lymphadenopathy (1). In most cases, RDD has a benign course and treatment is not necessary. However, severe cases of RDD require treatment, and the treatment strategy is determined on the basis of the severity of the disease or the extranodal involvement of vital organs. We report a single case of RDD with atypical presentation of persistent constitutional symptoms, progressing pathologic fractures, and end-organ dysfunction, including acute kidney failure and liver cirrhosis with esophageal varices.

Positron emission tomography/computed tomography findings during therapy predict outcome in patients with diffuse large B-cell lymphoma treated with chemotherapy alone but not in those who receive consolidation radiation

PURPOSE

To assess the value of mid-therapy positron emission tomography (PET) findings for predicting survival and disease progression in patients with diffuse large B-cell lymphoma, considering type of therapy (chemotherapy with or without radiation therapy).

METHODS AND MATERIALS

We retrospectively evaluated 294 patients with histologically confirmed diffuse large B-cell lymphoma with respect to age, sex, disease stage, International Prognostic Index score, mid-therapy PET findings (positive or negative), and disease status after therapy and at last follow-up. Overall survival (OS) and progression-free survival (PFS) were compared according to mid-therapy PET findings.

RESULTS

Of the 294 patients, 163 (55%) were male, 144 (49%) were age >61 years, 110 (37%) had stage I or II disease, 219 (74%) had International Prognostic Index score ≤2, 216 (73%) received ≥6 cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone, and 88 (30%) received consolidation radiation therapy. Five-year PFS and OS rates were associated with mid-therapy PET status: PFS was 78% for those with PET-negative (PET-) disease versus 63% for PET-positive (PET+) disease (P=.024), and OS was 82% for PET- versus 62% for PET+ (P<.002). These associations held true for patients who received chemotherapy only (PFS 71% for PET- vs 52% PET+ [P=.012], OS 78% for PET- and 51% for PET+ [P=.0055]) but not for those who received consolidation radiation therapy (PFS 84% PET- vs 81% PET+ [P=.88]; OS 90% PET- vs 81% PET+ [P=.39]).

CONCLUSION

Mid-therapy PET can predict patient outcome, but the use of consolidation radiation therapy may negate the significance of mid-therapy findings.

Sentinel Lymph Node Biopsy for Patients With Early-Stage Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline Update

Purpose

To provide evidence-based recommendations to practicing oncologists, surgeons, and radiation therapy clinicians to update the 2005 clinical practice guideline on the use of sentinel node biopsy (SNB) for patients with early-stage breast cancer.

Methods

The American Society of Clinical Oncology convened an Update Committee of experts in medical oncology, pathology, radiation oncology, surgical oncology, guideline implementation, and advocacy. A systematic review of the literature was conducted from February 2004 to January 2013 in Medline. Guideline recommendations were based on the review of the evidence by Update Committee.

Results

This guideline update reflects changes in practice since the 2005 guideline. Nine randomized clinical trials (RCTs) met systematic review criteria for clinical questions 1 and 2; 13 cohort studies informed clinical question 3.

Recommendations

Women without sentinel lymph node (SLN) metastases should not receive axillary lymph node dissection (ALND). Women with one to two metastatic SLNs planning to undergo breast-conserving surgery with whole-breast radiotherapy should not undergo ALND (in most cases). Women with SLN metastases who will undergo mastectomy should be offered ALND. These three recommendation are based on RCTs. Women with operable breast cancer and multicentric tumors, with ductal carcinoma in situ (DCIS) who will undergo mastectomy, who previously underwent breast and/or axillary surgery, or who received preoperative/neoadjuvant systemic therapy may be offered SNB. Women who have large or locally advanced invasive breast cancer (tumor size T3/T4), inflammatory breast cancer, or DCIS (when breast-conserving surgery is planned) or are pregnant should not undergo SNB. These recommendations are based on cohort studies and/or informal consensus. In some cases, updated evidence was insufficient to update previous recommendations.

Multimodality therapy: bone-targeted radioisotope therapy of prostate cancer

Accumulating data suggest that bone-seeking radiopharmaceuticals can be used to treat prostate cancer bone metastasis and improve the clinical outcome of patients with advanced prostate cancer. It remains to be elucidated whether radiopharmaceuticals enhance the disruption of the onco-niche or the eradication of micrometastatic cells in the bone marrow. The purpose of this review is to investigate the role of bone-targeted radioisotope therapy in the setting of multimodality therapy for advanced prostate cancer. We examine available data and evaluate whether dose escalation, newer generations, or repeated dosing of radiopharmaceuticals enhance their antitumor effects and whether their combination with hormone ablative therapy, chemotherapy, or novel targeted therapy can improve clinical efficacy.

NCCN task force: clinical utility of PET in a variety of tumor types

Use of PET is widespread and increasing in the United States, mainly for oncologic applications. In November 2006, the National Comprehensive Cancer Network (NCCN) gathered a panel of experts to review the literature and develop clinical recommendations for using PET scans in lymphoma and non-small cell lung, breast, and colorectal cancers. However, because its use is not restricted to these diseases, and evidence is accumulating for its application in other types of cancers, NCCN convened a second meeting in December 2008 to expand on the initial report. A multidisciplinary panel met to discuss the current data on PET application for various tumor types, including genitourinary, gynecologic, pancreatic, hepatobiliary, thyroid, brain, small cell lung, gastric, and esophageal cancers, and sarcoma and myeloma. This report summarizes the proceedings of this meeting, including discussions of the background of PET, the role of PET in oncology, principles of PET use, emerging applications, and possible future developments.

Activity of dasatinib against L576P KIT mutant melanoma: molecular, cellular, and clinical correlates

Point mutations in the KIT receptor tyrosine kinase gene have recently been identified in mucosal, acral lentiginous, and chronically sun-damaged melanomas. We have identified the first human melanoma cell line with an endogenous L576P mutation, the most common KIT mutation in melanoma ( approximately 30-40%). In vitro testing showed that the cell viability of the L576P mutant cell line was not reduced by imatinib, nilotinib, or sorafenib small molecule KIT inhibitors effective in nonmelanoma cells with other KIT mutations. However, the viability of the mutant cells was reduced by dasatinib at concentrations as low as 10 nM (P = 0.004). Molecular modeling studies found that the L576P mutation induces structural changes in KIT that reduce the affinity for imatinib (DeltaDeltaGbind = -2.52 kcal/mol) but not for dasatinib (DeltaDeltaGbind = +0.32 kcal/mol). Two metastatic melanoma patients with the L576P KIT mutation were treated with dasatinib, including one patient previously treated with imatinib. Both patients had marked reduction (>50%) and elimination of tumor F18-fluorodeoxyglucose (FDG)-avidity by positron emission tomography (PET) imaging after dasatinib treatment. These data support the selective inhibitory effect of dasatinib against cells harboring the most common KIT mutation in melanoma, and thus has therapeutic implications for acrallentiginous, chronic sun-damaged, and mucosal melanomas.

PET/CT and Occult Primary Tumors

Within the past 5 years, F-18 fluorodeoxyglucose (FDG) PET/CT has become one of the more frequent imaging modalities in the management of patients with cancer of unknown primary origin. FDG PET/CT detects more sites of metastasis than other modalities, and in 20% to 40% of cases it discloses the site of the primary tumor. Its exact role is yet to be defined because of a lack of prospective clinical trials comparing the performance of PET/CT with conventional anatomic imaging modalities. This article reviews the available literature, attempts to place PET/CT using F-18–labeled FDG in clinical perspective and compares the combined modality with conventional anatomic imaging technologies.

PET and PET/CT in management of the lymphomas

Within recent years, F-18 fluorodeoxyglucose (FDG) PET has become the most important nuclear medicine and radiology imaging modality in the management of lymphoma. FDG-PET detects more disease sites and involved organs than conventional staging procedures, including CT, and has a large influence on staging. FDG-PET performed during and after therapy seems to provide considerable prognostic information. The impact on patient outcome is not clear, however, because no controlled trials have yet been conducted and follow-up periods are generally short.

Correlation of computed tomography and positron emission tomography in patients with metastatic gastrointestinal stromal tumor treated at a single institution with imatinib mesylate: proposal of new computed tomography response criteria

PURPOSE

Response Evaluation Criteria in Solid Tumors (RECIST) are insensitive in evaluating gastrointestinal stromal tumors (GISTs) treated with imatinib. This study evaluates whether computed tomography (CT) findings of GIST after imatinib treatment correlate with tumor responses by [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) and develops reliable, quantitative, CT response criteria.

PATIENTS AND METHODS

A total of 172 lesions selected by RECIST were evaluated in 40 patients with metastatic GISTs treated with imatinib. All patients had pretreatment and 2-month follow-up CTs and FDG-PETs. Multivariate analysis was performed using tumor size and density (Hounsfield unit [HU]) on CT and maximum standardized uptake value (SUVmax) on FDG-PET. Patients were observed up to 28 months.

RESULTS

Mean baseline tumor size and density on CT were 5.3 cm and 72.8 HU, respectively, and mean baseline SUVmax on FDG-PET was 5.8. Thirty-three patients had good response on FDG-PET. A decrease in tumor size of more than 10% or a decrease in tumor density of more than 15% on CT had a sensitivity of 97% and a specificity of 100% in identifying PET responders versus 52% and 100% by RECIST. Good responders on CT at 2 months had significantly longer time to progression than those who did not respond (P = .01).

CONCLUSION

Small changes in tumor size or density on CT are sensitive and specific methods of assessing the response of GISTs. If the prognostic value of our proposed CT response criteria can be confirmed prospectively, the criteria should be employed in future studies of patients with GIST.

We should desist using RECIST, at least in GIST

PURPOSE

Response Evaluation Criteria in Solid Tumors (RECIST) are insensitive in evaluating imatinib-treated gastrointestinal stromal tumors (GISTs). Response by Choi criteria, a 10% decrease in size or a 15% decrease in density on contrast-enhanced CT, correlated well in a small training set of patients who showed response as measured by positron emission tomography, and was more predictive of time to tumor progression (TTP) than response by RECIST. This study was designed to validate these observations in an independent data set.

PATIENTS AND METHODS

Fifty-eight patients with imatinib-treated GISTs were evaluated by RECIST and Choi criteria. TTP was compared with TTP in the training set. Patients were analyzed initially with follow-up to 28 months, extended to 60 months for survival analysis.

RESULTS

Patients who met Choi response criteria on CT at 2 months had significantly better TTP than those who did not (P = .0002), whereas response group by RECIST was not significantly correlated with TTP. Even when the 98 patients from both sets were analyzed together, the response group by RECIST did not correlate significantly with TTP, whereas response group by Choi criteria did correlate significantly with TTP. Disease-specific survival (DSS) was also significantly correlated with response group by Choi criteria (P = .04), but not with response group by RECIST.

CONCLUSION

Choi response criteria are reproducible, more sensitive, and more precise than RECIST in assessing the response of GISTs to imatinib mesylate. Response by Choi criteria, unlike response by RECIST, correlates significantly with TTP and DSS. Response by Choi criteria should be incorporated routinely into future studies of GIST therapy. We should desist using RECIST, at least in GIST.

NCCN task force report: positron emission tomography (PET)/computed tomography (CT) scanning in cancer

The use of positron emission tomography (PET) is increasing rapidly in the United States, with the most common use of PET scanning related to oncology. It is especially useful in the staging and management of lymphoma, lung cancer, and colorectal cancer, according to a panel of expert radiologists, surgeons, radiation oncologists, nuclear medicine physicians, medical oncologists, and general internists convened in November 2006 by the National Comprehensive Cancer Network. The Task Force was charged with reviewing existing data and developing clinical recommendations for the use of PET scans in the evaluation and management of breast cancer, colon cancer, non-small cell lung cancer, and lymphoma. This report summarizes the proceedings of this meeting, including discussions of the background of PET, possible future developments, and the role of PET in oncology.

NCCN Task Force Report: Positron Emission Tomography (PET)/Computed Tomography (CT) Scanning in Cancer

The use of positron emission tomography (PET) is increasing rapidly in the United States, with the most common use of PET scanning related to oncology. It is especially useful in the staging and management of lymphoma, lung cancer, and colorectal cancer, according to a panel of expert radiologists, surgeons, radiation oncologists, nuclear medicine physicians, medical oncologists, and general internists convened in November 2006 by the National Comprehensive Cancer Network. The Task Force was charged with reviewing existing data and developing clinical recommendations for the use of PET scans in the evaluation and management of breast cancer, colon cancer, non-small cell lung cancer, and lymphoma. This report summarizes the proceedings of this meeting, including discussions of the background of PET, possible future developments, and the role of PET in oncology. (JNCCN 2007;5(Suppl 1):S1–S22)

Incidental Findings on Integrated PET/CT That Do Not Accumulate18F-FDG

OBJECTIVE

The purpose of this study was to report the prevalence of abnormalities that do not show increased 18F-FDG uptake on the CT component of integrated PET/CT in patients with non-small cell lung cancer.

MATERIALS AND METHODS

Images from all PET/CT studies performed consecutively between April and October 2003 on patients with non-small cell lung cancer were retrospectively reviewed. All abnormalities present on the CT component of the PET/CT scans that did not show abnormally increased 18F-FDG uptake were documented.

RESULTS

Three hundred twenty-one patients with non-small cell lung cancer (179 men, 142 women; mean age, 67 years; age range, 38-91 years) underwent initial staging (198/321 [62%]) or restaging (123/321 [38%]) PET/CT imaging during the study period. In 263 (82%) of the patients, CT showed 1,231 abnormalities that were not 18F-FDG avid. The abnormalities were located in the thorax (n = 650), abdomen and pelvis (n = 444), head and neck (n = 69), and bony skeleton (n = 68). In total, 298 (24%) of the abnormalities that were not 18F-FDG avid were located outside the range of a standard thoracic CT scan. The clinical importance of these abnormalities was classified as major (n = 48 [4%]), moderate (n = 465 [38%]), or minor (n = 718 [58%]). Four (1%) of the patients had findings of major clinical importance that did not show increased 18F-FDG uptake and were previously unsuspected.

CONCLUSION

Among patients with non-small cell lung cancer undergoing PET/CT, there is a high prevalence of CT abnormalities that do not show correlative 18F-FDG avidity but that may be clinically important.

Interobserver and Intraobserver Variability of Standardized Uptake Value Measurements in Non–small-cell Lung Cancer

OBJECTIVES

To assess interobserver and intraobserver variabilities in measuring the maximal standardized uptake value (SUV) of non-small-cell lung cancer.

METHODS

Positron emission tomography-computed tomography examinations of 20 consecutive patients referred for initial evaluation of newly diagnosed non-small-cell lung cancer were retrospectively reviewed by 5 experienced positron emission tomography-computed tomography readers, who independently measured the maximal SUV/body weight of the primary tumors. Interobserver and intraobserver variabilities were assessed by using 4 statistical methods: correlation, regression analysis, Bland-Altman analysis, and analysis of variance. The SUV measurements derived in the study were compared with the SUV measurements documented in the original reports using correlation and regression analysis. The percentages of tumors whose retrospective SUV measurements were more than 20% different and more than 25% different from those in the original report were assessed.

RESULTS

Both interobserver and intraobserver SUV measurements were highly reproducible. Pearson correlation coefficients were greater than 0.95 and 0.94, respectively. Good interobserver and intraobserver agreement was shown with regression analysis (F test P value >0.05), the Bland-Altman analysis, and analysis of variance (F test P value >0.95). The mean original SUV was much less than the mean study SUV (P<0.05). The study SUV differed from the SUV of the original report by more than 20% in 50% of the tumors, and by more than 25% in 45% of the tumors.

CONCLUSIONS

There was excellent interobserver and intraobserver agreement in SUVs measured in the study environment but poor agreement between study SUVs and those documented in original reports, which can affect treatment decisions substantially.

Truncation artifact on PET/CT: impact on measurements of activity concentration and assessment of a correction algorithm

OBJECTIVE

Discrepancy between fields of view (FOVs) in a PET/CT scanner causes a truncation artifact when imaging extends beyond the CT FOV. The purposes of this study were to evaluate the impact of this artifact on measurements of 18F-FDG activity concentrations and to assess a truncation correction algorithm.

MATERIALS AND METHODS

Two phantoms and five patients were used in this study. In the first phantom, three inserts (water, air, bone equivalent) were placed in a water-filled cylinder containing 18F-FDG. In the second phantom study, a chest phantom and a 2-L bottle fitted with a bone insert were used to simulate a patient's torso and arm. Both phantoms were imaged while positioned centrally (baseline) and at the edge of the CT FOV to induce truncation. PET images were reconstructed using attenuation maps from truncated and truncation-corrected CT images. Regions of interest (ROIs) drawn on the inserts, simulated arm, and background water of the baseline truncated and truncation-corrected PET images were compared. In addition, extremity malignancies of five patients truncated on CT images were reconstructed with and without correction and the maximum standard uptake values (SUVs) of the malignancies were compared.

RESULTS

Truncation artifact manifests as a rim of high activity concentration at the edge of the truncated CT image with an adjacent low-concentration region peripherally. The correction algorithm minimizes these effects. Phantom studies showed a maximum variation of -5.4% in the truncation-corrected background water image compared with the baseline image. Activity concentration in the water insert was 6.3% higher while that of air and bone inserts was similar to baseline. Extremity malignancies showed a consistent increase in the maximum SUV after truncation correction.

CONCLUSION

Truncation affects measurements of 18F-FDG activity concentrations in PET/CT. A truncation-correction algorithm corrects truncation artifacts with small residual error.

Lymphomatous involvement of gastrointestinal tract: evaluation by positron emission tomography with (18)F-fluorodeoxyglucose

AIM

To demonstrate the (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) findings in patients with non-Hodgkinos lymphoma (NHL) involving the gastrointestinal (GI) tract and the clinical utility of modality despite of the known normal uptake of FDG in the GI tract.

METHODS

Thirty-three patients with biopsy-proven gastrointestinal NHL who had undergone FDG-PET scan were included. All the patients were injected with 10-15 mCi FDG and scanned approximately 60 min later with a CTI/Siemens HR (+) PET scanner. PET scans were reviewed and the maximum standard uptake value (SUV(max)) of the lesions was measured before and after the treatment, if data were available and compared with histologic diagnoses.

RESULTS

Twenty-five patients had a high-grade lymphoma and eight had a low-grade lymphoma. The stomach was the most common site of the involvement (20 patients). In high-grade lymphoma, PET showed focal nodular or diffuse hypermetabolic activity. The average SUV(max)+/-SD was 11.58+/-5.83. After the therapy, the patients whose biopsies showed no evidence of lymphoma had a lower uptake without focal lesions. The SUV(max)+/-SD decreased from 11.58+/-5.83 to 2.21+/-0.78. In patients whose post-treatment biopsies showed lymphoma, the SUV(max)+/-SD was 9.42+/-6.27. Low-grade follicular lymphomas of the colon and stomach showed diffuse hypermetabolic activity in the bowel wall (SUV(max) 8.2 and 10.3, respectively). The SUV(max) was 2.02-3.8 (mean 3.02) in the stomach lesions of patients with MALT lymphoma. ONCLUSION: (18)F-FDG PET contributes to the diagnosis of high-grade gastrointestinal non-Hodgkin's lymphoma, even when there is the normal background FDG activity. Furthermore, the SUV plays a role in evaluating treatment response. Low-grade NHL demonstrates FDG uptake but at a lesser intensity than seen in high-grade NHL.

Quantifying the Effect of IV Contrast Media on Integrated PET/CT: Clinical Evaluation

OBJECTIVES

The use of IV contrast media in PET/CT can result in an overestimation of PET attenuation factors that potentially can affect interpretation. The objective of this study was to quantify the effect of IV contrast media in PET/CT and assess its impact on patients with intrathoracic malignancies.

MATERIALS AND METHODS

Nine patients had CTs performed with and without IV contrast media followed by (18)F-FDG PET. PET images were reconstructed using contrast-enhanced and unenhanced CT. To quantify the effect of contrast media on standardized uptake values (SUV), similar regions of interest (ROIs) were drawn on the subclavian vein, heart, liver, spleen, and site of malignancy on both CT and corresponding reconstructed PET images, and the mean and maximum values were compared. In addition, two physicians blinded to the imaging parameters that were used evaluated the reconstructed PET images to assess whether IV contrast media had an effect on clinical interpretation.

RESULTS

For all patient studies, the subclavian vein region on the ipsilateral side of contrast media administration had the highest increase in CT numbers with a corresponding average SUV(max) increase of 27.1%. Similarly, ROIs of the heart and at the site of malignancy showed an increase in the maximum attenuation value with a corresponding average SUV(max) increase of 16.7% and 8.4%, respectively. Other locations had relatively small attenuation value differences with a correspondingly negligible SUV variation.

CONCLUSION

Although there is a significant increase in SUV in regions of high-contrast concentration when contrast-enhanced CT is used for attenuation correction, this increase is clinically insignificant. Accordingly, in PET/CT, IV contrast-enhanced CT can be used in combination with the PET to evaluate patients with cancer.

Therapy Tolerance in Selected Patients With Androgen-Independent Prostate Cancer Following Strontium-89 Combined With Chemotherapy

Purpose

Clinicians may have reservations about using strontium-89 for the treatment of bone metastases because of concerns that it may limit future use of chemotherapy. We assessed the rate of bone marrow failure in patients with prostate cancer who had received a dose of strontium-89.

Patients and Methods

This subgroup analysis involved 34 patients with androgen-independent prostate cancer who had been given a dose of strontium-89 and six weekly doses of doxorubicin after response to induction chemotherapy. We assessed subsequent hematotoxicity in terms of bone marrow failure and the ability to tolerate additional treatments during a median of 25 months (range, 7 to 76 months) after the strontium-89 was administered.

Results

No patients developed bone marrow failure within 6 months of receiving strontium-89. Five (15%) of 34 patients developed bone marrow failure at a median 23 months (range, 6 to 53 months) after the strontium-89 treatment. Bone marrow biopsy performed in two of these five patients showed complete replacement of the marrow by tumor. Thirty-one patients (91%) received subsequent cytotoxic treatments at a median 11 months (range, 1 to 33 months) after the strontium-89 treatment.

Conclusion

This analysis demonstrated that a single dose of strontium-89 combined with chemotherapy did not affect the delivery of subsequent courses of chemotherapy in a select group of patients. However, a majority of these therapies were given off protocol and were administered at a dose schedule that might be considered inappropriate or inadequate. The clinical role and safety profile of radiopharmaceuticals combined with chemotherapy in prostate cancer therapy deserve further exploration.

American Society of Clinical Oncology guideline recommendations for sentinel lymph node biopsy in early-stage breast cancer

PURPOSE

To develop a guideline for the use of sentinel node biopsy (SNB) in early stage breast cancer.

METHODS

An American Society of Clinical Oncology (ASCO) Expert Panel conducted a systematic review of the literature available through February 2004 on the use of SNB in early-stage breast cancer. The panel developed a guideline for clinicians and patients regarding the appropriate use of a sentinel lymph node identification and sampling procedure from hereon referred to as SNB. The guideline was reviewed by selected experts in the field and the ASCO Health Services Committee and was approved by the ASCO Board of Directors.

RESULTS

The literature review identified one published prospective randomized controlled trial in which SNB was compared with axillary lymph node dissection (ALND), four limited meta-analyses, and 69 published single-institution and multicenter trials in which the test performance of SNB was evaluated with respect to the results of ALND (completion axillary dissection). There are currently no data on the effect of SLN biopsy on long-term survival of patients with breast cancer. However, a review of the available evidence demonstrates that, when performed by experienced clinicians, SNB appears to be a safe and acceptably accurate method for identifying early-stage breast cancer without involvement of the axillary lymph nodes.

CONCLUSION

SNB is an appropriate initial alternative to routine staging ALND for patients with early-stage breast cancer with clinically negative axillary nodes. Completion ALND remains standard treatment for patients with axillary metastases identified on SNB. Appropriately identified patients with negative results of SNB, when done under the direction of an experienced surgeon, need not have completion ALND. Isolated cancer cells detected by pathologic examination of the SLN with use of specialized techniques are currently of unknown clinical significance. Although such specialized techniques are often used, they are not a required part of SLN evaluation for breast cancer at this time. Data suggest that SNB is associated with less morbidity than ALND, but the comparative effects of these two approaches on tumor recurrence or patient survival are unknown.

Effect of colony-stimulating factor and conventional- or high-dose chemotherapy on FDG uptake in bone marrow

PURPOSE

Granulocyte or granulocyte-macrophage colony stimulating factor (CSF), usually used in conjunction with chemotherapy, may interfere with the( 18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) reading. The purpose of this study is to evaluate the effects of CSF, conventional-or high-dose chemotherapy on bone marrow FDG uptake.

METHODS

Two hundred and forty-one FDG PET scans obtained in 163 patients with lymphoma and no pathologically and radiologically proven bone marrow involvement were analyzed. The standardized uptake value (SUV) of each patient's spine was measured.

RESULTS

Among patients with no recent history of CSF use, the average SUV in 36 patients with no history of chemotherapy was 1.60+/-0.34, that in 49 patients with a history of conventional-dose chemotherapy was 1.37+/-0.32, and that in 12 patients with a history of high-dose chemotherapy was 1.26+/-0.25 (P=0.008 and 0.002, respectively by Mann-Whitney U test). In 80 patients treated with conventional-dose chemotherapy and CSF, the average SUV after discontinuation of CSF was as follows: 0-7 days, 2.37+/-1.19; 8-14 days: 2.04+/-0.67; 15-21 days: 1.87+/-0.52; 22-30 days: 1.59+/-0.18; 31-90 days: 1.54+/-0.36. In 45 patients treated with high-dose chemotherapy and CSF, no significant increase in bone marrow uptake was seen in most of them.

CONCLUSION

Bone marrow FDG uptake may be increased by CSF treatment and may be decreased by chemotherapy. In patients treated with conventional-dose chemotherapy and CSF, increased marrow uptake will return to the pretreatment value approximately 1 month after discontinuation of CSF.

Integrated computed tomography-positron emission tomography in patients with potentially resectable malignant pleural mesothelioma: Staging implications

BACKGROUND

Integrated computed tomography-positron emission tomography imaging with coregistration of anatomic and functional imaging data may improve the accuracy of malignant pleural mesothelioma staging. We evaluate the use of integrated computed tomography-positron emission tomography in patients with malignant pleural mesothelioma who are being considered for extrapleural pneumonectomy.

METHODS

Twenty-nine patients with malignant pleural mesothelioma who were judged to be candidates for extrapleural pneumonectomy after clinical and conventional radiologic evaluation underwent whole-body integrated computed tomography-positron emission tomography and pathologic staging. Two reviewers blinded to the results of clinical and pathologic staging retrospectively evaluated computed tomography, positron emission tomography, and coregistered computed tomography-positron emission tomography images. Staging was performed according to the International Mesothelioma Interest Group TNM staging system. Histopathology and/or results of further radiologic evaluation or follow-up served as the reference standard.

RESULTS

Integrated computed tomography-positron emission tomography provided additional information in 11 of 29 patients that precluded extrapleural pneumonectomy. The overall tumor stage was correctly classified in 21 of 29 patients. The tumor stage was correctly determined in 15 of 24 patients, 6 of whom had T4 (nonresectable) disease. The node stage was accurately determined in 6 of 17 patients. Extrathoracic metastases not identified by routine clinical and conventional radiologic evaluation were detected in 7 of 29 patients and were found to be diffuse (n = 2) or solitary (n = 5).

CONCLUSIONS

Integrated computed tomography-positron emission tomography increases the accuracy of malignant pleural mesothelioma staging and is important in determining the appropriate therapy in patients being considered for extrapleural pneumonectomy.

Focal Uptake of Fluorodeoxyglucose by the Thyroid in Patients Undergoing Initial Disease Staging with Combined PET/CT for Non–Small Cell Lung Cancer

PURPOSE

To retrospectively evaluate the prevalence of focal fluorodeoxyglucose (FDG) uptake by the thyroid gland on combined positron emission tomographic (PET) and computed tomographic (CT) scans in patients undergoing staging of newly diagnosed non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Institutional review board approval was obtained, informed consent was waived, and the study was Health Insurance Portability and Accountability Act-compliant. Whole-body PET/CT scans and medical records of 140 consecutive patients with newly diagnosed NSCLC (80 men, 60 women; mean age, 66 years; range, 39-89 years) were retrospectively reviewed by two experienced PET/CT scan readers. Maximum standardized uptake value (SUV) was calculated for FDG-avid thyroid foci. Corresponding thyroid CT findings were recorded in patients with focal increased FDG thyroid uptake.

RESULTS

PET results showed that six patients (4.3%) had seven foci of increased FDG uptake in the thyroid. Five of the seven foci (in four patients) corresponded to a low-attenuation thyroid lesion on the non-enhanced CT scan. Lesions ranged in diameter from 0.8 to 2.5 cm. Four of the lesions were found to be papillary thyroid cancers at fine-needle aspiration biopsy. The fifth lesion was found to be benign at thyroidectomy. The remaining two patients did not have histologic confirmation of their thyroid lesion because no specific biopsy site was visualized on CT or sonographic images and lesions were considered benign. Maximum SUV of the thyroid cancers ranged from 3.0 to 32.9 (mean, 13.7). Maximum SUV of benign thyroid lesions ranged from 4.6 to 6.2 (mean, 5.4).

CONCLUSION

Focal thyroid FDG uptake found during the initial staging of NSCLC at PET/CT indicates a high likelihood of primary thyroid cancer.

CT evaluation of the response of gastrointestinal stromal tumors after imatinib mesylate treatment: a quantitative analysis correlated with FDG PET findings

OBJECTIVE

We correlated changes in tumor density on CT with changes in glucose metabolism, or the maximum standardized uptake value (SUV(max)), on FDG PET and sought to develop CT imaging criteria that can be used to objectively evaluate tumor response in patients with metastatic gastrointestinal stromal tumors (GISTs) who undergo treatment with imatinib mesylate.

MATERIALS AND METHODS

Using the criteria established by the Response Evaluation Criteria in Solid Tumors (RECIST) group, we selected 173 tumors (in 36 patients) for study. Tumor size and density were determined objectively, and overall tumor response (OTR) was evaluated subjectively on CT images. The changes in these parameters before and after treatment were correlated with changes in SUV(max).

RESULTS

Significant decreases were seen in both tumor density (mean, 12.3 H [16.5%]; p < 0.0001) and SUV(max) (mean, 3.43 [64.9%]; p < 0.0001). OTR evaluated subjectively, correlated well with changes in SUV(max) (p < 0.0001). No statistically significant association was found between changes in tumor density and changes in SUV(max) (p = 0.3088), but 70% (14/20) of the patients with tumors that showed response on FDG PET exhibited at least a partial response by a change in tumor density. Tumor size was found to have decreased significantly 2 months after treatment (p = 0.0070). However, in 75% of the patients, the disease was stable according to the traditional tumor response criteria of RECIST.

CONCLUSION

FDG PET is sensitive and specific for evaluating tumor response but cannot be used in patients whose baseline FDG PET results are negative for tumors. Although subjective evaluation was a better indicator of treatment response than was tumor density alone, the tumor density measurement is a good indicator and provides a reliable quantitative means of monitoring the tumor. RECIST, using only tumor size, was unreliable for monitoring GISTs during the early stage of imatinib mesylate treatment.

[18F]fluorodeoxyglucose uptake by positron emission tomography predicts outcome of non-small-cell lung cancer

PURPOSE

To determine whether the standardized uptake value (SUV) of [(18)F]fluorodeoxyglucose uptake by positron emission tomography could be a prognostic factor for non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

One hundred sixty-two patients with stage I to IIIb NSCLC were analyzed. Overall survival (OS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and local-regional control (LRC) were calculated by the Kaplan-Meier method and evaluated with the log-rank test. The prognostic significance was assessed by univariate and multivariate analyses.

RESULTS

There were 93 patients treated with surgery and 69 patients treated with radiotherapy. A cutoff of 5 for the SUV for the primary tumor showed the best discriminative value. The SUV for the primary tumor was a significant predictor of OS (P = .02) in both groups. Low SUVs (</= 5.0) showed significantly better DFS rates than those with high SUVs (> 5.0; surgery group, P = .02; radiotherapy group, P = .0005). Low SUVs (</= 5.0) indicated a significantly better DFS than those with high SUVs (> 5.0; stage I or II, P = .02; stage IIIa or IIIb, P = .004). However, using the same cutoff point of 5, the SUV for regional lymph nodes was not a significant indicator for DFS (P = .19), LRC (P = .97), or DMFS (P = .17). The multivariate analysis showed that the SUV for the primary tumor was a significant prognostic factor for OS (P = .03) and DFS (P = .001).

CONCLUSION

The SUV of the primary tumor was the strongest prognostic factor among the patients treated by curative surgery or radiotherapy.

The value of 99mTc-sestamibi SPECT/CT over conventional SPECT in the evaluation of parathyroid adenomas or hyperplasia

As SPECT/CT technology evolves, its applications and indications need to be evaluated clinically for more efficient and cost-effective use. This retrospective study evaluated the clinical value of simultaneously acquired (99m)Tc-sestamibi SPECT/CT versus conventional SPECT in diagnosing and locating parathyroid adenomas or hyperplasia in patients with primary hyperparathyroidism.

METHODS

Immediately and 60 minutes after intravenous administration of 740-925 MBq of (99m)Tc-sestamibi, static planar images of the neck and chest were obtained. SPECT/CT images were acquired 30 minutes after injection. Two experienced masked readers independently evaluated whether conventional SPECT images provided information beyond what was available from the planar images either by changing the diagnosis or by better locating the glands and whether the SPECT/CT images provided information beyond what was available from the planar plus conventional SPECT images. Forty-eight consecutive patients with a clinical diagnosis of primary hyperparathyroidism were included in the study. The 32 whose scans showed positive results underwent surgical resection and were examined histopathologically.

RESULTS

Planar and SPECT imaging, with or without CT fusion, identified 89% of the surgically confirmed diseased parathyroid glands. Use of SPECT/CT changed the diagnosis in only 1 patient (2%) from positive to negative and better located the glands in only 4 patients (8%). SPECT/CT was particularly helpful in locating the 2 ectopic parathyroid adenomas diagnosed in this cohort. Tracer retention in diseased glands did not correlate with histologic characteristics. Also, biochemical markers did not correlate with the scan findings.

CONCLUSION

SPECT/CT has no significant clinical value additional to that of conventional SPECT for parathyroid imaging except in locating ectopic parathyroid glands. Eliminating the CT acquisition will spare patients the additional time, radiation exposure, and expense.

Radiation dosimetry of 99mTc-labeled C225 in patients with squamous cell carcinoma of the head and neck

This study assessed the radiation dosimetry of 99mTc-labeled ethylene dicysteine (EC) C225 (EC-C225), a promising radioligand for functional tumor imaging.

METHODS

Whole-body scanning was performed on 6 patients with head and neck squamous cell carcinoma up to 24 h after administration of 99mTc-EC-C225. Alternate patients who had been randomized to receive C225 in a phase III trial received 99mTc-EC-C225 before their 20-mg test dose or after their 400 mg/m2 loading dose of unlabeled C225 (patients 1/3/5 and 2/4/6, respectively). Radiation dosimetry was assessed using the MIRD method.

RESULTS

The critical organ was the kidney, with an average radiation-absorbed dose for all 6 patients of 0.0274 mGy/MBq. The average total-body absorbed dose was 0.0022 mGy/MBq (0.243 cGy/1,110 MBq).

CONCLUSION

The new radiopharmaceutical 99mTc-EC-C225 appears to have reasonable dosimetric properties for a diagnostic nuclear medicine agent. Correlation of the imaging results with clinical findings is the next step.

Performance characteristics of a newly developed PET/CT scanner using NEMA standards in 2D and 3D modes

This study evaluates the 2-dimensional (2D) and 3-dimensional (3D) performance characteristics of a newly developed PET/CT scanner using the National Electrical Manufacturers Association (NEMA) NU 2-1994 (NU94) and NEMA NU 2-2001 (NU01) standards. The PET detector array consists of 10,080 individual bismuth germanate crystals arranged in 24 rings of 420 crystals each. The size of each crystal is 6.3 x 6.3 x 30 mm in the axial, transaxial, and radial dimensions, respectively. The PET detector ring diameter is 88.6 cm with axial and transaxial fields of view (FOVs) of 15.7 and 70 cm, respectively. The scanner has a uniform patient port of 70 cm throughout the PET and CT FOV, and the PET scanner is equipped with retractable septa to allow 2D and 3D imaging.

METHODS

Spatial resolution, scatter fraction, sensitivity, counting rate, image quality, and accuracy as defined by the NEMA protocols of NU94 and NU01 for 2D and 3D modes are evaluated. The 2D mode data were acquired with a maximum ring difference of 5, whereas the 3D mode acquisition used ring differences of 23. Both 2D and 3D mode data were acquired with an energy window of 375-650 keV. Random estimation from singles counting rate was applied to all relevant analysis. In addition, images from 2 clinical whole-body oncology studies acquired in 2D and 3D modes are shown to demonstrate the image quality obtained from this scanner.

RESULTS

The 2D NU94 transaxial resolution is 6.1-mm full width at half maximum (FWHM) 1 cm off center and increases to 6.9 mm tangential and 8.1 mm radial at a radius (R) of 20 cm. NU01 2D average transaxial (axial) FWHM resolution measured 6.1 (5.2) mm at R = 1 cm and 6.7 (6.1) mm at R = 10 cm. The NU94 scatter fraction for 2D (3D) was 13% (29%), whereas the NU01 scatter fraction gave 19% (45%). NU01 peak 2D (3D) noise equivalent counting rate (T(2)/[T + R + S]) was 90.2 (67.8) kilocount per second (kcps) at 52.5 (12) kBq/mL. Total 2D (3D) system sensitivity for true events is 8 (32.9) kcps/kBq/mL for NU94 and 1.95 (9.2) kcps/Bq for NU01.

CONCLUSION

The results show excellent system sensitivity with relatively uniform resolution throughout the FOV, making this scanner highly suitable for whole-body studies.

Bone imaging in metastatic breast cancer

Bone is the most common site to which breast cancer metastasizes. Imaging-by skeletal scintigraphy, plain radiography, computed tomography, or magnetic resonance imaging-is an essential part, and positron emission tomography or single-photon emission computed tomography have a potential of evaluating bone metastases, but no consensus exists as to the best modality for diagnosing the lesion and for assessing its response to treatment. Imaging bone metastases is problematic because the lesions can be osteolytic, osteoblastic, or mixed, and imaging modalities are based on either direct anatomic visualization of the bone or tumor or indirect measurements of bone or tumor metabolism. Although bone metastases can be treated, their response to treatment is considered "unmeasurable" according to existing response criteria. Therefore, the process by which oncologists and radiologists diagnose and monitor the response of bone metastases needs revision, and the current inability to assess the response of bone metastases excludes patients with breast cancer and bone disease from participating in clinical trials of new treatments for breast cancer. In this review of the MEDLINE literature, we discuss the pros and cons of each modality for diagnosing bone metastases and for assessing their response to treatment and we present a practical approach for diagnosis and assessment of bone metastasis.

Assessment of cyclooxygense-2 expression with 99mTc-labeled celebrex

Cyclooxygenase-2 (COX-2) plays an important role in angiogenesis and cancer progression. Since many tumor cells exhibit COX-2 expression, functional imaging of COX-2 expression using celebrex (CBX, a COX-2 inhibitor) may provide not only a non-invasive, reproducible, quantifiable alternative to biopsies, but it also greatly complements pharmacokinetic studies by correlating clinical responses with biological effects. Moreover, molecular endpoints of anti-COX-2 therapy could also be assessed effectively. This study aimed at measuring uptake of Tc-EC-CBX in COX-2 expression in tumor-bearing animal models. In vitro Western blot analysis and cellular uptake assays were used to examine the feasibility of using Tc-EC-CBX to measure COX-2 activity. Tissue distribution studies of Tc-EC-CBX were evaluated in tumor-bearing rodents at 0.5-4 h. Dosimetric absorption was then estimated. Planar scintigraphy was performed in mice, rats and rabbits bearing tumors. In vitro cellular uptake indicated that cells with higher COX-2 expression (A549 and 13762) had higher uptake of Tc-EC-CBX than lower COX-2 expression (H226). In vivo biodistribution of Tc-EC-CBX in tumor-bearing rodents showed increased tumor:tissue ratios as a function of time. In vitro and biodistribution studies demonstrated the possibility of using Tc-EC-CBX to assess COX-2 expression. Planar images confirmed that the tumors could be visualized with Tc-EC-CBX from 0.5 to 4 h in tumor-bearing animal models. We conclude that Tc-EC-CBX may be useful to assess tumor COX-2 expression. This may be useful in the future for selecting patients for treatment with anti-COX-2 agents.

Imaging taxane-induced tumor apoptosis using PEGylated, 111In-labeled annexin V

99mTc-Labeled annexin V has been used for the imaging of tumor apoptosis induced by chemotherapy. However, owing to the short half-life of annexin V, multiple injections of the radiotracer are necessary to capture the peak apoptotic activity. In this study, we evaluated the imaging properties of an (111)In-labeled, long-circulating annexin V.

METHODS

Both polyethylene glycol (PEG) and the metal chelator diethylenetriaminepentaacetic acid (DTPA) were simultaneously introduced to annexin V or ovalbumin through the use of a heterofunctional PEG precursor. Imaging studies were performed in mice bearing subcutaneously inoculated human mammary MDA-MB-468 tumors. The mice were treated with poly(L-glutamic acid)-paclitaxel, monoclonal antibody C225, or a combination of poly(L-glutamic acid)-paclitaxel and C225, followed by intravenous injection of (111)In-DTPA-PEG-annexin V. Images were acquired 48 h after the injection of the radiotracer. Autoradiography and TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling) staining were performed on adjacent tumor slices for the localization of apoptotic cells. The imaging properties of unPEGylated annexin V and PEGylated ovalbumin were also determined to permit assessment of the specificity of (111)In-DTPA-PEG-annexin V.

RESULTS

Tumor apoptotic index increased from 1.67% +/- 0.31% at baseline to 7.60% +/- 0.72% and 11.07% +/- 1.81%, respectively, 4 d after treatment with poly(L-glutamic acid)-paclitaxel or combined poly(L-glutamic acid)-paclitaxel and C225. Tumor uptake (percentage of injected dose per gram of tumor [%ID/g]) of PEGylated (111)In-DTPA-PEG-annexin 4 d after treatment was significantly higher in tumors treated with poly(L-glutamic acid)-paclitaxel (10.76 +/- 1.38 %ID/g; P = 0.001) and with combined poly(L-glutamic acid)-paclitaxel and C225 (9.84 +/- 2.51 %ID/g; P = 0.029) than in nontreated tumors (6.14 +/- 0.67 %ID/g), resulting in enhanced visualization of treated tumors. (111)In-DTPA-PEG-annexin V distributed into the central zone of tumors, whereas (111)In-DTPA-annexin V was largely confined to the tumor periphery. Furthermore, uptake of (111)In-DTPA-PEG-annexin V by tumors correlated with apoptotic index (r = 0.87, P = 0.02). Increase in tumor uptake of the nonspecific PEGylated protein (111)In-DTPA-PEG-ovalbumin was also observed after poly(L-glutamic acid)-paclitaxel treatment (55.6%), although this increase was less than that observed for (111)In-DTPA-PEG-annexin V (96.7%).

CONCLUSION

Increased uptake of and improved visualization with (111)In-DTPA-PEG-annexin V in solid tumors after chemotherapy are mediated through both specific binding to apoptotic cells and nonspecific retention of macromolecular contrast agents in the tumors. (111)In-Labeled, PEGylated annexin V may be used to assess tumor response to chemotherapy.

Evaluation of 111In-DTPA-folate as a receptor-targeted diagnostic agent for ovarian cancer: initial clinical results

The cell-membrane folate receptor is a potential molecular target for tumor-selective drug delivery, including radiolabeled folate-chelate conjugates for diagnostic imaging. We report here the initial clinical study of such an agent, (111)In-diethylenetriaminepentaacetic acid (DTPA)-folate, evaluated for diagnosis of ovarian malignancy.

METHODS

Thirty-five women were enrolled in a phase I/II clinical study, with 33 completing the surgical follow-up required by the study protocol for definition of disease status. Patients either had a pathologically proven malignancy or were scheduled for surgery for suspected new ovarian cancer (n = 26), recurrent ovarian cancer (n = 5), or endometrial cancer (n = 2). (111)In-DTPA-folate was administered as an intravenous bolus, and whole-body images were obtained at 30 min, 4 h, and (for the first 19 patients) 24 h after injection; SPECT also was done at the delayed imaging times. For 19 of the patients, unlabeled free folic acid was injected before administration of (111)In-DTPA-folate to also assess the impact of folate loading on tracer biodistribution. Masked and unmasked readings of the images by 2 nuclear medicine physicians were compared with the pathologic findings after surgery.

RESULTS

Among 33 patients who had surgical intervention, 14 had new or recurrent malignant tumors. All of 7 newly diagnosed ovarian carcinomas were identified by both masked readers (sensitivity, 100%). The sensitivity for detection of 7 recurrent malignancies was 38% for masked readings and 85% for unmasked readings, indicating that correlation with anatomic imaging studies (CT) was highly important in diagnosis of these lesions. Eighteen of the studied patients were found to have benign masses; for this limited population, the specificity of (111)In-DTPA-folate scintigraphy was 76% and 82% for the masked and unmasked analyses, respectively.

CONCLUSION

(111)In-DTPA-folate is safe, and possibly effective, for scintigraphy differentiating between malignant and benign ovarian masses.

Radiation dosimetry results from a Phase II trial of ibritumomab tiuxetan (Zevalin) radioimmunotherapy for patients with non-Hodgkin's lymphoma and mild thrombocytopenia

This was a 30-patient Phase II trial of reduced-dose (90)Y ibritumomab tiuxetan (Zevalin) RIT for patients with low-grade, follicular, or transformed B-cell NHL and mild thrombocytopenia. Patients were given an imaging dose of (111)In-labeled ibritumomab tiuxetan for dosimetry measurements. One week later, patients were administered a therapeutic dose of 0.3 mCi/kg (11 MBq/kg) (90)Y ibritumomab tiuxetan. Both (111)In- and (90)Y-labeled ibritumomab tiuxetan doses were preceded by an infusion of 250 mg/m(2) rituximab (Rituxan, MabThera) an unlabeled chimeric anti-CD20 antibody, to clear peripheral blood B cells and improve biodistribution of the radiolabeled antibody. For all 30 patients, normal organ and red marrow radiation absorbed doses were well below protocol-defined limits of 2000 cGy and 300 cGy, respectively. Median radiation absorbed doses were 48 cGy to red marrow (range: 6.5-95 cGy), 393 cGy to liver (range: 92-1581 cGy), 522 cGy to spleen (range: 165-1711 cGy), 162 cGy to lungs (41-295 cGy), and 14 cGy to kidneys (0.03-65 cGy). Though most correlative analyses were negative, certain analyses demonstrated a statistically significant correlation between the severity or duration of thrombocytopenia and pharmacokinetic or dosimetric parameters. These correlations were not consistent across the total patient population, and therefore, could not be exploited to predict hematologic toxicity.

Radiation dosimetry results and safety correlations from 90Y-ibritumomab tiuxetan radioimmunotherapy for relapsed or refractory non-Hodgkin's lymphoma: combined data from 4 clinical trials

Ibritumomab tiuxetan is an anti-CD20 murine IgG1 kappa monoclonal antibody (ibritumomab) conjugated to the linker-chelator tiuxetan, which securely chelates (111)In for imaging or dosimetry and (90)Y for radioimmunotherapy (RIT). Dosimetry and pharmacokinetic data from 4 clinical trials of (90)Y-ibritumomab tiuxetan RIT for relapsed or refractory B-cell non-Hodgkin's lymphoma (NHL) were combined and assessed for correlations with toxicity data.

METHODS

Data from 179 patients were available for analysis. Common eligibility criteria included <25% bone marrow involvement by NHL, no prior myeloablative therapy, and no prior RIT. The baseline platelet count was required to be > or = 100,000 cells/mm(3) for the reduced (90)Y-ibritumomab tiuxetan administered dose (7.4-11 MBq/kg [0.2-0.3 mCi/kg]) or > or = 150,000 cells/mm(3) for the standard (90)Y-ibritumomab tiuxetan administered dose (15 MBq/kg [0.4 mCi/kg]). Patients were given a tracer administered dose of 185 MBq (5 mCi) (111)In-ibritumomab tiuxetan on day 0, evaluated with dosimetry, and then a therapeutic administered dose of 7.4-15 MBq/kg (0.2-0.4 mCi/kg) (90)Y-ibritumomab tiuxetan on day 7. Both ibritumomab tiuxetan administered doses were preceded by an infusion of 250 mg/m(2) rituximab to clear peripheral B-cells and improve ibritumomab tiuxetan biodistribution. Residence times for (90)Y in blood and major organs were estimated from (111)In biodistribution, and the MIRDOSE3 computer software program was used, with modifications to account for patient-specific organ masses, to calculate radiation absorbed doses to organs and red marrow.

RESULTS

Median radiation absorbed doses for (90)Y were 7.42 Gy to spleen, 4.50 Gy to liver, 2.11 Gy to lung, 0.23 Gy to kidney, 0.62 Gy (blood-derived method) and 0.97 Gy (sacral image-derived method) to red marrow, and 0.57 Gy to total body. The median effective blood half-life was 27 h, and the area under the curve (AUC) was 25 h. No patient failed to meet protocol-defined dosimetry safety criteria and all patients were eligible for treatment. Observed toxicity was primarily hematologic, transient, and reversible. Hematologic toxicity did not correlate with estimates of red marrow radiation absorbed dose, total-body radiation absorbed dose, blood effective half-life, or blood AUC.

CONCLUSION

Relapsed or refractory NHL in patients with adequate bone marrow reserve and <25% bone marrow involvement by NHL can be treated safely with (90)Y-ibritumomab tiuxetan RIT on the basis of a fixed, weight-adjusted dosing schedule. Dosimetry and pharmacokinetic results do not correlate with toxicity.

Diagnostic and therapeutic applications of radiolabeled somatostatin analogs: current status in an oncology center

From the prospective of a major oncology center in the United States, somatostatin analog radiopeptides currently have limited diagnostic and therapeutic utility. Diagnostic modalities utilitizing Somatostatin Receptor Imaging are now commercially available and the role of this type of method is currently being evaluated. Unlike the unique properties of thyroid tissue facilitating I-131 uptake, targeting of other tissues has required a carrier for the nuclide. Somastostatin peptide analogs have proved attractive based on the ubiquity of distribution and up-regulation in diseased tissue but prospective data is currently scarce. Interest in therapeutic applications of somatostatin analogs as carriers of yttrium, indium and more recently rhenium have resulted in trials with these agents both for endocrine and non-endocrine tumors. At this time, insufficient data exists to justify the indication of "first-line" therapy. The principles of Somatostatin Receptor Imaging and radiotherapy are discussed in this article along with the current status of these modalities in clinical practice as viewed by the author.

Imaging with 99mTc ECDG targeted at the multifunctional glucose transport system: feasibility study with rodents

PURPOSE

To evaluate the feasibility of technetium 99m ((99m)Tc) ethylenedicysteine-deoxyglucose (ECDG) imaging in tumor-bearing rodents.

MATERIALS AND METHODS

ECDG was synthesized by means of reacting ethylenedicysteine with glucosamine, with carbodiimide as the coupling agent. Hexokinase assays were performed at an ultraviolet wavelength of 340 nm. To determine whether blood glucose level could be altered, ECDG or glucosamine was injected into six rats. In a separate study, ECDG followed by insulin was administered to three rats. To determine biodistribution, lung tumor cells were intramuscularly injected into the hind legs of 18 nude mice. The animals were then injected with (99m)Tc ECDG or fluorine 18 ((18)F) fluorodeoxyglucose (FDG) (0.037-0.074 MBq per mouse). Radioactivity was measured in tissue excised from the animals. Scintigraphy was performed in three groups: in group 1 to demonstrate that different-sized tumors could be imaged after (99m)Tc ECDG administration, in group 2 to ascertain whether tumor uptake of (99m)Tc ECDG was perfusion related, and in group 3 to demonstrate that tumor uptake of (99m)Tc ECDG occurred by means of a glucose-mediated process.

RESULTS

ECDG was positive for phosphorylation at hexokinase assay. Blood glucose level increased with ECDG injection and decreased with insulin administration. Tumor-to-brain tissue and tumor-to-muscle tissue ratios of (99m)Tc ECDG uptake were higher than those of (18)F FDG uptake. Scintigraphic results demonstrated the feasibility of (99m)Tc ECDG imaging.

CONCLUSION

There are similarities between (99m)Tc ECDG uptake and (18)F FDG uptake in tumors, and study findings supported the potential use of (99m)Tc ECDG as a functional imaging agent.

Assessment of epidermal growth factor receptor with 99mTc-ethylenedicysteine-C225 monoclonal antibody

Epidermal growth factor receptor (EGFR) plays an important role in cell division and cancer progression, as well as angiogenesis and metastasis. Since many tumor cells exhibit the EGFR on their surface, functional imaging of EGFR provides not only a non-invasive, reproducible, quantifiable alternative to biopsies, but it also greatly complements pharmacokinetic studies by correlating clinical responses with biological effects. Moreover, molecular endpoints of anti-EGFR therapy could be assessed effectively. C225 is a chimeric monoclonal antibody that targets the human extracellular EGFR and inhibits the growth of EGFR-expressing tumor cells. Also, it has been demonstrated that C225, in combination with chemotherapeutic drugs or radiotherapy, is effective in eradicating well-established tumors in nude mice. We have developed 99mTc-labeled C225 using ethylenedicysteine (EC) as a chelator. This study aimed at measuring uptake of 99mTc-EC-C225 in EGFR+ tumor-bearing animal models and preliminary feasibility of imaging patients with head and neck carcinomas. In vitro Western blot analysis and cytotoxicity assays were used to examine the integrity of EC-C225. Tissue distribution studies of 99mTc-EC-C225 were evaluated in tumor-bearing rodents at 0.5-4 h. In vivo biodistribution of 99mTc-EC-C225 in tumor-bearing rodents showed increased tumor-to-tissue ratios as a function of time. In vitro and biodistribution studies demonstrated the possibility of using 99mTc-EC-C225 to assess EGFR expression. SPECT images confirmed that the tumors could be visualized with 99mTc-EC-C225 from 0.5 to 4 h in tumor bearing rodents. We conclude that 99mTc-EC-C225 may be useful to assess tumor EGFR expression. This may be useful in the future for selecting patients for treatment with C225.

Assessment of antiangiogenic effect using 99mTc-EC-endostatin

PURPOSE

Tumor vascular density may provide a prognostic indicator of metastatic potential or survival. The purpose of this study was to develop 99mTc-ethylenedicysteine-endostatin (99mTc-EC-endostatin) for the evaluation of anti-angiogenesis therapy.

METHOD

99mTc-EC-endostatin was prepared by conjugating ethylenedicysteine (EC) to endostatin, followed by adding pertechnetate and tin chloride. Radiochemical purity was > 95%. In vitro cell viability, affinity and TUNEL assays were performed. Tissue distribution and planar imaging of radiolabeled endostatin were determined in tumor-bearing rats. To assess anti-angiogenic treatment response, rats were treated with endostatin, paclitaxel and saline, followed by imaging with 99mTc-EC-endostatin. Tumor response to endostatin therapy in tumor-bearing animal models was assessed by correlating tumor uptake dose with microvessel density, VEGF, bFGF and IL-8 expression during endostatin therapy.

RESULTS

In vitro cell viability and TUNEL assays indicated no marked difference between EC-endostatin and endostatin. Cellular uptake assay suggests that endostatin binds to endostatin receptor. Biodistribution of 99mTc-EC-endostatin in tumor-bearing rats showed increased tumor-to-tissue count density ratios as a function of time. Tumor uptake (%ID/g) of 99mTc-EC-endostatin was 0.2-0.5. Planar images confirmed that the tumors could be visualized clearly with 99mTc-EC-endostatin. The optimal time for imaging using radiolabeled endostatin was 2 hrs. 99mTc-EC-endostatin could assess treatment response. There was a correlation between tumor uptake and cellular targets expression.

CONCLUSION

The results indicate that it is feasible to use 99mTc-EC-endostatin to assess efficiency of anti-angiogenesis therapy.

Whole-body lymphoscintigraphy using transmission scans

OBJECTIVE

Our objective was to show the advantages of performing whole-body lymphoscintigraphy using transmission sources. This technique should decrease scanning time, help locate the sentinel lymph node, and decrease radiation exposure to the technologist.

METHODS

Twenty patients with proven melanoma received 18.5 MBq (0.5 mCi) filtered (0.22 microm) (99m)Tc-sulfur colloid in a 0.2-mL volume, administered as multiple intradermal or subcutaneous injections around the known melanoma lesion or scar. All 20 patients underwent serial static imaging immediately after the injection, along with whole-body scanning after the static imaging. The static emission images were acquired for 5 min and the transmission images for 1 min using a 256 x 256 matrix. The whole-body transmission scans were acquired after the whole-body emission scans. The transmission scans were obtained with the same parameters as the emission scans, with the addition of placement of a (57)Co sheet source on one of the detectors of the large-field-of-view dual-head camera. The planar static axial images (transmission, emission) were compared with the whole-body images (transmission, emission) to determine whether the same number of lymph nodes was visualized with each technique. Posterior outlines were obtained through computer manipulation of anterior transmission images.

RESULTS

In all 20 patients, the number of lymph nodes seen on the static images was the same as that seen on the whole-body emission and transmission images. The whole-body emission and transmission scanning time was an average of 30 min less than the time required to acquire the serial static images.

CONCLUSION

The anatomic location of the sentinel lymph node is seen more easily on whole-body images, both anterior transmission and posterior transmission, than on planar static images. Whole-body emission and transmission imaging decreased scanning time and thus improved patient comfort and throughput. Technologists received less radiation exposure when handling the (57)Co source only twice during whole-body imaging, as opposed to several times during static imaging.

Can positron emission tomography improve the quality of care for head-and-neck cancer patients?

PURPOSE

Fluoro-2-deoxy-d-glucose-positron emission tomography (FDG-PET) is a functional imaging modality that measures the relative uptake of 18FDG with PET. The purpose of this review is to assess the potential contribution of FDG-PET scans to the treatment of head-and-neck cancer patients.

METHODS AND MATERIALS

Data were assessed from the literature with attention to what additional information may be gained from the use of FDG-PET in four clinical settings: (1) detection of occult metastatic disease in the neck, (2) detection of occult primaries in patients with neck metastases, (3) detection of synchronous primaries or metastatic disease in the chest, and (4) detection of residual/recurrent locoregional disease.

RESULTS

Although the data are somewhat conflicting, FDG-PET appears to add little additional value to the physical examination and conventional imaging studies (supplemented by biopsy when appropriate) for the detection of subclinical nodal metastases, unknown primaries, or disease in the chest. However, FDG-PET scans are quite useful in differentiating residual/recurrent disease from treatment-induced normal tissue changes. A positive FDG-PET scan at 1 month after radiotherapy is highly indicative of the presence of residual disease, and a negative scan at 4 months after treatment is highly predictive of tumor eradication.

CONCLUSIONS

Large-scale studies using newer generation equipment and more defined methods are needed to more rigorously assess the potential of FDG-PET in the detection of subclinical primary or simultaneous secondary tumors and of nodal or systemic spread. Currently, however, FDG-PET can contribute to the detection of residual/early recurrent tumors, leading to the timely institution of salvage therapy or the prevention of unnecessary biopsies of irradiated tissues, which may aggravate injury.

Biodistribution and dosimetry results from a phase III prospectively randomized controlled trial of Zevalin radioimmunotherapy for low-grade, follicular, or transformed B-cell non-Hodgkin's lymphoma

Radiation dosimetry studies were performed in patients with non-Hodgkin's lymphoma (NHL) treated with 90Y Zevalin (90yttrium ibritumomab tiuxetan, IDEC-Y2B8) on a Phase III open-label prospectively randomized multicenter trial. The trial was designed to evaluate the efficacy and safety of 90Y Zevalin radioimmunotherapy compared to rituximab (Rituxan, MabThera) immunotherapy for patients with relapsed or refractory low-grade, follicular, or transformed NHL. An important secondary objective was to determine if radiation dosimetry prior to 90Y Zevalin administration is required for safe treatment in this patient population.

METHODS

Patients randomized into the Zevalin arm were given a tracer dose of 5 mCi (185 MBq) (111)In Zevalin (111indium ibritumomab tiuxetan) on Day 0, evaluated with dosimetry, and then administered a therapeutic dose of 0.4 mCi/kg (15 MBq/kg) 90Y Zevalin on Day 7. Both Zevalin doses were preceded by an infusion of 250 mg/m(2) rituximab to clear peripheral B-cells and improve Zevalin biodistribution. Following administration of (111)In Zevalin, serial anterior and posterior whole-body scans were acquired and blood samples were obtained. Residence times for 90Y were estimated for major organs, and the MIRDOSE3 computer software program was used to calculate organ-specific and total body radiation absorbed dose. Patients randomized into the rituximab arm received a standard course of rituximab immunotherapy (375 mg/m(2) weekly x 4).

RESULTS

In a prospectively defined 90 patient interim analysis, the overall response rate was 80% for Zevalin vs. 44% for rituximab. For all patients with Zevalin dosimetry data (N=72), radiation absorbed doses were estimated to be below the protocol-defined upper limits of 300 cGy to red marrow and 2000 cGy to normal organs. The median estimated radiation absorbed doses were 71 cGy to red marrow (range: 18-221 cGy), 216 cGy to lungs (94-457 cGy), 532 cGy to liver (range: 234-1856 cGy), 848 cGy to spleen (range: 76-1902 cGy), 15 cGy to kidneys (0.27-76 cGy) and 1484 cGy to tumor (range: 61-24274 cGy). Toxicity was primarily hematologic, transient, and reversible. The severity of hematologic nadir did not correlate with estimates of effective half-life (half-life) or residence time of 90Y in blood, or radiation absorbed dose to the red marrow or total body.

CONCLUSION

90Y Zevalin administered to NHL patients at non-myeloablative maximum tolerated doses delivers acceptable radiation absorbed doses to uninvolved organs. Lack of correlation between dosimetric or pharmacokinetic parameters and the severity of hematologic nadir suggest that hematologic toxicity is more dependent on bone marrow reserve in this heavily pre-treated population. Based on these findings, it is safe to administer 90Y Zevalin in this defined patient population without pre-treatment (111)In-based radiation dosimetry.

Bone-targeted therapy for advanced androgen-independent carcinoma of the prostate: a randomised phase II trial

BACKGROUND

Prostate carcinoma is linked to osteoblastic metastasis. We therefore investigated the value of bone-targeted consolidation therapy in selected patients with advanced androgen-independent carcinoma of the prostate.

METHODS

103 patients received induction chemotherapy, consisting of ketoconazole and doxorubicin alternating with estramustine and vinblastine. After two or three cycles of induction chemotherapy, we randomly assigned 72 patients who were clinically stable or responders to receive doxorubicin with or without strontium-89 (Sr-89) every week for 6 weeks.

FINDINGS

Overall 62 of the 103 (60%, 95% CI 50-70) patients had a 50% or greater reduction in serum prostate-specific antigen concentration that was maintained for at least 8 weeks, and 43 (42%, 32-52) had an 80% or greater reduction. 49 (52%) patients with bone pain at registration had complete resolution of pain. After follow-up of 67 patients until death, the estimated median survival for all 103 patients was 17.5 months (range 0.5-37.7). For the 36 patients randomly assigned to receive Sr-89 and doxorubicin, the median survival time was 27.7 months (4.9-37.7), and for the 36 who received doxorubicin alone it was 16.8 months (4.4-34.2) (p=0.0014). The hazard ratio was 2.76 (95% CI 1.44-5.29).

INTERPRETATION

Bone-targeted consolidation therapy consisting of one dose of Sr-89 plus doxorubicin once a week for 6 weeks, when given to patients with stable or responding advanced androgen-independent carcinoma of the prostate after induction chemotherapy, improved overall survival.

In vivo and in vitro measurement of apoptosis in breast cancer cells using 99mTc-EC-annexin V

OBJECTIVE

The purpose of this study was to develop an imaging technique to measure and monitor tumor cells undergoing programmed death caused by radiation and chemotherapy using 99mTc-EC-annexin V. Annexin V has been used to measure programmed cell death both in vitro and in vivo. Assessment of apoptosis would be useful to evaluate the efficacy and mechanisms of therapy and disease progression or regression.

METHODS

Ethylenedicysteine (EC) was conjugated to annexin V using sulfo-N-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-HCl as coupling agents. The yield of EC-annexin V was 100%. In vitro cellular uptake, pre- and post-radiation (10-30 Gy) and paclitaxel treatment, was quantified using 99mTc-EC-annexin V. Tissue distribution and planar imaging of 99mTc-EC-annexin V were determined in breast tumor-bearing rats at 0.5, 2, and 4 hrs. To demonstrate in vivo cell apoptosis that occurred during chemotherapy, a group of rats was treated with paclitaxel and planar imaging studies were conducted at 0.5-4 hrs. Computer outlined region of interest (ROI) was used to quantify tumor uptake on day 3 and day 5 post-treatment.

RESULTS

In vitro cellular uptake showed that there was significantly increased uptake of 99mTc-EC-annexin V after irradiation (10-30 Gy) and paclitaxel treatment. In vivo biodistribution of 99mTc-EC-annexin in breast tumor-bearing rats showed increased tumor-to-blood, tumor-to-lung and tumor-to-muscle count density ratios as a function of time. Conversely, tumor-to-blood count density ratios showed a time-dependent decrease with 99mTc-EC in the same time period. Planar images confirmed that the tumors could be visualized clearly with 99mTc-EC-annexin. There was a significant difference of ROI ratios between pre- and post-paclitaxel treatment groups at 2 and 4 hrs post injection.

CONCLUSION

The results indicate that apoptosis can be quantified using 99mTc-EC-annexin and that it is feasible to use 99mTc-EC-annexin to image tumor apoptosis.