Imaging assessment of the responses of osteosarcoma patients to preoperative chemotherapy: angiography compared with thallium-201 scintigraphy

Practical use of imaging technique for management of bone and soft tissue tumors

Imaging modalities including radiography, computed tomography (CT), and magnetic resonance imaging (MRI) are necessary for the diagnosis of bone and soft tissue tumors. The history of imaging began with the discovery of X-rays in the 19th century. The development of CT, MRI, ultrasonography, and positron emission tomography (PET) have improved the management of bone and soft tissue tumors. X-ray imaging and CT scans enable the evaluation of bone destruction, periosteal reaction, sclerotic changes in lesions, condition of cortical bone, and ossification. MRI enables the assessment of tissue characteristics, tumor extent, and the reactive areas. Functional imaging modalities including ²⁰¹thallium (²⁰¹Tl) scintigraphy can be used to differentiate benign lesions from malignant lesions and to assess chemotherapeutic effects. Real-time assessment of soft tissue tumors by ultrasonography enables accurate and safe performance of surgery and biopsy. This article describes useful imaging modalities and characteristic findings in the management of bone and soft tissue tumors.

Location of residual viable tumor cells after neoadjuvant chemotherapy: A new concept with high prognostic performance in osteosarcoma

BACKGROUND AND OBJECTIVES

The purpose of this study was to establish a new concept for evaluating responses to neoadjuvant chemotherapy in osteosarcoma.

METHODS

A total of 56 high-grade extremity osteosarcoma patients were retrospectively reviewed. A new conceptual method was derived from locations of residual viable tumor cells (LRVTC) after chemotherapy, whether extracompartmental or intracompartmental, rather than quantitative measurements of necrosis rates of tumor cells.

RESULTS

LRVTC after chemotherapy was independently associated with overall survival ([OS]hazard ratio [HR] = 6.502, P = 0.008) after adjustment for Huvos grade (HR = 3.694, P = 0.045), alkaline phosphatase ([ALP] HR = 2.140, P = 0.226), size (HR = 0.318, P = 0.133), joint extension (HR = 2.309, P = 0.162), and metastasis at diagnosis (HR = 8.228, P = 0.009). LRVTC was also independently associated with metastasis (HR = 5.096, P = 0.002) after adjustment for Huvos grade (HR = 2.261, P = 0.101), ALP (HR = 2.558, P = 0.053), size (HR = 1.280, P = 0.641), and joint extension (HR = 1.800, P = 0.254). AUC values of LRVTC for OS and metastasis were superior to those of Huvos grade: AUCs for OS (LRVTC: 0.757, Confidence Interval [CI] = 0.618 to 0.865 vs Huvos grade: 0.590, [CI] = 0.445 to 0.725; AUC = 0.167, P = 0.086) and metastasis (LRVTC: 0.769, CI = 0.631 to 0.874 vs Huvos grade: 0.606, [CI] = 0.461 to 0.739; AUC = 0.163, P = 0.046).

CONCLUSIONS

LRVTC after chemotherapy may be useful as a new method with high performance for evaluating chemo-responses in osteosarcoma.

Thallium-201 Uptake of Giant Cell Tumor: One Step Toward the Differential Diagnosis to Atypically Presenting Osteosarcoma

OBJECTIVE

The radiologic differential diagnosis of giant cell tumors (GCTs) is challenging because there is a risk of misdiagnosis of GCTs as malignant lesions such as atypically presenting osteosarcomas (OSs). This study aims to assess the feasibility of ²⁰¹Tl scintigraphy for the differential diagnosis of GCT and atypical OS.

MATERIALS AND METHODS

Thallium-201 scintigraphy scans obtained between January 2006 and October 2015 of patients with histologically proven GCT (23 patients [male-to-female ratio, 15:8]; median age, 33.0 years; age range, 20-61 years) and patients with atypically presenting OS (20 patients [male-to-female ratio, 11:9]; median age, 30.0 years; age range, 12-69 years) were retrospectively reviewed. Morphologic classification of osseous lesions was performed on radiographs and CT scans. The ²⁰¹Tl scintigraphy-based tumor-to-background contrast (TBC) and washout rate (WR) were calculated on early phase and delayed phase scans. The laboratory parameters lactate dehydrogenase (LDH), C-reactive protein (CRP), and alkaline phosphatase were obtained. Statistical significance was estimated using the Mann-Whitney U test. Cutoff values were calculated for early phase TBC and delayed phase TBC.

RESULTS

Twenty-two of 23 GCTs were detected on the initial radiographs, whereas only six of 20 atypical OSs were detected on the initial radiographs. The early phase TBC was increased in GCT (median, 2.59; range, 0.51-12.26) compared with atypical OS (median, 1.68; range, 0.90-6.45) (p = 0.07). The delayed phase TBC was increased in GCT (median, 1.65; range, 0.22-5.26) compared with atypical OS (median, 0.96; range, 0.39-3.76) (p = 0.02). The median WR was not significantly decreased in GCT. The cutoff value for the early phase TBC was 3.90, and the cutoff value for the delayed phase TBC was 1.64; these cutoff values for early and delayed phase TBC yielded a sensitivity of 80.0% and a specificity of 47.8% and 52.2% respectively. Serum LDH (mean: atypical OS vs GCT, 215.5 vs 170.5 U/L, respectively; p = 0.01), alkaline phosphatase (median: 355.0 vs 252.0 U/L; p = 0.03), and CRP (median: 0.21 vs 0.09 mg/dL; p = 0.04) values were significantly increased in atypical OS compared with GCT.

CONCLUSION

The intense ²⁰¹Tl uptake of GCT in combination with laboratory OS biomarkers facilitate the differential diagnosis of GCT and atypically presenting OS.

Both a visual and a semiquantitative analysis for differentiating benign from malignant chondrogenic bone tumors using Tc-99m (V) DMSA scintigraphy: a prospective study

OBJECTIVE

The aims of this prospective study were to assess the relationship between tumor aggressiveness and Tc-99m (V) dimercaptosuccinic acid (DMSA) uptake in chondrogenic bone tumors and the value of Tc-99m (V) DMSA scintigraphy for differentiating benign from malignant tumors.

METHODS

Twenty-four patients with chondrogenic tumors (19 benign and five malignant) underwent Tc-99m DMSA (V) scintigraphy. Radiopharmaceutical uptake was classified using a three-point scale to allow a visual-only analysis, and a tumor-to-background contrast (TBC) was computed using regions of interest to provide a semiquantitative analysis. Spearman's correlation coefficient was used to assess the correlation between tumor aggressiveness and TBC. The difference in TBC between benign and malignant tumors was analyzed with the Mann-Whitney U-test. An appropriate cutoff value of TBC was chosen for the diagnosis of malignancy of a tumor using receiver operating characteristic analysis.

RESULTS

Six benign tumors showed negative uptake (uptake score 0), whereas 13 benign tumors showed positive uptake (n=10 uptake score 1; n=3 uptake score 2). All chondrosarcomas showed positive uptake (n=2 uptake score 1; n=3 uptake score 2). A significant correlation was found between tumor aggressiveness and TBC. A significant difference was seen in TBC between benign and malignant tumors. With the chosen cutoff value of TBC equal to 0.611, the sensitivity was 80.0%, specificity was 78.9%, the positive predictive value was 50.0%, and the negative predictive value was 93.8%.

CONCLUSION

Tc-99m (V) DMSA scintigraphy may have the potential to improve diagnostic methods for detecting chondrosarcomas using visual and/or semiquantitative analyses.

Quantitative (201)thallium scintigraphy for prediction of histological response to neoadjuvant chemotherapy in osteosarcoma; systematic review and meta-analysis

PURPOSE

The histological assessment of tumor necrosis of the excised lesion after neoadjuvant chemotherapy is the most important prognostic factor for patients with osteosarcoma, but more early prognostic factors are needed for the adjustment of adjuvant treatment regimen. The objective of this systematic review is to provide an up-to-date and unprecedented summary of the value of (201)thallium ((201)Tl) scintigraphy for the preoperative evaluation of the chemotherapy response of osteosarcoma.

METHODS

Studies evaluating (201)Tl scintigraphy for the preoperative evaluation of the chemotherapy response of osteosarcoma were systematically searched for in MEDLINE, EMBASE, and Web of Science. Pooled sensitivity and specificity for each study were calculated into 2 × 2 contingency tables. The DerSimonian-Laird random-effects method was used for determining the pooled diagnostic odds ratio and the area under curve (AUC) of the summary receiver operating characteristic (SROC) curve.

RESULTS

A total of six studies with 139 patients who fulfilled all of the inclusion criteria were considered for the meta-analysis. The pooled sensitivity and specificity were 0.93 (95% CI, 0.83-0.98) and 0.63 (95% CI, 0.52-0.74), respectively. A significant difference was found between the good and poor responders in the diagnostic odds ratio. The SROC curve showed that the AUC was 0.840, indicating excellent diagnostic accuracy. There was no statistically significant heterogeneity among the six studies.

CONCLUSIONS

The alteration ratio derived from (201)Tl scintigraphy was useful for evaluating the histological response of patients to neoadjuvant chemotherapy in osteosarcoma.

Diagnostic value of Thallium-201 scintigraphy in differentiating malignant bone tumors from benign bone lesions

OBJECTIVE

This retrospective study aims to evaluate the diagnostic capacity of thallium-201 (201Tl) scintigraphy for differentiating malignant bone tumors from benign bone lesions.

METHODS

Between January 2006 and December 2012, 279 patients with bone lesions (51 malignant and 228 benign) underwent 201Tl scintigraphy before treatment. To evaluate 201Tl uptake, we investigated tumor-to-background contrast (TBC) as well as TBC washout rate (WR). The differences of TBC on early and delayed images and WR were estimated by the Mann-Whitney U test. Receiver operating characteristic (ROC) analyses were used to determine the cut-off TBC values for differentiating malignant bone tumors from benign bone lesions.

RESULTS

There were statistically significant differences in median TBC between malignant tumors and benign lesions. These differences occurred for early imaging (1.57 vs. 0.09, p < 0.001) as well as for delayed imaging (0.83 vs. 0.07, p < 0.001). However, there was no statistical difference in WR between malignant tumors and benign lesions (44 vs. 43 %, NS). The chosen TBC cut-off value was 0.68 for early imaging and 0.38 for delayed imaging. Using these cut-off values, the prediction of malignancy had a 77 % sensitivity, 74 % specificity, and 75 % accuracy for early imaging and an 80 % sensitivity, 76 % specificity, and 77 % accuracy for delayed imaging.

CONCLUSIONS

201Tl scintigraphy may have the ability to distinguish malignant bone tumors from benign bone lesions.

Prognostic value of radiological response to chemotherapy in patients with osteosarcoma

BACKGROUND

Chemotherapy is essential to improve the prognosis of the patients with osteosarcoma, and the response to chemotherapy is an important prognostic factor. In this study, the impact of various radiological examinations on overall survival (OS) and event-free survival (EFS) was evaluated.

METHOD

Eighty-two patients with high-grade osteosarcoma were included in this study, and we evaluated the following factors for prognostic significance: age (≥40 years), gender (male), tumor location (truncal site), metastatic disease, histological response to chemotherapy, radiological response to chemotherapy assessed using X-ray, angiography, CT, MRI, (201)Tl scintigraphy, and (99m)Tc-MIBI scintigraphy ((99m)Tc-MIBI), and combined radiological score (CRS).

RESULTS

Univariate analyses revealed that metastatic disease, histological response, (99m)Tc-MIBI, and CRS were significantly correlated with OS. Multivariate analyses showed that metastatic disease (OS: HR 35.9, P<0.001; EFS: HR 17.32, P<0.001) was an independent predictor of OS and EFS. Tumor location (HR 36.1, P = 0.003), histological response (HR 31.1, P = 0.036), and (99m)Tc-MIBI (HR 18.4, P = 0.038) were significant prognostic factors for OS. Moreover, CRS was a marginally significant predictor of OS and EFS.

CONCLUSION

The chemotherapeutic effects evaluated by (99m)Tc-MIBI and CRS could be considered as prognostic factors in osteosarcoma.

A novel combined radiological method for evaluation of the response to chemotherapy for primary bone sarcoma

BACKGROUND

In the treatment of bone sarcoma, evaluation of chemotherapeutic effects is extremely important. In this study, we compared radiological evaluations and histological response, and developed a combined radiological scoring system for assessing the response to chemotherapy.

METHODS

A total of 79 patients with primary bone sarcomas were examined by X-ray photography (Xp), angiography, MRI, 201Tl scintigraphy (Tl) and 99mTc-MIBI scintigraphy (MIBI) to evaluate their response to preoperative chemotherapy. Patients were classified as responders and non-responders according to radiological images. All resected tumors were evaluated histologically and classified as a good response (≥90% necrosis) or a poor response (≤90% necrosis). The sensitivity, specificity, accuracy, and kappa values in radiological evaluation were calculated. Furthermore, we developed a combined radiological scoring system that correlated the results of radiological images with histological response.

RESULTS

Sensitivity, specificity, and accuracy were 90.9%, 38.2%, and 67.5% (K = 0.31), respectively, for Xp; 91.7%, 33.3%, and 66.7% (K = 0.27) for angiography; 81.0%, 67.6%, and 75.0% (K = 0.49) for MRI; 78.9%, 72.4%, and 76.1% (K = 0.51) for Tl; 85.3%, 69.2%, and 78.3% (K = 0.55) for MIBI; and 93.3%, 76.5%, and 86.1% (K = 0.71) for combined radiological scoring.

CONCLUSIONS

Combined radiological evaluations showed high correlation with histological response for assessing the effects of chemotherapy.

Thallium-201 scintigraphy is an effective diagnostic modality to distinguish malignant from benign soft-tissue tumors

BACKGROUND

The aim of this study is to evaluate whether thallium-201 (201-Tl) scintigraphy can differentiate malignant from benign soft-tissue tumors.

METHODS

Between April 1995 and December 2005, 192 patients with soft-tissue tumors (85 malignant and 107 benign) underwent 201-Tl scintigraphy before treatment. Isotope uptake was used as a proxy for tumor-to-background ratio (TBR). The accuracy of TBR on early and delayed imaging was evaluated using the Mann-Whitney U and χ(2) tests.

RESULTS

There was a statistically significant difference in mean TBR on early and delayed imaging of malignant and benign soft-tissue tumors (124% ± 109% vs. 22% ± 42%, and 82% ± 83% vs. 12% ± 25%, P < 0.0001). A TBR cutoff of 20% indicated the probability of malignancy on early and delayed imaging (82% sensitivity and 77% specificity; 82% sensitivity and 84% specificity, P < 0.0001). Well-differentiated liposarcomas showed low isotope accumulation, while pigmented villonodular synovitis and giant cell tumors of the tendon sheath showed high isotope accumulation.

CONCLUSIONS

Thallium-201 scintigraphy can distinguish malignant from benign tumors with relatively high accuracy. With the exception of low grade liposarcomas and locally aggressive benign tumors, 201-Tl scintigraphy may be an effective diagnostic modality to differentiate malignant from benign soft-tissue tumors.

Prognostic value of Tc-99m-MIBI performed during middle course of preoperative chemotherapy in patients with malignant bone and soft-tissue tumors

PURPOSE

This study was aimed to determine whether Tc-99m-hexakis-2-methoxyisobutylisonitrile (MIBI) scintigraphy performed in the middle of preoperative chemotherapy has a prognostic value in patients with malignant bone and soft tissue tumors (MBST).

MATERIALS AND METHODS

In 90 patients with MBST, Tc-99m-MIBI scintigraphy was performed 15 minutes after tracer injection before the first and after the third chemotherapy cycles. After 5 cycles of chemotherapy and tumor resection, therapeutic effect was assessed by histopathology. The percent reduction of uptake ratio (ΔUR) was calculated according to the following equation: 100 × ([prechemotherapy UR - post-middle course of chemotherapy UR]/prechemotherapy UR).

RESULTS

The average follow-up for the entire population was 52 months. Twenty-one patients had clinically detectable metastases at initial presentation (primary metastasis). Kaplan-Meier analysis demonstrated that absence of metastasis was associated with good survival in all patients, in patients with bone tumor, and those with soft tissue tumor (P < 0.0001, P < 0.0001, and P = 0.0003, respectively), and ΔUR ≧30% was also associated with survival in all patients and patients with bone tumor (P = 0.011 and P = 0.047, respectively), but was marginal in those with soft tissue tumor (P = 0.091). Multivariate analysis showed that primary metastasis was the most powerful independent predictor of a lethal clinical outcome in all patients, in both patients with bone and soft tissue tumors (hazard ratio [HR]: 4.9, 95% confidence interval [CI]: 2.61-9.08, P < 0.0001; HR: 15.1, CI: 4.86-52.7, P < 0.0001; HR: 3.7, CI: 1.45-8.94, P = 0.0069, respectively) and showed that Tc-99m-MIBI scintigraphy had a good independent long-term prognostic value in all patients and patients with bone tumor (HR: 2.2, CI: 1.14-4.43, P = 0.017; HR: 6.0, CI: 2.01-21.6, P = 0.0009, respectively) but not in those with soft tissue tumor (HR: 1.5, CI: 0.61-4.09, P = 0.38). Good disease-free survival was associated with ΔUR ≧30% in all patients and patients with soft tissue tumor (P = 0.0093 and P = 0.017, respectively) but not in those with bone tumor (P = 0.19).

CONCLUSIONS

Tc-99m-MIBI scintigraphy at the middle course of preoperative chemotherapy could be used as a prognostic indicator in patients with MBST.

Use of 99mTc-MIBI scintigraphy in the evaluation of the response to chemotherapy for osteosarcoma: comparison with 201Tl scintigraphy and angiography

BACKGROUND

In the treatment of osteosarcoma, the chemotherapeutic effect influences decisions regarding the surgical margin, continuation of chemotherapy, and choice of anticancer drugs for further chemotherapy. Therefore, it is necessary to evaluate the response to chemotherapy in the middle of the chemotherapy course. In this study, we investigated the use of (99m)Tc-hexakis-2-methoxyisobutyl-isonitrile ((99m)Tc-MIBI) scintigraphy in evaluating the response to chemotherapy of patients with osteosarcoma in comparison with (201)Tl scintigraphy and angiography.

METHODS

A total 45 patients with osteosarcoma were examined using (99m)Tc-MIBI scintigraphy, (201)Tl scintigraphy, and angiography to evaluate their response to chemotherapy. The percentage reduction in the uptake ratios (ΔUR) calculated as 100 × [(prechemotherapy value - postchemotherapy value)/prechemotherapy value] were compared with histological assessments. Similarly, changes in tumor vascularity assessed by angiograms were compared with histological assessments. On the angiographic findings, the results were classified as complete response (CR), partial response (PR), no change (NC), or progressive disease (PD). On the images, ΔUR in (99m)Tc-MIBI ≥ 30% and ΔUR in (201)Tl ≥ 30% were classified as responder, as were CR and PR in angiograms. The therapeutic effect was assessed by histopathological examination of the resected specimens. The tumors of poor responders showed less than 90% necrosis, whereas the tumors of good responders showed 90% or more necrosis.

RESULTS

Sensitivity, specificity, and accuracy were 73.9, 84.2, and 78.6%, respectively, for (99m)Tc-MIBI (κ = 0.57); 80.0, 61.1, and 72.1%, respectively, for (201)Tl (κ = 0.42); and 91.7, 35.0, and 65.9%, respectively for angiography (κ = 0.28).

CONCLUSION

(99m)Tc-MIBI could be effectively used to predict the final response to chemotherapy of osteosarcoma.

Noninvasive imaging with thallium-201 scintigraphy may not correlate with survival in patients with osteosarcoma

BACKGROUND

Histologic response to preoperative chemotherapy is a strong prognostic factor for osteosarcoma (OS). Thallium-201 (Tl-201) scintigraphic response to initial chemotherapy has previously been described as a predictor of histologic response. In the current study, the authors re-examined a series of patients studied using Tl-201 scintigraphy to determine the correlation between changes observed on Tl-201 scintigraphy and event-free survival (EFS).

METHODS

A total of 22 patients with biopsy-proven OS of the extremity underwent Tl-201 imaging before and immediately after preoperative chemotherapy. The maximum pixel counts taken over the tumor divided by those taken of a background region yielded a tumor-to-background ratio (TBR). The percentage of change in the TBR before and after adjuvant chemotherapy, defined as the alteration ratio (AR), was correlated with EFS.

RESULTS

The median AR was 85% (range, 28-100%). The 3-year EFS was 0.72 (95% confidence interval [95% CI], 0.48-0.86) and the 5-year EFS was 0.67 (95% CI, 0.43-0.86). There was no association between AR and EFS detected in this cohort (hazard ratio, 0.99; 95% CI, 0.95-1.02 [Somers rank correlation coefficient, 0.15]).

CONCLUSIONS

Although Tl-201 scintigraphy was used as a tool for the assessment of response to chemotherapy in patients with OS, the AR did not appear to be predictive of EFS in this small group of patients. It is necessary to use the outcome variables of ultimate interest-EFS and overall survival- and not rely on surrogates for outcome to evaluate potential prognostic factors.

Evaluation of chemotherapy response in osteosarcoma with FDG-PET

OBJECTIVE

The objective of this study is to evaluate the utility of positron emission tomography (PET) with 2-deoxy-[(18)F] fluoro-D-glucose (FDG) in the assessment of the chemotherapy response of osteosarcoma when compared with the degree of necrosis determined histologically.

METHODS

Whole-body FDG-PET scan was performed on 11 patients with osteosarcoma. All patients received neoadjuvant chemotherapy. The tumor size changes on magnetic resonance imaging; FDG-PET standardized uptake values prior to (SUV(1)) and following (SUV(2)) chemotherapy were analyzed and correlated with response to chemotherapy as assessed using histopathology in surgically excised tumors. Nine patients underwent FDG-PET scan both prior to and following neoadjuvant chemotherapy. The remaining two patients were examined only prior to surgery.

RESULTS

Histologically, five patients had a good histologic response to chemotherapy (>==90% necrosis). The changes in tumor size did not correlate with histologic response (P > 0.05). SUV(2) with good response was significantly lower than that with poor response (1.93 +/- 0.50, 5.86 +/- 2.55, respectively). Both the positive and negative predictive values of the SUV(2) of less than 2.5 for a good response were 100%. Patients with good response showed a significantly higher ratio of SUV2 to SUV1 (SUV(2:1)) than patients with poor response (0.74 +/- 0.11, 0.26 +/- 0.39, respectively, P < 0.05). The positive and negative predictive values of SUV(2:1) </= 0.5 for good and poor responses were 80% and 100%, respectively.

CONCLUSIONS

FDG-PET imaging of osteosarcoma correlates positively with histologic response to neoadjuvant chemotherapy. SUV(2) and SUV(2:1) could be feasible as non-invasive surrogate predictors of response in osteosarcoma patients.

Imaging assessment of osteosarcoma in childhood and adolescence: diagnosis, staging, and evaluating response to chemotherapy

Osteosarcoma is an aggressive tumor of mesenchymal origin, capable of producing osteoid and immature bone. It is the most frequent primary malignant skeletal neoplasm in children and adolescents. Imaging studies play a major role in initial diagnosis, staging, and assessment of tumor response to chemotherapy. Conventional radiography is the prime imaging modality for diagnosis of bony tumors. Radionuclide bone scan is used in detection of metastatic lesions in the other bones. Computed tomography may be used as an adjunct to conventional radiography, but its main role is detection of pulmonary metastasis. The standard magnetic resonance imaging is the most specific modality for local staging and monitoring response to chemotherapy, and distinguishing postsurgical changes from residual tumor. Dynamic contrast-enhanced magnetic resonance imaging has been introduced to quantify the percentage of tumor necrosis, identify early responders, and thus predict survival. The role of 18F fluorodeoxyglucose positron emission tomography (PET) in the staging and management of osteosarcoma is evolving. It has the advantage of total body imaging and may have an overall role in tumor staging and grading, detection of early response, and therefore, in the prognosis and detection of recurrence.

Osteosarcoma: review of the past, impact on the future. The American experience

Major advances have been achieved in the treatment of osteosarcoma with the discovery of several chemotherapeutic agents that were active in the disease. These agents comprise high-dose methotrexate with leucovorin rescue, Adriamycin, cisplatin, ifosfamide and cyclophosphamide. The agents were integrated into various regimens and administered in an effort to destroy silent pulmonary micrometastases which are considered to be present in at least 80% of patients at the time of diagnosis. Their efficacy in achieving this goal was realized and their use was further extended to the application of preoperative (neoadjuvant) chemotherapy to destroy the primary tumor and achieve safe surgical resections. Disease free survival was escalated from <20% prior to the introduction of effective chemotherapy to 55-75% and overall survival to 85%. Further, the opportunity to perform limb salvage was expanded to 80% of patients. Of interest also was an attempt in one series to treat the primary tumor exclusively with chemotherapy, and abrogation of surgery. Adding to these advances, varieties of subsequently discovered agents are currently undergoing investigations in patients who have relapsed and/or failed conventional therapy. The agents include Gemcitabine, Docetaxel, novel antifolate compounds, and a liposome formulation of adriamycin (Doxil). A biological agent, muramyl tripeptide phosphatidyl ethanolamine (MTPPE) was also recently investigated in a 2x2 factorial design to determine its efficacy in combination with chemotherapy (methotrexate, cisplatin, Adriamycin and ifosfamide).In circumstances where the tumor was considered inoperable, chemotherapy and radiotherapy were advocated for local control. High dose methotrexate, Adriamycin and cisplatin and Gemcitabine interact with radiation therapy and potentiate its therapeutic effect. This combination is also particularly useful in palliation. Occasionally, the combination of radiation and chemotherapy may render a tumor suitable for surgical ablation. Samarium153, a radio active agent, is also used as palliative therapy for bone metastases.However, despite the advances achieved with the multidisciplinary application of chemotherapy, radiotherapy and surgical ablation of the primary tumor over the past 3(1/2) decades, the improved cure rate reported initially has not altered. Particularly vexing is the problem of rescuing patients who develop pulmonary metastases after receiving seemingly effective multidisciplinary treatment. Approximately 15-25% of such patients only are rendered free of disease with the reintroduction of chemotherapy and resection of metastases. Extrapulmonary metastases and multifocal osteosarcoma also constitute a major problem. The arsenal of available agents to treat such patients has not made any substantial impact in improving their survival. New chemotherapeutic agents are urgently required to improve treatment and outcome. Additional strategies to be considered are targeted tumor therapy, anti tumor angiogenesis, biotherapy and therapy based upon molecular profiles. This communication outlines sequential discoveries in the chemotherapeutic research of osteosarcoma in the United States of America. It also describes the principles regulating the therapeutic application of the regimens and considers the impact of their results on the conduct in the design of future investigations and treatment.

Comparison of barium swallow, CT and thallium-201 SPECT in evaluating responses of patients with esophageal squamous cell carcinoma to preoperative chemoradiotherapy

The aims of this study were to compare the results of thallium-201 (Tl-201) SPECT, barium swallow and CT in the assessment of the effect of preoperative chemoradiotherapy. This study consisted of 28 patients with advanced esophageal squamous cell carcinoma (AESCC) who underwent the three imaging modalities before and after preoperative chemoradiotherapy. The results were quantified using the bidimensional method for barium swallow and contrast-enhanced CT and the tumor-to-lung ratio for SPECT. The percent decrease in these quantitative values after therapy was defined as %Dba, %Dct and %Dtl respectively. The histological effect of the chemoradiotherapy was determined from the resected surgical specimen of the esophagus: grade 0, 100% viable tumor cells; grade 1a, 99-67%; grade 1b, 66-34%; grade 2, 33-1%; grade 3, no viable cells. A statistically significant difference of %Dtl between the subgroups of each grade was evident (p = 0.0433), whereas no significant differences were evident for %Dba (p = 0.1778) or %Dct (p = 0.7377). However, the overlap of %Dtl between these groups was marked. Although thallium-201 SPECT cannot be used to evaluate the therapeutic effect with acceptable accuracy, SPECT may be of additional value to barium swallow and CT in assessing the response of AESCC to preoperative chemoradiotherapy.

Response of osteogenic sarcoma to neoadjuvant therapy: evaluated by 18F-FDG-PET

OBJECTIVE

The aim of this study was to evaluate the potential role of F-18-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in assessing the chemotherapy response of osteosarcoma when compared with histologically assessed tumor necrosis.

METHODS

Fifteen patients were examined with whole-body FDG-PET prior to and following neoadjuvant therapy. The maximum standard uptake value (SUV max) of tumor and tumor to background ratio (TBR) prior to and following chemotherapy was used for semiquantitative PET imaging analysis. The SUV max of prechemotherapy and post-chemotherapy was recorded as SUV1 and SUV2. TBR1 and TBR2 represented prechemotherapy and post-chemotherapy TBR. TBR was calculated by drawing an identical region of interest over the tumor and the contralateral normal limb or pelvis. Tumor necrosis was classified according to Salzer-Kuntschik's criteria.

RESULTS

Eight patients with more than 90% tumor necrosis were classified as showing good responses and seven patients with less than 90% tumor necrosis as showing poor responses. SUV2/SUV1, TBR2/TBR1, and TBR2 were significantly correlated with the tumor necrosis degree (P < 0.01, P < 0.001, P < 0.001). TBR2/TBR1 were below 0.46 in all the patients with favorable responses, and higher than 0.49 in all the patients with unfavorable responses. However, it was difficult to distinguish good responses from poor responses by SUV2/SUV1.

CONCLUSIONS

FDG-PET is a promising tool to assess the chemotherapy response of osteosarcoma noninvasively. The TBR was better than SUV max in evaluating the chemotherapy response in this study.

Intraarterial chemotherapy for extremity osteosarcoma and MFH in adults

The neoadjuvant treatment of osteosarcoma using intravenous agents has resulted in survival rates of 55% to 77% [3, 5, 6, 20, 22, 35]. We designed a neoadjuvant chemotherapy protocol using combined intraarterial and intravenous agents to treat high-grade osteosarcoma and malignant fibrous histiocytoma of bone in an attempt to improve survival. We report the results of treating 53 adults (age 18-77 years) diagnosed with nonmetastatic extremity osteosarcoma or malignant fibrous histiocytoma. Preoperative chemotherapy consisted of intravenous doxorubicin followed by intraarterial cisplatinum administered repetitively every 3 weeks for three to five cycles, depending on tumor response assessed by serial arteriography. Dose and duration of cisplatin were adjusted for tumor size. After resection, good responders (90% or greater necrosis) underwent treatment with the same agents and poor responders were treated with alternative agents for longer duration. Minimum followup was 24 months (mean, 111 months; range, 24-235 months). Estimated Kaplan-Meier survival at 10 years was 82% and event-free survival was 79%. Forty-one patients (77%) had a good histologic response and 92% (49 of 53) underwent limb-sparing procedures. Local recurrence occurred in two patients (4%). These results compared favorably with those reported in the current literature.

LEVEL OF EVIDENCE

Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Prediction of final tumor response to preoperative chemotherapy by Tc-99m MIBI imaging at the middle of chemotherapy in malignant bone and soft tissue tumors: comparison with Tl-201 imaging

The aim of this study was to assess the predictive power of 99mTc-MIBI scintigraphy performed in the middle of chemotherapy, for the final tumor response to chemotherapy, and compare it to that of (201)Tl in malignant bone and soft tissue tumors (MBST). Sixty-eight patients with MBST underwent 99mTc-MIBI and 201Tl scintigraphies at 15 min after tracer injection before the first, and after the third, chemotherapy cycles. After five cycles of chemotherapy and tumor resection, therapeutic effect was assessed by histopathology. Less than 90% and > or =90% necrosis were judged as poor and good response to chemotherapy, respectively. Tracers uptake ratios were calculated by dividing the lesion count density by that of the background. 99mTc-MIBI perfusion index was also calculated. The % reduction of the perfusion index (DeltaPI) and uptake ratios (DeltaUR) calculated by 100 x [(prechemotherapy value--postchemotherapy value)/prechemotherapy value] were compared with histologic response. The sensitivity, specificity, and accuracy for the prediction of effective chemotherapy in 99mTc-MIBI imaging were 80%, 95%, 88% in DeltaUR, and 74%, 74%, 74% in DeltaPI, respectively. The area under the receiver operator characteristic curve (A(z)) of the 99mTc-MIBI-DeltaUR (0.923) was significantly higher than that of DeltaPI (0.809, p = 0.025) but only marginally higher than that of the 201Tl-DeltaUR (0.865, p = 0.079). A(z) in 201Tl (0.865) was not significantly different from that of DeltaPI (0.809, p = 0.35). 99mTc-MIBI imaging performed in the middle of chemotherapy well predicts the final tumor response to chemotherapy in patients with malignant bone and soft tissue tumors.

Monitoring therapeutic responses of primary bone tumors by diffusion-weighted image: Initial results

The purpose of our study was to investigate whether quantitative diffusion-weighted images (DWI) were useful for monitoring the therapeutic response of primary bone tumors. We encountered 18 osteogenic and Ewing sarcomas. Magnetic resonance (MR) images were performed in all patients before and after therapy. We measured the apparent diffusion coefficient (ADC) values, contrast-to-noise ratio (CNR), and tumor volume of the bone tumors pre- and posttreatment. We determined change in ADC value, change in CNR on T2-weighted images (T2WI), change in CNR on gadopentetate dimeglumine (Gd)-T1-weighted images (Gd-T1WI), and change in tumor volume. The bone tumors were divided into two groups: group A was comprised of tumors with less than 90% necrosis after treatment and group B of tumors at least with 90%. Changes in ADC value, tumor volume, and CNR were compared between the groups. Change in the ADC value was statistically greater in group B than that in the group A (p = 0.003). There was no significant difference in the changes in CNR on T2WI (p = 0.683), in CNR on Gd-T1WI (p = 0.763), and tumor volume (p = 0.065). The ADC value on DWI is a promising tool for monitoring the therapeutic response of primary bone sarcomas.

Assessment of vascular invasion by musculoskeletal tumors of the limbs: use of contrast-enhanced MR angiography

PURPOSE

To prospectively evaluate the accuracy of contrast material-enhanced magnetic resonance (MR) angiography in the evaluation of vascular invasion by bone and soft-tissue tumors, with surgery serving as the reference standard.

MATERIALS AND METHODS

This study was approved by the regional ethics committee, and all patients gave informed consent. Preoperative MR angiograms and MR images of 31 sites in 30 patients with bone or soft-tissue sarcomas (n = 21) or other tumors (n = 9) were assessed for features of vascular invasion. All images were prospectively evaluated by two musculoskeletal radiologists working in consensus. MR images were evaluated for the presence of a fat plane between the vessels and the tumor and partial or total encasement of vessels. MR angiograms were evaluated for the presence of vascular displacement, stenosis, or occlusion. MR imaging and MR angiographic features of vascular invasion were graded. Imaging findings were correlated with surgical findings and classified as negative if there was no vascular invasion and as positive if there was vascular invasion.

RESULTS

Among the 31 cases, 20 were classified as negative and 11 were classified as positive at surgery. All but three cases with a gap between the tumor and the vessels on MR images were classified as free and without adhesions at surgery. All cases with arterial stenoses at MR angiography had tumoral adhesion or tumoral encasement at surgery. MR imaging had a sensitivity of 64%, a specificity of 95%, a positive predictive value of 88% a negative predictive value of 83%, and an accuracy of 84% in the detection of vascular invasion on the basis of findings of partial or total encasement. MR angiography had a sensitivity of 82%, a specificity of 85%, a positive predictive value of 75%, a negative predictive value of 90%, and an accuracy of 84% in the detection of vascular invasion on the basis of the findings of a stenosis.

CONCLUSION

On contrast-enhanced MR angiograms, findings of stenosis were sensitive and specific in the detection of arterial invasion. MR imaging evidence of partial or total encasement is highly specific in the detection of vascular invasion, while MR imaging evidence of a gap between the tumor and the vessels excludes an arterial invasion.

The Value of Serial Arteriography in Osteosarcoma: Delivery of Chemotherapy, Determination of Therapy Duration, and Prediction of Necrosis

PURPOSE

To investigate the value of serial arteriography to assess tumor response, predict necrosis, and individualize the duration of a combined intravenous (IV) and intraarterial (IA) neoadjuvant chemotherapy protocol in patients with biopsy-proven high-grade osteosarcoma or malignant fibrohistiocytoma of bone.

MATERIALS AND METHODS

Between July 1987 and March 2003, 109 patients completed a chemotherapy protocol of neoadjuvant IV doxorubicin and IA cisplatin. Patients were eligible regardless of age, disease stage, or disease site. A minimum of three IA cycles followed by definitive surgery was required for inclusion in the final analysis. IA dose and duration were increased for tumors larger than 10 cm. Initial arteriograms were scored as indicating mild, moderate, or marked tumor neovascularity (TNV). Subsequent arteriograms were prospectively compared with the baseline image for percent change in TNV. Treatment continued until a maximum of five cycles were administered or one of three criteria were met: (i) at least 90% decrease in TNV, (ii) plateau of effect, or (iii) no response.

RESULTS

Of 408 IA procedures, 42 patients underwent three cycles, 53 underwent four, and 14 required five cycles of neoadjuvant therapy. There was a 2.5% minor complication rate. Eighty-six percent of patients exhibited at least 90% decrease in TNV and 82% exhibited good histologic response (> or =90% tumor necrosis). Serial arteriography predicted a good histologic response with an accuracy of 90% and a sensitivity of 97%.

CONCLUSIONS

Serial arteriography was highly sensitive and accurately predicted good responses. This individually modified, dose-intensified neoadjuvant protocol yielded an excellent histologic response rate with minimal complications. Future endeavors should involve a multiinstitutional study of this unique approach.

A comparative study of2O1T1 scintigraphy and three-phase bone scintigraphy following therapy in patients with bone and soft-tissue tumors

OBJECTIVE

The purpose of this study was to evaluate the usefulness of 201Tl scintigraphy in comparison with three-phase bone scintigraphy in the differentiation of residual/recurrent tumors from post-therapeutic changes, in patients previously treated for bone and soft-tissue tumors.

METHODS

Thirty-five 201Tl and three-phase bone scintigraphy scans were obtained for 30 patients with a history of bone or soft-tissue tumor who had undergone chemotherapy, radiation therapy, tumor resection, or a combination of these treatments. The planar 201Tl images were acquired 10 mins (early) and 2 hrs (delayed) after the intravenous injection of 111 MBq 201Tl-chloride. Three-phase bone scintigraphy was performed using 740 MBq 99mTc-HMDP at the same lesion site as for 201Tl imaging. The blood flow images were obtained every 10 sec for 2 mins and were immediately followed by the blood pool image after 5 mins. Three to 4 hrs later, bone images were obtained. 201Tl and three-phase bone scintigraphies were correlated with the histopathologic findings and/or clinical follow-up of more than 3 months.

RESULTS

Of the 35 cases, 15 were free of disease and 20 had residual or recurrent tumors. Of the 20 residual or recurrent cases, all had true-positive 201Tl early and delayed scans, while bone scintigraphy was true-positive on the blood flow, blood pool and bone images in 16, 18 and 12 cases, respectively. 201Tl early and delayed images and 99mTc-HMDP blood flow and blood pool images were false-positive in one patient. The histology of this false-positive case showed the presence of lymph proliferative tissue.

CONCLUSIONS

Although 201Tl uptake after treatment does not always indicate recurrence, 201Tl scintigraphy may still be more useful than three-phase bone scintigraphy in the follow-up of patients with bone and soft-tissue tumors following therapy.

Noncardiac findings on dual-isotope myocardial perfusion SPECT

BACKGROUND

This study examined the frequency of reporting noncardiac findings (NCFs), such as malignancies from inspection of raw projection images with dual-isotope single photon emission computed tomography (SPECT) perfusion imaging, which could potentially be of greater clinical importance than myocardial perfusion imaging alone. Dual-isotope (ie, rest thallium 201 and stress technetium 99m sestamibi [MIBI] or Tc-99m tetrofosmin [TET]) SPECT myocardial perfusion imaging combines multipotential tracers for noncardiac purposes (Tl-201 for renal or splenic imaging, inflammation, or lymphoma and MIBI or TET for hepatobiliary imaging and detecting increased mitochondrial number or activity in neoplastic processes). These images are optimally interpreted with cinematic inspection of the raw projection data, but this may not be practiced uniformly in every laboratory.

METHODS AND RESULTS

We reviewed 12,526 computer-generated text reports of dual-isotope perfusion SPECT studies from a 6-year period for NCFs. NCFs were categorized by organ and by probability of malignancy: high (eg, focal breast or lung uptake of MIBI or TET), intermediate (eg, lymph node uptake or thyroid abnormalities), or low (eg, filling defects in liver, kidney, spleen, or gall bladder; ascites; or pleural effusions). Confirmatory imaging studies or clinical confirmation for each NCF was sought. There were a total of 207 NCFs identified in 180 reports (1.7% of reports, ranging from 0% to 2.8% of reports of individual interpreters). Of these, 107 NCFs were unsuspected before SPECT; 24% were considered at high probability for malignancy, and 24% were considered intermediate in likelihood of malignancy. Follow-up data were available for 178 NCFs, confirming 88% of these findings, including 82% of breast foci, 62% of lung foci, 86% of hepatobiliary/spleen abnormalities, and 94% of renal abnormalities. The probability of malignancy was highest (82%) in breast or lung foci in which uptake of both Tl-201 and the Tc-99m-labeled agent was present.

CONCLUSIONS

In patients referred for evaluation of myocardial perfusion, NCFs are unusual and require systematic and careful inspection of projection images for their detection. With Tl-201, TET, MIBI, or dual-isotope imaging, detecting and reporting NCFs may occasionally result in life-saving early cancer identification.

Clinical significance of thallium-201 scintigraphy in bone and soft tissue tumors

We evaluated sequential thallium scans on both early images (EI) and delayed images (DI) for 62 patients who had bone and soft tissue lesions. The purpose was to determine whether this technique could be used to ascertain accurately whether lesions were malignant or benign and to predict the response to chemotherapy. The thallium-201 chloride (201Tl) accumulation in malignant tumors and benign lesions was statistically different. Sensitivity, specificity, and accuracy for 201Tl scans in detecting malignant tumors was 94%, 65%, and 82%, respectively, for EI, and 94%, 85%, and 90%, respectively, for DI. On multivariate analysis, significant independent factors for 201Tl uptake were malignant lesions on EI and DI and high cellularity on EI. Thirteen patients with malignant bone and soft tissue tumors underwent 201Tl scans before and after preoperative chemotherapy. There was a good correlation between percentage of tumor necrosis and percentage change of accumulation in lesion-to-normal tissue ration, and the correlation coefficient was higher on EI ( r = 0.801) than on DI ( r = 0.664). These results support the notion that 201Tl scintigraphy, although showing some false-positive and false-negative findings, is a useful tool in the evaluation of either malignant tumors or benign lesions. Furthermore, 201Tl scans on EI provide benefit concerning the evaluation of chemotherapeutic response in patients with malignant bone and soft tissue tumors.

Monitoring therapy in breast cancer

Breast cancer remains one of the most common cancers in the developed world. New treatments are proving effective against both limited disease and metastases. Nuclear medicine is in a unique position as it is one of the only methods used to image the breast which is linked to cell cycle changes, the receptors on the cell surface and the cells' response to chemotherapy. Nuclear medicine is unaffected by the anatomical changes seen post-chemotherapy and radiotherapy and is uniquely placed to become a major methodology in the continued assessment of the breast cancer patient. However, before this can happen the utility of nuclear medicine techniques must be proved in multi-centre trials.

Malignant and benign bone tumors

The authors have intentionally included some confusing examples to demonstrate that the imaging findings of benign and malignant pediatric bone lesions are not always pathognomonic. The radiologist's role is to recognize malignant bone lesions and encourage the prompt referral of these patients to an appropriate institution for biopsy and treatment. The radiologist must also be able to identify benign lesions and help determine whether these lesions require biopsy and intervention or simply observation.

Osteosarcomas and other cancers of bone

The results of several studies suggest that alterations in various cell cycle regulatory genes are involved in the pathogenesis of osteosarcomas. Experiments in animal models provide preliminary data on the feasibility of gene therapy in osteosarcoma and chondrosarcoma. Prediction of response to chemotherapy remains a major focus of imaging research. Several clinicopathologic studies have explored the mechanisms underlying multidrug resistance in osteosarcoma patients receiving neoadjuvant chemotherapy. HER2/erbB2 expression, linked to poor prognosis, has been proposed as a therapeutic target in osteosarcoma. In clinical studies of osteosarcoma, further data confirm the activity of ifosfamide and carboplatin but provide little support for the use of immunotherapy. A retrospective analysis showed no value for dose intensification of doxorubicin/cisplatin, but the results of a prospective trial should be more informative. Recent evidence confirms that secondary osteosarcomas and malignant fibrous histiocytomas of bone should be treated with aggressive chemotherapy regimens, similar to those used for osteosarcomas.