Early prediction of histopathological tumor response to preoperative chemotherapy by Tc-99m MIBI imaging in bone and soft tissue sarcomas

99mTc-MIBI Scintigraphy for the Preoperative Assessment of Histological Response to Neoadjuvant Chemotherapy in Patients With Osteosarcoma: A Systematic Review and a Bivariate Meta-Analysis

Purpose: There have been many attempts to preoperatively evaluate the chemotherapy response of osteosarcoma patients using ^99mTc-MIBI scintigraphy. However, the evaluations were lacking in consistency. We performed this systematic review and meta-analysis to systematically evaluate the ability of ^99mTc-MIBI scintigraphy in preoperatively assessing the response of osteosarcoma patients to neoadjuvant chemotherapy. Methods: For this systematic review and meta-analysis, PubMed, Web of Science, OVID, the Cochrane Library, and CNKI were searched. Eligible studies were included based on the defined criteria. The index test was ^99mTc-MIBI scintigraphy, the reference standard was tumor necrosis rate. Quality Assessment of Diagnostic Accuracy Studies-2 was adopted for quality assessment of included studies. The statistical pooling analysis, meta-regression analysis, subgroup analysis, sensitivity analysis, and publication bias of our research were performed using STATA 15. Results: Eight articles with 189 osteosarcoma patients were included in this systematic review and meta-analysis. Our results demonstrated that the threshold effect of our meta-analysis was significant. The uptake change ratio of ^99mTc-MIBI scintigraphy had a pooled sensitivity, specificity, positive and negative likelihood ratio, diagnostic odds ratio, and the area under curve of 0.98 (0.58-1.00), 0.68 (0.47-0.84), 3.1 (1.7-5.5), 0.03 (0.00-0.90), 103 (4-3,003), and 0.91 (0.88-0.93) in preoperative assessment of response of osteosarcoma patients to neoadjuvant chemotherapy. Meta-regression analysis and subgroup analysis indicated the factors of method and cut off value may introduce the heterogeneity. The pooled sensitivity, specificity, positive and negative likelihood ratio, diagnostic odds ratio, and the area under curve of washout rate of ^99mTc-MIBI were 0.87 (0.69-0.95), 0.91 (0.75-0.97), 9.3 (3.2-27.0), 0.15 (0.06-0.37), 64 (14-301), and 0.89 (0.86-0.92), respectively. Sensitivity analysis and publication bias demonstrated our meta-analysis was reliable. Conclusion: Both the ΔUR and WR derived from ^99mTc-MIBI scintigraphy were valuable in preoperatively assessing the response of osteosarcoma patients to neoadjuvant chemotherapy, and ΔUR may possess a more outstanding diagnostic accuracy than WR.

Prediction and evaluation of neoadjuvant chemotherapy using the dual mechanisms of 99mTc-MIBI scintigraphy in patients with osteosarcoma

Purpose

To investigate the feasibility of applying the dual imaging mechanisms of ^99mTc-MIBI scintigraphy in predicting and evaluating the response to neoadjuvant chemotherapy in patients with osteosarcoma.

Materials and methods

Thirty patients with osteosarcoma who underwent both pre-and post-chemotherapy ^99mTc-MIBI scintigraphy were enrolled in the study. In each patient, the tumor to background ratio (T/B), tumor washout rate (WR) of MIBI and the alteration rate (AR) of tumor uptake after chemotherapy was calculated, respectively, on MIBI scintigraphy before or after chemotherapy. Based on the tumor necrosis rate histologically confirmed by tumor resection after chemotherapy, the diagnostic performance of MIBI scintigraphy was assessed in predicting tumor response with the WR of pre-chemotherapy imaging, as well as evaluating tumor response with the AR of both pre-and post-chemotherapy imaging.

Results

On pre-chemotherapy MIBI imaging, no statistical difference was found in T/B values between patients with good response and those with poor response, but the WR in patients with good response was significantly lower. Tumor WR was negatively correlated with the tumor necrosis rate (r = −0.510, P = 0.004). When WR ≤ 25% was taken as the threshold for predicting good response, a sensitivity of 100%, a specificity of 91.7% and an accuracy of 95.8% would be yielded. On post-chemotherapy imaging, T/B values both on early and delayed phases were significantly lower in responders and AR of tumor uptake was significantly higher in these responders. When AR ≥ 38% was used as the threshold for a good response, a sensitivity of 91.7%, a specificity of 94.4% and an accuracy of 93.3% would be yielded. The diagnostic coincidence rate between WR for predicting chemotherapy response and AR for evaluating chemotherapy response was 90.0% (kappa = 0.789, P < 0.001).

Conclusion

^99mTc-MIBI imaging is a useful tool for the evaluation of neoadjuvant chemotherapy in patients with osteosarcoma, and its dual mechanisms could be simultaneously used in predicting and evaluating tumor response to chemotherapy.

Triple-phase contrast-enhanced MRI for the prediction of preoperative chemotherapeutic effect in patients with osteosarcoma: comparison with (99m)Tc-MIBI scintigraphy

OBJECTIVE

This study aims to determine whether (99m)Tc-MIBI scintigraphy and triple-phase contrast-enhanced magnetic resonance imaging (TCE-MRI) performed during and after preoperative chemotherapy have the power to predict final chemotherapeutic effects in patients with osteosarcoma (OS).

MATERIALS AND METHODS

Seventeen patients underwent (99m)Tc-MIBI scintigraphy and TCE-MRI before and after the middle and last courses of preoperative chemotherapy. As for (99m)Tc-MIBI scintigraphy, an uptake ratio (UR) and a reduction rate of UR (ΔUR(MIBI)) were calculated. As for TCE-MRI, a ratio of contrast to background (CTB) was calculated in the whole tumor area (WA) at each phase on dynamic T1-weighted fat suppression images. Then a ratio of signal (R(WA)) was calculated by dividing CTB at triple-phase by CTB at pre-phase.

RESULTS

Nine and eight patients showed good and poor response in histopathologic evaluation. The sensitivity, specificity, and accuracy for the prediction of histopathological chemotherapeutic effect was 44, 100, 69% in R(WA) at the first phase, 100, 75, 88% in ΔUR(MIBI) after the middle course, 88, 100, 94% in R(WA) at the first phase, and 100, 75, 88% in ΔUR(MIBI) after the last course of the preoperative chemotherapy, respectively.

CONCLUSION

Both (99m)Tc-MIBI scintigrapy and TCE-MRI can predict the tumor response in patients with OS after the completion of the preoperative chemotherapy.

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.

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.