Radioguided Surgery Using Intravenous 99mTc Sestamibi Associated with Breast Magnetic Resonance Imaging for Guidance of Breast Cancer Resection

SPECT/CT with 99mTc-sestamibi for the evaluation of skeletal muscle perfusion after electrical muscle stimulation in athletes

Objective

The purpose of this study was to evaluate the effects of electrical muscle stimulation (EMS) on muscles, using ^99mTc-sestamibi SPECT/CT.

Materials and Methods

We prospectively enrolled 20 consecutive male professional water polo players. The mean age was 25 years (range, 18-36 years). All athletes underwent ^99mTc-sestamibi SPECT/CT of the thigh (rectus femoris and vastus medialis muscle groups) before and after EMS. Images were quantified to identify increases in perfusion after EMS.

Results

Before EMS, there were no significant differences between the right and left thigh (rectus femoris and vastus medialis muscles) in terms of perfusion (p = 0.4). However, the comparison between the pre- and post-EMS analyses of the same muscle groups showed significant differences in radiotracer uptake (p < 0.001), with a mean increase in perfusion of 128% for the rectus femoris muscle group (95% CI: 0.86-1.61) and 118% for the vastus medialis muscle group (95% CI: 0.96-1.79).

Conclusion

^99mTc-sestamibi SPECT/CT is an objective means of evaluating blood flow in muscles submitted to EMS, which appears to promote significant increases in such blood flow.

Radio-guided neurosurgery (RGNS): early experience with its use in brain tumour surgery

DEFINITION

Radio Guided Neurosurgery(1) (RGNS) is a technique using systemic administration of radionuclide in which a gamma probe is used intra-operatively to identify isotope-rich brain tumour, and check for residual lesions after excision of visually identifiable lesion.

AIMS

To assess the usefulness of this technique in surface-localizing brain tumours, in real time, intra-operative identification of tumour from brain, and in assessing completeness of excision. Tumours in or near eloquent areas are of special interest.

SETTINGS AND DESIGN

Prospective, non-randomized and non-blinded.

METHODS AND MATERIAL

The study included 19 patients with intrinsic brain tumours operated between July 2005 & December 2006. A high degree of radioisotope uptake was confirmed on Single Positron Emission Computed Tomography (SPECT) with fusion of Computed Tomographic (CT) images (SPECT-CT) in all patients after IV injections of 99m Technetium Sestamibi (Tc). We use a Euro 4 Probe (Euro Medical Instruments, Paris) which detects gamma emissions. Intra-operatively, the probe was used to identify tumour from normal brain using a difference in activity of a factor of 2. The end point was complete tumour removal as determined by absence of significant residual activity.

RESULTS AND CONCLUSIONS

This inexpensive and highly portable system provides realtime, intra-operative identification of tumour and assessment of completeness of tumour excision. It can guide the location of craniotomy and identify visually indistinct tumor from normal brain, a situation where the surgeon may leave behind residual tumour to avoid serious deficits. The use of RGNS enhances the neurosurgeon's confidence with tumours in or near eloquent areas and provides reliable proof of the completeness of excision in real time.

A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology.

Radioguided Intraoperative Margins Evaluation (RIME): Preliminary results of a new technique to aid breast cancer resection

AIMS

Women undergoing breast-conserving surgery for cancer can present residual disease. We have developed a technique called Radioguided Intraoperative Margins Evaluation (RIME) that uses a radiopharmaceutical to distinguish normal and cancer tissues. The aim of this study was to assess whether RIME is a feasible technique, and if it could help in breast cancer resection with free margins, minimizing residual disease.

METHODS

Twenty-three breast cancer patients programmed for mastectomy were selected. Before surgery, the patients were submitted to scintimammography with 99mTc-sestamibi to estimate the optimal time to begin radioguided surgery. Twenty patients were submitted to magnetic resonance imaging (MRI), to evaluate skin, deep fascia and to detect other tumor foci. At the beginning of the surgery, the same dose of 99mTc-sestamibi was intravenously injected into patients. Tumor resection was performed under guidance of a gamma-probe, characterizing the RIME technique. Finally, modified radical mastectomy was performed. Tumor and residual breast were histopathologically examined.

RESULTS

The RIME technique was successfully performed in all patients. The principal tumor was removed by this technique and provided 82.6% of histologically free margins (mean margins, 4.8 mm). Additionally, 47.8% of patients were without residual disease. The mean size of residual carcinoma was 3.67 mm and generally located near the tumor bed (<1.5 cm). There was no significant association between presence of residual disease and tumor size or margin status.

CONCLUSION

RIME is a feasible technique that could help tumor resection with free margins; however, it seems to be limited for small carcinoma foci.

Fusion of Magnetic Resonance and Scintimammography Images for Breast Cancer Evaluation: A Pilot Study

BACKGROUND

To achieve a more specific method to estimate the real size of breast cancer, we have developed a method to fuse magnetic resonance imaging (MRI) and scintimammography (SM) images. The aim of this study was to assess the feasibility of this method and to evaluate its accuracy to measure the size of breast cancer compared with MRI alone, mammography, and clinical examination, employing pathologic size as the gold standard.

METHODS

Twenty consecutive breast cancer women at stages IIA-IIIA, scheduled for mastectomies, underwent SM with (99m)Tc-sestamibi and MRI with gadolinium 2-10 days before surgery. All patients had had recent mammographies and were examined clinically. Software was developed in visual language to perform the fusion between MRI and SM images and tumor measurements (MRI/SM). The tumor size, in 3 diameters (anteroposterior, longitudinal, and transverse), for each examination was correlated with pathological measurements using linear regression.

RESULTS

The MRI/SM technique was successfully performed in all patients, and the principal tumor was measured by this method. The MRI/SM cancer measurements correlated better with pathology than MRI, mammography, and clinical exam in all diameters analyzed (r = 0.88, 0.81, 0.81; SE = 0.11, 0.14, 0.11 in anteroposterior, longitudinal, and transverse diameters, respectively).

CONCLUSIONS

The MRI/SM is a feasible technique and appears to be more accurate than other examinations (MRI alone, mammography, and clinical exam) to measure breast cancer size.