Purpose: In Gamma Knife (GK) radiosurgery, the occurrence of reapplying the stereotactic frame due to collision with the collimator leads to re‐ examination and re‐planning. For the treatment of vascular lesions, it is a burden not only to physicians but also to patients to get invasive angiography procedure again. To avoid undergoing second angiography examination, and reduce re‐planning time, a mathematical coordinate transformation method using the stereotactic images has been developed. Methods: The MR or CT images of a patient brain before and after frame reapplication can be correlated with each other using the Affine transformation. The transformation parameters which minimize the RMS error of the original and transformed coordinates between the images were determined using a genetic algorithm. Three CT image studies of skull phantom were used for the verification of the algorithm. Moreover, five MR image studies of patients who underwent more than one GK procedure were used for the clinical evaluation. The coordinates under the original treatment plan were converted to new coordinates using the transformation matrix, and their dosimetric outcomes were compared. Results: The RMS error in the coordinate transformation of skull phantom and clinical images was 0.3 mm and 0.6 mm, respectively. For total 9 treatment lesions of 0.2 ∼14.1 cc, 3% and 11% RMS error in the irradiation time and target coverage were found respectively. The patients with only translational movement during the frame reapplication showed similar plan conversion results with the original plan. Also, deeply‐located lesions showed a better RMS error of 3% in the conformity index than superficial lesions close to the skull. Conclusions: New treatment plans were obtained by applying the coordinate transformation to the original plans after the frame reapplication. The converted plans maintained the quality of the original plans with a little change in dose distribution arising from head rotation. This work was supported by a grant no. 04‐2011‐0320110130 from the Seoul National University Hospital Research Fund and a National Research Foundation of Korea (NRFK) grant funded by the Korean government (MEST) (Grant No. K20901000001‐09E0100‐00110).
A 73-year-old woman with rectal adenocarcinoma at 10 cm from the anal verge underwent laparoscopy-assisted low anterior resection with a protective loop ileostomy. Postoperatively the patient received adjuvant radiotherapy and chemotherapy for 6 months. After the chemoradiation treatments, a digital rectal examination prior to ileostomy takedown revealed anastomotic obstruction. Under direct visualization using a colonoscope (CF-Q240; Olympus Optical Co, Ltd, Japan), no opening was found in the anastomotic occlusive web (Figure [1]). Fluoroscopy showed a blind end at the level of the anastomosis (Figure [2]). An injector (NM-200U; Olympus) was inserted into the center of the circular staple line at the level of the anastomosis, and diluted dye (Telebrix; Guerbet, France) was injected to identify the proximal lumen under fluoroscopic guidance (Figure [3]). Injection of water through the injector dilated the lumen of the proximal atrophied bowel. The anastomotic occlusive web was incised in a radial fashion using a needle-papillotome (MTW Endoskopie, Germany) (Figure [4]). Under endoscopic observation, a controlled radial expansion balloon dilator (Boston Scientific Cork Ltd, Ireland) was inserted through the web opening and insufflated with water (Figure [5]). The successful destruction of the occlusive web facilitated passage of the colonoscope, allowing evaluation of the entire colon (Figure [6]). The patient tolerated the procedure well without complications.
5587 Background: Previosly, we reported the accuracy of positron emission tomography with 2-[fluorine18] fluoro-2-deoxy-D- glucose (FDG-PET) for detecting metastatic lymph node (LN) in cervical cancer (Eur J Cancer 2005: 41; 2086–92). The aim of this prospective study was to evaluate the accuracy of PET/CT for detecting lymph node metastasis in cervical cancer and to compare the accuracy between PET and PET/CT. Methods: From May 2002 to Jul 2006, 86 patients with untreated stage IB-IVA cervical cancer were enrolled. All patients underwent pretreatment clinical staging including PET (May 2002-Aug 2003, 54 patients) or PET/CT (Jan 2004-Jul 2006, 32 patients) followed by surgical staging including systematic pelvic and paraaortic lymph node (PLN and PALN) dissection. To enable region specific comparisons, PALN and PLN were divided into eight regions: both PALN, both common iliac areas, both external iliac areas, and both internal iliac/obturator areas. Each lymph node was sliced at 2-mm intervals perpendicular to the greatest dimension to maximize the likelihood of detecting micrometastases. All metastatic tumor size in each involved lymph node was measured. Histopathologic evaluation of lymph nodes was the diagnostic standard. The study protocol was approved by Institutioal Review Board, and a written informed consent was obtained. Results: A total of 688 LN regions were evaluated. The sensitivity, specificity, positive predictive value, and negative predictive value of PET and PET/CT are shown in Table 1 . As the metastatic tumor size increased, the sensitivity of PET and PET/CT was improved. Although there were no differences in sensitivity for detecting large sized (> 5mm or 10mm) metastatic tumor, PET/CT was more sensitive than PET for all pathologically proven LN metastasis which included small sized (< 5mm) metastatic tumor. Conclusions: PET/CT was more sensitive than PET for detecting small sized (<5mm) lymph node metastasis in cervical cancer. [Table: see text] No significant financial relationships to disclose.
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