Radiation therapy has multiple roles in the treatment of meningioma although surgery remains the primary treatment of choice. In this retrospective study, we report the results of radiation therapy for meningioma as definitive, postoperative or salvage therapies.

Seventeen patients diagnosed with meningioma were treated with radiation therapy in our institute from May 2000 to October 2009. Radiation therapies were performed as definitive therapies in 8 patients, as postoperative therapies in 5 and as salvage therapies in 4. Nine patients received stereotactic radiosurgery (SRS), 2 patients fractionated stereotactic radiotherapy (FSRT), and 5 patients 3-dimensional conformal radiotherapy (3DCRT). Radiation dose were 12 to 20 Gy for SRS, 36 Gy in 9 fractions for FSRT and 50.4 Gy in 28 fractions for 3DCRT. Follow-up imaging study of computed tomography or magnetic resonance imaging was performed at 6 to 12 months intervals and neurologic exam was performed with an interval less than 6 months.

The median follow-up duration was 38 months (range, 12 to 85 months). Tumor progression after radiation therapy developed in one patient. The reduction of tumor volume measured on follow-up images were more than 20% in 4 patients and minimal change of tumor volume less than 20% were observed in 12 patients. Peritumoral edema developed in 4 patients and disappeared without any treatment. One patient had radiation necrosis.

Our experience is consistent with the current understanding that radiotherapy is as an effective and safe treatment modality for meningiomas when the tumor cannot be resected completely or when recurred after surgery.

The EGFR plays an important role in tumorigenesis and tumor progression of colorectal cancer, and leads to the activation of intracellular signaling pathways. The use of anti-EGFR-targeted therapy has increased for patients with colorectal cancer, but patients with EGFR mutations will be resistant to anti-EGFR-targeted therapy. The identification of gene mutations is critical in cancer treatment; therefore, the aim of this study is to investigate the incidences of EGFR mutations in colorectal cancer patients in Korea.

We reviewed 58 colorectal cancer patients who underwent operations between 2003 and 2006, retrospectively. We analyzed their EGFR mutations in 4 loci by DNA sequencing. In addition, we analyzed the correlation between the presence of EGFR mutation and patients' clinicopathologic features.

Of the 58 patients, 35 patients were male and 23 were female. Their mean age was 63.28±11.18 years. Two patients (3.45%) were diagnosed as stage Tis, 7 patients (12.07%) had stage I, 24 patients (41.38%) had stage II, 20 patients (34.48%) had stage III, and 5 patients (8.62%) had stage IV. As a result of mutational analysis, EGFR mutations on exon 20 were detected in 13 patients (22.41%, G→A transitions). EGFR mutations on exon 18, 19 and 21 were not detected. EGFR mutation increased in the earlier stage and the absence of lymph node metastasis (P=0.028).

The incidence of EGFR mutation in Korean colorectal cancer patients is 22.41%. In addition, EGFR mutation significantly increased in the earlier stage and the absence of lymph node metastasis.