Optical Surface-guided Radiation Therapy for Upper and Lower Limb Sarcomas: An Analysis of Setup Errors and Clinical Target Volume-To-Planning Target Volume Margins.

Purpose: To assess the clinical benefits of surface-guided radiation therapy (SGRT) in terms of setup error, positioning time, and clinical target volume-to-planning target volume (CTV-PTV) margin in extremity soft tissue sarcoma (STS). Methods and Materials: Fifty consecutive patients treated with radiation therapy were selected retrospectively. Treatment setup was performed with either laser-based imaging only (control group), or with laser-based and daily optical surface-based imaging (SGRT group). Pretreatment cone beam computed tomography images were acquired daily for the first 3 to 5 fractions and weekly thereafter, with the frequency adjusted as necessary. Translational and rotational errors were collected. CTV-PTV margin was calculated using the formula, 2.5Σ + 0.7σ. Results: Each group consisted of 10 and 15 upper and lower limb STSs, respectively. For patients with upper limb sarcomas, the translation errors were 1.64 ± 1.34 mm, 1.10 ± 1.50 mm, and 1.24 ± 1.45 mm in the SGRT group, and 1.48 ± 3.16 mm, 2.84 ± 2.85 mm, and 3.14 ± 3.29 mm in control group in the left-right, supero-inferior, and antero-posterior directions, respectively. Correspondingly, for patients with lower limb sarcomas, the translation errors were 1.21 ± 1.65 mm, 1.39 ± 1.71 mm, and 1.48 ± 2.10 mm in the SGRT group, and 1.81 ± 2.60 mm, 2.93 ± 3.28 mm, and 3.53 ± 3.75 mm in control group, respectively. The calculated CTV-PTV margins of the SGRT group and control group were 5.0, 3.8, 4.1 versus 5.9, 9.1, 10.1 mm for upper limb sarcomas; and 4.2, 4.7, 5.2 mm versus 6.3, 9.6, and 11.4 mm for lower limb sarcomas in the left-right, supero-inferior, and antero-posterior directions, respectively. Conclusions: Daily optical surface guidance can effectively improve the setup accuracy of extremity STS patients, and safely reduce the required CTV-PTV margins.

Fractionated stereotactic radiotherapy for 136 patients with locally residual nasopharyngeal carcinoma.

BACKGROUND: To evaluate the efficacy and toxicity of fractionated stereotactic radiotherapy (FSRT) in patients with residual nasopharyngeal carcinoma (NPC). METHODS: From January 2000 to December 2009, 136 NPC patients with residual lesions after primary radiotherapy (RT) were treated by FSRT. The total dose of primary RT was 68.0-78.0 Gy (median, 70.0 Gy). The median time from the primary RT to FSRT was 24.5 days. Tumor volumes for FSRT ranged from 0.60 to 77.13 cm3 (median, 13.45 cm3). The total FSRT doses were 8.0-32.0Gy (median, 19.5 Gy) with 2.0-10.0 Gy per fraction. RESULTS: Five-year local failure-free survival (LFFS), freedom from distant metastasis (FFDM), overall survival (OS), and disease free survival (DFS) rates for all patients were 92.5%, 77.0%, 76.2%, and 73.6%, respectively. No statistical significant differences were found in LFFS, DFS and OS in patients with stage I/II versus stage III/ IV diseases. Nineteen patients exhibited late toxicity. T stage at diagnosis was a significant prognostic factor for OS and DFS. Age was a prognostic factor for OS. CONCLUSION: FSRT after external beam radiotherapy provides excellent local control for patients with residual NPC. The incidence of severe late toxicity is low and acceptable. Further investigation of optimal fractionation regimens will facilitate reduction of long-term complications.

Fractionated stereotactic radiotherapy with vagina carotica protection technique for local residual nasopharyngeal carcinoma after primary radiotherapy.

BACKGROUND: Local failure of nasopharyngeal carcinoma (NPC) after radiotherapy (RT) remains one of the major treatment failures. This study aimed to evaluate the clinical efficacy and complications of fractionated stereotactic radiotherapy (FSRT) with vagina carotica protection technique for local residual of NPC patients after the primary RT. METHODS: From August 2006 to August 2010, FSRT with vagina carotica protection technique was applied to 36 patients in our department, the patients aged between 13 and 76 years with a median of 41.3 years, 25 of them were male and 11 were female. According to 2002 Union for International Cancer Control (UICC) Staging System, the stages before primary radiotherapy were: IIa 2, IIb 5, III 18, IVa 7, IVb 4. In the first course of radiotherapy, 9 patients received conventional RT, 27 patients received intensity modulated radiotherapy (IMRT) and 20 out of the 36 patients received concurrent chemoradiotherapy. The total dose in the first course of RT was 69.96 - 76.90 Gy (median, 72.58 Gy). The intervals between the primary RT and FSRT ranged from 12 to 147 days (median, 39.8 days). Target volumes ranged from 1.46 to 32.98 cm(3) (median, 14.94 cm(3)). The total FSRT doses were 10.0 - 24.0 Gy (median, 16.5 Gy) with 2.0 - 5.0 Gy per fraction. The most common regimen was 15 Gy in 5 fractions of 3 Gy, the irradiation dose to vagina carotica was less than 2 Gy per fraction. RESULTS: The median follow-up time was 34 months (range, 12 - 59 months). The 3-year local control rate was 100%; the 3-year overall survival rate was 94.4%; the 3-year disease-free survival rate was 77.8%. In this study, we had one case of cranial nerve injury, two cases of temporal lobe necrosis, and no nasopharyngeal massive hemorrhage was observed. CONCLUSION: FSRT with vagina carotica protection technique is an effective and safe RT regimen for local residual of NPC with reduction of radiation-related neurovascular lesions.