Image-guided-radiotherapy retreatment of spine metastasis: a case report and radiobiological evaluation.

AIMS AND BACKGROUND: The present case report describes vertebral metastasis retreatment using kilovoltage cone-beam computed tomography (CBCT) for setup error correction, in order to improve target irradiation and prevent spinal cord toxicity. We evaluated the feasibility of the second radiation therapy course on the overlapping treatment volume. METHODS AND STUDY DESIGN: A patient with metastatic kidney cancer, previously treated to the tenth dorsal vertebra with conventional radiation planning (21 Gy; 3 x 7 Gy), underwent retreatment. In order to deliver 30 Gy (15 x 2 Gy) to the target volume with the second irradiation, we evaluated the residual dose that could be received by the spinal cord. We calculated the biologically effective dose according to the linear-quadratic model, using an alpha/beta ratio of 2 Gy. A 3-dimensional conformal plan was generated; CBCT imaging was used to ensure accurate repositioning. RESULTS: A total of 15 CBCT scans were performed; the mean setup corrections in the lateral, longitudinal and vertical directions were 3.38 mm (SD 2.09; range, -0.2 mm division by 7.6 mm), 2.13 mm (SD 3.38; range, -5.9 mm divison by 6 mm), and -1.28 mm (SD 2.02; range, -7.1 mm division by 0.3 mm), respectively. CONCLUSION: Image-guided radiotherapy is an alternative approach for the retreatment of spine tumors; it ensures accurate patient setup correction and high-precision treatment delivery, which are required for target volumes very close to critical structures.

Hypofractionated stereotactic radiotherapy in combination with whole brain radiotherapy for brain metastases.

BACKGROUND: The efficacy and toxicity of hypofractionated stereotactic radiotherapy (HSRT) in combination with whole brain radiotherapy (WBRT), for the treatment of 1-4 brain metastases, using a non invasive fixation of the skull, was investigated. METHODS: Between 04/2001 and 01/2006 30 patients with 44 brain metastases underwent irradiation. Every patient received WBRT (10 x 3 Gy); 41/44 lesions received HSRT boost with a median dose fraction of 6 Gy, the fractionation schemes were 3 x 6 Gy and 4 x 8 Gy; a median total dose of 18 Gy was delivered to the tumor isocenter. RESULTS: The median survival period was 9.15 months, the actuarial 1-year overall survival and freedom from new brain metastases were 36.6% and 87.9%, respectively; at univariate analysis Karnofsky Performance Status (KPS) was statistically significant (P = 0.05); the actuarial 1-year local control for the 41/44 lesions was 86.1%. No patient had acute or late complications. CONCLUSIONS: HSRT as a concomitant boost during WBRT is a safe and well tolerated treatment for selected patients with brain metastases.

Retro-orbital granulocytic sarcoma: case report.

Granulocytic sarcomas (chloromas) are rare extra-medullary tumors arising from primitive granulocytic cells. The term "chloroma" is derived from the Greek word chloros (green), and it refers to the frequently greenish color of the tumor, which is due to the presence and oxidation of the myeloperoxidase enzyme. These tumors can arise de novo or can be associated with other myeloid disorders, such as acute or chronic myeloid leukemia, myeloproliferative or myelodysplastic conditions. Presentation can occur prior to, in association with the underlying myeloid disorder, or upon relapse. The location of the tumor can vary: sub-periosteal bone, skull, pelvis, ribs, sternum or lymph nodes. We report the case of a 58-year-old man who presented right exophthalmos and ophthalmoplegy with computerized tomography (CT) evidence of a retro-orbital mass, which histology confirmed to be a granulocytic sarcoma.