Renal Shielding and Dosimetry for Patients With Severe Systemic Sclerosis Receiving Immunoablation With Total Body Irradiation in the Scleroderma: Cyclophosphamide or Transplantation Trial

Journal Article · Tue Mar 15 04:00:00 EDT 2011 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2010.05.036· OSTI ID:21491659

Steffey, Beverly A; Kelsey, Chris R; Larrier, Nicole A ^[1]; Paarz-Largay, Cathy J ^[2]; Prosnitz, Robert G ^[3]; Chao, Nelson; Chute, John; Gasparetto, Cristina; Horwitz, Mitchell; Long, Gwynn; Rizzieri, David; Sullivan, Keith M ^[2]

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1. Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)
2. Division of Cellular Therapy, Duke University Medical Center, Durham, North Carolina (United States)
3. Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States)

Purpose: To describe renal shielding techniques and dosimetry in delivering total body irradiation (TBI) to patients with severe systemic sclerosis (SSc) enrolled in a hematopoietic stem cell transplant protocol. Methods and Materials: The Scleroderma: Cyclophosphamide or Transplantation (SCOT) protocol uses a lymphoablative preparative regimen including 800 cGy TBI delivered in two 200-cGy fractions twice a day before CD34{sup +} selected autologous hematopoietic stem cell transplantation. Lung and kidney doses are limited to 200 cGy to protect organs damaged by SSc. Kidney block proximity to the spinal cord was investigated, and guidelines were developed for acceptable lumbar area TBI dosing. Information about kidney size and the organ shifts from supine to standing positions were recorded using diagnostic ultrasound (US). Minimum distance between the kidney blocks (dkB) and the lumbar spine region dose was recorded, and in vivo dosimetry was performed at several locations to determine the radiation doses delivered. Results: Eleven patients were treated at our center with an anteroposterior (AP)/posteroanterior (PA) TBI technique. A 10% to 20% dose inhomogeneity in the lumbar spine region was achieved with a minimum kidney block separation of 4 to 5 cm. The average lumbar spine dose was 179.6 {+-} 18.1 cGy, with an average dkB of 5.0 {+-} 1.0 cm. Kidney block shield design was accomplished using a combination of US and noncontrast computerized tomography (CT) or CT imaging alone. The renal US revealed a wide range of kidney displacement from upright to supine positions. Overall, the average in vivo dose for the kidney prescription point was 193.4 {+-} 5.1 cGy. Conclusions: The dose to the kidneys can be attenuated while maintaining a 10% to 20% dose inhomogeneity in the lumbar spine area. Kidneys were localized more accurately using both US and CT imaging. With this technique, renal function has been preserved, and the study continues to enroll patients.

• OSTI ID: 21491659
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 4 Vol. 79; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
ALKYLATING AGENTS
ANIMAL CELLS
BODY
CENTRAL NERVOUS SYSTEM
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
DOSES
DRUGS
ENDOXAN
EXTERNAL IRRADIATION
IMMUNOSUPPRESSIVE DRUGS
IRRADIATION
KIDNEYS
LUNGS
NERVOUS SYSTEM
ORGANS
RADIATION DOSES
RESPIRATORY SYSTEM
SHIELDING
SKELETON
SOMATIC CELLS
SPINAL CORD
STEM CELLS
TOMOGRAPHY
TRANSPLANTS
VERTEBRAE
WHOLE-BODY IRRADIATION