**7. Appendix**

546 Advances in Cancer Therapy

from an HLA matching donor or cells collected from the patient while in remission are provided to the leukemia recipient. The clinical desire of the transplant is repopulation and

Preparative regimens for marrow transplantation are required to rid the leukemia patient of any microscopic disease. Rigorous protocols of chemotherapy or radiation therapy combined with chemotherapy are provided prior to transplantation to reduce relapse. Radiotherapy includes fractionated treatments delivered to the total body (TBI). TBI treatments pose several concern issues in methodology and fractionation. High-energy fields with opposing beam arrangements lead to improved dose uniformity. Acrylic plates can serve as beam spoilers to increase the dose to an adequate dose for shallow depths. The lung tissue is sensitive to radiation and limits the dose delivered to the rest of the body. Accurate lung dose calculations are necessary to determine if attenuators are necessary to reduce the total lung dose. Fractionation of the TBI dose requires an increase in the total dose delivered as repair and repopulation occurs between fractions. Repair processes are minimal for the leukemia cell and therefore the therapeutic ratio is enhanced. Analysis of the disease-free survival rates and evaluation of the percentage of patients relapsing or recurring measure the effect of these preparatory regimens. TBI shows a marked improvement in both factors for AML and ALL. Studies reviewing the effects of treatments for CML show excellent results for both chemotherapy only protocols and TBI-

Over the last 35 years, TBI delivery protocols have evolved due to toxicity concerns. Radiationinduced toxicity is influenced by the dose rate and total dose. The total dose was predominantly restricted by pulmonary toxicity from interstitial pneumonitis. Single fraction TBI was replaced with fractionated and hyperfractionated techniques. Radiobiological principles of preferential normal tissue repair with fractionation forecast improved antileukemic effects without increasing toxicity. Dose rate was considered a strong factor in the causation of interstitial pneumonitis and most protocols restrict the delivery dose rate to less than 10 cGy/min. TBI protocols vary with the primary malignancy and complementary chemotherapy conditioning regimen. Current TBI protocols include: a single fraction of 200 Gy; two BID fractions of 2 Gy/fraction; eight BID fractions of 1.5 Gy/fraction with or without lung and liver dose reduction to 8-10 Gy; and eight BID fractions of 1.65 Gy/fraction with or

Factors influencing large field treatment technique choice include dose homogeneity, accurate and reproducible delivery, ease of set up, treatment room limitations, and the treatment protocol used. For example, if a reduced organ dose is required with blocking, an AP/PA treatment technique is required. Different techniques have been described recently including those utilizing tomotherapy or translational couch options. Two methods of comfortable total body irradiation using conventional linear accelerators without machine modifications are presented here. A technique for lateral treatments and a process for AP/PA treatments with blocking are described. Techniques described here enhance other reported design specifications. The technique options represent an evolution in our process and should aid facilities looking to begin a TBI program or facilities desiring modifications

Dose uniformity is the primary criterion when creating a treatment technique. The use of beam spoilers, strategically placed bolus, missing tissue compensators, and opposed fields with high energy x-rays will accomplish the uniformity goal. While dose uniformity is the major priority in developing a suitable treatment technique, patient comfort and support are equally important. Patients presenting for TBI are often weak and recovering from other

re-growth of the stem cells triggering a balanced regulated hemopoietic system.

chemotherapy combined protocols.

without partial transmission blocking of the lung and liver.

to adjust to different treatment protocols.

Legend: 1. 5/8" stainless steel rod, 2. Angle iron for stabilization and support, 3. Adjustable cassette holder, 4. Double track system support for bicycle seat placement, 5. Platform with ¾"plywood on oak framework

Fig. A-1 Front and side view of AP/PA stand .

Photon Total Body Irradiation

for Leukemia Transplantation Therapy: Rationale and Technique Options 549

Legend: 6. 1-1/2"x3-1/2" Oak frame support, 7. Lexan beam spoiler, 8. Support for block tray with galvanized metal support, 9. Galvanized metal lock, 10. Crank, 11. Bearing location & cap (2 bearings/crank), 12. Ball bearing track for horizontal block adjustment, 13. ¼" block tray, 14. 7/16"

thread rod, 15. ¼" channel for rod adjustment system

Fig. A-3 AP/PA Beam Spoiler and Blocking Support Front View

Legend: 1. 5/8" stainless steel rod, 2. Angle iron for stabilization and support, 3. Adjustable cassette holder, 4. Double track system support for bicycle seat placement, 5. Platform with ¾"plywood on oak framework

Fig. A-2 AP/PA Stand Side View

Legend: 1. 5/8" stainless steel rod, 2. Angle iron for stabilization and support, 3. Adjustable cassette holder, 4. Double track system support for bicycle seat placement, 5. Platform with ¾"plywood on oak

framework

Fig. A-2 AP/PA Stand Side View

Legend: 6. 1-1/2"x3-1/2" Oak frame support, 7. Lexan beam spoiler, 8. Support for block tray with galvanized metal support, 9. Galvanized metal lock, 10. Crank, 11. Bearing location & cap (2 bearings/crank), 12. Ball bearing track for horizontal block adjustment, 13. ¼" block tray, 14. 7/16" thread rod, 15. ¼" channel for rod adjustment system

Fig. A-3 AP/PA Beam Spoiler and Blocking Support Front View

Photon Total Body Irradiation

**8. Acknowledgement** 

*40,* 391-396.

27-31.

1941-1949.

*Biology and Physics, 42,* 767-771.

*Radiation Isotopes, 55,* 623-630.

*Investigation, 16,* 397-404.

*Transplantation, 29,* 639-646.

transplantation. *Cancer Investigation, 16,* 424-425.

*Oncology, Biology and Physics, 42,* 1925-1931.

(pp. 2404-2432). Philadelphia, PA: J.B. Lippincott.

system.

**9. References** 

for Leukemia Transplantation Therapy: Rationale and Technique Options 551

The authors express their gratitude to Craig Nicholson for his thoughtful efforts and insight in the construction of the AP/PA stand and the beam spoiler/block support

Bradley, J., Reft, C., Goldman, S., Rubin, C., Nachman, J., Larson, R., et al. (1998).

Bredeson, C., Perry G., Martens C., McDiarmid S., Bence-Bruckler, I. Atkins, H., et al. (2002).

Corns, R., Evans, M., Olivares M., Syke, L., & Pogorsak, E. (2000). Designing attenuators

Evans, R. (2000). Radiobiological considerations in magna-field irradiation. *International* 

Galvin, J., D'Angio, G., & Walsh, G. (1999). Use of tissue compensators to improve dose

Lin, J., & Chu, T. (2001). Dose compensation of the total body irradiation therapy*. Applied* 

Lindsley, K. & Deeg, H.J. (1998). Total body irradiation for marrow or stem-cell

Serota, F., Burkey, E., August, C., & D'Angio, G. (1998). Total body irradiation as

Shank, B. (1999). Techniques of magna-field irradiation. *International Journal of Radiation* 

Shank, B. (1998). Total body irradiation for marrow or stem-cell transplantation. *Cancer* 

Scheinberg, D., Maslak, P., & Weiss, M. (2001). Acute leukemias. In V.T. DeVita & S.

Urbano-Ispizua, A., Schmitz, N., de Witte, T., Frassoni, F., Rosti, G., Schrezenmeier, H., et al.

High-energy total body irradiation as preparation for bone marrow transplantation in leukemia patients: treatment technique and related complications. *International Journal of Radiation Oncology, Biology and Physics,* 

Outpatient total body irradiation as a component of a comprehensive outpatient

for total body irradiation using virtual simulation. *Medical Dosimetry, 25,* 

uniformity for total body irradiation. *International Journal of Radiation Oncology,* 

preparation for bone marrow transplantation in treatment of acute leukemia and aplastic anemia. *International Journal of Radiation Oncology, Biology and Physics, 12,* 

Hellman & S. Rosenberg (Eds.), *Cancer-Principles and Practice of Oncology, (*6th ed.),

(2002). Allogenic and autologous transplantation for hematologic diseases, solid tumors, and immune disorders: definitions and current practice. *Bone Marrow* 

Bentel, G. (1992). *Radiation Therapy Planning* (4th ed.). New York, NY: Macmillan.

transplant program. *Bone Marrow Transplantation, 29,* 667-671.

*Journal of Radiation, Oncology, Biology and Physics, 43,* 1907-1911.

Legend: 6. 1-1/2"x3-1/2" Oak frame support, 7. Lexan beam spoiler, 8. Support for block tray with galvanized metal support, 9. Galvanized metal lock, 10. Crank, 11. Bearing location & cap (2 bearings/crank), 12. Ball bearing track for horizontal block adjustment, 13. ¼" block tray, 14. 7/16" thread rod, 15. ¼" channel for rod adjustment system

Fig. A-4 AP/PA Beam Spoiler and Blocking Support Side View
