Total body irradiation (TBI) prior to bone marrow transplantation – the St. Luke’s Medical Center experience
In recent years, total body irradiation (TBI) has been utilized mainly as a conditioning regimen prior to transplantation for its cytotoxic and immunologic effects. The technique of fractionated TBI prior to bone marrow transplantation for hematologic malignancies, and the immediate toxicities while undergoing TBI in the Department of Radiation Oncology, St. Luke’s Medical Center, Quezon City, are presented.
From 2007 – 2011, 7 patients with acute lymphocytic or myelogenous leukemia underwent TBI prior to bone marrow transplantation. Total doses administered ranged from 800 – 1200 cGy given in 120 – 200 cGy fractions, in 2 – 3 fractions a day for 2 – 4 days. 6 MV photon beams produced by the CLINAC EX linear accelerator via lateral opposed fields at a source to skin distance of 366.8 cm were used. Patients were treated in a supine position, with arms over the chest, positioned in an alpha cradle. Beam spoiler and bolus materials were placed on setup to ensure dose homogeneity. In vivo dosimetry diodes were placed over 12 anatomical regions of the patients for dose monitoring using the PTW Multi-Dose system.Evaluation of immediate toxicity was done through clinical assessment and patient interview during the entire course of TBI.
The technique used for TBI in our department was well tolerated by the patients and setup was reproducible. Data collected from the in vivo dosimetry diodes showed an acceptable dosimetric variability in all patients.
Total body irradiation in our institution was well tolerated, and patients did not have severe immediate side effects during the course of TBI. The most common treatment-related side effects of patients were gastrointestinal and skin toxicity. All the patients experienced RTOG Grade 1 gastrointestinal toxicity: 57% experienced nausea and 57% had episodes of vomiting. These were resolved by oral or intravenous anti-emetics, and did not require additional intravenous hydration or electrolyte correction. There were no reports of diarrhea. 71% experienced pruritus during TBI. Pruritus was managed by application of skin emollients and intake of oral anti-histamines. Pruritus was not associated with erythema, hyperpigmentation or desquamation. Fatigue was reported by 42% of the patients while undergoing TBI. 1 patient experienced headache during TBI, which resolved spontaneously.
All the patients completed TBI in good clinical condition, and were able to proceed with subsequent bone marrow transplantation.
Total body irradiation in the Department of Radiation Oncology, St. Luke’s Medical Center, performed in preparation for transplantation produced acceptable dose homogeneity and was a well-tolerated procedure with no severe immediate side effects.