Article Figures & Data
Figures
- FIGURE 1.
Distribution of 157 total-body residence times for patients receiving 131I-tositumomab obtained from 3 to 8 total-body γ-counts obtained over 6–7 d during dosimetric study.
- FIGURE 2.
Distribution of 157 measured dose rates at 1 m obtained immediately after therapeutic administration of 131I- tositumomab (1,221–5,957 MBq).
- FIGURE 3.
Comparison of measured and theoretic dose rate at 1 m after therapeutic administration of 131I-tositumomab (n = 157). Theoretic dose rate is calculated using dose equivalent rate per unit activity of 131I (5.95 × 10−5 mSv/MBq h [0.22 mrem/mCi h] at 1 m), which is intended for point source of radioactivity in air and not distributed source in patient. Correlation between 2 measures was 0.858, with measured dose rate, on average, 60% of theoretic dose rate.
- FIGURE 4.
Plot of measured dose rate per MBq (mCi) versus patient mass obtained at 1 m immediately after therapeutic dose of 131I-tositumomab. Measured dose rates per MBq (mCi) were below theoretic dose rate per mCi and tended to be lower in patients with greater mass (r = −0.547).
- FIGURE 5.
Distribution of 157 maximum predicted doses to individuals exposed to patients receiving tositumomab and 131I-tositumomab therapy after immediate release following therapeutic administration. Maximum doses are based on occupancy factor of 0.25 at 1 m.
Tables
- TABLE 1
Determination of 131I-Tositumomab–Treated Patient Releasability According to Patient Dose Rate at 1 Meter and Total-Body Residence Time
Total-body residence time (h) Maximum releasable dose rate at 1 m* (mSv/h) 35 0.460 40 0.413 45 0.375 50 0.343 55 0.316 60 0.294 65 0.274 70 0.257 75 0.241 80 0.228 85 0.216 90 0.205 95 0.195 100 0.186 105 0.178 110 0.171 115 0.164 120 0.157 125 0.151 130 0.146 135 0.141 140 0.136 145 0.132 150 0.128 155 0.124 160 0.120 165 0.117 170 0.114 175 0.110 180 0.108 185 0.105 190 0.102 195 0.100 200 0.097 ↵* Derived in Equation 4.
Instruction no.† Calculated dose at release* (D∞) (mSv) 1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00 3.25 3.50 3.75 4.00 4.25 4.50 4.75 5.00 1 .019 .030 .040 .048 .056 .063 .070 .076 .083 .089 .095 .102 .108 .115 .121 .129 .137 2 .000 .000 .000 .000 .000 .000 .000 .000 .001 .005 .008 .011 .013 .016 .018 .020 .023 3 .041 .050 .058 .064 .070 .075 .079 .083 .087 .090 .093 .096 .099 .101 .104 .106 .108 4 .000 .009 .017 .023 .029 .034 .038 .042 .046 .049 .052 .055 .058 .060 .063 .065 .067 ↵* Calculated dose for individual spending 6 h/d at 1 m from patient (Eq. 3).
↵† Instructions: 1. Sleep in separate bed (at least 2-m separation). 2. Do not take a long trip (≤4 h) sitting near others (e.g., car, train, airplane, bus). 3. Stay at least 2 m from children and pregnant women (calculated using dose of 1 mSv); if no direct contact, use instruction values in row 4. 4. Minimize time spent in close contact with others and delay return to work (calculated using dose of 1 mSv).
Values are days of avoidance per hour total-body residence time (15). Multiply values in appropriate column by patient’s residence time (h) to obtain days required for each instruction to remain in place.
Patient characteristics Value Sex (n) Male 79 (57)* Female 60 (43)* Median age (y) 51 (23–82)† Median patient mass (kg) 79 (48–136)† Median body surface area (mm2) 1.96 (1.43–2.60)† Tumor grade (n) Low-grade 102 (73)* Transformed low-grade 33 (24)* Intermediate to high-grade 4 (3)* Disease stage (n) I 3 (2)* II 7 (5)* III 36 (25)* IV 93 (67)* Bone marrow involvement (n) Yes 70 (51)* No 67 (49)* Bulky disease (n) Yes 54 (39)* No 85 (61)* - TABLE 4
Recommended Times to Avoid Close Contact with Others After Tositumomab and 131I-Tositumomab Therapy
Behavior Mean time (d) Sleeping in common bed for 6 h at distance of 0.3 m 7.8 (2.8–14.6)* Travel for 4 h at distance of 0.3 m 0.3 (0–2.4)* Close contact with infant or pregnant woman at distance of 0.1 m (to limit exposure to 1 mSv) 8.1 (3.5–12.9)* Contact with others of >6 h at 1 m (to limit exposure to 1 mSv) 4.3 (1.5–7.2)* ↵* Values in parentheses are range.
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