Measurement of radiation dose delivered to breast tissue during mantle field irradiation for Hodgkin's disease.
The treatment of Hodgkin's disease involves mantle field irradiation. Patients with early stage (I-II) Hodgkin's are often in their 20's or 30's and can expect to live for many decades after the successful management of their disease; however, complications, including second cancers in the treatment area, occur in some survivors. Breast cancer is among the leading second solid cancers that develop in patients who have undergone mantle field irradiation. This paper attempts to determine the dose that may be delivered to breast tissue from mantle field irradiation to treat Hodgkin's disease. Utilizing an anthropomorphic phantom, thermoluminescent dosimeters (TLDs) were placed into a breast phantom constructed of Superflab and TX-150, and were irradiated with 6 MV photons. Readings from 170 TLDs in five layers of breast phantom were analyzed. The results show considerable doses reaching portions of breast tissue. In measured points under the blocks, 8-15% of the prescribed isocenter dose was delivered. For points in the primary beam, readings of up to 91% of the isocentric dose were obtained. Points in the breast near block or collimator edges also received substantial doses; upwards of 70% of the prescribed dose. Several points in the breast outside the treatment field were also measured and readings ranged from 2 to 29% of the prescribed dose. Similar patterns of dose distribution were found on computer plans; however, point-by-point comparisons were not performed. These results are compared with published reports.
Kowalski
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The University of Texas M.D. Anderson Cancer Center, Department of Radiation Physics, Houston 77030, USA.
Smith
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S
D001940:Breast / Q000528:radiation effects*; D005260:Female; D006689:Hodgkin Disease / Q000532:radiotherapy*; D006801:Humans; D008961:Models, Structural; D011878:Radiotherapy / Q000009:adverse effects / Q000379:methods; D011879:Radiotherapy Dosage; D013819:Thermoluminescent Dosimetry