Radiation doses to contralateral breast during irradiation of breast cancer

External beam radiotherapy is being used regularly to treat the breast malignancy postoperatively. The contribution of collimator leakage and scatter radiation the dose, as well as the dose of the treatment fields, to contralateral breast is of concern because of high radio sensitivity of breast tissue for carcinogenesis. This becomes more important when the treated cancer breast patient is younger than 45 years and therefore the contralateral breast must be treated as organ at risk. Quantification of contralateral dose during primary breast irradiation is helpful to estimate the risk and reduce scatter se to the contralateral breast. In present study contralateral breast dose was measured in 30 cancer breast patients undergoing extenal beam therapy. Postoperative radiotherapy was delivered by medial and lateral tangential fields daily, in addition to supraclavicle field with 200cGy/F to a total dose of 5000cGy in 25 fractions. A themoluminescence dosimeter chips were employed for these measurements. TLD chips were put on the surface of skin of contralateral breast, on the level of nipple, with and without shield, TLD chips were removed and measured for dose after 2h on Harshaw reader 5500. The dose at the contralateral breast nipple mea sured by TLD chips and it was between 4.5 and 17% of the totaI primary breast dose which is 5000cGy in 25 fractions. Further it was observed that the maximum contribution of contralateral breast dose was due to medial tangential half blocked field [in Kds2]. Dose was reduced to one third of the scatter dose to the contralateral breast using 2mm of lead shield and some modifications in the treatment technique. Thermoluminescence dosimetry is quite easy, accurate and convenient method to measure the contralateral breast dose. Reduction in unwanted scatter dose to the trilateral breast is in accord with the philosophy of keeping radiation exposure as low as reasonably achievable and might be of most benefit for young patients

Concurrent weekly cisplatinum and radical radiotherapy versus radical radiotherapy in patients with locally advanced carcinoma of the cervix

Primary end point is to purpose assess the rate of local control for patients with stage IIB-IVA [FIGO] epithelial cervical cancer treated with concomitant weekly cisplatin plus radical radiotherapy compared to a comparable group of patients treated with radical radiotherapy alone. Secondary end points, Diseases free survival, time to progression toxicity profile and overall survival. 60 patients locally advanced carcinoma of cervix [stage lIB, IlIA, IIIB] has been collected and treated with concomitant weekly cisplatin 40-mg/m[2] minutes before radiation plus radical radiotherapy with external radiotherapy 46 Gys in 23 fraction to the whole pelvic followed by single intracavitary brachytherapy insertion using Cs-137 to deliver 40 Gys equivalent to point. A the data was collected and compared to the results of another 60 patients treated with radical radiotherapy alone with same dose EBR and ICR. The incidence of local recurrence and distant metastasis were reduced from 26.6%, 13.3% in group A to 13.3% in group B patients respectively [P = 0.03, P = 0.38]. Disease free and overall survival were higher 76.6% and 85.0% for group B patients compared to 60.0% and 76.6% for group A patients [P = 0.03, P = 0.12]. Time to progression was significantly longer in group B patients compared to group A median 36 months and 18 months respectively. The incidence of a cute treatment toxicity was almost comparable in the two group with group B patients showed slightly higher heamotologic toxicity [P = 0.01]. The results reported in this study showed that concomitant weekly cisplatin plus radical radiotherapy significantly reduce the incidence of pelvic failure and distant metastasis and improve disease free and overlay survival with low toxicity profile in patients with locally advanced carcinoma of cervix