A Novel Method to Set Appropriate Gating Window for Deep Inspiration Breath Hold Patients

Abstract

was longest for patients with breast conservation receiving lumpectomy and radiation (BCT), 5.0 years, and shortest for patients with lumpectomy alone, 2.4 years, consistent with our recent change in practice to allow observation in patients with low risk tumors. Overall, there were 2 ipsilateral recurrences in 28 patients treated with lumpectomy alone, 2 in patients treated with mastectomy, and 19 in patients treated with BCT. Five and 15 year ipsilateral recurrence rate was 6% and 32.6% respectively for patients treated with BCT versus 1% and 2.8% respectively for those treated with mastectomy. Ten of the 19 recurrences in patients treated with BCT were invasive ductal carcinoma (IDC), of which 9 patients received HDR brachytherapy as either APBI (2) or as a boost (7). Nine of the 19 recurrences in the BCT population were DCIS and none of these patients underwent HDR based APBI, while only two of the nine had HDR boost. Time to ipsilateral DCIS recurrence ranged from 0.6 to 17.7 years, with a median of 2.9 years. Time to ipsilateral IDC recurrence ranged from 0.5 to 15.5 years, with a median of 9.3 years. Conclusion: Our findings are consistent with historical data, showing a low rate of recurrence for mastectomy as compared to BCT and equivalent numbers of DCIS and invasive recurrences. However, 15 year recurrence rates in the lumpectomy and radiation group were higher than expected, 32.6%. Furthermore, a majority of our IDC recurrences received catheter based APBI. While the numbers are small, these findings certainly warrant caution for use of APBI for patients with DCIS.

Is 5 mm breath-hold window (BHW) sufficient to treat carcinoma left breast patients post-conservative surgery: a comparative study using forward intensity-modulated radiotherapy (FIMRT) and volumetric modulated arc therapy (VMAT)

“…There are some studies suggesting that a 5 mm BHW would be an optimal window level and this is being widely followed. 13,14 The treatment can be performed while selecting a 5 mm BHW, only if the inspiration lies anywhere within the window level. Inspiration level may not be uniform during the entire course of the treatment, and it may vary from time to time.…”