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The purpose of this study was the prospective comparison of objective and subjective effects of target volume region of interest (ROI) delineation using mousekeyboard and pen-tablet user input devices (UIDs). The study was designed as a prospective test/retest sequence, with Wilcoxon signed rank test for matchedpair comparison. Twenty-one physician-observers contoured target volume ROIs on four standardized cases (representative of brain, prostate, lung, and head and neck malignancies) twice: once using QWERTY keyboard/scroll-wheel mouse UID and once with pen-tablet UID (DTX2100, Wacom Technology Corporation, Vancouver, WA, USA). Active task time, ROI manipulation task data, and subjective survey data were collected. One hundred twenty-nine target volume ROI sets were collected, with 62 paired pen-tablet/mouse-keyboard sessions. Active contouring time was reduced using the pen-tablet UID, with mean ± SD active contouring time of 26 ±23 min, compared with 32 ± 25 with the mouse (p ≤ 0.01). Subjective estimation of time spent was also reduced from 31 ±26 with mouse to 27 ± 22 min with the pen (p = 0.02). Task analysis showed ROI correction task reduction (p = 0.045) and decreased panning and scrolling tasks (p < 0.01) with the pen-tablet; drawing, window/ level changes, and zoom commands were unchanged (p = n.s.) Volumetric analysis demonstrated no detectable differences in ROI volume nor intra-or inter-observer volumetric coverage. Fifty-two of 62 (84%) users preferred the tablet for each contouring task; 5 of 62 (8%) denoted no preference, and 5 of 62 (8%) chose the mouse interface. The pen-tablet UID reduced active contouring time and reduced correction of ROIs, without substantially altering ROI volume/coverage.

To investigate the impact of hyperthermia thermal dose (TD) on locoregional control (LRC), overall survival (OS) and toxicity in locoregional recurrent breast cancer patients treated with postoperative re-irradiation and hyperthermia. Methods: In this retrospective study, 112 women with resected locoregional recurrent breast cancer treated in 2010-2017 with postoperative re-irradiation 8frx4Gy (n = 34) or 23frx2Gy (n = 78), combined with 4-5 weekly hyperthermia sessions guided by invasive thermometry, were subdivided into 'low' (n = 56) and 'high' TD (n = 56) groups by the best session with highest median cumulative equivalent minutes at 43 °C (Best CEM43T50) < 7.2 min and 7.2 min, respectively. Actuarial LRC, OS and late toxicity incidence were analyzed. Backward multivariable Cox regression and inverse probability weighting (IPW) analysis were performed. Results: TD subgroups showed no significant differences in patient/treatment characteristics. Median follow-up was 43 months (range 1-107 months). High vs. low TD was associated with LRC (p = 0.0013), but not with OS (p = 0.29) or late toxicity (p = 0.58). Three-year LRC was 74.0% vs. 92.3% in the low and high TD group, respectively (p = 0.008). After three years, 25.0% and 0.9% of the patients had late toxicity grade 3 and 4, respectively. Multivariable analysis showed that distant metastasis (HR 17.6; 95%CI 5.2-60.2), lymph node involvement (HR 2.9; 95%CI 1.2-7.2), recurrence site (chest wall vs. breast; HR 4.6; HR 4.1; were associated with LRC. TD was associated with LRC in IPW analysis (p = 0.0018). Conclusions: High thermal dose (best CEM43T50 7.2 min) was associated with significantly higher LRC for patients with locoregional recurrent breast cancer treated with postoperative re-irradiation and hyperthermia, without augmenting toxicity.

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