BackgroundComparing radiation treatment plans to ascertain the optimal intensity-modulated radiation technique for low-risk prostate cancer.MethodsTreatment plans for 20 randomly selected patients were generated using the same dose objectives. A dosimetric comparison was performed between various intensity-modulated techniques, including protons. All treatment plans provided conventional treatment with 79.2Gy. Dosimetric indices for the target volume and organs at risk (OAR), including homogeneity index and four conformity indices were analyzed.ResultsNo statistically significant differences between techniques were observed for homogeneity values. Dose distributions showed significant differences at low-to-medium doses. At doses above 50Gy all techniques revealed a steep dose gradient outside the planning target volume (PTV). Protons demonstrated superior rectum sparing at low-to-higher doses (V10-V70, P < .05) and bladder sparing at low-to-medium doses (V10–V30, P < .05). Helical tomotherapy (HT) provided superior rectum sparing compared to Sliding Window (SW) and Rapid Arc (RA) (V10–V70, P < .05). SW displayed superior bladder sparing compared to HT and RA (V10–V50, P < .05). Protons generated significantly higher femoral heads exposure and HT had superior sparing of those.ConclusionAll techniques are able to provide a homogeneous and highly conformal dose distribution. Protons demonstrated superior sparing of the rectum and bladder at a wide dose spectrum. The radiation technique itself as well as treatment planning algorithms result in different OAR sparing between HT, SW and RA, with superior rectum sparing by HT and superior bladder sparing by SW. Radiation plans can be further optimized by individual modification of dose objectives dependent on treatment plan strategy.Electronic supplementary materialThe online version of this article (doi:10.1186/s13014-016-0707-6) contains supplementary material, which is available to authorized users.

Introduction: Brain metastases (BM) have a very poor prognosis, creating a demand for effective local therapies, such as radiotherapy (RT) and neurosurgery, the combination of which is debatable. The aim of the present study was to investigate prognostic factors and to develop treatment recommendations for patients with BM. Material and Methods: A total of 84 patients treated between May 2011 and July 2016 were analyzed in a single-institution retrospective study. Results: Overall survival (OS) was 10.3 months. Poor OS was defined by a Karnofsky performance index of ≤70% (2.9 vs. 15.8 months; p = 0.009), male gender (6.5 vs. 18.3 months; p = 0.044), and incomplete neurosurgical resection (2.5 vs. 15.8 months; p = 0.017). These factors were also shown to be significant in univariate analysis, while only radical resection remained significant in multivariate testing (p = 0.023). A direct comparison between whole-brain RT (with or without boost) and local RT illustrated a superior OS for local therapy (22.7 vs. 9.5 months; p = 0.022), especially in case of up to 3 metastases (p = 0.041). Intracranial control was 81% with a median duration of 31.6 months. Conclusion: Combined modality treatment of RT and neurosurgery is effective and feasible. A complete removal of all metastases is the cardinal prognostic factor.

Conventionally fractionated moderate-dose RT appears to be a tolerable and effective treatment option for localized PTLD if a sufficient systemic treatment cannot be applied.

There were no differences in the D90 or V100 of the whole prostate, midgland or base when calculated by MRI only dosimetry compared to CT-MRI fusion (P >0.19), but prostate apex D90 was 13% higher when calculated by MRI alone (P Z 0.034). In both methods the D90 and V100 of the base of the prostate gland was reduced 22% compared to the prostate apex and mid-gland. Conclusion: Post-implant MRI only based dosimetry with positive contrast, brachytherapy strand MRI markers is reliable and provides dosimetric values equivalent to CT-MRI fusion, reducing the need for postimplant CT imaging.