Introduction: External radiation therapy for bladder cancer requires large planning target volumes (PTVs) due to the daily anatomy of the bladder. Online adaptive radiotherapy (oART) can reduce the PTV by considering daily anatomical changes. Patients and methods: We performed oART in 8 patients with muscle-invasive bladder cancer between June 10, 2022, and April 14, 2023, on an Ethos linear accelerator (Varian, Palo Alto, USA). Using the 496 cone-beam computed tomography (CBCT) images of the fractions, we retrospectively compared the differences in volumetric changes between oART and image-guided and intensity-modulated radiotherapy (IGRT/IMRT). According to our local protocol, for oART, a patient-specific PTV margin was created based on the intrafractional clinical target volume (CTV) changes observed during the first three fractions. Results: The average duration of treatment was 14.8 min (range 7–49 min). The average volume of the PTV with oART and IGRT/IMRT was 296.8 cm ³ (range 114.5–810.4 cm ³ ) and 416.5 cm ³ (range 188.2–991.3 cm ³ ), respectively, representing a 30% reduction with oART. This new technique resulted in an average reduction of 43.9% in the volume of unnecessarily irradiated healthy tissues. Geometrical miss of the CTV occurred in 13 fractions with IGRT/IMRT, with an average of 9.4 cm ³ of missed volume (range 0.4–56.4 cm ³ , standard deviation [SD] 15.73), for oART in 7 fractions, with an average missed volume of 4 cm ³ (range 0.4–21.2 cm ³ , SD: 7.6). Conclusion: The use of patient-specific margins in oART allows for reduction of the PTV and dose to healthy tissues while achieving equal or better target coverage.

Background: The development of cancer and anti-tumor therapies can lead to systemic immune alterations but little is known about how long immune dysfunction persists in cancer survivors. Methods: We followed changes in the cellular immune parameters of prostate cancer patients with good prognostic criteria treated with low dose rate brachytherapy before and up to 3 years after the initiation of therapy. Results: Patients before therapy had a reduced CD4+ T cell pool and increased regulatory T cell fraction and these alterations persisted or got amplified during the 36-month follow-up. A significant decrease in the total NK cell number and a redistribution of the circulating NK cells in favor of a less functional anergic subpopulation was seen in patients before therapy but tumor regression led to the regeneration of the NK cell pool and functional integrity. The fraction of lymphoid DCs was increased in patients both before therapy and throughout the whole follow-up. Increased PDGF-AA, BB, CCL5 and CXCL5 levels were measured in patients before treatment but protein levels rapidly normalized. Conclusions: while NK cell dysfunction recovered, long-term, residual alterations persisted in the adaptive and partly in the innate immune system.

The aim of the study was to compare the side effects of high-dose-rate brachytherapy (HDRBT) and low-dose-rate brachytherapy (LDRBT), with a particular focus on the effects on sexual functions and sexual well-being (PROMOBRA study, NCT02258087). Localized low-risk and low-intermediate-risk prostate cancer patients were treated with mono LDR (N=123, 145Gy dose) or mono HDR brachytherapy (N=117, 19/21Gy). Prior to the treatment and during follow-up (at 3, 6, 9, 12, 18, and 24months after treatment, and then annually after two years), patients completed patient-reported outcome measurement (PROM) questionnaires EORTC QLQ-PR-25, International Index of Erectile Function (IIEF), and IIEF-5 (SHIM). We compared the patients in different group breakdowns (HDR vs. LDR, hormone naïve and hormone-receiving HDR vs. LDR, hormone naïve and hormone-receiving patients in general, and 19Gy HDR vs. 21Gy HDR). In the hormone-naive LDR group, erectile function, orgasm function, sexual desire, satisfaction with intercourse, and overall satisfaction functions significantly decreased compared to baseline throughout the whole follow-up period. However, there were significant decreases in function at a maximum of three time points after HDR therapy without hormone therapy. In hormone-receiving patients, the orgasm function was significantly better in the HDR group at multiple time points compared to the baseline, and sexual desire improved at four time points. According to our results, both LDRBT and HDRBT can be safely administered to patients with localized prostate cancer. In hormone-naive patients, the HDR group showed only recovering decreases in sexual functions, while the LDR group showed a lasting decline in multiple areas. Thus, HDR appears to be more advantageous to hormone-naive patients.

In the treatment of node-negative, non-metastatic high-risk (HR) and very high-risk (VHR) prostate cancer, the necessity of elective pelvic irradiation is controversial. According to our in-house treatment protocol − elective pelvic irradiation is generally omitted for HR and VHR patients over the age of 70 or those in poor general health due to its toxicity. To retrospectively examine the outcome for HR and VHR prostate cancer patients treated with elective whole pelvic radiotherapy (WPRT) versus prostate-only radiotherapy (PORT). The study included 434 patients treated with definitive radiotherapy, 203 patients received PORT (HR: 127, VHR: 76) and 231 WPRT (HR: 113, VHR: 118) with a boost to the prostate. Patients also received 2–3 years of androgen deprivation. Patients’ average age who received PORT vs. WPRT was 73.9 ± 4.3 years vs. 66.4 ± 5.4 years respectively. An inverse propensity score weighting method was utilized to create homogeneous WPRT and PORT treatment groups that are balanced for T stage, PSA, and Gleason score, but not for age. The survival outcomes for HR and VHR subgroups were examined depending on whether they received WPRT or PORT. Biochemical- (BRFS), local- (LRFS) and regional relapse-free survival (RRFS), distant metastasis-free- (DMFS), disease-free- (DFS), failure-free- (FFS), and overall survival (OS) were compared using the Kaplan −Meier method and Cox regression analysis. The median follow-up time was 76 months (3–134 months). In the VHR subgroup five-year outcomes showed a significant advantage for patients receiving WPRT vs. PORT in BRFS (82.2 % vs. 73 %; p = 0.028), in DMFS (87.5 % vs. 73.6 %; p = 0.025), in DFS (86.1 % vs. 70.5 %; p = 0.012), and in FFS (82.3 % vs. 68.9 %; p = 0.005), respectively. The OS (92.8 % vs. 81.8 %; p = 0.056) showed a trend favoring the WPRT group. There was no significant difference between WPRT vs. PORT in LRFS (95.8 % vs. 96.4 %; p = 0.763) and RRFS (95.8 % vs. 89.9 %; p = 0.099). On the contrary, in the HR group, no significant survival differences were observed between WPRT vs. PORT groups: BRFS 93.0 % vs. 93.3 % (p = 0.978), LRFS 99.0 % vs. 100 % (p = 0.120), RRFS 98.2 % vs. 95.1 % (p = 0.813), DMFS 93.5 % vs. 95.5 % (p = 0.793), DFS 91.7 % vs. 92.9 % (p = 0.691), FFS 89.5 % vs. 90.9 % (p = 0.853), OS 91.0 % vs. 87.7 % (p = 0.407). Based on our retrospective data elective pelvic irradiation can be omitted in HR patients, especially over the age of 70. For VHR patients, elective pelvic irradiation should be considered even for the subgroup of elderly patients.

The Hadwiger–Nelson problem is about determining the chromatic number of the plane (CNP), defined as the minimum number of colours needed to colour the plane so that no two points of distance 1 have the same colour. In this paper we investigate a related problem for spheres and we use a few natural restrictions on the colouring. Thomassen showed that with these restrictions, the chromatic number of all manifolds satisfying certain properties (including the plane and all spheres with a large enough radius) is at least 7. We prove that with these restrictions, the chromatic number of any sphere with a large enough radius is at least 8. This also gives a new lower bound for the minimum colours needed for colouring the 3-dimensional space with the same restrictions.