CyberKnife stereotactic radiotherapy for isolated recurrence in the prostatic bed.

PURPOSE: To report a clinical experience of stereotactic body radiation therapy (SBRT) for isolated recurrence in the prostatic bed from prostate cancer. MATERIALS AND METHODS: Between November 2011 and November 2013, 16 patients were treated with SBRT for a macroscopic isolated recurrence of prostate cancer in the prostatic bed. All patients were initially treated with radical prostatectomy, and half of them also received radiotherapy. Two schedules of SBRT were used: 30 Gy in 5 fractions in previously irradiated patients, 35 Gy in five fractions in radiotherapy-naïve patients. RESULTS: At a median follow-up of 10 months (range 2-21 months), a significant biochemical response was found in all but one patient. At imaging evaluation, no local progression was noted: 10 patients showed partial response while four stable disease. At the moment of analysis, all 16 patients were alive. Seven of them experienced distant relapse, while nine maintained biochemical control, with no further therapy. Median time to relapse was 9.3 months (range 3-15.2 months). The treatment was well tolerated: One patient experienced G2 acute genitourinary and gastrointestinal toxicity. CONCLUSIONS: Our experience shows that SBRT with CyberKnife for isolated nodal relapse is a safe and well-tolerated treatment.

Cyberknife treatment for low and intermediate risk prostate cancer.

Cyberknife is an emerging treatment for early stage prostate cancer. Between October 2012 and January 2014, 32 patients were treated in our institution. Prescribed dose was 35-36.25 Gy in five fractions. Biochemical response was observed in 22 patients. Four patients experienced G2 acute genitourinary toxicity and in two cases we recorded G3 acute GU toxicity. 5 patients experienced G2 acute proctitis. At last follow up visit, all patients were still alive. 29 remained free of disease at last follow up appointment, while three developed a biochemical recurrence. Our experience confirms the efficacy and safety of Cyberknife for localized prostate cancer.

Stereotactic radiotherapy for isolated nodal recurrence of prostate cancer.

PURPOSE: To report a clinical experience in stereotactic body radiation therapy (SBRT) for isolated nodal metastases from prostate cancer. MATERIALS AND METHODS: Between November 2011 and December 2013, 30 patients (39 lesions) were treated with SBRT, delivered using Cyberknife, for recurrent prostate cancer with isolated nodal metastases. Prescribed doses and schedules of fractionation varied, ranging from 24 Gy in 1 fraction to 36 Gy in 3 fractions. Most commonly used schedules were 30 Gy in 3 fractions and 36 in Gy in 3 fractions on alternating days. Biochemical response, acute and late toxicity were analyzed. RESULTS: At a median follow-up of 12 months (range 2-24.9), a significant reduction of PSA was observed in 24 cases, while PSA was stable in 1 case and raised in 9 cases. At the time of analysis, among the 30 patients treated, two were dead for systemic disease; 12 patients experienced a relapse of disease in other sites. Sixteen patients were still free of disease. In 24 cases, imaging evaluation 3 months after treatment was available. No in-field recurrence was detected. SBRT was well tolerated: One patient experienced G2 acute genitourinary toxicity. Late toxicity was evaluated in patients with more than 6 months of follow-up, and only one complained G1 proctitis. We did not observe any acute or late severe toxicity (≥G3). CONCLUSIONS: Our experience shows that SBRT for isolated nodal relapse from prostate cancer is a safe treatment, with promising results in terms of efficacy.

Full-genome sequencing of a Hungarian canine G3P[3] Rotavirus A strain reveals high genetic relatedness with a historic Italian human strain.

A canine Rotavirus A strain was identified in the fecal specimen of a young dog during 2012 in Hungary. The strain RVA/Dog-wt/HUN/135/2012/G3P[3] shared complete genotype constellation (G3-P[3]-I3-R3-C3-M3-A15-N2-T3-E3-H6) and high genome sequence similarity (nt, 98.8 %) with a historic human strain, RVA/Human-tc/ITA/PA260-97/1997/G3P[3]. This study provides evidence for the canine origin of the unusual NSP1 genotype, A15, and reinforces the hypothesis of direct interspecies transmission of canine rotaviruses to humans.

Stereotactic Re-irradiation in Recurrent Prostate Cancer after Previous Postoperative or Definitive Radiotherapy: Long-term Results after a Median Follow-up of 4 Years.

AIMS: In 2018, we published early results from a cohort of patients treated with stereotactic body radiotherapy (SBRT) after previous radiotherapy with definitive or postoperative intent. We sought to provide extended follow-up of this cohort to confirm the safety and efficacy of this approach in a real-world scenario. MATERIALS AND METHODS: Fifty patients affected by local relapse after previous definitive or postoperative radiotherapy were treated with SBRT. Treatment provided a total dose of 30 Gy in five fractions. Data about biochemical relapse-free survival (BRFS) and metastasis-free survival (MFS), together with adverse events, were analysed. Toxicity was reported according to Common Terminology Criteria for Adverse Events (CTCAE) score v.4.03. RESULTS: After a median follow-up of 48.2 months, the median BRFS was 43 months. A Gleason score >7 and concomitant androgen deprivation therapy were shown to be predictors of the worst BRFS (hazard ratio 2.42, 95% confidence interval 1.09-5.41, P = 0.02; hazard ratio 2.83, 95% confidence interval 1.17-6.8, P = 0.02, respectively). The median MFS was not reached; concomitant androgen deprivation therapy was confirmed to be predictive of the worst MFS (hazard ratio 4.75, 95% confidence interval 1.52-14.8, P = 0.007). Late grade 1 and 2 rectal and bladder toxicity occurred in three (6%) and 13 (26%) patients, respectively. One patient experienced both grade 3 acute and chronic bladder toxicity. CONCLUSION: Salvage SBRT re-irradiation after previous postoperative or definitive radiotherapy for local prostate cancer recurrence confirmed promising results in terms of oncological outcomes and the safety of this approach.

Quality assurance of volumetric modulated arc therapy: evaluation and comparison of different dosimetric systems.

PURPOSE: To compare and evaluate different dosimetric techniques and devices for the QA of VMAT plans created by two treatment planning systems (TPSs). METHODS: A total of 50 VMAT plans were optimized for treatment of anatomical sites of various complexities by two TPSs which use rather different approaches to VMAT optimization. Dosimetric plan verifications were performed both as part of commissioning and as patient specific QA of clinical treatments. Absolute point doses were measured for all plans by a micro ion chamber inserted in a dedicated water-filled cylindrical phantom. Delivered dose distributions were verified by four techniques based on different detectors: radiographic and gafchromic films, two systems based on 2D diode arrays and an ion chamber array. Gamma index analysis with various tolerance levels (3%, 3 mm and 3%, 2 mm) was used to analyze differences between calculated and delivered doses. Sensitivity to possible delivery errors was also evaluated for three of the considered devices introducing +/-3 mm shifts along the three directions and a 3 degrees gantry offset. RESULTS: Ion chamber measured point doses were within 3% of calculated ones for 48 out of 50 values. For delivered dose distribution, the average fraction of passed gamma values using 3% and 3 mm criteria was above 95% for both TPSs and all detectors except gafchromic film which yielded on average of 91.4%. For 49 out of 50 plans, a pass-rate above 94% was obtained by at least one of the four techniques. Shrinking the tolerance to 3% and 2 mm, the average pass-rate by all detectors (except film) was still above 95% for one of the two TPSs, but lower for the other one. The detector sensitivity to 3 mm shifts and to gantry angle offset was strongly plan and partially detector dependent: the obtained pass-rate reduction ranged from 2% to 30%. CONCLUSIONS: The presented results for VMAT plans QA assess the reliability of the delivered doses for both TPSs. The slightly lower pass-rate obtained for one of the considered TPS can be attributed to a higher level of complexity of the optimized plans. The results by different dosimetric techniques are coherent, apart from a few measurements by gafchromic films. The detector sensitivity to delivery errors, being strongly plan dependent, is not easy to evaluate.

Pancreatic function and gene deletion F508 in cystic fibrosis.

In view of the possible relation between pancreatic function and cystic fibrosis (CF) gene mutations, a detailed study on Italian patients was performed. Seventy pancreatic insufficient and 48 pancreatic sufficient patients were included after very accurate characterisation of their pancreatic and digestive function, all performed in the same CF centre. The CF gene deletion F508 was tested to define the patients' genotypes. The results confirm that the mutation correlates with pancreatic insufficiency, and is recessive to other, as yet unreported, mutant alleles that determine pancreatic sufficiency. An indication that duodenal bicarbonate output is more severely reduced in the presence of deletion F508 is also presented. The data are discussed in relation to a hypothesis on the primary effects of CF gene deletion F508.