Influence of localization of PSMA-positive oligo-metastases on efficacy of metastasis-directed external-beam radiotherapy-a multicenter retrospective study.

PURPOSE: Approximately 40-70% of biochemically persistent or recurrent prostate cancer (PCa) patients after radical prostatectomy (RPE) are oligo-metastatic in 68gallium-prostate-specific membrane antigen positron emission tomography (68Ga-PSMA PET). Those lesions are frequently located outside the prostate bed, and therefore not cured by the current standards of care like external-beam radiotherapy (EBRT) of the prostatic fossa. This retrospective study analyzes the influence of oligo-metastases' site on outcome after metastasis-directed radiotherapy (MDR). METHODS: Retrospectively, 359 patients with PET-positive PCa recurrences after RPE were analyzed. Biochemical recurrence-free survival (BRFS) (prostate-specific antigen (PSA) < post-radiotherapy nadir + 0.2 ng/mL) was assessed using Kaplan-Meier survival and Cox regression analysis. RESULTS: All patients were initially clinically without distant metastases (cM0). Seventy-five patients had local recurrence within the prostatic fossa, 32 patients had pelvic nodal plus local recurrence, 117 patients had pelvic nodal recurrence, 51 patients had paraaortic lymph node metastases with/without locoregional recurrence, and 84 patients had bone or visceral metastases with/without locoregional recurrence. Median PSA before MDR was 1.2 ng/mL (range, 0.04-47.5). Additive androgen deprivation therapy (ADT) was given in 35% (125/359) of patients. Median PSA nadir after MDR was 0.23 ng/mL (range, < 0.03-18.30). After a median follow-up of 16 months (1-57), 239/351 (68%) patients had no biochemical recurrence. Patients with distant lymph node and/or distant metastases, the so-called oligo-body cohort, had an overall in-field control of 90/98 (91%) but at the same time, an ex-field progress of 44/96 (46%). In comparison, an ex-field progress was detected in 28/154 (18%) patients with local and/or pelvic nodal recurrence (oligo-pelvis group). Compared with the oligo-pelvis group, there was a significantly lower BRFS in oligo-body patients at the last follow-up. CONCLUSION: Overall, BRFS was dependent on patterns of metastatic disease. Thus, MDR of PSMA PET-positive oligo-metastases can be offered considering that about one-third of the patients progressed within a median follow-up of 16 months.

Interobserver variability in target volume delineation of hepatocellular carcinoma : An analysis of the working group "Stereotactic Radiotherapy" of the German Society for Radiation Oncology (DEGRO).

BACKGROUND: Definition of gross tumor volume (GTV) in hepatocellular carcinoma (HCC) requires dedicated imaging in multiple contrast medium phases. The aim of this study was to evaluate the interobserver agreement (IOA) in gross tumor delineation of HCC in a multicenter panel. METHODS: The analysis was performed within the "Stereotactic Radiotherapy" working group of the German Society for Radiation Oncology (DEGRO). The GTVs of three anonymized HCC cases were delineated by 16 physicians from nine centers using multiphasic CT scans. In the first case the tumor was well defined. The second patient had multifocal HCC (one conglomerate and one peripheral tumor) and was previously treated with transarterial chemoembolization (TACE). The peripheral lesion was adjacent to the previous TACE site. The last patient had an extensive HCC with a portal vein thrombosis (PVT) and an inhomogeneous liver parenchyma due to cirrhosis. The IOA was evaluated according to Landis and Koch. RESULTS: The IOA for the first case was excellent (kappa: 0.85); for the second case moderate (kappa: 0.48) for the peripheral tumor and substantial (kappa: 0.73) for the conglomerate. In the case of the peripheral tumor the inconsistency is most likely explained by the necrotic tumor cavity after TACE caudal to the viable tumor. In the last case the IOA was fair, with a kappa of 0.34, with significant heterogeneity concerning the borders of the tumor and the PVT. CONCLUSION: The IOA was very good among the cases were the tumor was well defined. In complex cases, where the tumor did not show the typical characteristics, or in cases with Lipiodol (Guerbet, Paris, France) deposits, IOA agreement was compromised.

Stereotactic body radiotherapy (SBRT) in recurrent or oligometastatic pancreatic cancer : A toxicity review of simultaneous integrated protection (SIP) versus conventional SBRT.

BACKGROUND: Stereotactic body radiotherapy (SBRT) in pancreatic cancer can be limited by its proximity to organs at risk (OAR). In this analysis, we evaluated the toxicity and efficacy of two different treatment approaches in patients with locally recurrent or oligometastatic pancreatic cancer. MATERIALS AND METHODS: According to the prescription method, patients were divided in two cohorts (C1 and C2). The planning target volume (PTV) was created through a 4 mm expansion of the internal target volume. In C2, a subvolume was additionally created, a simultaneous integrated protection (SIP), which is the overlap of the PTV with the planning risk volume of an OAR to which we prescribed a reduced dose. RESULTS: In all, 18 patients were treated (7 with local recurrences, 9 for oligometastases, 2 for both). Twelve of 23 lesions were treated without SIP (C1) and 11 with SIP (C2). The median follow-up was 12.8 months. Median overall survival (OS) was 13.2 (95% confidence interval [CI] 9.8-14.6) months. The OS rates at 6 and 12 months were 87 and 58%, respectively. Freedom from local progression for combined cohorts at 6 and 12 months was 93 and 67% (95% CI 15-36), respectively. Local control was not statistically different between the two groups. One patient in C2 experienced grade ≥3 acute toxicities and 1 patient in C1 experienced a grade ≥3 late toxicity. CONCLUSION: The SIP approach is a useful prescription method for abdominal SBRT with a favorable toxicity profile which does not compromise local control and overall survival despite dose sacrifices in small subvolumes.

Treatment of recurrent prostate cancer following radical prostatectomy: the radiation-oncologists point of view.

Recurrence of prostate cancer after radical prostatectomy is a common event. Salvage radiation therapy (RT) is the mainstay of treatment in cases with recurrence defined as PSA failure, offering the chance of cure. Multiple studies showed that the lower the PSA level at the beginning of salvage RT, the better the treatment outcome. There is evidence that higher radiation doses are associated with improved PSA relapse free rates. Four different recurrence patterns exist: 1) local recurrence in the prostatectomy bed only; 2) loco-regional metastases in the pelvic lymph nodes; 3) distant metastases (most commonly nodal or osseous); 4) a combination of local and distant recurrence. Modern functional imaging modalities like magnetic resonance imaging (MRI) and choline-PET/CT offer additional information to clinical and therapeutic variables and provide high accuracy depending on the level of PSA recurrence and PSA kinetics. These image modalities are valuable tools that can be used for gross tumor volume (GTV) definition in the RT-planning process in the salvage RT setting and guide interdisciplinary salvage therapy strategies in case of locoregional relapse. We discuss the impact of MRI and choline-PET/CT in the salvage setting from the radiation-oncologist point of view.

[Xerostomia. Improved care using a spray with herbal polysaccharides]. / Xerostomie. Verbesserte Linderung durch ein Spray mit pflanzlichen Polysacchariden.

BACKGROUND: In a prospective clinical study the topical use of a polysaccharide-containing spray for the treatment of xerostomia after radiotherapy in the head and neck area was tested. PATIENTS AND METHODS: A total of 83 patients (evaluable return: n=55) with xerostomia after radiotherapy in the head and neck area received a pump spray with 50 ml Saliva natura (medac, Wedel, Germany) to test for 1 week. The patients were asked to fill in a questionnaire about their xerostomia with and without use of the spray. Individual items included: xerostomia in the state of rest, difficulties speaking, eating and sleeping, frequency of the use of treatment against xerostomia, changes in taste, and saliva viscosity. Additionally, they assessed the spray in general and for taste. RESULTS: Patients reported an improvement in all areas included in the questionnaire. The greatest effect of the spray was seen in sleeping difficulties, which improved by almost a whole point from 3.65 to 2.67, as well as in the frequency of use of xerostomia treatment (averagely 15x/day without and 10x/day with the spray). On average the spray was graded as "satisfactory" (3.09), while its taste was graded as "good" (2.17). CONCLUSION: The tested spray may help improve the situation of patients with xerostomia following radiotherapy in the head and neck area. These patients should be given the opportunity to test a spray of this kind.

Analysis of spatial cross-correlations in multi-constituent volume data.

We investigate spatial cross-correlations between two constituents, both belonging to the same microstructure. These investigations are based on two approaches: one via the measurement of the cross-correlation function and the other uses the spatial distances between the constituents. The cross-correlation function can be measured using the fast Fourier transform, whereas the distances are determined via the Euclidean distance transform. The characteristics are derived from volume images obtained by synchrotron microtomography. As an example we consider pore formation in metallic foams, knowledge of which is important to control the foam production process. For this example, we discuss the spatial cross-correlation between the pore space and the blowing agent particles in detail.