Whole-pelvic irradiation with boost to involved nodes and prostate in node-positive prostate cancer-long-term data from the prospective PLATIN-2 trial

PURPOSE

Node-positive prostate cancer is a potentially curable disease. Definitive radiotherapy to the prostate and lymphatic drainage is an effective treatment option but prospective long-term outcome data are scarce. Thus, the current study aimed to evaluate the toxicity and efficacy of definitive radiation therapy for men with prostate cancer and nodal metastases using modern irradiation techniques.

METHODS

A total of 40 treatment-naïve men with node-positive prostate cancer were allocated to the trial. All patients received definitive radiation therapy at two German university hospitals between 2009 and 2018. Radiation was delivered as intensity-modulated radiation therapy (IMRT) with 51 Gy to the lymphatic drainage with simultaneous integrated boost (SIB) up to 61.2 Gy to involved nodes and 76.5 Gy to the prostate in 34 fractions. Feasibility and safety, overall and progression-free survival, toxicity, and quality of life measurements were analyzed.

RESULTS

During a median follow-up of 79 months, median overall survival was 107 months and progression-free survival was 78 months. Based on imaging follow-up, no infield relapse was reported during the first 24 months of follow-up. There were 3 (8%) potentially treatment-related grade 3 toxicities. Common iliac node involvement was associated with a higher risk of progression (HR 15.8; 95% CI 2.1-119.8; p = 0.007).

CONCLUSION

Definitive radiation to the lymphatic drainage with SIB to the involved nodes and prostate is a safe and effective treatment approach for patients with treatment-naïve, node-positive prostate cancer with excellent infield tumor control rates and tolerable toxicity. Location rather than number of involved nodes is a major risk factor for progression.

Stereotactic MRI-guided radiation therapy for localized prostate cancer (SMILE): a prospective, multicentric phase-II-trial

Background

Normofractionated radiation regimes for definitive prostate cancer treatment usually extend over 7–8 weeks. Recently, moderate hypofractionation with doses per fraction between 2.2 and 4 Gy has been shown to be safe and feasible with oncologic non-inferiority compared to normofractionation. Radiobiologic considerations lead to the assumption that prostate cancer might benefit in particular from hypofractionation in terms of tumor control and toxicity. First data related to ultrahypofractionation demonstrate that the overall treatment time can be reduced to 5–7 fractions with single doses > 6 Gy safely, even with simultaneous focal boosting of macroscopic tumor(s). With MR-guided linear accelerators (MR-linacs) entering clinical routine, invasive fiducial implantations become unnecessary. The aim of the multicentric SMILE study is to evaluate the use of MRI-guided stereotactic radiotherapy for localized prostate cancer in 5 fractions regarding safety and feasibility.

Methods

The study is designed as a prospective, one-armed, two-stage, multi-center phase-II-trial with 68 patients planned. Low- and intermediate-risk localized prostate cancer patients will be eligible for the study as well as early high-risk patients (cT3a and/or Gleason Score ≤ 8 and/or PSA ≤ 20 ng/ml) according to d’Amico. All patients will receive definitive MRI-guided stereotactic radiation therapy with a total dose of 37.5 Gy in 5 fractions (single dose 7.5 Gy) on alternating days. A focal simultaneous integrated boost to MRI-defined tumor(s) up to 40 Gy can optionally be applied. The primary composite endpoint includes the assessment of urogenital or gastrointestinal toxicity ≥ grade 2 or treatment-related discontinuation of therapy. The use of MRI-guided radiotherapy enables online plan adaptation and intrafractional gating to ensure optimal target volume coverage and protection of organs at risk.

Discussion

With moderate hypofractionation being the standard in definitive radiation therapy for localized prostate cancer at many institutions, ultrahypofractionation could be the next step towards reducing treatment time without compromising oncologic outcomes and toxicities. MRI-guided radiotherapy could qualify as an advantageous tool as no invasive procedures have to precede in therapeutic workflows. Furthermore, MRI guidance combined with gating and plan adaptation might be essential in order to increase treatment effectivity and reduce toxicity at the same time.

P05.07 Effect of Tumor-Treating Fields plus Short-Course Radiation with or without Temozolomide in Elderly Patients with Glioblastoma (GERAS Trial)

BACKGROUND

Despite advances in the therapy of glioblastomas (GBM) in the last decades, the most common malignancy of glial origin is still associated with poor prognosis. At present, maximal safe resection followed by adjuvant chemoradiotherapy (CRT) with temozolomide (TMZ) is the standard of care. After completion of CRT, patients usually receive 6 maintenance cycles of TMZ that may be complemented by Tumor-Treating Fields (TTFields). Regardless of age and other prognostic factors, the recent EF-14 trial has shown that addition of TTFields to the maintenance therapy significantly increases overall survival in all patient subgroups. In the EF-14 trial, TTFields were used during maintenance therapy, however a potential benefit of concomitant TTFields therapy during CRT remains unclear. In elderly patients aged >65–70 years, depending on performance status, hypofractionated (chemo)radiotherapy with or without TMZ is the recommended treatment.The primary aim of the GERAS trials is to investigate the optimal time point to start TTFields therapy in elderly patients, as well as feasibility and safety of treatment with the TTFields device in elderly patients with newly diagnosed glioblastoma during hypofractionated (chemo)radiotherapy. Secondary endpoints include progression-free survival at 6 months, overall survival and quality of life during combined treatment.

MATERIAL AND METHODS

The GERAS trial is a single centre, randomized, two-arm, phase I/II trial that will recruit a total of 64 patients. Patients undergo stratified randomization into treatment arm A or control arm B.Patients in arm A start TTFields therapy at the beginning of hypofractionated radiotherapy with or without TMZ and continue treatment during maintenance chemotherapy. Patients in arm B receive hypofractionated radiotherapy with or without TMZ and begin TTFields therapy together with maintenance chemotherapy. Patients in both arms will be trained in using the TTFields device by certified device support specialists. Follow-up includes MRI imaging four weeks after (chemo)radiotherapy and then every 12 weeks as well as regular lab testing according to the current standard of care. Patients will be assessed for neurological status, neurocognitive function, compliance with TTFields therapy and adverse events during, four weeks after (C)RT and then every 12 weeks for up to 52 weeks.

RESULTS

Not applicable due to ongoing trial.

CONCLUSION

With TTFields, a new element in the maintenance therapy of glioblastomas has found its way into clinical routine. The GERAS trial aims to determine the optimal time point to start TTFields therapy as well as the safety and feasibility of concomitant TTFields- and hypofractionated (C)RT in elderly patients. This may lead the way for further phase II/III trials that evaluate survival benefits in this subpopulation of elderly patients treated with hypofractionated (C)RT.

The classification of antiseptic products to be administered to wounds--another borderline case between medicinal products and medical devices?

The importance of a correct demarcation between a Medicinal Product (MP) and a Medical Device (MD) is undisputedly one of the major topics related to the development and launch of a new healthcare product. However, for some products the correct demarcation between MPs and MDs can turn out to be somewhat complicated. This article aims to provide an overview on the existing legislation and its adequate application based on a suitable example at hand. Article 2 (2) of the European Directive 2001/83/EC as amended by Directive 2004/27/EC on the Community code relating to medicinal products for human use stipulates that the respective Medicinal Products Legislation must be applied whenever a product can be covered by both the definitions for MPs and for products regulated by other legal provisions enacted by the European Community, e.g. Cosmetic Products (CPs) or MDs. This basic principle implies that the decision to base the risk-benefit assessment of the product in question on the Medical Device Directive (MDD) would contradict the aforementioned constitutional principle, pursuant to which the stricter of the regulatory procedures theoretically possible is to apply in cases of doubt. In contrast to the approval procedure established for MPs, the MDD requires a Conformity Assessment Procedure to be performed by the manufacturer himself and a "Notified Body". Thus, in the majority of cases the responsibility for the risk assessment of MDs lies solely with the manufacturer and is prior to launch not subject to further scrutiny by regulators. Only in specific cases, i.e. for the Conformity Assessment Procedure of Class III MDs which contain an Active Pharmaceutical Ingredient one of the Member States competent authorities designated in accordance with Directive 65/ 65/EEC has to be involved before taking a decision. It is therefore important that the classification of the product is carried out carefully in full compliance with existing legal provisions, also taking into account the related guidance documents issued by the European Commission. The adequate application of these rules is explained using the example of the antiseptic compound polihexanide, which is used both in approved medicinal products (wound antiseptics) and wound irrigation solutions labelled as medical devices.

Alveolar recruitment promotes homogeneous surfactant distribution in a piglet model of lung injury

Uneven distribution of exogenous surfactant contributes to a poor clinical response in animal models of respiratory distress syndrome. Alveolar recruitment at the time of surfactant administration may lead to more homogeneous distribution within the lungs and result in a superior clinical response. To investigate the effects of three different volume recruitment maneuvers on gas exchange, lung function, and homogeneity of surfactant distribution, we studied 35 newborn piglets made surfactant deficient by repeated airway lavage with warm saline. Volume recruitment was achieved by either a temporal increase in tidal volume or an increase in end-expiratory pressure during surfactant administration, yielding an increase in dynamic compliance of the respiratory system of 77% in the first group and an increase in functional residual capacity of 108% in the second group. A third group of piglets (all n = 7) received a combination of both volume recruitment maneuvers, with increases in dynamic compliance of the respiratory system of 100% and in functional residual capacity of 192%. Those animals subjected to increased tidal volume showed an improved surfactant response in terms of oxygenation, ventilation, lung volumes, lung mechanics, and homogeneity of surfactant distribution. Increased end-expiratory volume augmented the surfactant effect only to some extent. The combination of both volume recruitment maneuvers, however, needed lung volumes beyond total lung capacity (approximately 56 mL/kg), thus probably inducing early sequelae of ventilator-induced lung injury. We conclude that volume recruitment by means of increased tidal volumes at the time of surfactant administration leads to a superior surfactant effect owing to more homogeneous surfactant distribution within a collapsed lung.

[Development of a sandwich ELISA for detection of specific antibodies against fimbrial antigens K88, K99 and 987p of Escherichia coli]

For the assessment of the efficacy of a E. coli-vaccine it was important to detect the specific antibodies against the protective antigens. Under the use of monoclonal antibodies against the fimbrial antigens K88, K99 and 987p a sandwich-elisa was developed. With these elisa-tests we detected significant titre conversion after repeated immunisation of rabbits. The results are highly reproducible. That is why the elisa-tests are qualified for testing of vaccine batches. The use of an anti-pig-conjugate makes it possible to detect antibodies in colostrum and serum from pigs.