PD L 506 for Stereotactic Interstitial Photodynamic Therapy of Newly Diagnosed Supratentorial IDH Wild-type Glioblastoma

Inclusion Criteria: * Biopsy proven, newly diagnosed, supratentorial, unifocal, lobar located IDH wild-type glioblastoma according to the criteria of the 2016 WHO classification. * Not safely and/or not completely resectable, lobar located, unifocal, supratentorial IDH wild-type glioblastomas with a largest diameter ≤ 40 mm (largest diameter of the contrast enhanced tumor, as defined by enhanced T1 MRI sequences) are eligible in case of corresponding tumor board re-estimations. * Potentially completely resectable, lobar located, unifocal, supratentorial, IDH wild-type glioblastoma with a largest diameter ≤ 40 mm are eligible in case of both patient's informed preference in favour of iPDT and corresponding tumor board recommendations. * Age 18 - 70 years * Karnofsky Performance status (KPS) of ≥ 70 % * Minimal life expectancy of 3 months. * Patients eligible for radiotherapy plus concomitant and adjuvant chemotherapy with temozolomide: Adequate haematological function (Absolute neutrophil count (ANC) \> 1.5 x 109/L, Platelet count \> 100 x 109/L, Haemoglobin \> 10 g/dL (may be transfused to maintain or exceed this level)). * International normalized ratio (INR) or PT (secs) and activated partial thromboplastin time (aPTT) ≤ 1,5 times of the upper limit of normal in the laboratory where it was measured. * Negative pregnancy test in fertile women * For female and male patients of reproductive potential: Willingness to apply highly effective contraception (Pearl index \<1) during the entire study. Such methods include : * combined (estrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation: * oral * intravaginal * transdermal * progestogen-only hormonal contraception associated with inhibition of ovulation : * oral * injectable * implantable * intrauterine device (IUD) * intrauterine hormone-releasing system (IUS) * bilateral tubal occlusion * vasectomised partner * sexual abstinence • Written informed consent has been signed and dated prior to or at the beginning of Visit -1 Exclusion criteria: * Glioblastomas involving the basal ganglia, the corpus callosum, the primary motor cortex, the ventricular system, multifocal tumors, and those involving the brain stem and/or the cerebellum. * Glioblastomas exceeding the 40 mm threshold in their largest diameter * Simultaneous use of other potentially phototoxic substances (e.g. tetracyclines, sulfonamides, fluoroquinolones, hypericin extracts) * Hypersensitivity against porphyrins * Known diagnosis of porphyria * Acute or chronic hepatic diseases (levels of ASAT, ALAT and/or gamma-GT more than 2.5 times the upper limit of normal in the laboratory where it was measured) * Manifest renal diseases with renal dysfunction (serum creatinine level \> 1.5 times of the upper limit of normal in the laboratory where it was measured) * Severe, active co-morbidity: * Unstable angina and/or congestive heart failure within the last 6 months * Transmural myocardial infarction within the last 6 months * History of stroke, cerebral vascular accident, or transient ischemic attack within 6 months * Serious and inadequately controlled cardiac arrhythmia * Significant vascular disease (e.g. aortic aneurysm) * Evidence of bleeding diathesis or coagulopathy * Acute bacterial or fungal infections * Acute exacerbation of chronic obstructive pulmonary disease * Hepatic insufficiency resulting in clinical jaundice and/or coagulopathy * Acquired immune deficiency syndrome; note, however, that HIV testing is not required for study entry. * Inability to undergo MRI (e.g., presence of a pacemaker) * Known intolerance to study medication * Dementia or psychic condition that might interfere with the ability to understand the study and thus give a written informed consent * Simultaneous participation in another clinical study or participation in another clinical study in the 30 days directly preceding treatment or within 5 plasma half-life of the preceding study drug, whatever is longer. * Pregnancy or breastfeeding * In case of both complete absence of intra-operative fluorescence between any of the inserted light diffusers and absence of significant surgery-associated bleedings (i.e. light transmission is detectable between at least two of the inserted light diffusers), the tumor will be classified as 'fluorescence-negative tumor'. iPDT will however be performed. Regarding efficacy evaluation, patients with fluorescence-negative tumors will be excluded from PP-, but included in the ITT-evaluation, and will be evaluated regarding safety.