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.