DÄ internationalArchive29-30/2021Further Interdisciplinary Considerations
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The authors succeeded in presenting a comprehensive overview of the diagnostic evaluation and surgical options (1). As an addendum, we wish to explain modern radiotherapeutic treatment options in combination with neurosurgical resection. Indications for radiotherapy include a (progressive) residual tumor residue, recurrence, or a high risk of re-operation and thus, radiotherapy is not a matter of routine postoperatively. In addition to conventional fractionated radiotherapy, the available radiation techniques are single-dosestereotactic radiosurgery and fractionated stereotactic radiotherapy. Local control rates rates range between 72% and 100% after five years (2). Furthermore, after radiotherapy, normalization of the dysregulated hormonal axes is possible, as are improvements in visual acuity due to tumor regression (2, 3).

The radiotherapy concept and dose to be administered should be chosen depending on the size of the adenoma and the distance to critical organs at risk, especially the optic chiasm. Typical doses prescribed for conventional (normofractionated) radiotherapy are 45–54 Gy (Gray) in fractions of 1.8–2 Gy (3). By contrast, radiosurgery uses 13–16 Gy or 16–25 Gy for non-secreting or secreting adenomas, respectively (3). For the optimal administration of radiotherapy, precise planning imaging, exact contouring of the target volume and organs at risk, and the option of image guided radiotherapy are essential. The high local control rate has to be balanced against potential (long term) toxicities, such as hypopituitarism, which can affect 20–50% of patients (2). Its occurrence is dose-dependent. In a modern radiosurgical collective, 11 Gy or more were identified as a dosimetric predictor (4). By contrast, the risk of radiogenic optic neuropathy is low, at 1–5% (2).

Overall, the risks and benefits of radiotherapy should be balanced for the individual patient. The neurosurgical and radiotherapeutic exchange required to achieve this, taking into account neuropathological and neuroradiological expertise, should ideally take place in the context of an interdisciplinary tumor board.

DOI: 10.3238/arztebl.m2021.0255

Dr. med. Michael Oertel
Klinik für Strahlentherapie – Radioonkologie
Universitätsklinikum Münster (UKM)
michael.oertel@ukmuenster.de

PD Dr. med Eric Suero Molina
Prof. Dr. med. Walter Stummer

Klinik für Neurochirurgie
Universitätsklinikum Münster (UKM)

Prof. Dr. med. Hans Theodor Eich
Klinik für Strahlentherapie – Radioonkologie
Universitätsklinikum Münster (UKM)

1.
Jaursch-Hancke C, Deutschbein T, Knappe UJ, Saeger W, Flitsch J, Fassnacht M: The interdisciplinary management of newly diagnosed pituitary tumors. Dtsch Arztebl Int 2021; 118: 237–43 VOLLTEXT
2.
Chanson P, Dormoy A, Dekkers OM: Use of radiotherapy after pituitary surgery for non-functioning pituitary adenomas. Eur J Endocrinol 2019; 181: D1–13 CrossRef MEDLINE
3.
ESTRO ACROP guideline for target volume delineation of skull basetumors. Radiother and Oncol 2021; 56: 80–9 CrossRef MEDLINE
4.
Graffeo CS, Link MJ, Brown PD, Young WF, Pollock BE: Hypopituitarism after single-fraction pituitary adenoma radiosurgery: dosimetric analysis based on patients treated using contemporary techniques. Int J Radiat Oncol Biol Phys 2018; 101: 618–23 CrossRef MEDLINE
1.Jaursch-Hancke C, Deutschbein T, Knappe UJ, Saeger W, Flitsch J, Fassnacht M: The interdisciplinary management of newly diagnosed pituitary tumors. Dtsch Arztebl Int 2021; 118: 237–43 VOLLTEXT
2.Chanson P, Dormoy A, Dekkers OM: Use of radiotherapy after pituitary surgery for non-functioning pituitary adenomas. Eur J Endocrinol 2019; 181: D1–13 CrossRef MEDLINE
3.ESTRO ACROP guideline for target volume delineation of skull basetumors. Radiother and Oncol 2021; 56: 80–9 CrossRef MEDLINE
4.Graffeo CS, Link MJ, Brown PD, Young WF, Pollock BE: Hypopituitarism after single-fraction pituitary adenoma radiosurgery: dosimetric analysis based on patients treated using contemporary techniques. Int J Radiat Oncol Biol Phys 2018; 101: 618–23 CrossRef MEDLINE

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