Local Control and Toxicity Assessment of Pituitary Adenoma Patients Treated with Different Radiotherapy Techniques

• Arora Kanakdeepsingh Rajendrasingh

  Department of Radiation Oncology, Vydehi Institute of Medical Sciences and Research Centre, Bengaluru, India

• Geeta S. Narayanan

  Department of Radiation Oncology, Vydehi Institute of Medical Sciences and Research Centre, Bengaluru, India

• B.R. Kiran Kumar

  Department of Radiation Oncology, Vydehi Institute of Medical Sciences and Research Centre, Bengaluru, India

  https://orcid.org/0000-0002-5375-3116

Background: Pituitary adenomas often require radiotherapy (RT) for residual or recurrent disease, but optimal techniques balancing tumour control and toxicity remain debated. This prospective study compares outcomes between conventional and stereotactic RT approaches.

Methods: From 2014 to 2022, 22 patients with pituitary adenomas treated with RT were retrospectively enrolled (10 conventional RT [3DCRT/IMRT/VMAT], 12 stereotactic [SRS/fSRT]). All the patients disease, treatment and follow-up details were analyzed from the medical records. Primary endpoint was 3-year local control, secondary endpoints included toxicity (CTCAE v5.0) and endocrine function assessment.

Results: Stereotactic RT demonstrated superior 3-year local control (91.7% vs 80%, p=0.03) with lower hypopituitarism rates (33.3% vs 60%, p=0.02). All recurrences occurred in Knosp grade 3-4 tumours. Conventional RT was associated with higher pituitary doses (>45 Gy, OR 3.2, p=0.03 for hypopituitarism). No grade ≥3 toxicities occurred in either group. Visual complications were rare (8.3% stereotactic vs 20% conventional, p=0.39).

Conclusion: Stereotactic radiotherapy provides significantly better tumour control and endocrine preservation compared to conventional techniques for pituitary adenomas, particularly for non-invasive tumours. Dose constraints are critical for minimizing toxicity.

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