Neuro-Modulation for Intractable Pain From Bone Metastasis Using Real-Time Adaptive Motion Management on a Robotic Radiation Therapy Platform: A Case Report and Review of the Literature.

Radiosurgical hypophysectomy has emerged as a promising noninvasive approach for management of intractable cancer pain, particularly in patients with bone metastases, offering a safer alternative to traditional surgical hypophysectomy. Here, we present the case of a premenopausal woman with metastatic breast cancer who developed severe, refractory pain despite conventional pain management. To alleviate worsening pain, the patient underwent radiosurgical hypophysectomy targeting approximately 8 mm of the inferior pituitary stalk and at least 50% of the pituitary gland, using a single 75.0 Gy fraction prescribed to the 50% isodose line. Robotic real-time adaptive radiotherapy was utilized for precision and to avoid unnecessary damage to surrounding critical structures. Following treatment, the patient experienced immediate and significant pain relief. Specifically, pain scores measured using the visual analogue pain score showed a decrease in pain level from 8/10 pre-treatment to 4/10 by day 10 post-treatment. The baseline pain remained around 4-5/10 over time with occasional spikes to 7/10. No meaningful adverse effects were reported, supporting the safety aspect of this approach. These findings are consistent with existing studies that reported immediate pain relief after radiosurgical hypophysectomy, although longer-term outcomes remain variable. This case highlights the potential of radiosurgical hypophysectomy as a valuable option for patients with severe cancer pain, underscoring the need for further clinical studies to validate its effectiveness and explain the underlying mechanisms as well as pain outcome in the long term.