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Updated: Mar 11, 2026
Endoscopic Endonasal Trans-sphenoidal Approach: Minimally Invasive Surgery for Pituitary Adenomas
Published on: January 17, 2018
Therapeutic Strategy for Cavernous Sinus-Invading Non-Functioning Pituitary Adenomas Based on the Modified Knosp
Juyoung Hwang1, Ho Jun Seol1, Do-Hyun Nam1
1Department of Neurosurgery, Endoscopic Skull Base Surgery Clinic, Brain Tumor Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Background:
Non-functioning pituitary adenomas (NFPA) invading into the cavernous sinus are surgically challenging. To decrease recurrence rate, surgeon makes a strong endeavor to resect tumor gross totally. However, gross total resection (GTR) is difficult to achieve with cavernous sinus invasion. Recently, a new classification system for cavernous invasion of pituitary adenomas was suggested. The aim of this study is to validate this new classification system and to identify limitations and considerations in designing treatment strategies for patients with NFPA involving the cavernous sinus.
Methods:
Between January 2000 and January 2012, 275 patients who underwent operation for NFPA were enrolled in the study. Median age was 50 years (15-79 years). There were 145 males and 130 females. The median follow-up duration was 4 years (range 1-12.5 years).
Results:
Related to extent of tumor removal, GTR was obtained in 184 patients (66.9%), near total resection (NTR) was obtained in 45 patients (16.3%), and sub-total resection (STR) was obtained in 46 patients (16.7%) of a total 275 patients. There were statistically significant differences between the extent of resection and the new Knosp classification (p<0.001). In the high-grade group of the new Knosp classification, there was no difference in recurrence between patients who underwent GTR or NTR only and those who underwent STR with adjuvant radiation therapy (p=0.515).
Conclusion:
In case of high risk of surgical complications, STR with adjuvant radiation therapy can be considered as an alternative strategy for safe treatment of cavernous-invading adenomas.
Insights
Surgical resection of non-functioning pituitary adenomas invading the cavernous sinus is challenging. Subtotal resection with radiation therapy offers a safe alternative for high-risk cavernous adenomas.
Area of Science:
- Neurosurgery
- Endocrinology
- Oncology
Background:
- Non-functioning pituitary adenomas (NFPA) invading the cavernous sinus present significant surgical challenges.
- Gross total resection (GTR) is often difficult to achieve in these cases, potentially leading to higher recurrence rates.
- A new classification system for cavernous sinus invasion has been proposed to guide treatment strategies.
Purpose of the Study:
- To validate a new classification system for cavernous sinus invasion in NFPA.
- To identify limitations and considerations for treatment strategies in NFPA with cavernous sinus involvement.
Main Methods:
- A retrospective study of 275 patients with NFPA who underwent surgery between January 2000 and January 2012.
- Patients were followed for a median of 4 years.
- Tumor resection extent (GTR, NTR, STR) was correlated with the new Knosp classification.
Main Results:
- GTR was achieved in 66.9% of patients, near total resection (NTR) in 16.3%, and subtotal resection (STR) in 16.7%.
- Significant differences were observed between the extent of resection and the new Knosp classification (p<0.001).
- In the high-grade Knosp classification group, recurrence rates did not differ between GTR/NTR and STR with adjuvant radiation therapy (p=0.515).
Conclusions:
- The new Knosp classification system shows significant correlation with the extent of tumor resection.
- For NFPA with cavernous sinus invasion, particularly in high-grade cases, STR combined with adjuvant radiation therapy is a viable and safe treatment alternative when surgical complications are a high risk.
