Effect of repeated transsphenoidal surgery in recurrent or residual pituitary adenomas: A systematic review and meta-analysis

Assessment of multimodal treatment options in recurrent and persistent acromegaly: a systematic review and meta-analysis

PURPOSE

In patients with acromegaly, secondary treatment options in cases of hormonal non-remission or tumor progression include repeat transsphenoidal surgery (TSS), radiation-based treatment (RT), or medical therapy (MT). In this study, we aim to evaluate the clinical effectiveness of various second-line treatment options for acromegaly.

METHODS

Using the PRISMA guideline, a systematic review was performed by searching MEDLINE (PubMed), Web of Science, Scopus, and Cochrane electronic bibliographic databases from conception to the end of 2022. Outcomes of interest included hormonal remission rate, complications, and mortality associated with each treatment modality for refractory acromegaly.

RESULTS

A total of 79 studies including 3,208 refractory acromegaly patients (44.90% males) were analyzed, with a mean patient age of 43.89 years. There was a statistically significant difference between various therapeutic modalities in terms of remission rate, with MT offering the highest remission rate (62.55%), followed by RT (50.15%) and TSS (37.39%). Subgroup analysis of radiotherapeutic and medical modalities did not show a significant difference in remission rate between different kinds of sub-modalities in each treatment approach. Recurrence following secondary treatment was not different in patients treated with reoperation TSS compared to other modalities.

CONCLUSIONS

The management of persistent and recurrent acromegaly optimally requires a multimodal approach. In different scenarios of refractory acromegaly based on previous treatment, secondary treatments may vary in terms of remission rate and complications. Medical agents provide considerable effectiveness as a second-line therapy for recurrent or persistent disease. In selected cases, however, reoperation still provides an opportunity for cure or freedom from medications. The findings of this study may help clinicians to prioritize varying options involved in this multifaceted decision-making process.

Cost-effectiveness of direct surgery versus preoperative octreotide therapy for growth-hormone secreting pituitary adenomas

PURPOSE

The objective of this study was to compare the cost-effectiveness of preoperative octreotide therapy followed by surgery versus the standard treatment modality for growth-hormone secreting pituitary adenomas, direct surgery (that is, surgery without preoperative treatment) from a public third-party payer perspective.

METHODS

We developed an individual-level state-transition microsimulation model to simulate costs and outcomes associated with preoperative octreotide therapy followed by surgery and direct surgery for patients with growth-hormone secreting pituitary adenomas. Transition probabilities, utilities, and costs were estimated from recent published data and discounted by 3% annually over a lifetime time horizon. Model outcomes included lifetime costs [2020 United States (US) Dollars], quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs).

RESULTS

Under base case assumptions, direct surgery was found to be the dominant strategy as it yielded lower costs and greater health effects (QALYs) compared to preoperative octreotide strategy in the second-order Monte Carlo microsimulation. The ICER was most sensitive to probability of remission following primary therapy and duration of preoperative octreotide therapy. Accounting for joint parameter uncertainty, direct surgery had a higher probability of demonstrating a cost-effective profile compared to preoperative octreotide treatment at 77% compared to 23%, respectively.

CONCLUSIONS

Using standard benchmarks for cost-effectiveness in the US ($100,000/QALY), preoperative octreotide therapy followed by surgery may not be cost-effective compared to direct surgery for patients with growth-hormone secreting pituitary adenomas but the result is highly sensitive to initial treatment failure and duration of preoperative treatment.

A Review of Particle Therapy for Skull Base Tumors: Modern Considerations and Future Directions

Skull base tumors constitute one of the established indications for particle therapy, specifically proton therapy. However, a number of prognostic factors, practical clinical management issues, and the emerging role of carbon ion therapy remain subjects of active clinical investigation. This review summarizes these topics, assesses the present status, and reflects on future research directions focusing on the management of chordomas, one of the most aggressive skull base tumors. In addition, the role of particle therapy for benign tumors of the skull base, including pituitary adenoma and acoustic neuroma, is reviewed.

Simulations and human cadaver head studies to identify optimal acoustic receiver locations for minimally invasive photoacoustic-guided neurosurgery

Real-time intraoperative guidance during minimally invasive neurosurgical procedures (e.g., endonasal transsphenoidal surgery) is often limited to endoscopy and CT-guided image navigation, which can be suboptimal at locating underlying blood vessels and nerves. Accidental damage to these critical structures can have severe surgical complications, including patient blindness and death. Photoacoustic image guidance was previously proposed as a method to prevent accidental injury. While the proposed technique remains promising, the original light delivery and sound reception components of this technology require alterations to make the technique suitable for patient use. This paper presents simulation and experimental studies performed with both an intact human skull (which was cleaned from tissue attachments) and a complete human cadaver head (with contents and surrounding tissue intact) in order to investigate optimal locations for ultrasound probe placement during photoacoustic imaging and to test the feasibility of a modified light delivery design. Volumetric x-ray CT images of the human skull were used to create k-Wave simulations of acoustic wave propagation within this cranial environment. Photoacoustic imaging of the internal carotid artery (ICA) was performed with this same skull. Optical fibers emitting 750 nm light were inserted into the nasal cavity for ICA illumination. The ultrasound probe was placed on three optimal regions identified by simulations: (1) nasal cavity, (2) ocular region, and (3) 1 mm-thick temporal bone (which received 9.2%, 4.7%, and 3.8% of the initial photoacoustic pressure, respectively, in simulations). For these three probe locations, the contrast of the ICA in comparative experimental photoacoustic images was 27 dB, 19 dB, and 12 dB, respectively, with delay-and-sum (DAS) beamforming and laser pulse energies of 3 mJ, 5 mJ, and 4.2 mJ, respectively. Short-lag spatial coherence (SLSC) beamforming improved the contrast of these DAS images by up to 15 dB, enabled visualization of multiple cross-sectional ICA views in a single image, and enabled the use of lower laser energies. Combined simulation and experimental results with the emptied skull and >1 mm-thick temporal bone indicated that the ocular and nasal regions were more optimal probe locations than the temporal ultrasound probe location. Results from both the same skull filled with ovine brains and eyes and the human cadaver head validate the ocular region as an optimal acoustic window for our current system setup, producing high-contrast (i.e., up to 35 dB) DAS and SLSC photoacoustic images within the laser safety limits of a novel, compact light delivery system design that is independent of surgical tools (i.e., a fiber bundle with 6.8 mm outer diameter, 2 mm-diameter optical aperture, and an air gap spacing between the sphenoid bone and fiber tips). These results are promising toward identifying, quantifying, and overcoming major system design barriers to proceed with future patient testing.

Comparative study of complications after primary and revision transsphenoidal endoscopic surgeries

A preferred treatment for residual/recurrent pituitary adenomas has not been established. The existence of higher complication rates for revision surgeries remains under debate. This study aimed to compare complication rates of primary and revision transsphenoidal endoscopic surgeries and to identify risk factors for complications. Data from 144 primary and 39 revision surgeries were analysed. The surgical complications evaluated were intraoperative and postoperative cerebrospinal fluid (CSF) leaks; meningitis; permanent diabetes insipidus (DI) and hypopituitarism; worsening visual acuity; ophthalmoplegias; visual field defects; otorhinolaryngological, systemic and vascular complications; and death. The variables that were potentially associated with surgical complications were gender, age, comorbidities, lumbar drain use, duration of lumbar drain use, invasion of the sphenoid and cavernous sinuses, presence and degree of suprasellar expansion, preoperative identification of the pituitary, CSF leaks and intraoperative pituitary identification. Intraoperative CSF leaks, visual field losses and worsening visual acuity were more common for revision surgeries. There were no between-group differences in the occurrence of postoperative CSF leaks; systemic, vascular and otorhinolaryngological complications; meningitis; DI and hypopituitarism; ophthalmoplegias; or death. Intraoperative identification of the pituitary was associated with lower rates of permanent DI and hypopituitarism, systemic complications, intraoperative CSF leaks and worsening visual acuity. Suprasellar expansion increased the risk of intraoperative CSF leaks but not endocrinological deficits or visual impairment. Intraoperative CSF leaks were associated with postoperative CSF leaks, meningitis, anterior hypopituitarism, DI and worsening visual acuity. Intraoperative CSF leaks, worsening visual acuity and visual field losses were more common in reoperated patients.

Effect of Stereotactic Radiosurgery on Residual or Relapsed Pituitary Adenoma: A Systematic Review and Meta-Analysis

BACKGROUND

In pituitary tumors, the presence of residual tumor after transsphenoidal surgery and recurrence of the tumor after resection are frequent, and the best treatment is not well established. The effects and complications of stereotactic radiosurgery have not been extensively studied.

OBJECTIVE

We aimed to reveal the effect of stereotactic radiosurgery on residual and recurrent adenomas.

METHODS

A systematic review of the literature in the MEDLINE/PubMed, Cochrane Central Database, and Google Scholar was conducted using the criteria of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The search was structured according to the PICOT (i.e., Participants, types of Interventions, Comparator between the treatments, types of Outcome measures, and Follow-up [Time of duration]) strategy. The methodologic quality assessment (risk of bias) was performed according to the Methodological Index for Non-Randomized Studies scale. The studies were grouped and analyzed after data extraction using the software "R".

RESULTS

Twenty-six articles including 2315 patients were analyzed, with an average follow-up duration of 57.8 months and mean radiation marginal dose of 19.6 Gy. The overall tumor control rate was 95%, tumor reduction rate was 46%, and hormonal control rate was 67%. The side effects were evaluated.

CONCLUSIONS

Stereotactic radiosurgery was efficient in residual or recurrence tumor control, with few side effects, and is recommended for treating residual or recurrent tumors, both secreting and nonsecreting tumors. A limitation of this study is that there were no randomized trials included in the synthesis.

Management of Nonfunctioning Recurrent Pituitary Adenomas

Pituitary adenomas are typically slow-growing benign tumors. However, 50% to 60% of tumors progress following subtotal resection and up to 30% recur after apparent complete resection. Options for treatment of recurrent pituitary adenomas include repeat surgical resection, radiation therapy, and systemic therapies. There is no consensus approach for the management of recurrent pituitary adenomas. This article reviews the natural history of recurrent adenomas and emerging biomarkers predictive of clinical behavior as well as the outcomes associated with the various treatment modalities for these challenging tumors, with an emphasis on the surgical treatment.

The Utility of Using Preoperative MRI as a Predictor for Intraoperative Pituitary Adenoma Consistency and Surgical Resection Technique

Objective  Most pituitary adenomas are of soft consistency and can be resected during surgery with routine suction instruments. However, fibrous adenomas may require more aggressive techniques. The ability to predict consistency on magnetic resonance imaging (MRI) would improve preoperative preparation and may have implications on the extent of resection. Design  A retrospective review of MRI and tumor histology of 50 consecutive patients who underwent endoscopic endonasal resection for nonfunctional adenomas was performed. Methods  An intensity ratio was calculated based on quantitative MRI signal intensity of the adenoma and pons. Intraoperatively, a sequentially graded technique required for resection ranged from suction (R1) for softer tumors, curettes (R2) for tumors with intermediate consistency, and aspirators and/or other microinstruments (R3) for firmer tumors. Fibrotic content was determined from histologic collagen percentage, and rates of gross total resection (GTR) were calculated from postoperative imaging. Statistical analyses were performed to determine if resection classification could be predicted by intensity ratio or collagen percentage, calculate ratio of cut-off points for clinical use, and assess for correlation between intensity ratios and collagen percentage. Results  Tumors with ratios < 1.6 on the T2-weighted coronal image and collagen content > 5.3% were likely to have required a more aggressive resection technique. Statistically significant lower rates of GTR and higher rates of perioperative complications were seen with such tumors. Conclusion  Preoperative MRI analyses can be helpful but not definitive in predicting adenoma consistency. Fibrous adenomas, associated with higher collagen content, are more difficult to resect and have higher rates of subtotal resection.

The Treatment of Refractory Pituitary Adenomas

Refractory pituitary adenomas (PAs) are defined as aggressive-invasive PAs characterized by a high Ki-67 index, rapid growth, frequent recurrence, and resistance to conventional treatments. It is notoriously difficult to manage refractory PAs because the efficacy of current therapeutic options is limited. The purpose of this review is to address currently employed and promising therapeutic strategies for the treatment of refractory PAs. Except for prolactinomas, neurosurgery is the first-line option, but most refractory PAs often recur or re-grow after initial surgery and require further treatments. Medical therapy, radiotherapy and re-operation are explored when surgery has failed to completely resect tumors; however, refractory PAs are usually resistant to these treatments. As a salvage treatment, temozolomide (TMZ) has shown promising results and is currently used for all types of refractory PAs. However, not all refractory PAs are responsive to TMZ treatment, and some of these PAs are resistant to TMZ. Although targeted therapies such as vascular endothelial growth factor, epidermal growth factor and mTOR inhibitors have also been used to treat refractory PAs, the effectiveness of these targeted therapies is still not known due to a lack of data from randomized prospective trials. As a novel therapeutic method, cancer immunotherapy is a promising strategy for the treatment of refractory PAs, but further preclinical research and clinical trials are needed to assess the efficacy of this new approach. In summary, early identification and a multidisciplinary approach are required to treat refractory PAs.