Stereotactic Radiotherapy (SRT) — Cost, Top Hospitals & Success Rates | MyMedicPlus

<p>Stereotactic radiotherapy (SRT) combines the millimetre-precision targeting technology of stereotactic radiosurgery (SRS) with the radiobiological benefits of dose fractionation — delivering the radiation dose in multiple smaller fractions rather than in a single large fraction. In its conventional form, fractionated stereotactic radiotherapy (FSRT) delivers doses of 1.8–2 Gy per fraction over 25–30 treatment sessions, just like conventional radiotherapy but with the superior geometric precision of stereotactic targeting. In its hypofractionated form (hypo-SRT), doses of 3–8 Gy per fraction are delivered over 3–15 sessions, sitting between SRS and conventional FSRT on the dose-per-fraction spectrum.</p><p>The rationale for fractionation — delivering radiation in multiple smaller doses separated by hours or days — is rooted in the four classical R's of radiobiology: <strong>Repair</strong> of sublethal DNA damage in normal tissues between fractions (tumour cells repair less efficiently); <strong>Repopulation</strong> of surviving cells between fractions; <strong>Redistribution</strong> of cells through the cell cycle between fractions (making previously radiation-resistant cells sensitive); and <strong>Reoxygenation</strong> of hypoxic cells (hypoxic cells are radiation-resistant; killing the initially oxygenated cells reoxygenates the hypoxic fraction). For tumours immediately adjacent to critical serial structures — particularly the optic nerves, chiasm, brainstem, cochlea, and cranial nerves — these differential repair mechanisms give normal tissue a significant survival advantage over tumour cells during fractionated treatment, enabling higher total tumour doses with lower risk of permanent injury to the adjacent structure.</p><p>SRT is therefore the treatment of choice when the tumour abuts or surrounds critical neural structures where single-fraction SRS doses would carry an unacceptably high risk of permanent toxicity. The optic nerve and chiasm have a maximum tolerable single-fraction dose of approximately 8–10 Gy; delivering SRS at a dose that would control a meningioma compressing the optic chiasm (>12–15 Gy) risks permanent blindness. FSRT distributes the same biologically effective tumour dose over 25–30 fractions, reducing the per-fraction dose to the optic chiasm below its repair threshold and making treatment safe and effective simultaneously.</p><p>This guide explains the conditions best suited to SRT, how it differs from single-fraction SRS, who is eligible, what to expect from treatment, and how to assess cost and alternatives in the context of a multi-disciplinary treatment decision.</p>

<p>Stereotactic radiotherapy is the preferred treatment modality for a range of intracranial benign and low-grade tumours, particularly those involving or abutting critical cranial nerves, vascular structures, or the optic pathway.</p><h4>Acoustic Neuroma (Vestibular Schwannoma)</h4><p>Acoustic neuroma — a benign tumour arising from the vestibular branch of the eighth cranial nerve — is one of the leading indications for both SRS and SRT. Small tumours (less than 2–2.5 cm) are typically treated with single-fraction Gamma Knife SRS (12–13 Gy), achieving tumour control in 90–95% at 5 years and hearing preservation in 50–65% of patients with serviceable pre-treatment hearing. For medium-to-large schwannomas (>2.5 cm), particularly those where the cochlea or facial nerve is in very close proximity to the planning target volume, fractionated SRT (50 Gy in 25 fractions or 25 Gy in 5 hypofractionated sessions) reduces the risk of radionecrosis, cochlear damage, and facial nerve injury while maintaining equivalent tumour control rates.</p><h4>Skull-Base and Intracranial Meningioma</h4><p>Meningiomas involving the cavernous sinus, petroclival region, optic canal, clinoid process, or foramen magnum — where surgical resection would inevitably damage critical cranial nerves or the brainstem — are ideally suited to SRT. Fractionated SRT (50.4 Gy in 28 fractions, or 45 Gy in 25 fractions) achieves 5-year progression-free survival rates of 90–95% for WHO Grade I meningiomas with acceptable cranial nerve preservation rates. For larger tumours (>3–4 cm) adjacent to the optic chiasm, FSRT is strongly preferred over single-fraction SRS because per-fraction doses achievable with SRS would risk optic neuropathy.</p><h4>Pituitary Adenoma</h4><p>SRT for pituitary adenomas is indicated when tumour growth continues despite surgical debulking (transsphenoidal resection) and/or medical therapy (dopamine agonists for prolactinoma, somatostatin analogues for acromegaly, cabergoline for Cushing's disease). For adenomas with suprasellar extension and proximity to the optic chiasm (defined as less than 3–5 mm of separation), fractionated SRT is strongly preferred over SRS. FSRT (45–54 Gy in 25–30 fractions) achieves biochemical normalisation rates of 40–60% for secreting adenomas at 5 years, and tumour volume control in over 90% for all adenoma types.</p><h4>Craniopharyngioma</h4><p>Craniopharyngioma — a benign but clinically challenging tumour of the sellar-suprasellar region that intimately involves the hypothalamus, optic apparatus, and pituitary stalk — is a paradigmatic indication for SRT. Given its proximity to multiple critical structures, fractionated SRT (50.4–54 Gy in 28–30 fractions) following subtotal surgical resection provides durable tumour control (5-year PFS of 75–90%) while limiting hypothalamic, visual, and pituitary injury compared with aggressive surgery.</p><h4>Optic Nerve Sheath Meningioma</h4><p>Optic nerve sheath meningioma (ONSM) is a rare tumour that grows along the sheath of the optic nerve, compressing the nerve and causing progressive visual loss. Surgical resection inevitably sacrifices the optic nerve. SRT (50–54 Gy in 25–30 fractions) applied to the tumour volume using daily fractions of 1.8–2 Gy preserves and often improves visual function in 70–85% of patients, making it the definitive treatment of choice for this condition.</p><h4>Other Skull-Base Tumours</h4><p>SRT is also used for chordomas (combined with proton therapy where available), glomus jugulare tumours, and selected cases of orbital and paranasal sinus tumours. Reirradiation SRT for recurrent skull-base tumours after prior surgical and radiation treatment is a growing application at specialised centres.</p>

<p>Patient selection for SRT is guided by the same multi-disciplinary tumour board process as for other brain tumour treatments, with specific attention to the characteristics that differentiate SRT from single-fraction SRS.</p><h4>Tumour-to-Critical-Structure Distance</h4><p>The primary clinical trigger for choosing fractionated SRT over single-fraction SRS is the proximity of the tumour to a critical serial structure. The key dose-limiting structures for intracranial SRT are: optic chiasm and optic nerves (maximum single-fraction tolerance approximately 8–10 Gy; FSRT allows total dose of 50–54 Gy with fractions of 1.8–2 Gy); brainstem (maximum single-fraction point dose of 15 Gy for volumes <0.1 cc; fractionation substantially relaxes this constraint); cochlea (single-fraction dose <4 Gy to preserve hearing; fractionated mean cochlear dose <45 Gy is preferred); and facial nerve (single-fraction dose at nerve <12–13 Gy for schwannoma; FSRT reduces per-fraction facial nerve dose).</p><p>When the tumour margin is within 2–3 mm of the optic chiasm, fractionated SRT is the standard recommendation from major radiation oncology societies (ASTRO, ESTRO, ISRS).</p><h4>Tumour Size</h4><p>Larger tumours — those greater than 3 cm for intracranial targets, and greater than 4–5 cm for some body SRT applications — typically benefit from fractionation because: the risk of radiation necrosis increases steeply with single-fraction doses for large volumes; inhomogeneous dose distribution within large targets is better managed with fractionated plans; and larger tumours have more heterogeneous oxygenation, favouring the reoxygenation advantage of fractionation. For meningiomas and schwannomas greater than 3 cm, FSRT or hypo-SRT is preferred over single-fraction SRS.</p><h4>Performance Status and General Health</h4><p>SRT requires patients to attend multiple treatment sessions (typically 25–30 for FSRT, 5–10 for hypo-SRT) and to maintain precise positioning with a thermoplastic mask or relocatable frame at each visit. Patients must be able to lie still for 15–30 minutes per session and to reliably attend the treatment centre. Cognitive impairment, severe claustrophobia, or inability to remain supine may be relative contraindications. For elderly or frail patients, hypofractionated SRT (fewer, slightly larger fractions over 2–3 weeks) can reduce the overall treatment burden.</p><h4>Prior Treatment History</h4><p>SRT can be used as primary treatment (definitive), as adjuvant treatment after subtotal surgical resection, or as salvage treatment following prior surgery or prior radiotherapy. For tumours recurrent after prior fractionated RT, reirradiation with SRT requires careful dosimetric analysis to ensure cumulative doses to critical structures remain within safe limits. The technical feasibility of reirradiation with SRT should be evaluated by an experienced radiation oncology team with access to prior treatment dose-volume data.</p>

<p>Stereotactic radiotherapy is delivered using the same technology platforms as SRS, but the fractionation schedule, immobilisation system, and treatment planning philosophy differ according to the number of fractions and the biological intent of treatment.</p><h4>Conventional Fractionated SRT (FSRT)</h4><p>FSRT uses conventional fractionation (1.8–2 Gy per fraction) with stereotactic targeting precision. Standard FSRT schedules include: 50.4 Gy in 28 fractions (1.8 Gy/fraction) for craniopharyngioma and skull-base meningioma near the optic pathway; 54 Gy in 30 fractions for optic nerve sheath meningioma; 54 Gy in 30 fractions for pituitary adenoma with optic chiasm compression; and 50 Gy in 25 fractions for acoustic neuroma requiring fractionated approach. The key distinction from conventional RT is the millimetre-precision positioning and smaller planning target volume margins (2–3 mm vs 5–10 mm in conventional RT), which allows a steeper dose gradient and better sparing of non-target normal brain.</p><h4>Hypofractionated SRT (Hypo-SRT)</h4><p>Hypo-SRT delivers 3–8 Gy per fraction over 3–15 sessions, providing a middle ground between single-fraction SRS and conventional FSRT. Representative hypo-SRT schedules include: 25 Gy in 5 fractions for acoustic neuroma (<2.5 cm with favourable cochlear relationship); 30 Gy in 5 fractions for meningioma not in close contact with optic apparatus; and 35–45 Gy in 10–15 fractions for medium-sized meningiomas. Hypo-SRT balances reduced treatment duration (2–3 weeks vs 5–6 weeks for FSRT) with the radiobiological benefits of fractionation for normal tissue sparing. It is increasingly used at centres with efficient patient scheduling and high-precision LINAC or Gamma Knife Icon systems.</p><h4>Technology Platforms for SRT</h4><p><strong>Gamma Knife Icon (Elekta):</strong> The Gamma Knife Icon model incorporates stereotactic cone-beam CT image guidance and infrared motion tracking, enabling frameless fractionated treatments with sub-millimetre repositioning accuracy across multiple sessions. FSRT on the Gamma Knife Icon uses a custom-fitted thermoplastic mask rather than an invasive frame, and online CBCT verification at each fraction confirms patient positioning before treatment.</p><p><strong>CyberKnife (Accuray):</strong> The CyberKnife's frameless, real-time image-guided delivery makes it intrinsically suited to fractionated SRT. Its Synchrony system tracks intrafraction patient motion and adjusts beam direction dynamically, making it ideal for SRT where precision across multiple sessions is critical. CyberKnife FSRT is widely used for acoustic neuroma, meningioma, and pituitary adenoma.</p><p><strong>LINAC-Based SRT (Varian, Elekta, Brainlab):</strong> Modern LINACs with 6-degree-of-freedom patient positioning couches, high-definition MLCs, and onboard CBCT imaging deliver FSRT and hypo-SRT using VMAT or dynamic arc techniques. LINAC-based SRT is the most widely available platform globally and allows highly conformal dose distributions. Daily online CBCT imaging verifies patient setup before each fraction, and any residual positioning error is corrected before beam delivery.</p><h4>Immobilisation for Fractionated SRT</h4><p>Unlike single-fraction SRS — where an invasive skull-fixed head frame provides the ultimate in positional accuracy — fractionated SRT requires a non-invasive but highly reproducible patient immobilisation system across multiple sessions. Options include: thermoplastic head-and-shoulder masks (most common, sub-2 mm repositioning accuracy); custom-made oral stents with dental impressions; and relocatable Leksell frames (semi-invasive, used for short courses of 3–5 fractions requiring very high precision). Daily pre-treatment CBCT imaging is mandatory to detect and correct any inter-fraction patient repositioning error before beam delivery.</p>

<p>Stereotactic radiotherapy offers a specific set of clinical benefits that distinguish it from both single-fraction SRS and conventional lower-precision radiotherapy, making it the optimal treatment for a defined group of tumour types and locations.</p><h4>Superior Tumour Control Near Critical Structures</h4><p>The defining benefit of SRT over single-fraction SRS is the ability to deliver a radiobiologically equivalent — or higher — total dose to the tumour while keeping each fraction's dose to adjacent critical structures below the threshold for irreversible injury. For optic nerve sheath meningioma, SRT achieves visual preservation or improvement in 70–85% of patients, with tumour control rates exceeding 90% at 10 years. This combination of high tumour control and preserved neurological function is unmatched by any other treatment modality for this condition.</p><h4>Preservation of Cranial Nerve Function</h4><p>For acoustic neuroma, the priority after tumour control is preservation of facial nerve function and, where possible, hearing. Published series of FSRT for acoustic neuroma report facial nerve preservation rates of 97–100% (compared with surgical rates of 80–90% even in expert hands) and hearing preservation in 60–75% of patients with useful pre-treatment hearing. These outcomes drive the strong preference for SRT/SRS over surgery at many specialised neuro-oncology centres, particularly for younger patients with serviceable hearing.</p><h4>Non-Invasive Treatment Avoiding Surgical Risks</h4><p>Surgery at the skull base — for tumours of the cavernous sinus, petroclival region, clivus, or foramen magnum — carries significant risks: cerebrospinal fluid leak, meningitis, cranial nerve damage (particularly nerves III, IV, V, VI, VII), vascular injury, and stroke. SRT eliminates all of these surgical risks while achieving equivalent long-term tumour control for appropriately selected tumours. For elderly patients, those with significant medical co-morbidities precluding general anaesthesia, or those who prefer to avoid surgery, SRT offers a compelling alternative.</p><h4>Outpatient Treatment With Maintained Quality of Life</h4><p>Although FSRT requires daily visits over 5–6 weeks (or 2–3 weeks for hypo-SRT), each session is brief (15–30 minutes in the treatment room), non-invasive, and does not interfere with normal activities. Patients typically maintain full independence and quality of life throughout the treatment course. This is in stark contrast to the post-operative recovery from skull-base surgery, which may require weeks of hospitalisation, weeks to months of cranial nerve rehabilitation, and significantly impaired quality of life during recovery.</p><h4>Durable Long-Term Tumour Control</h4><p>Long-term published data for SRT in benign intracranial tumours demonstrate durable tumour control across multiple decades: 10-year progression-free survival rates of 90–95% for WHO Grade I meningioma; 90–95% tumour control at 10 years for acoustic neuroma; and 85–90% 10-year control for pituitary adenoma. These outcomes are equivalent to or better than those achievable with aggressive surgical resection, without the attendant morbidity.</p>

<p>Stereotactic radiotherapy, when delivered with modern precision and adherence to published dose-volume constraints, carries a favourable toxicity profile. However, certain risks are inherent to intracranial radiation and must be discussed with patients before consent.</p><h4>Acute Side Effects During Treatment</h4><p>Acute side effects during a 5–6 week FSRT course are typically mild. The most common include: fatigue (mild to moderate, experienced by 50–70% of patients, most pronounced in the final week and 1–2 weeks after completion); alopecia — localised, patchy hair loss in the scalp areas traversed by the radiation beams, typically covering 1–3 cm patches rather than diffuse hair loss (total alopecia is not expected with modern conformal planning); scalp erythema or skin reaction at beam entry points; nausea and headache, particularly during the first week; and, rarely, acute exacerbation of neurological symptoms from transient radiation-induced oedema (treated with dexamethasone).</p><h4>Subacute Effects (1–3 Months Post-Treatment)</h4><p>A subacute somnolence syndrome — characterised by fatigue, drowsiness, and mild cognitive dulling — may occur 1–2 months after completion of cranial SRT, reflecting transient demyelination. This is self-limiting and resolves over 4–8 weeks without specific treatment.</p><h4>Radiation Necrosis</h4><p>Late radiation necrosis — focal necrosis of normal brain tissue adjacent to the treated tumour — can occur months to years after SRT. With conventional fractionation (1.8–2 Gy/fraction) to doses of 54 Gy and modern FSRT techniques, the risk of symptomatic radiation necrosis is low (approximately 2–5%) but not negligible. Risk increases with re-irradiation, larger treatment volumes, concurrent sensitising chemotherapy, and sites in proximity to the temporal lobes (which are more radiosensitive). Radiation necrosis is managed with corticosteroids, bevacizumab (highly effective for radionecrosis on MRI), or, rarely, surgery.</p><h4>Cranial Nerve Toxicity</h4><p>Despite fractionation providing radiobiological protection for cranial nerves, some risk of cranial nerve toxicity remains, particularly when nerves are within or immediately adjacent to the tumour target. For trigeminal nerve (CN V): sensory disturbance (facial numbness, paraesthesia) occurs in approximately 5–10% of patients treated for skull-base meningioma or acoustic neuroma. For cochlear toxicity in acoustic neuroma SRT: sensorineural hearing loss progressing beyond the natural history of the disease occurs in 20–40% over 5–10 years (similar to natural progression rates, making attribution to treatment difficult). Facial nerve palsy after FSRT for acoustic neuroma is rare (<2%), representing a major advantage over surgery.</p><h4>Endocrine Dysfunction (Pituitary and Sellar SRT)</h4><p>SRT for pituitary adenoma and craniopharyngioma carries a significant long-term risk of hypopituitarism, which develops progressively over years post-treatment in 30–60% of patients depending on the dose to the pituitary gland and the pre-existing endocrine function. All patients treated with SRT in the sellar region require annual endocrine assessment (thyroid function, cortisol, IGF-1, gonadal hormones, prolactin) and appropriate hormone replacement as deficiencies develop.</p><h4>Risk of Secondary Malignancy</h4><p>The long-term risk of radiation-induced secondary brain tumour is a rare but recognised complication of cranial radiotherapy. The absolute risk is estimated at 0.5–1.5% at 10 years and increases with time. This risk must be contextualised against the natural history of the tumour being treated (which, if untreated, may produce severe morbidity or mortality from growth or compression). For benign tumours in young patients, this consideration strengthens the case for exploring surgical options first if feasible.</p>

<p>Follow-up after stereotactic radiotherapy extends over many years, because the radiobiological effects of fractionated radiation — both therapeutic (tumour control) and potentially toxic — evolve slowly over months to years.</p><h4>Immediate Post-Treatment Period</h4><p>In the first 4–6 weeks following completion of SRT, patients typically experience the peak of radiation-related fatigue. A short course of dexamethasone may be prescribed if acute cerebral oedema develops during or immediately after treatment. Alopecia patches, if present, typically begin to resolve 2–3 months post-treatment. Patients are encouraged to maintain normal activity levels throughout and after treatment; the non-invasive nature of SRT means there are no restrictions on driving, exercise, or work beyond those imposed by the tumour itself or by fatigue.</p><h4>Imaging Surveillance Protocol</h4><p>MRI brain with gadolinium contrast is the standard imaging modality for post-SRT tumour surveillance. Recommended schedules: (1) Baseline post-SRT MRI at 3–4 months (important because treated benign tumours commonly show transient swelling or contrast enhancement in the first 3–6 months that can be confused with recurrence); (2) MRI at 6 months and 12 months post-treatment; (3) Annual MRI for years 2–5; (4) MRI every 18–24 months from year 5 onwards, or more frequently if imaging suggests progression. For pituitary adenomas, MRI also assesses response of the pituitary tumour and the optic chiasm, which may show improvement in mass effect as the tumour responds to treatment.</p><h4>Neurological Assessment</h4><p>Formal audiological testing (audiogram) is performed annually for all patients treated for acoustic neuroma to track hearing trajectory. Ophthalmological assessment — formal visual field testing (Humphrey visual fields) and visual acuity measurement — is performed every 6–12 months for patients treated for optic nerve sheath meningioma, pituitary adenoma, or any tumour adjacent to the visual pathway, to detect early signs of radiation optic neuropathy or tumour progression causing visual deterioration.</p><h4>Endocrine Monitoring for Sellar/Parasellar SRT</h4><p>For patients treated for pituitary adenoma, craniopharyngioma, or other sellar/parasellar tumours, annual endocrine assessments are mandatory: morning cortisol and ACTH stimulation test (to detect secondary adrenal insufficiency — the most dangerous endocrine deficiency); TSH and free T4 (secondary hypothyroidism); IGF-1 and growth hormone stimulation test; FSH, LH, testosterone (males) / oestradiol (females); and prolactin. Hormone replacement therapy is initiated as deficiencies are documented.</p><h4>Tumour Response Assessment</h4><p>Unlike malignant tumours where a rapid response to treatment is expected, benign tumours treated with SRT typically show stable size or very gradual volume reduction on serial MRI over 3–5 years. Transient volume increase in the first 6–12 months post-treatment (a recognised pseudo-progression phenomenon) should not prompt hasty surgical intervention without clinical correlation. True tumour progression after SRT is uncommon and warrants repeat multi-disciplinary review to consider re-irradiation, surgery, or systemic therapy.</p>

<p>The cost of a fractionated SRT course reflects both the sophisticated technology used and the substantial physics and clinical personnel investment required for planning and delivery of each fraction with sub-millimetre precision. Costs vary significantly by country, fractionation schedule, and treatment platform.</p><h4>Cost by Country</h4><p>In the <strong>United States</strong>, a full 25–30 fraction FSRT course (including simulation, MRI planning, treatment planning, physics quality assurance, daily delivery, and oncology review) costs approximately USD 30,000–65,000. Single-institution Gamma Knife FSRT (5–10 fractions) may cost USD 25,000–45,000. In the <strong>United Kingdom</strong> (private sector), FSRT costs GBP 20,000–40,000.</p><p>In <strong>India</strong>, major cancer centres with SRT capability (Tata Memorial, AIIMS, Apollo, HCG, Manipal, Fortis) offer a complete FSRT course (25–30 fractions) for approximately USD 4,500–12,000, depending on the platform (Gamma Knife Icon, CyberKnife, or LINAC-based). Hypofractionated SRT (5–10 fractions) is available for USD 3,500–8,000. <strong>Thailand</strong> (Bumrungrad, Bangkok Hospital): USD 10,000–20,000. <strong>Turkey</strong>: USD 8,000–15,000. <strong>Singapore</strong> (Mount Elizabeth, National Cancer Centre Singapore): USD 15,000–30,000.</p><h4>Key Cost Drivers</h4><p>(1) <strong>Number of fractions:</strong> FSRT (25–30 fractions) costs more than hypo-SRT (5–10 fractions) due to more patient visits, daily imaging, and more QA sessions. (2) <strong>Treatment platform:</strong> Gamma Knife Icon and CyberKnife have higher capital costs and associated higher per-session charges than LINAC-based SRT at high-volume centres. Clinical outcomes are equivalent. (3) <strong>Treatment planning complexity:</strong> Skull-base tumours adjacent to multiple critical structures (cranial nerves, brainstem, optic chiasm, cochlea simultaneously) require highly complex inverse treatment planning with many dosimetric objectives and constraints, adding significant physics time. (4) <strong>Multi-disciplinary evaluation:</strong> SRT for skull-base tumours typically involves neurosurgery, radiation oncology, neuro-otology, and endocrinology consultations at diagnosis, each contributing to the overall care episode cost. (5) <strong>Diagnostic imaging:</strong> High-resolution gadolinium MRI for treatment planning, cochlear-protocol thin-slice imaging for acoustic neuroma, and dedicated pituitary imaging for sellar tumours add to pre-treatment investigation costs.</p><h4>Medical Travel for SRT — Practical Notes</h4><p>SRT is more logistically demanding for medical travellers than single-fraction SRS because of the multi-week treatment course. Patients planning to receive FSRT (25–30 fractions) internationally need to budget for approximately 6–7 weeks in the destination country (including simulation week, treatment weeks, and final review). Hypo-SRT (5–10 fractions) reduces this to 2–3 weeks. Patients should ensure their accommodation is within easy distance of the treatment centre and that a treatment summary and DICOM plan files will be provided for follow-up imaging interpretation at home.</p>

<p>For conditions commonly treated with SRT, a range of alternatives exists — from active surveillance at one end of the spectrum to aggressive surgery at the other. The choice depends on tumour characteristics, patient age, symptoms, hearing/cranial nerve status, and institutional expertise.</p><h4>Watchful Waiting (Active Observation)</h4><p>Many benign intracranial tumours — particularly small acoustic neuromas, incidentally discovered meningiomas, and non-secreting pituitary microadenomas — grow slowly or not at all. Active surveillance with serial MRI every 6–12 months is appropriate for tumours that are small, asymptomatic, not in contact with critical structures, and in elderly or frail patients where treatment risks may outweigh benefits. Published series show that 50–60% of acoustic neuromas do not grow over 5 years of observation. Surveillance avoids all treatment-related side effects but carries the risk of delayed treatment if the tumour grows significantly before intervention.</p><h4>Single-Fraction Stereotactic Radiosurgery (SRS)</h4><p>For small tumours (<2.5 cm) sufficiently distant from critical serial structures (at least 3–4 mm from the optic chiasm, brainstem), single-fraction SRS on Gamma Knife, CyberKnife, or LINAC achieves equivalent tumour control in a single treatment session. It eliminates the need for multiple treatment visits and the logistical complexity of a fractionated course. SRS vs FSRT is a nuanced choice guided primarily by tumour-to-critical-structure distance, tumour volume, and institutional expertise; both approaches should be discussed by a multi-disciplinary team.</p><h4>Microsurgical Resection</h4><p>Surgery remains the primary treatment for large tumours causing acute neurological deterioration (optic nerve compression causing rapid visual loss, brainstem compression causing gait disturbance), for tumours where histological diagnosis is uncertain, or for tumours not adequately controlled by prior radiation. At skull-base neurosurgery centres with high case volumes, surgical outcomes for acoustic neuroma (retrosigmoid or translabyrinthine approach) and meningioma (various skull-base approaches) are excellent; complications increase dramatically at low-volume centres. Surgery and SRT are complementary: subtotal resection decompresses critical structures and SRT controls residual tumour, achieving better combined outcomes than either modality alone for many large skull-base tumours.</p><h4>Proton Beam Therapy</h4><p>Proton beam radiotherapy offers a unique physical advantage for skull-base tumours and tumours adjacent to critical structures: the Bragg peak deposits the proton dose within the target volume with minimal exit dose to structures posterior to the tumour. For tumours immediately adjacent to the brainstem, optic chiasm, or temporal lobes, proton FSRT may further reduce the integral radiation dose to these structures compared with photon SRT. Proton therapy is particularly well-established for skull-base chordoma and chondrosarcoma, where local control rates of 70–80% at 5 years are substantially better than with photon RT. Access is limited to specialist proton centres, and costs are significantly higher than photon SRT.</p><h4>Medical Management for Secreting Pituitary Adenomas</h4><p>For secreting pituitary adenomas (growth hormone-secreting adenomas causing acromegaly, prolactinomas, ACTH-secreting adenomas causing Cushing's disease), medical therapy is often the appropriate first-line approach. Somatostatin analogues (octreotide, lanreotide, pasireotide) normalise IGF-1 in 20–40% of acromegaly patients; dopamine agonists (cabergoline) normalise prolactin in 80–90% of prolactinoma patients. SRT is considered for adenomas that progress or are insufficiently controlled despite medical therapy and surgery.</p>