Evidence Index / Radiation Oncology
Protocol-focused reference for ROSEL, STARS, CHISEL, SPACE, LUSTRE, HILUS, RTOG 0813 and SUNSET. Dose constraints below are protocol/trial-specific; they are not interchangeable planning recommendations.
| Study | Location definition / eligible population | SABR prescription | OARs / constraints reported in protocol or publication |
|---|---|---|---|
| ROSEL | Stage IA; only lesions ≥2 cm from hilar structures (peripheral by protocol). | 54 Gy/3 fractions, or 60 Gy/5 fractions according to centre protocol. | ROSEL OAR constraints: spinal cord point max 18 Gy/3 fractions or 25 Gy/5; oesophagus 1 cc ≤24 or 27 Gy; ipsilateral brachial plexus 1 cc ≤24 or 27 Gy; heart 1 cc ≤24 or 27 Gy; trachea/mainstem bronchus 1 cc ≤30 or 32 Gy. These are the “no protocol deviation” limits; protocol also listed minor-deviation bands. Skin point ≤24 Gy was referenced separately. This was a peripheral-only trial (tumour ≥2 cm from hilar structures). |
| STARS | Operable stage I NSCLC; peripheral and central cases were treated with different schedules. Central was described as within 2 cm of critical structures in pooled reports. | Peripheral: 54 Gy/3; central: 50 Gy/4. | Definition: peripheral lesions were >2 cm in every direction from PBT, major vessels, oesophagus, heart, trachea, vertebral body, pericardium, mediastinal pleura and brachial plexus; lesions within 2 cm were treated as central. Central dose 50 Gy/4. The pooled report states normal-tissue constraints were met but a full STARS constraint table was not available in the retrieved publication; do not substitute RTOG 0813 limits as if they were the STARS protocol. |
| CHISEL (TROG 09.02) | Peripheral stage I NSCLC only. Tumours <2 cm from chest wall used 4-fraction schedule; this is not the central-tumour definition. | 54 Gy/3 fractions, or 48 Gy/4 fractions if tumour <2 cm from chest wall. | CHISEL protocol constraints (hypofractionated arm): lung (whole lung minus ITV) V20 ≤15%; heart maximum 30 Gy; oesophagus maximum 27 Gy; spinal canal maximum 18 Gy; brachial plexus maximum 24 Gy; skin/chest wall maximum-dose threshold not specified in the table; chest wall D70cc ≤30 Gy (initially D30cc ≤30 Gy at trial commencement). Conventional-arm lung V20 ≤35%, mean lung dose ≤20 Gy; heart, oesophagus and spinal canal maxima 65, 65 and 45 Gy respectively. Maximum dose defined to 0.035 cc. CHISEL excluded tumours within 1 cm of chest wall and used exclusion zones around mediastinum and lobar bronchial bifurcation; it is a peripheral-tumour trial, not a central SBRT trial. |
| SPACE | Medically inoperable stage I NSCLC; study was not designed as an ultracentral dose-escalation trial. Check the original protocol for location eligibility. | SBRT 66 Gy/3 fractions vs conventionally fractionated RT 70 Gy/35 fractions. | SPACE used SBRT 66 Gy/3 versus 70 Gy/35. The primary reports available in this review did not provide a verified protocol-level OAR table, so numeric limits are intentionally not imputed from another trial. OARs to document include whole lung minus GTV, spinal cord, oesophagus, heart/pericardium, trachea/PBT, major vessels, brachial plexus and chest wall/ribs as relevant. |
| LUSTRE | Stage I NSCLC ≤5 cm. Central: within 1 cm of mediastinum and/or within 2 cm of PBT. Ultracentral cases were included and analysed as a subgroup. | Peripheral: 48 Gy/4 alternate-day fractions; central: 60 Gy/8 daily fractions. Comparator: 60 Gy/15 fractions. | Trial-specific planning guide and RT quality assurance applied. OARs included central airways, esophagus, great vessels, heart/pericardium, spinal cord and lung as relevant. One grade-5 hemoptysis occurred in an ultracentral case despite meeting planning objectives. |
| HILUS | Ultracentral tumours ≤1 cm from PBT; group A ≤1 cm from main bronchi/trachea, group B other eligible locations. | 56 Gy/8 fractions (7 Gy × 8), prescribed to the 67% isodose covering PTV (hotspot about 150%). | Reported constraints: spinal canal Dmax <33.6 Gy; trachea/main bronchi Dmax <48.8 Gy; heart/pericardium and esophagus 41.6 Gy (as reported in trial constraint summaries). Fatal bronchopulmonary bleeding, pneumonitis and fistula were observed; do not use this schedule without careful protocol-specific review. |
| RTOG 0813 | Medically inoperable, biopsy-proven, central T1–T2 N0M0 NSCLC. Central framework based on proximity to PBT and included PTV abutting mediastinum. | 50–60 Gy/5 fractions, dose-escalation; 60 Gy/5 is the highest cohort. Prescription to 80% isodose (approx. 125% hotspot). | Protocol-derived limits (5 fractions; verify structure names and metrics in protocol): spinal cord Dmax <30 Gy; PBT/trachea-bronchial tree Dmax ≤105% of prescription and D4cc ≤18 Gy; esophagus Dmax ≤105% and D5cc ≤27.5 Gy; heart/pericardium Dmax ≤105% and D15cc ≤32 Gy; great vessels Dmax ≤105% and D10cc ≤47 Gy; total lung minus GTV V20 ≤10% (≤15% variation), D1500cc ≤12.5 Gy and D1000cc ≤13.5 Gy; brachial plexus Dmax ≤32 Gy. RTOG 0813 eligibility: tumour ≤5 cm, within or touching the 2-cm zone around PBT or immediately adjacent to mediastinal/pericardial pleura. |
| SUNSET | Ultracentral NSCLC; PTV abutting PBT, esophagus, pulmonary vein or pulmonary artery was allowed. Endobronchial invasion excluded. | 60 Gy/8 fractions; hotspot capped at 120% and confined within PTV. | Published constraint summary: spinal cord Dmax <32 Gy; trachea, main bronchi, heart/pericardium and great vessels D10cc <60 Gy and Dmax <64 Gy; esophagus D5cc <40 Gy and Dmax <45 Gy. Verify the exact structure definitions and any additional lung limits in the full protocol. |
Randomized surgery versus SABR trial in stage IA NSCLC; closed early with very small accrual. Only tumours at least 2 cm from hilar structures were eligible. SABR schedules were 54 Gy/3 fractions or 60 Gy/5 fractions depending on centre protocol.
Pooled STARS/ROSEL report (Lancet Oncology) · Protocol comparison table
Randomized study of CyberKnife SABR versus surgical resection. The pooled STARS/ROSEL report describes 54 Gy/3 fractions for peripheral lesions and 50 Gy/4 fractions for central lesions in STARS. Do not conflate this with the later single-arm STARS trial, which used a different protocol.
Peripheral stage I NSCLC; SABR improved local control over standard radiotherapy. SABR was 54 Gy/3 fractions, or 48 Gy/4 fractions for tumours less than 2 cm from chest wall. This chest-wall adaptation is not a centrality definition.
Randomized phase II study comparing SBRT with conventional radiotherapy in medically inoperable stage I NSCLC. SBRT schedule: 66 Gy/3 fractions; comparator: 70 Gy/35 fractions. The study did not establish a universal central/ultracentral definition.
Phase III randomized trial. Central was defined as within 1 cm of mediastinum and/or within 2 cm of PBT. SBRT was 48 Gy/4 fractions for peripheral and 60 Gy/8 for central disease versus 60 Gy/15 fractions. Three-year local control was 87.6% versus 81.2% (HR 0.61; p=.15); the difference was not statistically significant. One grade-5 hemoptysis occurred in an ultracentral SBRT case.
Prospective phase II study of ultracentral tumours ≤1 cm from PBT; 56 Gy/8 fractions prescribed to the 67% isodose. Two-year local control was 83%; 22/65 patients had grade 3–5 toxicity, including 10 treatment-related deaths. This trial is a toxicity caution, not a default prescription template.
Phase I/II dose-escalation for central NSCLC using 50–60 Gy/5 fractions. Published summaries report PBT, esophagus, great vessels and heart/pericardium maximum doses up to 105% of prescription, spinal cord Dmax 30 Gy and brachial plexus Dmax 32 Gy. Check the protocol version for all volume constraints and contour definitions.
Original NRG/RTOG 0813 protocol page (protocol PDF) · Primary report · Open OAR-constraint review
Prospective phase I/II study in ultracentral NSCLC; 60 Gy/8 fractions with hotspot limited to 120% within PTV; endobronchial invasion excluded. Three-year local control was 89.6%. Grade 3–5 adverse events occurred in 2/30 patients (6.7%), including one grade-5 pneumonia in a patient with imaging consistent with background interstitial lung disease.
Primary report, PubMed · Review table of ultracentral OAR constraints