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SBRT bei NSCLC (Dr Kuczer – 2024)

Radiation Oncology specialist, Dr. Kuczer

 

3D-CRT vs. SBRT

 

Respiratory Motion Management

Conventional (ITV-based)
– Contour and treat full tumor ROM

Accelerator beam gating
– Patient breathes normally; beam only on while patient is in a certain phase of the respiratory cycle

Active breathing control
– Patient holds breath in a certain position; beam only on in that phase of the respiratory cycle

Dynamic tumor tracking
– Patient breathes normally; tumor is tracked; beam always on and moves with tumor

Regardless of the motion management used, an additional “CTV/PTV” margin around our target is needed to ensure that we hit it.

 

 

Curative Indication - NCCN Guidelines – NSCLC

 

Curative Indication - NCCN Guidelines – NSCLC

  • Surgical resection is the preferred local treatment
    – An anatomical resection with lobectomy or segmentectomy is preferred to wedge resection
    – Includes sampling of at-risk ipsilateral hilar and mediastinal LN
  • SBRT for patients who are medically inoperable or refuse surgery
    –Limitations: High volume (DM > 5cm) and  “ultra-central” tumors should be treated more cautiously (e.g. 10 instead of 3 fractions)
    –Limited data yet supporting the addition of systemic therapy to SBRT

Potential SBRT Toxicity Depends on Tumor Site

Risk of toxicity can be reduced through risk-adapted dose-fractionation

 

Outcomes of SBRT for Early Stage NSCLC

 

Take Home Pearl and Further Indications of SBRT for NSCLC

 

Reirradiation of Recurrent disease

 

  • Feasibility of treating with curative intent depends on site of primary (P) and recurrent (R) tumors
  • Advanced treatment techniques are particularly useful for sparing normal tissue (e.g., IMRT, SBRT, protons)
    – Reirradiating central structures (e.g., esophagus, airway) most challenging
    – Long-term toxicity is the major concern – impacted by dose/fraction

SBRT in the Management of Stage IV NSCLC

Palliative Radiation For Symptom Relief

  • Pain
    –Bone metastases
  • Neurologic symptoms
    –Spinal cord compression
    –Brain metastases
  • Bleeding
    –Endobronchial tumor
  • Dyspnea/Dysphagia
    –Tumor obstruction causing SVC, respiratory distress or esophageal narrowing

Is all metastatic disease the same?

  • No! Lung cancer has M1a, M1b and M1c designations because the metastatic state at diagnosis impacts prognosis; a small subset of patients may be cured
  • “Oligometastatic” refers to a situation where distant metastases may be limited in number (typically defined as < 5 mets in < 3 organs), and potentially curative treatment can be delivered prior to the development of widespread disease

 

UT Southwestern Randomized Phase II Trial

  • Iyengar et al, JAMA Oncol, 2018
  • 29 patients, oligometastatic NSCLC with < 5 sites of disease (EGFR/ALK negative), PR or SD after induction chemo, randomized to +/- SAbR
  • SAbR à ↑ M-PFS (3.5à9.7mo)

 

SABR-COMET Randomized Phase II Trial

  • Palma et al, Lancet, 2019
  • 99 patients, variety of oligometastatic cancers with < 5 sites of disease, PR/SD on systemic therapy, randomized 1:2 to +/- SAbR (at ablative doses)
    – Most common histologies: breast, lung, colorectal, prostate
  • SAbR à ↑ M-PFS (6à12mo, p<0.001) & M-OS (28à41mo, p=0.09)
    – Also ↑ G2 or higher toxicity, but no difference in QOL

 

Multi-Institutional Randomized Phase II Trial

  • Gomez et al, J Clin Oncol, 2019
  • 49 patients with oligometastatic NSCLC with < 3 sites of disease, SD/PR after Pt-based doublet or EGFR/ALK inhibitor, randomized to maintenance systemic therapy +/- local consolidative surgery/RT
  • RT à ↑ M-PFS (4.4à14.2mo) and M-OS (17à41mo, p=0.02)

 

The Future…

Immunotherapy May Change Our Approach to Locoregional Management Too

A stronger immune response may be elicited by leaving a tumor in and irradiating it, rather than removing the largest source of antigenic stimulation.

 

 

 

The Future……Aktive Protokolle

PACIFIC-4 / RTOG 3515

Inclusion Criteria

  • Clinical Stage I/II node negative (T1 – T3 N0)
  • Medically inoperable or refuse surgery
  • ECOG PS 0-2
  • All comers for histology and PDL-1 status
  • Sync/Metach allowed

The Future…A Few Examples of Active Clinical Trials in Lung Cancer

CAVE: Not all new substances proofed to be safe with SBRT. Additional surveys needed!

  • NRG LU002: Adds RT (to all sites of disease) to systemic therapy for oligometastatic NSCLC
  • NRG LU004: Adds immunotherapy to IMRT or 3-D CRT for stage II-III NSCLC with high PD-L1 expression (instead of chemotherapy)
  • PACIFIC 4 and NRG/S1914: Adds consolidative immunotherapy to SBRT for stage I NSCLC
  • AEGEAN: Adds neoadjuvant immunotherapy to surgery for resectable stage II-III NSCLC
  • ALCHEMIST: Evaluating adjuvant use of targeted agents for resected NSCLC
  • RTOG 1308: Compares proton therapy to photon therapy for LA-NSCLC
  • NRG LU005: Adds immunotherapy to chemoradiation for limited-stage SCLC
  • NRG CC003: Hippocampal avoidance PCI for SCLC

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SBRT bei NSCLC

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