Lattice radiotherapy boost integrated with thoracic VMAT in bulky stage IIIB non–small cell lung cancer: a case report
- 1Department of Radiotherapy, The First Hospital of Lanzhou University
- 2Department of Pediatrics, The Second Hospital of Lanzhou University
- 3Department of General Surgery, The First Hospital of Lanzhou University
Abstract
Background: Bulky unresectable stage III non-small cell lung cancer (NSCLC) presents a clinical challenge during definitive radiotherapy, as homogeneous dose escalation is often constrained by organ-at-risk (OAR) tolerance. Spatially fractionated radiotherapy (SFRT), including lattice radiotherapy (LRT), creates an intratumoral peak-valley dose distribution and may provide a means to intensify local dose delivery. However, the optimal dose, fractionation, vertex geometry, treatment sequence, and contribution of LRT to clinical response remain uncertain.
Case presentation: We report a 41-year-old never-smoking Han Chinese man with bulky unresectable stage IIIB (cT4N2M0, AJCC 8th edition) disease, with a primary tumor measuring 71×53 mm at baseline. After two cycles of induction platinum-based chemotherapy, the disease was classified as stable disease. The patient subsequently received thoracic VMAT to 60 Gy in 15 fractions, during this course, a LRT plan was interleaved within the VMAT plan and delivered using an interleaved “4 VMAT treatments plus 1 LRT per week” pattern. Sixteen spheres were placed within the gross tumor volume (GTV), achieving a peak-to-valley dose ratio (PVDR) of 3.52. Serial CT showed a reduction in the sum of lesion diameters (SOD) of 20.7% after eight VMAT fractions, 29.6% after 14 fractions, and 40% at the 2-month post-treatment assessment. The patient developed grade 4 hematologic toxicity and grade 1 radiation pneumonitis after additional systemic therapy.
Conclusion: This case demonstrates the delivery of weekly LRT during thoracic VMAT in a patient with bulky stage IIIB NSCLC, with significant tumor regression observed. This approach should be regarded as technically feasible in this case only, rather than as evidence that LRT can circumvent OAR (organs at risk) constraints or improve tumor control.
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BibTeX
@article{wang2026lattice,
title = {{Lattice radiotherapy boost integrated with thoracic VMAT in bulky stage IIIB non–small cell lung cancer: a case report}},
author = {Song Wang and Xing-Chuan Li and Jun-tao Ran and Quan-Lin Guan},
journal = {Frontiers in Oncology},
year = {2026},
month = oct,
doi = {10.3389/fonc.2026.1965056},
url = {https://www.frontiersin.org/articles/10.3389/fonc.2026.1965056/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Lattice radiotherapy boost integrated with thoracic VMAT in bulky stage IIIB non–small cell lung cancer: a case report
AU - Song Wang
AU - Xing-Chuan Li
AU - Jun-tao Ran
AU - Quan-Lin Guan
PY - 2026
DA - 2026/10/28
JO - Frontiers in Oncology
DO - 10.3389/fonc.2026.1965056
UR - https://www.frontiersin.org/articles/10.3389/fonc.2026.1965056/full
AB - Background: Bulky unresectable stage III non-small cell lung cancer (NSCLC) presents a clinical challenge during definitive radiotherapy, as homogeneous dose escalation is often constrained by organ-at-risk (OAR) tolerance. Spatially fractionated radiotherapy (SFRT), including lattice radiotherapy (LRT), creates an intratumoral peak-valley dose distribution and may provide a means to intensify local dose delivery. However, the optimal dose, fractionation, vertex geometry, treatment sequence, and contribution of LRT to clinical response remain uncertain. Case presentation: We report a 41-year-old never-smoking Han Chinese man with bulky unresectable stage IIIB (cT4N2M0, AJCC 8th edition) disease, with a primary tumor measuring 71×53 mm at baseline. After two cycles of induction platinum-based chemotherapy, the disease was classified as stable disease. The patient subsequently received thoracic VMAT to 60 Gy in 15 fractions, during this course, a LRT plan was interleaved within the VMAT plan and delivered using an interleaved “4 VMAT treatments plus 1 LRT per week” pattern. Sixteen spheres were placed within the gross tumor volume (GTV), achieving a peak-to-valley dose ratio (PVDR) of 3.52. Serial CT showed a reduction in the sum of lesion diameters (SOD) of 20.7% after eight VMAT fractions, 29.6% after 14 fractions, and 40% at the 2-month post-treatment assessment. The patient developed grade 4 hematologic toxicity and grade 1 radiation pneumonitis after additional systemic therapy. Conclusion: This case demonstrates the delivery of weekly LRT during thoracic VMAT in a patient with bulky stage IIIB NSCLC, with significant tumor regression observed. This approach should be regarded as technically feasible in this case only, rather than as evidence that LRT can circumvent OAR (organs at risk) constraints or improve tumor control.
SN - 2234-943X
ER -