1. Dose Prescription Methods in Stereotactic Body Radiotherapy for Small Peripheral Lung Tumors: Approaches Based on the Gross Tumor Volume Are Superior to Prescribing a Dose That Covers 95% of the Planning Target Volume
- Author
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Takafumi Komiyama MD, PhD, Masahide Saito PhD, Kengo Kuriyama MD, PhD, Kan Marino MD, Shinichi Aoki MD, Ryo Saito MD, Juria Muramatsu MD, Yoshiyasu Maehata MD, PhD, Chen Ze MD, Tomoko Akita MD, Takashi Yamada MD, Naoki Sano PhD, Kazuya Yoshizawa RTT, Ashizawa Kazunari RTT, Suzuki Hidekazu MSc, Koji Ueda RTT, Nam Vu MD, and Hiroshi Onishi MD, PhD
- Subjects
Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background and Purpose: We aimed to validate the usefulness of prescriptions based on gross tumor volume for stereotactic body radiotherapy for small peripheral lung tumors. Materials and Methods: Radiotherapy treatment planning data of 50 patients with small peripheral lung tumors (adenocarcinoma: 24, squamous cell carcinoma: 10, other: 1, unknown: 15) receiving breath-hold computed tomography-guided stereotactic body radiotherapy at our institution during 2013–2016 were analyzed. For each case, 3 dose prescription methods were applied: one based on 95% (PTVD 95% ) of the planning target volume, one based on 50% of the gross tumor volume (GTVD 50% ), and one based on 98% (GTVD 98% ) of the gross tumor volume. The maximum (GTVDmax), minimum (GTVDmin), and mean gross tumor volume dose (GTVDmean) and the dose covering 98% of the gross tumor volume were calculated to evaluate variations in the gross tumor volume dose. Results: Upon switching to GTVD 50% , the variations in GTVDmax and GTVDmean decreased significantly, compared with variations observed for PTVD 95% (p < 0.01), but the variation in GTVDmin increased significantly (p < 0.01). Upon switching to the GTVD 98% , the variation in GTVDmean decreased significantly compared with that observed for PTVD 95% (p < 0.01). Conclusion: Switching from prescriptions based on 95% of the planning target volume to those based on 98% of the gross tumor volume decreased variations among cases in the overall gross tumor volume dose. Overall, prescriptions based on 98% of the gross tumor volume appear to be more suitable than those based on 95% of the planning target volume in cases of small peripheral lung tumors treated with stereotactic body radiotherapy.
- Published
- 2020
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