Limits...
Impact of different beam directions on intensity-modulated radiation therapy dose delivered to functioning lung tissue identified using single-photon emission computed tomography.

Tian Q, Zhang F, Wang Y, Qu W - Contemp Oncol (Pozn) (2014)

Bottom Line: The seven-beam SPECT (SPECT-7) plan reduced the volume of the functional lung irradiated with at least 20 Gy (FV20) and 30 Gy (FV30) by 26.02% ±15.45% and 14.41% ±16.66%, respectively, as compared to the seven-beam computed tomography (CT-7) plan.The heterogeneity index significantly differed among the three SPECT plans and was best in the SPECT-7 plan.The low-dose volumes were lower in SPECT-4.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiotherapy, The General Hospital of Jinan Military Command, Jinan, Shandong Province, China ; Qin Tian and Fucheng Zhang contributed equally to this work.

ABSTRACT

Aim of the study: To use different beam arrangements and numbers to plan intensity-modulated radiation therapy (IMRT) and investigate their effects on low and high radiation doses delivered to the functional lung, in order to reduce radiation-induced lung damage.

Material and methods: Ten patients with stage I-III non-small cell lung carcinoma (NSCLC) underwent IMRT. Beam arrangements were selected on the basis of orientation and dose-volume histograms to create SPECT-guided IMRT plans that spared the functional lung and maintained target coverage. Four different plans, including CT-7, SPECT-7, SPECT-4, SPECT-5 with different beam arrangements, were used. The differences of conformity index (CI), heterogeneity index (HI) between the plans were analyzed, by using a paired t-test.

Results: The seven-beam SPECT (SPECT-7) plan reduced the volume of the functional lung irradiated with at least 20 Gy (FV20) and 30 Gy (FV30) by 26.02% ±15.45% and 14.41% ±16.66%, respectively, as compared to the seven-beam computed tomography (CT-7) plan. The CI significantly differed between the SPECT-7 and SPECT-4 plans and between the SPECT-5 and SPECT-4 plans, but not between the SPECT-5 and SPECT-7 plans. The CIs in the SPECT-5 and SPECT-7 plans were better than that in the SPECT-4 plan. The heterogeneity index significantly differed among the three SPECT plans and was best in the SPECT-7 plan.

Conclusions: The incorporation of SPECT images into IMRT planning for NSCLC greatly affected beam angles and number of beams. Fewer beams and modified beam angles achieved similar or better IMRT quality. The low-dose volumes were lower in SPECT-4.

No MeSH data available.


Related in: MedlinePlus

Dose-volume histograms of seven-beam computed tomography (CT-7) and single-photon emission CT (SPECT-7) plans for the planning target volume (PTV; green lines) and the total lung volume (blue lines) of a patient with stage III non-small cell lung cancer
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4355654&req=5

Figure 0004: Dose-volume histograms of seven-beam computed tomography (CT-7) and single-photon emission CT (SPECT-7) plans for the planning target volume (PTV; green lines) and the total lung volume (blue lines) of a patient with stage III non-small cell lung cancer

Mentions: Dose-volume histograms of different plans are shown in Figs. 4 and 5. The lung doses and other radiotherapy parameters are shown in Table 3. The FV5 value for the lung was highest in the SPECT-7 plan. The FV20 and FV30 values were lowest in the SPECT-7 plan. Thus, the SPECT-4 plan may be beneficial in lowering lung volumes receiving low-dose radiation, while the SPECT-7 plan may be beneficial in lowering lung volumes receiving high-dose radiation. The MLD was lower in the SPECT-4 plan than in the SPECT-5 and SPECT-7 plans; the MLD did not significantly differ between the SPECT-5 and SPECT-7 plans.


Impact of different beam directions on intensity-modulated radiation therapy dose delivered to functioning lung tissue identified using single-photon emission computed tomography.

Tian Q, Zhang F, Wang Y, Qu W - Contemp Oncol (Pozn) (2014)

Dose-volume histograms of seven-beam computed tomography (CT-7) and single-photon emission CT (SPECT-7) plans for the planning target volume (PTV; green lines) and the total lung volume (blue lines) of a patient with stage III non-small cell lung cancer
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4355654&req=5

Figure 0004: Dose-volume histograms of seven-beam computed tomography (CT-7) and single-photon emission CT (SPECT-7) plans for the planning target volume (PTV; green lines) and the total lung volume (blue lines) of a patient with stage III non-small cell lung cancer
Mentions: Dose-volume histograms of different plans are shown in Figs. 4 and 5. The lung doses and other radiotherapy parameters are shown in Table 3. The FV5 value for the lung was highest in the SPECT-7 plan. The FV20 and FV30 values were lowest in the SPECT-7 plan. Thus, the SPECT-4 plan may be beneficial in lowering lung volumes receiving low-dose radiation, while the SPECT-7 plan may be beneficial in lowering lung volumes receiving high-dose radiation. The MLD was lower in the SPECT-4 plan than in the SPECT-5 and SPECT-7 plans; the MLD did not significantly differ between the SPECT-5 and SPECT-7 plans.

Bottom Line: The seven-beam SPECT (SPECT-7) plan reduced the volume of the functional lung irradiated with at least 20 Gy (FV20) and 30 Gy (FV30) by 26.02% ±15.45% and 14.41% ±16.66%, respectively, as compared to the seven-beam computed tomography (CT-7) plan.The heterogeneity index significantly differed among the three SPECT plans and was best in the SPECT-7 plan.The low-dose volumes were lower in SPECT-4.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiotherapy, The General Hospital of Jinan Military Command, Jinan, Shandong Province, China ; Qin Tian and Fucheng Zhang contributed equally to this work.

ABSTRACT

Aim of the study: To use different beam arrangements and numbers to plan intensity-modulated radiation therapy (IMRT) and investigate their effects on low and high radiation doses delivered to the functional lung, in order to reduce radiation-induced lung damage.

Material and methods: Ten patients with stage I-III non-small cell lung carcinoma (NSCLC) underwent IMRT. Beam arrangements were selected on the basis of orientation and dose-volume histograms to create SPECT-guided IMRT plans that spared the functional lung and maintained target coverage. Four different plans, including CT-7, SPECT-7, SPECT-4, SPECT-5 with different beam arrangements, were used. The differences of conformity index (CI), heterogeneity index (HI) between the plans were analyzed, by using a paired t-test.

Results: The seven-beam SPECT (SPECT-7) plan reduced the volume of the functional lung irradiated with at least 20 Gy (FV20) and 30 Gy (FV30) by 26.02% ±15.45% and 14.41% ±16.66%, respectively, as compared to the seven-beam computed tomography (CT-7) plan. The CI significantly differed between the SPECT-7 and SPECT-4 plans and between the SPECT-5 and SPECT-4 plans, but not between the SPECT-5 and SPECT-7 plans. The CIs in the SPECT-5 and SPECT-7 plans were better than that in the SPECT-4 plan. The heterogeneity index significantly differed among the three SPECT plans and was best in the SPECT-7 plan.

Conclusions: The incorporation of SPECT images into IMRT planning for NSCLC greatly affected beam angles and number of beams. Fewer beams and modified beam angles achieved similar or better IMRT quality. The low-dose volumes were lower in SPECT-4.

No MeSH data available.


Related in: MedlinePlus