Dataset Information

Real-time interactive planning for radiotherapy of head and neck cancer with volumetric modulated arc therapy.

ABSTRACT:

Background and purpose

Planning complex radiotherapy treatments can be inefficient, with large variation in plan quality. In this study we evaluated plan quality and planning efficiency using real-time interactive planning (RTIP) for head and neck (HN) volumetric modulated arc therapy (VMAT).

Materials and methods

RTIP allows manipulation of dose volume histograms (DVHs) in real-time to assess achievable planning target volume (PTV) coverage and organ at risk (OAR) sparing. For 20 HN patients previously treated with VMAT, RTIP was used to minimize OAR dose while maintaining PTV coverage. RTIP DVHs were used to guide VMAT optimization. Dosimetric differences between RTIP-assisted plans and original clinical plans were assessed. Five blinded radiation oncologists indicated their preference for each PTV, OAR and overall plan. To assess efficiency, ten patients were planned de novo by experienced and novice planners and a RTIP user.

Results

The average planning time with RTIP was <20?min, and most plans required only one optimization. All 20 RTIP plans were preferred by a majority of oncologists due to improvements in OAR sparing. The average maximum dose to the spinal cord was reduced by 10.5?Gy (from 49.5 to 39.0?Gy), and the average mean doses for the oral cavity, laryngopharynx, contralateral parotid and submandibular glands were reduced by 3.5?Gy (39.1-35.7?Gy), 6.8?Gy (42.5-35.7?Gy), 1.7?Gy (17.0-15.3?Gy) and 3.3?Gy (22.9-19.5?Gy), respectively.

Conclusions

Incorporating RTIP into clinical workflows may increase both planning efficiency and OAR sparing.

SUBMITTER: Baker L

PROVIDER: S-EPMC7807618 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

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Publications

Real-time interactive planning for radiotherapy of head and neck cancer with volumetric modulated arc therapy.

Baker Lindsey L Olson Robert R Braich Taran T Koulis Theodora T Ye Allison A Ahmed Nisar N Tran Eric E Lawyer Kim K Otto Karl K Smith Sally S Mestrovic Ante A Matthews Quinn Q

Physics and imaging in radiation oncology 20190101

<h4>Background and purpose</h4>Planning complex radiotherapy treatments can be inefficient, with large variation in plan quality. In this study we evaluated plan quality and planning efficiency using real-time interactive planning (RTIP) for head and neck (HN) volumetric modulated arc therapy (VMAT).<h4>Materials and methods</h4>RTIP allows manipulation of dose volume histograms (DVHs) in real-time to assess achievable planning target volume (PTV) coverage and organ at risk (OAR) sparing. For 20 ...[more]

PMID: 33458430

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Project description:This dosimetric study investigated the impact of multileaf collimators (MLC) leaf width in volumetric-modulated arc therapy (VMAT) for head and neck cancers (HNC), either with a "standard" simultaneously integrated boost technique (S-SIB) or with a "dose painting" SIB technique (DP-SIB). HNC patients were planned either with an S-SIB comprising three dose levels, from 56 to 70 Gy (16 patients), or with a DP-SIB comprising five dose levels, from 56 to 84 Gy (8 patients), in 35 fractions. Two VMAT plans were calculated for each SIB technique using two Elekta MLCs: MLCi2 with 10 mm leaf width and Beam Modulator (BM) with 4 mm leaf width. Dose distributions were evaluated by comparing doses on PTVs, main OARs, and healthy tissue, and by comparing conformation indexes. Treatment efficiencies were evaluated by comparing the number of monitor units and the number of needed arcs. Comparisons of the two MLCs depending on the two SIB techniques showed: i) Regarding PTVs: Dmean and D2% on lower doses PTV decreased respectively by 0.5 Gy (p = 0.01) and 0.9 Gy (p = 0.01) with BM than with MLCi2 for S-SIB; no significant difference was found for DP-SIB;ii) Regarding OARs: for spinal cord and brainstem, D2% decreased respectively by 1.2 Gy (p = 0.03) and 4.2 Gy (p = 0.04) with BM than with MLCi2 for S-SIB; for controlateral parotid, D50% decreased by 1.5 Gy (p = 0.01) with BM than with MLCi2 for S-SIB; iii) Regarding treatment efficiency: the number of monitor units was 44% (p = 0.00) and 51% (p = 0.01) higher with BM for S-SIB and DP-SIB, respectively. Two arcs were more frequently needed with BM to reach an acceptable dose distribution. This study demonstrated that Beam Modulator (4 mm leaf width) and MLCi2 (10 mm leaf width) MLCs from Elekta provided satisfactory dose distributions for treatment delivery with VMAT technique for complex HNC cases with standard and dose painting prescriptions. OAR sparing was better with BM, mainly for brainstem and spinal cord. However, delivery efficiency of VMAT plans was better with MLCi2.

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Dataset Information

Real-time interactive planning for radiotherapy of head and neck cancer with volumetric modulated arc therapy.

Background and purpose

Materials and methods

Results

Conclusions

Publications

Real-time interactive planning for radiotherapy of head and neck cancer with volumetric modulated arc therapy.

Similar Datasets

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