Dosimetry and efficiency comparison of knowledge-based and manual planning using volumetric modulated arc therapy for craniospinal irradiation

Wei-Ta Tsai; Hui-Ling Hsieh; Shih-Kai Hung; Chi-Fu Zeng; Ming-Fen Lee; Po-Hao Lin; Chia-Yi Lin; Wei-Chih Li; Wen-Yen Chiou; Tung-Hsin Wu

doi:10.2478/raon-2024-0018

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Dosimetry and efficiency comparison of knowledge-based and manual planning using volumetric modulated arc therapy for craniospinal irradiation

Radiology and Oncology

Volume 58 (2024): Issue 2 (June 2024)

By: Wei-Ta Tsai, Hui-Ling Hsieh, Shih-Kai Hung, Chi-Fu Zeng, Ming-Fen Lee, Po-Hao Lin, Chia-Yi Lin, Wei-Chih Li, Wen-Yen Chiou and Tung-Hsin Wu

Open Access

|Mar 2024

Figures & Tables

Flowchart of the study design.
CSI = craniospinal irradiation; CT = computed tomography; KBP = knowledge-based planning; VMAT = volumetric modulated arc therapy

Example of the target and field setup. **(A)** The arrangement of the brain field (dotted lines), spine-superior field (solid lines), spine-inferior field (dashed lines), and their isocenters. Each field overlaps at least 5 cm for the low-dose gradient junction. **(B)** Full arc was used on the brain field. **(C)** Partial arc was used in the spinal fields for arm sparing.

TABLE 1.

Dosimetric comparison between manual plans, RapidPlan initial, and RapidPlan final

Parameters	Goals	Results			*P value*
Parameters	Goals	MP	RP_I	RP_F	*MP vs.* RP_I**	*MP vs.* RP_F**	*RP_I vs.* RP_F**
CTV
V₉₅ [%]	> 99	99.99 ± 0.03	99.98 ± 0.03	99.97 ± 0.03	0.36	0.03^*	0.09
V₁₀₀ [%]	> 99	99.20 ± 0.17	98.37 ± 0.33	99.37 ± 0.23	< 0.01^**	0.07	< 0.01^**
V₁₀₇ [%]	Minimize	0.62 ± 0.59	2.94 ± 4.33	0.46 ± 0.66	< 0.01^**	0.16	< 0.01^**
D_mean [Gy]	36	37.23 ± 0.18	37.31 ± 0.21	37.22 ± 0.24	0.07	0.87	0.13
D_max [Gy]	Minimize	39.38 ± 0.40	40.38 ± 0.57	39.42 ± 0.41	< 0.01^**	0.78	< 0.01^**
D₂ [%]	< 107	106.12 ± 0.73	106.95 ± 0.96	105.72 ± 0.84	< 0.01^**	0.19	< 0.01^**
PTV
V₉₅ [%]	> 98	99.68 ± 0.15	99.55 ± 0.23	99.24 ± 0.32	0.03^*	< 0.01^**	< 0.01^**
V₁₀₀ [%]	= 95	95.00 ± 0.00	95.00 ± 0.00	95.00 ± 0.00	-	-	-
V₁₀₇ [%]	Minimize	0.62 ± 0.57	3.01 ± 4.12	0.44 ± 0.61	< 0.01^**	0.17	< 0.01^**
D_mean [Gy]	36	37.10 ± 0.16	37.22 ± 0.18	37.08 ± 0.20	0.05	0.73	0.01^*
D_max [%]	< 112	109.99 ± 1.17	112.89 ± 1.78	110.17 ± 1.14	< 0.01^**	0.57	< 0.01^**
D₂ [%]	< 107	106.09 ± 0.73	107.00 ± 0.93	105.71 ± 0.80	< 0.01^**	0.21	< 0.01^**
CI	1	0.98 ± 0.01	1.01 ± 0.01	1.00 ± 0.01	< 0.01^**	< 0.01^**	0.01^*
HI	1	1.10 ± 0.01	1.13 ± 0.02	1.10 ± 0.01	< 0.01^**	0.57	< 0.01^**

CI = conformity index; CTV = clinical target volume; Dx = minimum dose received by the hottest x% volume; HI = homogeneity index; MP = manual plan; PTV = planning target volume; RP_I = RapidPlan initial; RP_F = RapidPlan final; Vx = volume receiving at least x dose;

* = P < 0.05;

** = P < 0.01

TABLE 2.

Dosimetric goals and results for organs at risk

OAR parameters	Goals	Results			*P value*
OAR parameters	Goals	MP	RP_I	RP_F	*MP vs.* RP_F**	*MP vs.* RP_F**	*RP_I vs.* RP_I**
Brain
D_max [Gy]	< 60	39.34 ± 0.39	40.24 ± 0.61	39.28 ± 0.37	< 0.01^**	0.46	< 0.01^**
Brain stem
D_max [Gy]	< 54	38.48 ± 0.41	39.03 ± 0.46	38.51 ± 0.28	< 0.01^**	0.91	< 0.01^**
Chiasm
D_mean [Gy]	< 50	37.15 ± 0.35	37.10 ± 0.32	36.95 ± 0.32	0.69	0.07	0.06
D_max [Gy]	< 55	38.13 ± 0.40	38.73 ± 0.55	38.20 ± 0.26	0.01^*	0.46	< 0.01^**
Optic nerves
D_mean [Gy]	< 50	27.61 ± 3.40	22.90 ± 2.39	22.42 ± 2.29	< 0.01^**	< 0.01^**	0.05
D_max [Gy]	< 55	37.13 ± 0.69	36.36 ± 1.72	36.15 ± 1.39	0.13	0.02^*	0.13
Eyes
D_max [Gy]	< 50	25.55 ± 3.57	22.52 ± 3.83	21.60 ± 3.86	0.02^*	0.01^*	0.01^*
Lens
D_max [Gy]	< 10	8.40 ± 0.68	8.87 ± 1.00	8.10 ± 0.55	0.11	0.21	< 0.01^**
Parotid glands
D_mean [Gy]	< 25	7.38 ± 2.52	5.16 ± 0.39	4.95 ± 0.39	< 0.01^**	< 0.01^**	< 0.01^**
Spinal cord
D_max [Gy]	< 50	38.93 ± 0.51	39.81 ± 0.67	39.04 ± 0.56	< 0.01^**	< 0.01^**	< 0.01^**
Thyroid
D_max [Gy]	< 45	17.23 ± 4.04	16.68 ± 2.13	16.38 ± 2.04	0.59	0.36	0.07
Lungs
D_mean [Gy]	< 13	4.63 ± 0.30	4.95 ± 0.43	4.63 ± 0.24	0.03^*	0.73	< 0.01^**
V_20Gy [%]	< 22	0.06 ± 0.11	0.04 ± 0.08	0.03 ± 0.04	0.64	0.44	0.33
V_5Gy [%]	< 42	36.48 ± 2.88	42.77 ± 5.62	37.11 ± 2.87	0.01^*	0.69	< 0.01^**
Heart
D_mean [Gy]	< 10	6.76 ± 1.47	5.53 ± 0.82	5.70 ± 0.93	0.01^*	0.02^*	0.33
V_40Gy [%]	< 3	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	-	-	-
V_18Gy [%]	< 5	0.04 ± 0.10	0.01 ± 0.03	0.01 ± 0.02	0.31	0.23	0.41
Esophagus
D_mean [Gy]	< 34	14.34 ± 1.62	13.23 ± 1.63	13.30 ± 1.74	0.01^*	< 0.01^**	0.96
Liver
D_mean [Gy]	< 30	4.82 ± 0.94	4.57 ± 0.73	4.45 ± 0.70	0.61	0.33	< 0.01^**
Kidneys
D_mean [Gy]	< 18	2.81 ± 1.17	2.47 ± 0.46	2.38 ± 0.43	0.96	0.73	< 0.01^**

OAR = organ at risk; MP = manual plan; RP_I = RapidPlan initial; RP_F = RapidPlan final; Vx = volume receiving at least x dose;

* = P < 0.05;

** = P < 0.01

TABLE 3.

The mean dose of the OARs outside the targets contours

Organ	Mean dose			*P value*
Organ	MP	RP_I	RP_F	*MP vs.* RP_I**	*MP vs.* RP_F**	*RP_I vs.* RP_F**
Optic nerves	27.61 ± 3.40	22.90 ± 2.39	22.42 ± 2.29	< 0.01^**	< 0.01^**	0.05
Eyes	12.11 ± 1.99	10.16 ± 0.55	9.83 ± 0.74	0.01^*	0.01^*	0.02^*
Lens	7.09 ± 0.67	7.21 ± 0.52	6.78 ± 0.39	0.43	0.16	< 0.01^**
Parotid glands	7.38 ± 2.52	5.16 ± 0.39	4.95 ± 0.39	< 0.01^**	< 0.01^**	< 0.01^**
Thyroid	10.41 ± 3.37	9.00 ± 1.94	8.51 ± 2.07	0.06	0.04^*	< 0.01^**
Lungs	4.63 ± 0.30	4.95 ± 0.43	4.63 ± 0.24	0.03^*	0.73	< 0.01^**
Heart	6.76 ± 1.47	5.53 ± 0.82	5.70 ± 0.93	0.01^*	0.02^*	0.33
Liver	4.82 ± 0.94	4.57 ± 0.73	4.45 ± 0.70	0.61	0.33	< 0.01^**
Kidneys	2.81 ± 1.17	2.47 ± 0.46	2.38 ± 0.43	0.96	0.73	< 0.01^**

Bold type = the highest D_mean in the three groups; MP = manual plan; RP_I = RapidPlan initial; RP_F = RapidPlan final; Underline mark = the lowest D_mean in the three groups;

* = P < 0.05;

** = P < 0.01

**(A)** Population-averaged dose-volume histogram (DVH) for all organs at risk and targets. **(B)** The population-averaged DVH for targets only.
CTV = clinical target volume; MP = manual optimization plan; PTV = planning target volumes; RP_I = RapidPlan initial; RP_F = final RapidPlan after manual re-optimization

Comparison of the planning time for MP, RP_I, and RP_F. The error bar represents one standard deviation.
MP = manual optimization plan; RP_I = RapidPlan initial; RP_F = final RapidPlan after manual re-optimization

References

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DOI: https://doi.org/10.2478/raon-2024-0018 | Journal eISSN: 1581-3207 | Journal ISSN: 1318-2099

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Language: English

Page range: 289 - 299

Submitted on: Nov 4, 2023

Accepted on: Jan 3, 2024

Published on: Mar 7, 2024

Published by: Association of Radiology and Oncology

In partnership with: Paradigm Publishing Services

Publication frequency: 4 issues per year

Keywords:

knowledge-based planning,

RapidPlan,

craniospinal irradiation,

volumetric modulated arc therapy

Related subjects:

Medicine,

Clinical medicine,

Radiology

© 2024 Wei-Ta Tsai, Hui-Ling Hsieh, Shih-Kai Hung, Chi-Fu Zeng, Ming-Fen Lee, Po-Hao Lin, Chia-Yi Lin, Wei-Chih Li, Wen-Yen Chiou, Tung-Hsin Wu, published by Association of Radiology and Oncology
This work is licensed under the Creative Commons Attribution 4.0 License.

Volume 58 (2024): Issue 2 (June 2024)

Dosimetry and efficiency comparison of knowledge-based and manual planning using volumetric modulated arc therapy for craniospinal irradiation

Figures & Tables

FIGURE 1.

FIGURE 2.

TABLE 1.

TABLE 2.

TABLE 3.

FIGURE 3.

FIGURE 4.

Paradigm

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