Prognosis-guided optimization of intensity-modulated radiation therapy plans for lung cancer

doi:10.12122/j.issn.1673-4254.2025.03.22

Abstract

Abstract:

Objective To propose a new method for optimizing radiotherapy planning for lung cancer by incorporating prognostic models that take into account individual patient information and assess the feasibility of treatment planning optimization directly guided by minimizing the predicted prognostic risk. Methods A mixed fluence map optimization objective was constructed, incorporating the outcome-based objective and the physical dose constraints. The outcome-based objective function was constructed as an equally weighted summation of prognostic prediction models for local control failure, radiation-induced cardiac toxicity, and radiation pneumonitis considering clinical risk factors. These models were derived using Cox regression analysis or Logistic regression. The primary goal was to minimize the outcome-based objective with the physical dose constraints recommended by the clinical guidelines. The efficacy of the proposed method for optimizing treatment plans was tested in 15 cases of non-small cell lung cancer in comparison with the conventional dose-based optimization method (clinical plan), and the dosimetric indicators and predicted prognostic outcomes were compared between different plans. Results In terms of the dosemetric indicators, D_95% of the planning target volume obtained using the proposed method was basically consistent with that of the clinical plan (100.33% vs 102.57%, P=0.056), and the average dose of the heart and lungs was significantly decreased from 9.83 Gy and 9.50 Gy to 7.02 Gy (t=4.537, P<0.05) and 8.40 Gy (t=4.104, P<0.05), respectively. The predicted probability of local control failure was similar between the proposed plan and the clinical plan (60.05% vs 59.66%), while the probability of radiation-induced cardiac toxicity was reduced by 1.41% in the proposed plan. Conclusion The proposed optimization method based on a mixed objective function of outcome prediction and physical dose provides effective protection against normal tissue exposure to improve the outcomes of lung cancer patients following radiotherapy.

Key words: prognosis-guided treatment planning optimization, intensity-modulated radiation therapy, inverse planning optimization

Huali LI, Ting SONG, Jiawen LIU, Yongbao LI, Zhaojing JIANG, Wen DOU, Linghong ZHOU. Prognosis-guided optimization of intensity-modulated radiation therapy plans for lung cancer[J]. Journal of Southern Medical University, 2025, 45(3): 643-649.

Figures/Tables 7

References 31

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Model	Form	Dose metric	Clinical metric
LRF^［17］	Cox	Average BED for PTV	Age, Sex, Stage, Combined chemotherapy or not
RCT^［18］	Cox	Average EQD2 for heart	Previous cardiac history
RP≥2^［19］	Logistic	Average EQD2 for lungs	Age, Chemotherapy, Smoke

Model	Form	Dose metric	Clinical metric
LRF^［17］	Cox	Average BED for PTV	Age, Sex, Stage, Combined chemotherapy or not
RCT^［18］	Cox	Average EQD2 for heart	Previous cardiac history
RP≥2^［19］	Logistic	Average EQD2 for lungs	Age, Chemotherapy, Smoke

ROI	Metric	Constraint	Clinical plan	Proposed plan	t/z	P
PTV	D_95%(%)	≥98	100.33±1.93	102.57±3.30	-2.087	0.056
PTV	D_98%(%)	-	95.52±5.23	99.80±2.66	-1.647	0.100^a
Lungs	V_20Gy(%)	≤30	18.21±6.23	16.74±7.12	2.007	0.064
	V_10Gy(%)	≤45	29.09±11.03	26.27±8.91	3.216	0.006
	V_5Gy(%)	≤60	40.40±14.75	34.98±13.15	2.759	0.015
	D_mean(Gy)	-	9.50±3.24	8.40±4.01	4.104	0.001
Heart	V_30Gy(%)	≤40	13.4±16.07	7.83±11.90	-2.845	0.004^a
	V_40Gy(%)	≤30	7.21±10.46	4.18±8.51	-2.803	0.005^a
	D_mean(Gy)	-	9.83±9.41	7.02±8.16	4.537	<0.001
Esophagus	D_max(Gy)	≤105	74.51±39.51	80.19±38.48	-0.722	0.470^a
Esophagus	V_60%(%)	-	1.20±3.27	0.93±2.24	-0.338	0.735^a
Spinal cord	D_max(Gy)	≤45	31.49±15.49	30.11±14.04	0.809	0.432

ROI	Metric	Constraint	Clinical plan	Proposed plan	t/z	P
PTV	D_95%(%)	≥98	100.33±1.93	102.57±3.30	-2.087	0.056
PTV	D_98%(%)	-	95.52±5.23	99.80±2.66	-1.647	0.100^a
Lungs	V_20Gy(%)	≤30	18.21±6.23	16.74±7.12	2.007	0.064
	V_10Gy(%)	≤45	29.09±11.03	26.27±8.91	3.216	0.006
	V_5Gy(%)	≤60	40.40±14.75	34.98±13.15	2.759	0.015
	D_mean(Gy)	-	9.50±3.24	8.40±4.01	4.104	0.001
Heart	V_30Gy(%)	≤40	13.4±16.07	7.83±11.90	-2.845	0.004^a
	V_40Gy(%)	≤30	7.21±10.46	4.18±8.51	-2.803	0.005^a
	D_mean(Gy)	-	9.83±9.41	7.02±8.16	4.537	<0.001
Esophagus	D_max(Gy)	≤105	74.51±39.51	80.19±38.48	-0.722	0.470^a
Esophagus	V_60%(%)	-	1.20±3.27	0.93±2.24	-0.338	0.735^a
Spinal cord	D_max(Gy)	≤45	31.49±15.49	30.11±14.04	0.809	0.432

Prognostic	Clinical plan	Proposed plan	t/z	P
LRF	60.05±12.38	59.66±11.88	1.053	0.310
CE	7.99±5.20	6.55±3.97	-3.296	0.001^a
RP	3.84±1.60	3.59±2.08	-2.556	0.011^a
TCP	57.37±11.26	57.95±11.36	-0.614	0.549
NTCP_heart	3.67±5.78	2.20±5.56	-3.045	0.002^a
NTCP_lung	2.56±2.10	2.34±2.92	-2.556	0.011^a