The mean lung dose (MLD)

2015 ◽  
Vol 191 (7) ◽  
pp. 557-565 ◽  
Author(s):  
Thomas Herrmann ◽  
Peter Geyer ◽  
Steffen Appold
Keyword(s):  
Lung Dose ◽  
The Mean ◽  
Mean Lung Dose

Method of predicting the mean lung dose based on a patient׳s anatomy and dose-volume histograms

2017 ◽  
Vol 42 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Anna Zawadzka ◽  
Marta Nesteruk ◽  
Beata Brzozowska ◽  
Paweł F. Kukołowicz
Keyword(s):  
Lung Dose ◽  
Dose Volume Histograms ◽  
Dose Volume ◽  
The Mean ◽  
Mean Lung Dose

Effect of Radiotherapy and Chemotherapy on Pulmonary Function After Treatment for Breast Cancer and Lymphoma: A Follow-Up Study

1999 ◽  
Vol 17 (10) ◽  
pp. 3091-3100 ◽  
Author(s):  
Jacqueline C.M. Theuws ◽  
Sara H. Muller ◽  
Yvette Seppenwoolde ◽  
Stefan L.S. Kwa ◽  
Liesbeth J. Boersma ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Pulmonary Function ◽  
Pulmonary Function Tests ◽  
Three Dimensional ◽  
Forced Expiratory Volume ◽  
Lung Dose ◽  
Alveolar Volume ◽  
Initial Reduction ◽  
The Mean ◽  
Mean Lung Dose

PURPOSE: To determine the changes in pulmonary function tests (PFTs) 0 to 48 months after treatment for breast cancer and lymphoma. PATIENTS AND METHODS: The alveolar volume (VA), vital capacity, forced expiratory volume in 1 second, and corrected transfer factor of carbon monoxide (TL,COc) were measured in 69 breast cancer and 41 lymphoma patients before treatment and 3, 18, and 48 months after treatment with radiotherapy alone or radiotherapy in combination with chemotherapy (mechlorethamine, vincristine, procarbazine, prednisone, doxorubicin, bleomycin, vinblastine; cyclophosphamide, epidoxorubicin, fluorouracil; cyclophosphamide, thiotepa, carboplatin; cyclophosphamide, methotrexate, fluorouracil). The three-dimensional dose distribution in the lung of each patient was converted to the mean lung dose. Statistical analysis was used to evaluate the changes in PFT values over time in relation to age, sex, smoking, chemotherapy, and the mean lung dose. RESULTS: After an initial reduction in PFT values at 3 months, significant recovery was seen at 18 months for all patients. Thereafter, no further improvement could be demonstrated. Reductions in spirometry values and VA were related to the mean lung dose only (0.9% per Gy at 3 months and 0.4% per Gy mean dose at 18 months). TL,COc decreased 1.1% per Gy mean dose and additionally decreased 6% when chemotherapy was given after radiotherapy. Chemotherapy administered before radiotherapy reduced baseline TL,COc values by 8% to 21%. All patients showed an improvement of 5% at 18 months. CONCLUSION: On the basis of the mean lung dose and the chemotherapy regimen, the changes in PFT values can be estimated before treatment within 10% of the values actually observed in 72% to 85% of our patients with healthy lungs.

Dosimetric evaluation of organs at risk to toxicities between multicatheter accelerated partial-breast irradiation and whole-breast external beam radiotherapy.

2014 ◽  
Vol 32 (26_suppl) ◽  
pp. 94-94
Author(s):  
Tabitha Y Chan ◽  
Poh Wee Tan ◽  
Chek Wee Tan ◽  
Johann I Tang
Keyword(s):  
External Beam Radiotherapy ◽  
Accelerated Partial Breast Irradiation ◽  
Partial Breast Irradiation ◽  
Lung Dose ◽  
Ipsilateral Lung ◽  
Heart Dose ◽  
Peak Dose ◽  
The Mean ◽  
Mean Lung Dose ◽  
Mean Heart Dose

94 Background: This study aims to quantify the dosimetric reduction to the heart and lung when comparing Whole Breast External Beam Radiotherapy(WBEBRT) with Multicatheter Accelerated Partial Breast Irradiation(MCAPBI) for early stage left sided breast cancer. Methods: Planning CT data sets of 13 patients with left breast cancer receiving multicatheter brachytherapy post breast conserving surgery were used to create two independent treatment plans – WBEBRT prescribed to 50Gy/25fractions and MCAPBI prescribed to 34Gy/10fractions. Dose parameters for (i) heart, (ii) left anterior descending(LAD) artery and (iii) ipsilateral lung were calculated and compared between the two treatment modalities. Results: After adjusting for Equivalent Dose in 2Gy Fractions(EQD2), comparing MCAPBI with WBEBRT, the largest dose reduction was for the LAD artery whose point dose differed by a factor of 4.9. Although somewhat less pronounced, this was also true for the mean lung dose of the ipsilateral lung and mean heart dose with a factor of 3.8 and 2.1 respectively. Compared to WBEBRT, the mean MCAPBI heart D0.1cc (representing the dose received by the most highly exposed 0.1 cc of the risk organ, i.e. the dose peak) was significantly lower(16.43Gy vs 48.82Gy;p<0.01) as well as mean heart dose(MHD) was significantly lower(2.33Gy vs 4.85Gy; p<0.01). Similarly, mean point dose for MCAPBI LAD was significantly lower compared to WBEBRT(9.85Gy vs 47.92Gy; p<0.05). Peak dose and mean lung dose(MLD) for ipsilateral lung was also lower for MCAPBI compared to WBEBRT (Peak dose: 22.19Gy vs 50.45Gy(p<0.05); MLD: 2.31Gy vs 8.73Gy(p<0.05). Conclusions: Compared to WBEBRT, MCAPBI showed a significant reduction in radiation dose for the heart and lung. This may translate into better cardiac and pulmonary toxicities for patients undergoing MCAPBI.

scholarly journals Volume-based algorithm of lung dose optimization in novel dynamic arc radiotherapy for esophageal cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kuan-Heng Lin ◽  
Chen-Xiong Hsu ◽  
Shan-Ying Wang ◽  
Greta S. P. Mok ◽  
Chiu-Han Chang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Esophageal Cancer ◽  
Maximum Dose ◽  
Treatment Plan ◽  
Conformity Index ◽  
Lung Dose ◽  
Heart Dose ◽  
The Mean ◽  
Mean Lung Dose ◽  
Mean Heart Dose

AbstractThis study aims to develop a volume-based algorithm (VBA) that can rapidly optimize rotating gantry arc angles and predict the lung V5 preceding the treatment planning. This phantom study was performed in the dynamic arc therapy planning systems for an esophageal cancer model. The angle of rotation of the gantry around the isocenter as defined as arc angle (θA), ranging from 360° to 80° with an interval of 20°, resulting in 15 different θA of treatment plans. The corresponding predicted lung V5 was calculated by the VBA, the mean lung dose, lung V5, lung V20, mean heart dose, heart V30, the spinal cord maximum dose and conformity index were assessed from dose–volume histogram in the treatment plan. Correlations between the predicted lung V5 and the dosimetric indices were evaluated using Pearson’s correlation coefficient. The results showed that the predicted lung V5 and the lung V5 in the treatment plan were positively correlated (r = 0.996, p < 0.001). As the θA decreased, lung V5, lung V20, and the mean lung dose decreased while the mean heart dose, V30 and the spinal cord maximum dose increased. The V20 and the mean lung dose also showed high correlations with the predicted lung V5 (r = 0.974, 0.999, p < 0.001). This study successfully developed an efficient VBA to rapidly calculate the θA to predict the lung V5 and reduce the lung dose, with potentials to improve the current clinical practice of dynamic arc radiotherapy.

Predicting Pneumonitis Risk: A Dosimetric Alternative to Mean Lung Dose

2013 ◽  
Vol 85 (2) ◽  
pp. 522-527 ◽  
Author(s):  
Susan L. Tucker ◽  
Radhe Mohan ◽  
Raweewan Liengsawangwong ◽  
Mary K. Martel ◽  
Zhongxing Liao
Keyword(s):  
Lung Dose ◽  
Mean Lung Dose

scholarly journals Cone-Beam-CT Guided Adaptive Radiotherapy for Locally Advanced Non-small Cell Lung Cancer Enables Quality Assurance and Superior Sparing of Healthy Lung

2020 ◽  
Vol 10 ◽  
Author(s):  
Philipp Hoegen ◽  
Clemens Lang ◽  
Sati Akbaba ◽  
Peter Häring ◽  
Mona Splinter ◽  
...  
Keyword(s):  
Advanced Nsclc ◽  
Cone Beam Ct ◽  
Locally Advanced ◽  
Cone Beam ◽  
Lung Dose ◽  
Ct Guided ◽  
Locally Advanced Nsclc ◽  
Plan Adaptation ◽  
Mean Lung Dose ◽  
Healthy Lung

PurposeTo evaluate the potential of cone-beam-CT (CB-CT) guided adaptive radiotherapy (ART) for locally advanced non-small cell lung cancer (NSCLC) for sparing of surrounding organs-at-risk (OAR).Materials and MethodsIn 10 patients with locally advanced NSCLC, daily CB-CT imaging was acquired during radio- (n = 4) or radiochemotherapy (n = 6) for simulation of ART. Patients were treated with conventionally fractionated intensity-modulated radiotherapy (IMRT) with total doses of 60–66 Gy (pPlan) (311 fraction CB-CTs). OAR were segmented on every daily CB-CT and the tumor volumes were modified weekly depending on tumor changes. Doses actually delivered were recalculated on daily images (dPlan), and voxel-wise dose accumulation was performed using a deformable registration algorithm. For simulation of ART, treatment plans were adapted using the new contours and re-optimized weekly (aPlan).ResultsCB-CT showed continuous tumor regression of 1.1 ± 0.4% per day, leading to a residual gross tumor volume (GTV) of 65.3 ± 13.4% after 6 weeks of radiotherapy (p = 0.005). Corresponding PTVs decreased to 83.7 ± 7.8% (p = 0.005). In the actually delivered plans (dPlan), both conformity (p = 0.005) and homogeneity (p = 0.059) indices were impaired compared to the initial plans (pPlan). This resulted in higher actual lung doses than planned: V20Gy was 34.6 ± 6.8% instead of 32.8 ± 4.9% (p = 0.066), mean lung dose was 19.0 ± 3.1 Gy instead of 17.9 ± 2.5 Gy (p = 0.013). The generalized equivalent uniform dose (gEUD) of the lung was 18.9 ± 3.1 Gy instead of 17.8 ± 2.5 Gy (p = 0.013), leading to an increased lung normal tissue complication probability (NTCP) of 15.2 ± 13.9% instead of 9.6 ± 7.3% (p = 0.017). Weekly plan adaptation enabled decreased lung V20Gy of 31.6 ± 6.2% (−3.0%, p = 0.007), decreased mean lung dose of 17.7 ± 2.9 Gy (−1.3 Gy, p = 0.005), and decreased lung gEUD of 17.6 ± 2.9 Gy (−1.3 Gy, p = 0.005). Thus, resulting lung NTCP was reduced to 10.0 ± 9.5% (−5.2%, p = 0.005). Target volume coverage represented by conformity and homogeneity indices could be improved by weekly plan adaptation (CI: p = 0.007, HI: p = 0.114) and reached levels of the initial plan (CI: p = 0.721, HI: p = 0.333).ConclusionIGRT with CB-CT detects continuous GTV and PTV changes. CB-CT-guided ART for locally advanced NSCLC is feasible and enables superior sparing of healthy lung at high levels of plan conformity.

The impact of breast size on mean lung dose for patients receiving tangential radiotherapy to the whole breast

2016 ◽  
Vol 15 (2) ◽  
pp. 181-188
Author(s):  
Ashley Schembri ◽  
Susan Mercieca ◽  
Nick Courtier ◽  
Francis Zarb
Keyword(s):  
Significant Variation ◽  
Target Volume ◽  
Breast Size ◽  
Lung Dose ◽  
Breast Radiotherapy ◽  
Large Breast ◽  
Significant Difference ◽  
Mean Lung Dose ◽  
The Impact ◽  
Radiotherapy Treatment

AbstractPurposeTo explore the impact of breast size on mean lung dose (MLD) for patients receiving breast radiotherapy.MethodologyChest wall separation (CWS), volume of tissue receiving 95% isodose and MLD were measured on 80 radiotherapy treatment plans of patients receiving tangential radiotherapy treatment to the whole breast. Breast size was categorised as small (CWS<25 cm and planned target volume (PTV)<1,500 cm3) and large (CWS>25 cm and PTV>1500 cm3). Pearson’s correlation and independent sample t-test were used to analyse data.ResultsMLD was not affected by CWS (r=−0·13, p=0·24) nor volume of tissue receiving 95% isodose (r=−0·08, p=0·49). Significant variation between small and large breasts was noted for CWS (t=8·24, p=0·00) and volume of tissue receiving 95% isodose (t=5·68, p=0·00). No significant variation was noted between small and large breast for MLD (t=−0·26, p=0·80) and between left and right breasts for CWS (t=1·42, p=0·16) and volume of tissue receiving 95% isodose (t=−1·08, p=0·28). Significant difference between left (18–808 cGy) and right breast (325–365 cGy) was demonstrated for MLD (t=3·03, p=0·00).ConclusionThis study demonstrated lack of correlation between breast size and MLD. Further research is recommended for justification of alternative techniques for this subgroup of patients to provide optimised radiotherapy delivery.

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