scholarly journals Dynamic Three-Dimensional ADC Changes of Parotid Glands During Radiotherapy Predict the Salivary Secretary Function in Patients With Head and Neck Squamous Carcinoma

2021 ◽  
Vol 11 ◽  
Author(s):  
Mei Feng ◽  
Qingping Yin ◽  
Jing Ren ◽  
Fei Wu ◽  
Mei Lan ◽  
...  

ObjectiveTo investigate the changes of three-dimensional apparent diffusion coefficient (3D-ADC) of bilateral parotid glands during radiotherapy for head and neck squamous cell carcinoma (HNSCC) patients and explore the correlations with the radiation dose, volume reduction of parotid gland and the salivary secretary function.Materials and Methods60 HNSCC were retrospectively collected in Sichuan cancer hospital. The patients were all received diffusion-weighted imaging (DWI) scan at pre-radiation, the 15th radiation, the 25th radiation and completion of radiation. Dynamic 3D-ADC were measured in different lobes of parotid glands (P1: deep lobe of ipsilateral; P2: superficial lobe of ipsilateral; P3: deep lobe of contralateral; P4: superficial lobe of contralateral), and the 3D-ADC of spinal cord were also recorded. Chewing stimulates test, radionuclide scan and RTOG criteria were recorded to evaluate the salivary secretary function. Pearson analysis was used to assess the correlation between 3D-ADC value, radiation dose, volume change, and salivary secretary function.ResultsThe mean 3D-ADC of parotid glands increased. It began to change at the 15th radiation and the mostly increased in P1. However, there was no change for the maximum and minimum 3D-ADC. The 3D-ADC values of spinal cord changes were almost invisible (ratio ≤ 0.03 ± 0.01). The mean 3D-ADC was negatively correlated with the salivary secretary function (r=-0.72) and volume reduction of different lobes of parotid glands (r1=-0.64; r2=-0.61; r3=-0.57; r4=-0.49), but it was positively correlated with the delivered dose (r1 = 0.73; r2 = 0.69; r3 = 0.65; r4 = 0.78).ConclusionDynamic 3D-ADC changes might be a new and early indicator to predict and evaluate the secretary function of parotid glands during radiotherapy.

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e22134-e22134
Author(s):  
S. Bhide ◽  
S. Gulliford ◽  
R. A'Hern ◽  
E. Hall ◽  
K. Newbold ◽  
...  

e22134 Purpose: To generate quantitative parameters describing the effect of concomitant chemotherapy on incidence of grade 3 dysphagia (CTCAE v3.0, assisted feeding) using dose response curves in patients receiving radical treatment for head and neck cancer. Methods: Patients treated at a single centre in prospective phase I and II trials of concomitant chemo-IMRT (CRT) (n=85) and the phase III trial of IMRT vs. conventional radiotherapy (PARSPORT) (n=82) formed the basis of this non-randomized comparison. Patients in the PARSPORT trial received radiation alone (RT). Radiation dose for all patients was radiobiologically equivalent to at least 70Gy in 35 fractions. Concomitant chemotherapy was cisplatin (100 mg/m2) on days 1 and 29. G3 dysphagia was recorded prospectively. Dose volume histograms (DVH) were generated for the pharyngeal mucosa. The mean dose (converted to equivalent dose in 2Gy/fraction, MD2) was used as a univariate descriptor of the DVH, for the generation of the dose response curves. A logistic function of the form p=1/[1+(MD50/D)k] was fitted where, p is the probability of the incidence of toxicity, D is the mean dose, MD50 is the mean dose at which 50% of patients experience toxicity and k describes the increase in incidence with increasing dose. The dose response curves were fitted using non-linear logistic regression. Results: The mean MD2 to the pharyngeal mucosa were 56Gy and 55.8Gy respectively, in the CRT and RT groups. There was a statistically significant difference of 25% (95% CI: 10–38, p=0.002) in the incidence of G3 dysphagia between the CRT (68%) and RT (43%) groups. Fitting dose response curves to the clinical data yielded parameter values (95% CIs) of MD50=46 Gy (42–49), k=4.8 (2.3–7.2) for the CRT group and MD50= 58 Gy (55–61), k=3 (1.6-.45) for RT group. Dose response gradients for CRT and RT showed approximately 1.95% and 1.3% increase (respectively) in probability of G3 dysphagia resulting from an increase in mean dose of 1Gy between doses of 30Gy to 70Gy. Conclusions: Addition of concomitant chemotherapy increases the incidence of G3 dysphagia by 0.65% for every 1 Gy increase in radiation dose. The observed MD50 for G3 dysphagia is lower for RT alone (46 Gy vs. 58 Gy). No significant financial relationships to disclose.


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Wufei Cao ◽  
Yongdong Zhuang ◽  
Lixin Chen ◽  
Xiaowei Liu

Abstract Purpose In this study, we employed a gated recurrent unit (GRU)-based recurrent neural network (RNN) using dosimetric information induced by individual beam to predict the dose-volume histogram (DVH) and investigated the feasibility and usefulness of this method in biologically related models for nasopharyngeal carcinomas (NPC) treatment planning. Methods and materials One hundred patients with NPC undergoing volumetric modulated arc therapy (VMAT) between 2018 and 2019 were randomly selected for this study. All the VMAT plans were created using the Monaco treatment planning system (Elekta, Sweden) and clinically approved: > 98% of PGTVnx received the prescribed doses of 70 Gy, > 98% of PGTVnd received the prescribed doses of 66 Gy and > 98% of PCTV received 60 Gy. Of these, the data from 80 patients were used to train the GRU-RNN, and the data from the other 20 patients were used for testing. For each NPC patient, the DVHs of different organs at risk were predicted by a trained GRU-based RNN using the information given by individual conformal beams. Based on the predicted DVHs, the equivalent uniform doses (EUD) were calculated and applied as dose constraints during treatment planning optimization. The regenerated VMAT experimental plans (EPs) were evaluated by comparing them with the clinical plans (CPs). Results For the 20 test patients, the regenerated EPs guided by the GRU-RNN predictive model achieved good consistency relative to the CPs. The EPs showed better consistency in PTV dose distribution and better dose sparing for many organs at risk, and significant differences were found in the maximum/mean doses to the brainstem, brainstem PRV, spinal cord, lenses, temporal lobes, parotid glands and larynx with P-values < 0.05. On average, compared with the CPs, the maximum/mean doses to these OARs were altered by − 3.44 Gy, − 1.94 Gy, − 1.88 Gy, 0.44 Gy, 1.98 Gy, − 1.82 Gy and 2.27 Gy, respectively. In addition, significant differences were also found in brainstem and spinal cord for the dose received by 1 cc volume with 4.11 and 1.67 Gy dose reduction in EPs on average. Conclusion The GRU-RNN-based DVH prediction method was capable of accurate DVH prediction. The regenerated plans guided by the predicted EUDs were not inferior to the manual plans, had better consistency in PTVs and better dose sparing in critical OARs, indicating the usefulness and effectiveness of biologically related model in knowledge-based planning.


Author(s):  
Sajal Goel ◽  
Ritu Bhutani ◽  
Vivek Bansal ◽  
Ruchika Goel

Abstract Introduction Xerostomia is an imminent complication of head and neck radiotherapy best assessed subjectively. This study aimed to evaluate the effects of sparing parotid glands with intensity-modulated radiation therapy (IMRT) on subjective xerostomia scores in patients with locoregionally advanced head and neck cancer. Subjects and Methods This is a prospective longitudinal study conducted in an outpatient department setting. A total of 43 patients with head and neck cancer were planned with IMRT as per the ICRU 62 (International Commission on Radiation Units and Measurement Report 62). The constraints to ipsilateral and contralateral parotid glands were 35 and 25 Gy, respectively. Treatment plan was assessed for doses to 100, 67, 50, and 33% volume of individual parotid glands. Patients were subjectively assessed using the Amosson’s Questionnaire and graded as per Eisbruch’s xerostomia Radiation Therapy Oncology Group scores. Dose volume histogram (DVH) was plotted and correlated with grades of xerostomia postradiation at 1, 3, 6, 9 and 12 months follow-ups. Statistical analysis was performed suing SPSS version 16, chi-square test, and one-way analysis of variance test. Results No statistically significant correlation between mean dose of radiation, volume of the parotid glands, and grades of xerostomia was noted postradiation. A statistically significant improvement in grades of xerostomia between 3 and 6 months (p = 0.0), 3 and 9 months (p = 0.020), 6 and 9 months (p = 0.009), 6 and 12 months (p = 0.05), and 9 and 12 months (p = 0.00) was noted. Recovery in grades was noted at 9 months. Conclusion There is no statistically significant direct correlation between DVH of the parotid glands and grades of xerostomia, although recovery in grades was statistically significant at 9 months.


2010 ◽  
Vol 2010 ◽  
pp. 1-4 ◽  
Author(s):  
Dong C. Lim ◽  
Patrick J. Gagnon ◽  
Sophia Meranvil ◽  
Darryl Kaurin ◽  
Linda Lipp ◽  
...  

Background. Lhermitte's sign (LS) is a benign form of myelopathy with neck flexion producing an unpleasant electric-shock sensation radiating down the extremities. Although rare, it can occur after head and neck radiotherapy.Results. We report a case of Lhermitte's developing after curative intensity-modulated radiotherapy (IMRT) for a patient with locoregionally advanced oropharyngeal cancer. IMRT delivers a conformal dose of radiation in head and neck cancer resulting in a gradient of radiation dose throughout the spinal cord. Using IMRT, more dose is delivered to the anterior spinal cord than the posterior cord.Conclusions. Lhermitte's sign can develop after IMRT for head and neck cancer. We propose an anterior spinal cord structure, the spinothalamic tract to be the target of IMRT-caused LS.


2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Louise Belshaw ◽  
Christina E. Agnew ◽  
Denise M. Irvine ◽  
Keith P. Rooney ◽  
Conor K. McGarry

Abstract Background Patients treated with radiotherapy for head and neck (H&N) cancer often experience anatomical changes. The potential compromises to Planning Target Volume (PTV) coverage or Organ at Risk (OAR) sparing has prompted the use of adaptive radiotherapy (ART) for these patients. However, implementation of ART is time and resource intensive. This study seeks to define a clinical trigger for H&N re-plans based on spinal cord safety using kV Cone-Beam Computed Tomography (CBCT) verification imaging, in order to best balance clinical benefit with additional workload. Methods Thirty-one H&N patients treated with Volumetric Modulated Arc Therapy (VMAT) who had a rescan CT (rCT) during treatment were included in this study. Contour volume changes between the planning CT (pCT) and rCT were determined. The original treatment plan was calculated on the pCT, CBCT prior to the rCT, pCT deformed to the anatomy of the CBCT (dCT), and rCT (considered the gold standard). The dose to 0.1 cc (D0.1cc) spinal cord was evaluated from the Dose Volume Histograms (DVHs). Results The median dose increase to D0.1cc between the pCT and rCT was 0.7 Gy (inter-quartile range 0.2–1.9 Gy, p < 0.05). No correlation was found between contour volume changes and the spinal cord dose increase. Three patients exhibited an increase of 7.0–7.2 Gy to D0.1cc, resulting in a re-plan; these patients were correctly identified using calculations on the CBCT/dCT. Conclusions An adaptive re-plan can be triggered using spinal cord doses calculated on the CBCT/dCT. Implementing this trigger can reduce patient appointments and radiation dose by eliminating up to 90% of additional un-necessary CT scans, reducing the workload for radiographers, physicists, dosimetrists, and clinicians.


Sign in / Sign up

Export Citation Format

Share Document