Impact of Anatomical Variations during Intensity Modulated Radiotherapy on Target Volumes, Organs at Risk, and Dose Volume Histograms in Locally Advanced Head and Neck Cancers – A Prospective Interventional Study from Hyderabad, Telangana

2021 ◽  
Vol 8 (25) ◽  
pp. 2173-2179
Author(s):  
Akkineni Naga Prasanthi
Keyword(s):  
Head And Neck ◽  
Organs At Risk ◽  
Locally Advanced ◽  
Anatomical Variations ◽  
Parotid Glands ◽  
Intensity Modulated ◽  
Dose Volume ◽  
Target Volumes ◽  
Experienced Grade ◽  
Grade Iii

BACKGROUND Intensity modulated radiation therapy (IMRT) has become the standard treatment in head & neck cancer (HNC). Anatomic changes during IMRT can have impact on dose coverage and organs at risk (OAR) doses. These changes can be compensated by modifying the plan during treatment. The purpose of this study is to evaluate the impact of anatomical variations during IMRT on target volumes, OAR and dose volume histogram (DVH) in locally advanced HNC patients. METHODS Twenty-four HNC patients undergoing definitive chemoradiotherapy were planned with initial plan. Repeated computerised tomography (CT) scans were performed at 2nd week (repeat CT1) and 4th week (repeat CT2). Previous plan was transferred to new CT for dosimetric analysis. Patient received remaining fractions with adaptive plan if needed based on triggers (1. more than 5 % deviation in OAR doses 2. If PTV dose did not conform to ICRU83). Plan 1 was generated by replanning on repeat CT and plan 2 was by superimposition of previous plan. DVH of both plans were compared for volumetric and dosimetric parameters in patients who required re-planning. RESULTS Fifty-eight percent of patients required adaptive plan. Seventy-one percent required re-plan at the end of 4th week and 28.5 % at 2nd week. Parotid glands and gross tumour volume (GTV) node reduction were significant in patients who required re-plan compared to patients who did not require re-plan. Patients with significant GTV node reduction experienced grade III/IV mucositis. Patients with significant GTV node and parotid glands reduction experienced grade III/IV dermatitis. CONCLUSIONS More than half of HNC patients required re-planning. Most of them required replanning at 4th week. GTV node and parotid glands reduction can predict the requirement of re-plan, risk of grade III/IV dermatitis. GTV node reduction can predict the risk of grade III/IV mucositis. KEYWORDS IMRT, Adaptive Radiotherapy, Anatomical Variations in Head and Neck Cancer, Implementation of Adaptive Plan

scholarly journals CBCT-guided radiotherapy for locally advanced head and cancer: dosimetric impact of weight loss on VMAT and IMRT plans for selected organs at risk structures (OARs)

2015 ◽  
Vol 14 (4) ◽  
pp. 336-342
Author(s):  
Mahmud Moallim ◽  
Peter Maungwe ◽  
Crispen Chamunyonga
Keyword(s):  
At Risk ◽  
Weight Loss ◽  
Head And Neck Cancer ◽  
Head And Neck ◽  
Neck Cancer ◽  
Organs At Risk ◽  
Locally Advanced ◽  
Advanced Head ◽  
Parotid Glands ◽  
The Right

AbstractPurposeIt is common for head and neck patients to be affected by time trend errors as a result of weight loss during a course of radiation treatment. The objective of this planning study was to investigate the impact of weight loss on volumetric modulated arc therapy (VMAT) as well as intensity modulated radiation therapy (IMRT) for locally advanced head and neck cancer using automatic co-registration of the cone beam computed tomography.Materials and methodsA retrospective analysis of previously treated IMRT plans for ten patients with locally advanced head and neck cancer was done. A VMAT plan was also produced for all patients. We calculated the dose–volume histograms (DVH) indices for spinal cord planning at risk volumes (PRVs), the brainstem PRVs (SC+0·5 cm and BS+0·5 cm, respectively) as well as mean dose to the parotid glands.ResultsThe results show that the mean difference in dose to the SC+0·5 cm was 1·03% and 1·27% for the IMRT and VMAT plans, respectively. As for dose to the BS+0·5, the percentage difference was 0·63% for the IMRT plans and 0·61% for the VMAT plans. The analysis of the parotid gland doses shows that the percentage change in mean dose to left parotid was −8·0% whereas that of the right parotid was −6·4% for the IMRT treatment plans. In the VMAT plans, the percentages change for the left and the right parotid glands were −6·6 and −6·7% respectively.ConclusionsThis study shows a clinically significant impact of weight loss on DVH indices analysed in head and neck organs at risk. It highlights the importance of adaptive radiotherapy in head and neck patients if organ at risk sparing is to be maintained.

To segment or not to segment the PTV in SIB-VMAT of head-and-neck cancer: a dosimetric comparison with relevance to clinical practice

2021 ◽  
pp. 1-6
Author(s):  
Manu Mathew ◽  
Henry F. Godson ◽  
Abel J. Thomas ◽  
Sasidharan Balu Krishna ◽  
Sathish Kumar A ◽  
...  
Keyword(s):  
Head And Neck ◽  
Locally Advanced ◽  
Volumetric Modulated Arc Therapy ◽  
Target Volume ◽  
Intermediate Risk ◽  
Dose Volume ◽  
Arc Therapy ◽  
Integrated Boost ◽  
Target Volumes ◽  
Ct Data

Abstract Aim: This study aimed to evaluate and compare simultaneous integrated boost-based volumetric modulated arc therapy (SIB-VMAT) of head-and-neck plans optimised using segmented and non-segmented intermediate-risk target volumes. Materials and methods: CT data of 20 patients with locally advanced laryngeal cancer treated with radical chemoradiation were included retrospectively. Both segmented [planning target volume (PTV) IR!] and non-segmented PTV (PTV IR) volumes were created for the intermediate-risk volume. Correspondingly, two VMAT plans were generated for every CT dataset. Dosimetry parameters obtained from cumulative dose volume histogram and the quality indices such as conformity and homogeneity indices were evaluated for both plans and were statistically analysed. Results: Maximum dose of PTV IR! was observed to be higher in the non-segmented plans (7281·45 versus 7075·75 cGy) and was statistically significant (p = 0·002). Homogeneity index (HI) of PTV IR! in segmented plans fared better compared to non-segmented plans (0·1 versus 0·12, p = 0·01). All other dosimetry parameters were found to be similar in both plans. Conclusion: This study shows that using segmented volumes for planning will lead to more homogenous plans with regard to intermediate- and low-risk volumes, especially under controlled settings.

scholarly journals Synergies Radiotherapy-Immunotherapy in Head and Neck Cancers. A New Concept for Radiotherapy Target Volumes-“Immunological Dose Painting”

Medicina ◽  
2020 ◽  
Vol 57 (1) ◽  
pp. 6
Author(s):  
Camil Ciprian Mireştean ◽  
Anda Crişan ◽  
Călin Buzea ◽  
Roxana Irina Iancu ◽  
DragoşPetru Teodor Iancu
Keyword(s):  
Immune System ◽  
Synergistic Effect ◽  
Head And Neck ◽  
Multimodal Treatment ◽  
Clinical Target Volume ◽  
Locally Advanced ◽  
Target Volume ◽  
Head And Neck Cancers ◽  
Dose Painting ◽  
Target Volumes

The combination of immune checkpoint inhibitors and definitive radiotherapy is investigated for the multimodal treatment of cisplatin non-eligible locally advanced head and neck cancers (HNC). In the case of recurrent and metastatic HNC, immunotherapy has shown benefit over the EXTREME protocol, being already considered the standard treatment. One of the biggest challenges of multimodal treatment is to establish the optimal therapy sequence so that the synergistic effect is maximal. Thus, superior results were obtained for the administration of anti-CTLA4 immunotherapy followed by hypofractionated radiotherapy, but the anti-PD-L1 therapy demonstrates the maximum potential of radio-sensitization of the tumor in case of concurrent administration. The synergistic effect of radiotherapy–immunotherapy (RT–IT) has been demonstrated in clinical practice, with an overall response rate of about 18% for HNC. Given the demonstrated potential of radiotherapy to activate the immune system through already known mechanisms, it is necessary to identify biomarkers that direct the “nonresponders” of immunotherapy towards a synergistic RT–IT stimulation strategy. Stimulation of the immune system by irradiation can convert “nonresponder” to “responder”. With the development of modern techniques, re-irradiation is becoming an increasingly common option for patients who have previously been treated with higher doses of radiation. In this context, radiotherapy in combination with immunotherapy, both in the advanced local stage and in recurrent/metastatic of HNC radiotherapy, could evolve from the “first level” of knowledge (i.e., ballistic precision, dose conformity and homogeneity) to “level two” of “biological dose painting” (in which the concept of tumor heterogeneity and radio-resistance supports the need for doses escalation based on biological criteria), and finally to the “third level“ ofthe new concept of “immunological dose painting”. The peculiarity of this concept is that the radiotherapy target volumes and tumoricidal dose can be completely reevaluated, taking into account the immune-modulatory effect of irradiation. In this case, the tumor target volume can include even the tumor microenvironment or a partial volume of the primary tumor or metastasis, not all the gross and microscopic disease. Tumoricidal biologically equivalent dose (BED) may be completely different from the currently estimated values, radiotherapy treating the tumor in this case indirectly by boosting the immune response. Thus, the clinical target volume (CTV) can be replaced with a new immunological-clinical target volume (ICTV) for patients who benefit from the RT–IT association (Image 1).

scholarly journals Adaptive radiotherapy for head and neck cancer

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Enis Tinjak ◽  
Velda Smajlbegović ◽  
Adnan Beganović ◽  
Mirjana Ristanić ◽  
Halil Ćorović ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Head And Neck Cancer ◽  
Head And Neck ◽  
Neck Cancer ◽  
Locally Advanced ◽  
Adaptive Radiotherapy ◽  
Tumor Control ◽  
Parotid Glands ◽  
Image Guided Radiotherapy ◽  
The Impact

Introduction: Radiation therapy has long played an integral role in the manage¬ment of locally advanced head and neck cancer (HNC), both for organ preservation and to improve tumor control in the postoperative setting. The aim of this research is to investigate the effects of adaptive radiotherapy on dosimetric, clinical, and toxicity outcomes for patients with head and neck cancer undergoing radiation therapy treatment. Many sources have reported volume reductions in the primary target, nodal volumes, and parotid glands over treatment, which may result in unintended dosimetric changes affecting the side effect profile and even efficacy of the treatment. Adaptive radiotherapy (ART) is an interesting treatment paradigm that has been developed to directly adjust to these changes.Material and methods: This research contains the results of 15 studies, including clinical trials, randomized prospective and retrospective studies. The researches analyze the impact of radiation therapy on changes in tumor volume and the relationship with planned radiation dose delivery, as well as the possibility of using adaptive radiotherapy in response to identified changes. Also, medical articles and abstracts that are closely related to the title of adaptive radiotherapy were researched.Results: The application of ART significantly improved the quality of life of patients with head and neck cancer, as well as two-year locoregional control of the disease. The average time to apply ART is the middle of the treatment course approximately 17 to 20 fractions of the treatment.Conclusion: Based on systematic review of the literature, evidence based changes in target volumes and dose reduction at OAR, adaptive radiotherapy is recommended treatment for most of the patients with head and neck cancer with the support of image-guided radiotherapy.

scholarly journals Carbon ion reirradiation compared to intensity-modulated re-radiotherapy for recurrent head and neck cancer (CARE): a randomized controlled trial

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Thomas Held ◽  
Kristin Lang ◽  
Sebastian Regnery ◽  
Katharina Weusthof ◽  
Adriane Hommertgen ◽  
...  
Keyword(s):  
Head And Neck Cancer ◽  
Clinical Outcome ◽  
Head And Neck ◽  
Neck Cancer ◽  
Severe Toxicity ◽  
Carbon Ion ◽  
Intensity Modulated ◽  
Link Type ◽  
Recurrent Head ◽  
Grade Iii

Abstract Background Intensity-modulated re-radiotherapy (reIMRT) has been established as a standard local treatment option in patients with non-resectable, recurrent head and neck cancer (rHNC). However, the clinical outcome is unfavorable and severe toxicities (≥grade III) occurred in 30–40% of patients. The primary aim of the current trial is to investigate carbon ion reirradiation (reCIRT) compared to reIMRT in patients with rHNC regarding safety/toxicity as well as local control, overall survival (OS), and quality of life (QoL). Methods The present trial will be performed as a single center, two-armed, prospective phase II study. A maximum of 72 patients will be treated with either reIMRT or reCIRT to evaluate severe (≥grade III) treatment-related toxicities (randomization ratio 1:1). The primary target value is to generate less than 35% acute/subacute severe toxicity (≥grade III), according to the Common Terminology Criteria for Adverse Events v5.0, within 6 months after study treatment. The total dose of reirradiation will range between 51 and 60 Gy or Gy (RBE), depending primarily on the radiotherapy interval and the cumulative dose to organs at risk. Individual dose prescription will be at the discretion of the treating radiation oncologist. The local and distant progression-free survival 12 months after reirradiation, the OS, and the QoL are the secondary endpoints of the trial. Explorative trial objectives are the longitudinal investigation of clinical patient-related parameters, tumor parameters on radiological imaging, and blood-based tumor analytics. Discussion Recent retrospective studies suggested that reCIRT could represent a feasible and effective treatment modality for rHNC. This current randomized prospective trial is the first to investigate the toxicity and clinical outcome of reCIRT compared to reIMRT in patients with rHNC. Trial registration ClinicalTrials.gov; NCT04185974; December 4th 2019.

Sign in / Sign up

Export Citation Format

Share Document