|Ahead of print publication
Intensity-modulated radiotherapy in locally advanced head-and-neck cancers in elderly patients
Neeraj Jain1, Sakshi Jain2, Ramita Sharma1, Kanchan Sachdeva3, Amandeep Kaur4, Abhimanyu Rakesh1, Deepak Abrol5, Meena Sudan1
1 Department of Radiation Oncology, Sri Guru Ram Das University of Health Sciences, Amritsar, Punjab, India
2 Department of Dentistry, Himachal Institute of Dental Sciences, Paonta Sahib, Himachal Pradesh, India
3 Department of Medical Physics, TMH, Mumbai, Maharashtra, India
4 Department of Medical Physics, GCRI, Ahmedabad, Gujarat, India
5 Department of Radiation Oncology, GMC, Kathua, Jammu and Kashmir, India
|Date of Submission||07-Jan-2020|
|Date of Decision||07-Apr-2020|
|Date of Acceptance||18-Jun-2020|
|Date of Web Publication||23-Oct-2021|
Department of Radiation Oncology, Sri Guru Ram Das University of Health Sciences, Amritsar, Punjab
Source of Support: None, Conflict of Interest: None
Introduction: Head and neck cancer is one of the most common malignancies in Indian males. Due to poor socioeconomic status, presentation is usually in advanced stage. Treatment option is limited to radiotherapy with or without chemotherapy. Intensity-modulated radiotherapy (IMRT) provides highly conformal dose distributions creating nonuniform spatial intensity using different segments in the beam. Concomitant chemoradiation is highly toxic in this age group.
Material and Methods: During 2016–2017, 44 patients with locally advanced head-and-neck cancers were treated with a curative intent with IMRT. They were in the age range of 65–75. The median age was 69 years. Thirty five were male and nine were female. Histopathologically, all had squamous cell carcinoma. Stage wise, all were T3N2 or more. The standard technique of IMRT was used with sparing of organs at risk and defining treatment volumes: gross, clinical, and planning. Patients were assessed after 4 weeks of completion of treatment for response and toxicities.
Results: Response vise, 14 patients achieved complete response, 28 patients had partial response, and 2 had stable disease. There was no treatment-related mortality. Six patients had treatment interruptions due to toxicity. Incidence of mucositis was of Grade 1–2 in all patients. No hematological toxicity was seen. Patients having dysphagia during treatment were given nasogastric feed.
Keywords: Elderly, head and neck, intensity modulated radiotherapy
|How to cite this URL:|
Jain N, Jain S, Sharma R, Sachdeva K, Kaur A, Rakesh A, Abrol D, Sudan M. Intensity-modulated radiotherapy in locally advanced head-and-neck cancers in elderly patients. J Can Res Ther [Epub ahead of print] [cited 2021 Nov 28]. Available from: https://www.cancerjournal.net/preprintarticle.asp?id=329052
| > Introduction|| |
Head-and-neck cancer is one of the most common malignancies in Indian males. Due to poor socioeconomic status, presentation is usually in advanced stage. Treatment option is limited to radiotherapy with or without chemotherapy. Intensity-modulated radiotherapy (IMRT) provides highly conformal dose distributions creating nonuniform spatial intensity using different segments in the beam. To deliver IMRT, multileaf collimator (MLC) divides beam fields in different segments, getting a different fluence in each beam. Modulation of the fluence creates nonuniform spatial intensity distributions that produce highly conformal dose distributions.
Modulation of intensity is performed by the movement of the MLC that can deliver the radiation in different ways such as static field segments, dynamic field segments, and rotational delivery (arc therapy and tomotherapy). There are slight differences among the different techniques in terms of homogeneity, dose conformity, and treatment delivery time. The best method to deliver IMRT depends on multiple factors such as deliverability, practicality, user training, and plan quality.
Aim of the study
The aim of the study was to assess response and tolerability of IMRT treatment in elderly patients with locally advanced disease without concomitant chemotherapy.
| > Materials and Methods|| |
During 2016–2017, 44 patients with locally advanced head-and-neck cancers were treated with a curative intent with IMRT. They were in the age range of 65–75. The median age was 69 years. Thirty-five patients were male and nine were female. Histopathologically, all had squamous cell carcinoma. Stage wise, all were T3N2 or more. There was no comorbid disease. No concurrent chemotherapy was given. Patients were immobilized with thermoplastic casts, and contrast computed tomography (CT) was taken for simulation. Images were contoured for organ at risks mainly salivary glands, dysphagia/aspiration risk structures, pharyngeal constrictors, spinal cord, optic apparatus, and midbrain. Treatment volumes, gross, clinical, and planning, were contoured as per the RTOG guidelines and planned for IMRT. Doses to organ at risks were tried to keep at par with guidelines laid down by RTOG. Dose to one parotid was kept below 26 Gy and to both parotids to <39 Gy for 50% volume. Dose to larynx and pharyngeal constrictors was below 55 Gy (30% volume). A total dose of 70 Gy in 35 fractions was planned to gross tumor volume. Cone-beam CT was taken every week, and treatment plan verification was done [Table 1], [Table 2], [Table 3], [Table 4].
| > Results|| |
Patients were assessed after 4 weeks of completion of treatment then monthly for 1 year. Response wise, 14 patients achieved complete response, 28 patients had partial response, and 2 had stable disease. There was no treatment-related mortality.
Both acute and chronic toxicities were assessed. Incidence of acute mucositis was of Grade 1–2 in 37 patients and patients experienced severe mucositis. Six patients had treatment interruptions due to mucositis. Xerostomia was Grade 1–2 in 42 patients and Grade 3 in 2 patients. Dysphagia was Grade 1–2 only. No hematological toxicity was seen. Patients having dysphagia during treatment were given nasogastric feed. ECOG criteria were used for grading the toxicities.
| > Discussion|| |
Radiation therapy has evolved from conventional two-dimensional (2D) treatment planning to 3D conformal radiation therapy (3DCRT) and IMRT over the years, and it has been an important advancement in radiation delivery. 3DCRT and IMRT are based on CT. Head-and-neck tumors are located in close vicinity of vital organs. It is very important to contour these vital organs along with tumor volume to achieving a precise tumor definition and a more accurate dose calculation by accounting for axial anatomy and complex volumes. The use of multiple beams, including oblique and noncoplanar together with MLCs, achieves adequate tumor coverage and sparing of vital organs. Three of the most crucial parts of IMRT are target delineation, treatment planning, and quality assurance. This results in steeper absorbed-dose gradients. Optimal IMRT requires more accurate delineation of both tumor and normal tissue than does conventional radiotherapy. Optimization is a key point in radiotherapy planning. It explores the possibilities to find the optimum intensity pattern for the desired outcome, which is specified with dose and volume constraints. However, there is a significant heterogeneity in target definition and prescription among radiation oncologists. Efforts to standardize and simplify the IMRT process have been suggested for head-and-neck IMRT practice. The organs that are not contoured as organ at risk receive significant high dose. The planning process can be summarized in three points: first, the desired outcome is specified in terms of dose and volume constraints and objectives for organs at risk and planning target volume using a system of priorities. Second, an objective function will be constructed to specify the accuracy of the plan. Finally, once the optimal fluence map is found, it is converted into deliverable field segments according to the specified method of delivery.
This study provided a reliable evaluation of the effect of sequential IMRT in elderly patients with locally advanced head-and-neck cancer. The results suggested that definitive IMRT with standard fractionation was effective in achieving effective local control and tolerable toxicity.
Interestingly, our results showed no significant differences in clinical outcomes, toxicity manifestation, and compliance with IMRT compared with literature. In a study, 1589 patients were enrolled and 185 patients were over 70 years (11.6%). Although underrepresented, the absolute number of elderly patients was considered sufficient to perform the analysis. Overall, radiotherapy tolerance was worse in elderly patients than younger patients, whereas there were no differences in terms of local control and overall survival between age groups. The authors concluded that old age was not a bar to administer radical radiotherapy in head-and-neck cancers. However, there are two main limitations of this study. First, there is no information regarding comorbidity. Second, patient data are from 1980 to 1995, and toxicity profile may have been negatively influenced by radiotherapy technique. Recently, Nguyen et al. presented a series of 27 patients with locally advanced head-and-neck cancer aged ≥70 years treated with concurrent CRT. The 2-year overall survival of the entire elderly cohort was 67.5%. In total, 16 patients developed Grade 3 or more acute mucositis, seven had Grade 3 or more hematological toxicity, five had severe skin reaction, and three presented severe vomiting. The mean treatment break was 7 days. Our patients experienced a less severe toxicity profile, and we believe that this was because IMRT was not combined with chemotherapy. Moreover, if we compare results, our survival rate was better, but due to the short follow-up (median 12 months) observed by Nguyen et al., no definitive conclusions can be drawn. Majority of the patients with head-and-neck cancer are aged 60 years and over in our country. This underrepresentation of the elderly suggests that it is necessary to better understand age-based differences in presentation, response to therapy, and prognosis. Further studies should be designed exclusively for elderly patients.
| > Conclusion|| |
This study is useful to identify the right therapeutic approach in elderly patients with locally advanced head-and-neck cancer. The use of IMRT appears to be safe and efficacious. However, these results should be viewed with caution in view of small sample size, making results less robust. However, homogeneity in the patient population, treatment strategy, and accurate data represents the study strengths. There are no set guidelines on treatment recommendations for older patients with locally advanced head-and-neck cancer, and this study can be helpful to assist the radiation oncologist in elderly patient counseling and clinical decision-making.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| > References|| |
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[Table 1], [Table 2], [Table 3], [Table 4]