|Year : 2022 | Volume
| Issue : 1 | Page : 80-83
High-dose-rate brachytherapy boost following external radiotherapy in a case of carcinoma external ear
Jayesh Singh, Aastha Shah, Ankita Parikh, Isha Shah, Dinesh Anand, Himanshi Jain, U Suryanarayan
Department of Radiation Oncology, GCRI, Ahmedabad, Gujarat, India
|Date of Submission||12-Jul-2021|
|Date of Acceptance||03-Dec-2021|
|Date of Web Publication||25-Apr-2022|
Dr. Jayesh Singh
Department of Radiation Oncology, GCRI, Ahmedabad, Gujarat
Source of Support: None, Conflict of Interest: None
Squamous cell carcinoma of the external ear is rare and the combination of external beam radiotherapy and brachytherapy has been beneficial for tumors in this location due to the advantage of organ preservation and thereby cosmesis. The incorporation of brachytherapy allows the delivery of doses large enough for the eradication of tumor and the advantage of rapid dose fall off due to brachytherapy minimizes the radiation damage to the nearby organs at risk. Herein we report a case of elderly male with early stage squamous cell carcinoma of external ear treated with a combination of external beam radiation with brachytherapy. An eighty nine year old male reported to our hospital with the complaints of left sided ear ache the presence of some mass in the left external ear. A diagnostic Contrast enhanced Computed Tomography (CECT) scan of head and neck showed a 1.6*1.5*1.4 cm mass lesion (maximum diameter) involving anterior cartilaginous part of left external auditory canal and preauricular soft tissue,thereby staged as T2N0,stage II. Patient was planned for External Beam Radiotherapy (EBRT) using 3D CRT(Conformal Radiotherapy) technique by 6 MV photon beam to a dose of 50 Gy in 25 fractions (2 Gy/#) and following this,a gap of seven days was given and after that four fractions of HDR brachytherapy using Iridium 192 of 3 Gy/# keeping a gap of six hours between two fractions on a single day,Two flexible plastic tubes were used for radiation delivery. The size of the catheter used for radiation delivery was 6 French. Planning CT scan was taken and target volume defined as PTV and a dose of 3 Gy per fraction to a total of 4 fractions was prescribed to the target volume. The spike of intravenous site was used for fixing the plastic tube in the mould. The tumor responded ver well to radiotherapy. Brachytherapy is an effective modality to boost high risk areas without significant damage to the surrounding area. External Beam Radiotherapy in case of early stage carcinoma external auditory canal combined with brachytherapy boost can be considered as a better modality with less severe side effects and better cosmesis.
Keywords: External ear carcinoma, HDR brachytherapy boost, radiation, rare case
|How to cite this article:|
Singh J, Shah A, Parikh A, Shah I, Anand D, Jain H, Suryanarayan U. High-dose-rate brachytherapy boost following external radiotherapy in a case of carcinoma external ear. Indian J Otol 2022;28:80-3
|How to cite this URL:|
Singh J, Shah A, Parikh A, Shah I, Anand D, Jain H, Suryanarayan U. High-dose-rate brachytherapy boost following external radiotherapy in a case of carcinoma external ear. Indian J Otol [serial online] 2022 [cited 2022 May 18];28:80-3. Available from: https://www.indianjotol.org/text.asp?2022/28/1/80/343746
| Introduction|| |
Squamous cell carcinoma of the external ear is rare, and the combination of external beam radiotherapy (EBRT) and brachytherapy has been beneficial for tumors in this location due to the advantage of organ preservation and thereby cosmesis. The advantage of this location of tumor is that they can be treated with a radical approach if an early diagnosis is made. The incorporation of brachytherapy allows the delivery of doses large enough for the eradication of tumor and the advantage of rapid dose fall off due to brachytherapy minimizes the radiation damage to the nearby organs at risk., Herein, we report a case of an elderly male with early-stage squamous cell carcinoma of external ear treated with a combination of external beam radiation with brachytherapy.
| Case Report|| |
The aim is to report the outcome in a case of squamous cell carcinoma external ear treated by external radiotherapy followed by brachytherapy boost using remote afterloading system Ir192. An 89-year-old male nonsmoker was reported to our hospital with the complaints of left-sided earache for 25 days and the presence of some mass in the left external ear. There were no associated complaints of any ear discharge or trauma or fever. On history and physical examination, the presence of pale-colored growth was seen in the external auditory canal without the presence of any discharge or bleeding. There was no any abnormality detected in the opposite right ear. Neck examination and oral examination revealed no any abnormality. Biopsy from the external auditory canal mass came out to be well-differentiated squamous cell carcinoma. Complete blood hemogram, renal and liver function test, coagulation profile, and viral markers were done which revealed no abnormality. A diagnostic contrast-enhanced computed tomography scan of head and neck showed a 1.6 cm × 1.5 cm × 1.4 cm mass lesion (maximum diameter) involving anterior cartilaginous part of left external auditory canal and preauricular soft tissue. There was no evidence of bony erosion or any lymphadenopathy therefore staged as T2N0, stage II as per the American Joint Cancer Committee eighth edition tumor, node, and metastasis (TNM) classification. The patient was planned for EBRT using three-dimensional conformal radiotherapy technique by 6-MV photon beam to a dose of 50 Gy in 25 fractions (2 Gy/#), the BED (biological effective dose) of which came out to be 60 Gy. The Monaco system was used for planning. A bolus using cotton soaked in water was used to increase the surface dose during the planning computed tomography (CT) scan with slice thickness of 3 mm and during the whole external radiation treatment time. The gross tumor volume (GTV) was contoured, and the clinical target volume (CTV) was contoured by adding one-centimeter margin to GTV respecting the normal anatomic boundaries, and planning target volume (PTV) was contoured by adding five-millimeter margin to CTV. Organs at risk include brainstem, spinal cord, cochlea, temporal bone, lens, eyeball, mandible, optic nerve, optic chiasma, parotid gland, and larynx as shown in [Figure 1]. Chemotherapy was deferred taking into consideration the age of the patient. Following this, a gap of 7 days was given, and after that, four fractions of HDR brachytherapy using iridium 192 of 3 Gy/# keeping a gap of 6 h between two fractions on a single day, the BED of which came out to be 15.6 Gy and EQD2 of 13 Gy. A customized mold using dental material was made for the brachytherapy which was very well comfortable to the patient as shown in [Figure 2]. The same position was maintained during all the four fraction delivery. Two flexible plastic tubes were used for radiation delivery. The size of the catheter used for radiation delivery was 6 French. Planning CT scan was taken, and target volume was defined as PTV, and a dose of 3 Gy per fraction to a total of four fractions was prescribed to the target volume. V200 (target volume receiving 200% of the prescribed dose) V150 (target volume receiving 150% of the prescribed dose), V100 (target volume receiving100% of the prescribed dose), D100 (minimum dose covering 100% of the target volume), D90 (minimum dose covering 90% of the target volume), and dose to the organ at risk were recorded, and the plan was executed as shown in [Figure 3] and [Figure 4]. The spike of intravenous site was used for fixing the plastic tube in the mold as shown in [Figure 5] and [Figure 6]. The tumor responded very well to radiotherapy as shown in [Figure 7] and [Figure 8] depicted by the CT scan images.
|Figure 5: Showing brachytherapy execution with catheter tube and mould in position|
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| Discussion|| |
Tumors of ear are much more common in elderly than in young and more common in female than male. Squamous cell carcinoma of the external ear is staged as per TNM staging of cutaneous malignancies of head and neck. Mostly patients have complains of pain and pruritus which are generally managed conservatively and often delay the diagnosis. Advanced cases generally present with decreased hearing, swelling behind ear, and facial paralysis. Carcinomas of external ear are extremely rare, and surgery has been the standard of care but currently combined modality of radiotherapy combined with chemotherapy is been emerging with the advantage of organ preservation. Cutaneous carcinomas constitute 3%–7% of all malignancies, and among them, carcinoma external ear constitutes 0.2% of the cases, and among them, squamous cell carcinomas constitute 85% of the cases. Treating solely by radiation as a single modality needs the incorporation of brachytherapy along with external beam radiation to achieve higher Biological Effective Dose (BED) to achieve complete tumor eradication., For early-stage tumors with no cartilage, invasion prophylactic treatment of draining lymphatics is not necessary. A wide variety of radiation techniques can be employed for external radiation like using mixed beam.
Combination of photon and electron or else by using wedged pair portal beams. The skin of the external ear responds to radiation in a similar way as skin over the other areas, but the skin over external ear is slightly more sensitive. Brachytherapy is an effective modality to boost high-risk areas without significant damage to the surrounding area, keeping in mind, the risk of osteoradionecrosis of temporal bone. Limit the dose of temporal bone to <70 Gy to reduce the chance of osteoradionecrosis.
| Results|| |
Post-1-year treatment, there is no evidence of any disease clinically and radiographically.
| Conclusion|| |
EBRT in case of early-stage carcinoma external auditory canal combined with brachytherapy boost can be considered as a better modality with less severe side effects and better cosmesis.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8]