Long-term outcomes with high-dose-rate brachytherapy for the management of base of tongue cancer

Three-Dimensional-Printed Template-Guided Radioactive Seed Brachytherapy via a Submental Approach for Recurrent Base of Tongue and Floor of Mouth Cancer

Background

This study assessed clinical outcomes of three-dimensional-printed template (3DPT)-guided radioactive seed brachytherapy (RSBT) via a submental approach for recurrent base of tongue and floor of mouth cancer.

Methods

Thirty-one patients with recurrent lingual and floor of mouth squamous cell carcinoma after surgery and radiotherapy were treated with 3DPT-guided RSBT from 2015 to 2022. Seeds were implanted through a submental approach guided by 3DPTs. Local control (LC), overall survival (OS), disease control (DC) and quality of life (QOL) were evaluated.

Results

The median follow-up was 13.7 months. The 1-, 3- and 5-year LC rates were 66.1%, 66.1%, and 55.1% respectively. The 1-, 3- and 5-year OS rates were 63.4%, 33.4%, and 8.3%. The 1-, 3- and 5-year DC rates were 37.8%, 26.5%, and 21.2%. Univariate analysis showed tumor size significantly affected LC (P = 0.031). The presence of extraterritorial lesions affected DC and OS on multivariate analysis (P < 0.01). QOL improved significantly in domains of pain, swallowing, chewing, taste, and emotion after treatment compared to baseline. Four patients (13%) developed necrosis and osteoradionecrosis.

Conclusions

3DPT-guided submental RSBT provided favorable LC and QOL for recurrent tongue/floor of mouth cancer with minimal toxicity; moreover, severe toxicity should be noted.

Function Preservation in Head and Neck Cancers

The treatment of head and neck cancers can have a significant impact on function and appearance, which results in impairment of quality of life. Various long-term sequelae of treatment include speech and swallowing difficulty, oral incompetence, trismus, xerostomia, dental caries and osteoradionecrosis. Management has evolved from single modality treatment of either surgery or radiation to multimodality treatment to attain acceptable functional outcomes. Brachytherapy, also known as interventional radiotherapy, with its ability to deliver high doses centrally to the target, has been shown to improve local control rates. Due to the rapid fall-off of the dose of brachytherapy there is better organ at risk sparing as compared with that of external beam radiotherapy. In the head and neck region, brachytherapy has been practiced in various sites, including the oral cavity, oropharynx, nasopharynx, nasal vestibule and paranasal sinuses. Additionally, brachytherapy has also been considered for reirradiation as a salvage. Brachytherapy can also be considered as a perioperative technique together with surgery. Close multidisciplinary cooperation is required for a successful brachytherapy programme. In oral cavity cancers, depending on the location of the tumour, brachytherapy has been shown to preserve oral competence, maintain tongue mobility, maintain speech, swallowing and the hard palate. Brachytherapy in oropharyngeal cancers has been shown to reduce xerostomia and also reduce dysphagia and aspiration post-radiation therapy. For the nasopharynx, paranasal sinus and nasal vestibule, brachytherapy preserves the respiratory function of the mucosa. Despite such an incomparable impact on function and organ preservation, brachytherapy is an underutilised technique for head and neck cancers. There is a strong need to improve brachytherapy utilisation in head and neck cancers.

Gel spacer to protect carotid artery and reconstructed jejunum in image-guided interstitial brachytherapy for recurrent hypopharyngeal cancer: a technical report

In this technical report, patient with total pharyngolaryngectomy and jejunum interposition experienced lymph node metastasis in the reconstructed mesenteric lymph nodes. Because this patient received 45 Gy of whole neck radiation therapy 24 years ago and small bowel's tolerance dose of the reconstructed jejunum was considered to be low, spacer gel injection was applied during image-guided interstitial brachytherapy to decrease doses to the reconstructed jejunum and previously irradiated carotid artery.

ACR-ABS-ASTRO practice parameter for the performance of radionuclide-based high-dose-rate brachytherapy

PURPOSE

This practice parameter aims to detail the processes, qualifications of personnel, patient selection, equipment, patient and personnel safety, documentation, and quality control and improvement necessary for an HDR brachytherapy program.

METHODS AND MATERIALS

This practice parameter was revised collaboratively by the American College of Radiology (ACR), the American Brachytherapy Society (ABS), and the American Society for Radiation Oncology (ASTRO).

RESULTS

Brachytherapy is a radiotherapeutic modality in which radionuclide or electronic sources are used to deliver a radiation dose at a distance of up to a few centimeters by surface, intracavitary, intraluminal, or interstitial application. Brachytherapy alone or combined with external beam radiotherapy plays an important role in the management and treatment of patients with cancer. High-dose-rate (HDR) brachytherapy uses radionuclides, such as iridium-192, at dose rates of ≥12 Gy/hr to a designated target point or volume, and it is an important treatment for a variety of malignant and benign conditions. Its use allows for application of high doses of radiation to defined target volumes with relative sparing of adjacent critical structures.

CONCLUSIONS

HDR brachytherapy requires detailed attention to personnel, equipment, patient and personnel safety, and continuing staff education. Coordination between the radiation oncologist and treatment planning staff and effective quality assurance procedures are important components of successful HDR brachytherapy programs.

The efficacy of iodine-125 interstitial brachytherapy for the treatment of locally advanced adenoid cystic carcinoma of the base of tongue: a non-surgical approach

Purpose

The present study retrospectively evaluated the effectiveness and safety of iodine-125 interstitial brachytherapy for treatment of primary locally advanced adenoid cystic carcinoma (ACC) of the base of tongue (BOT).

Material and methods

This study was a retrospective analysis of data of 19 patients with ACC, who were treated with iodine-125 interstitial brachytherapy between March 2008 and April 2018. Overall survival (OS), disease-free survival (DFS), local control (LC), and radiation-related toxicities were determined. Factors affecting the outcomes were evaluated.

Results

Six males and 13 females were included in our study, with a median follow-up time of 35 months. 3- and 5-year OS rates were 71.5% and 47.6%, respectively. 3- and 5-year LC rates were 88.5% and 34.5%, respectively. 3- and 5-year DFS rates were 54.7% and 21.9%, respectively. A significant difference was observed in patients with or without brain metastases for OS rate. No severe acute toxicity was observed, while severe late toxicity was observed in one patient.

Conclusions

The results suggest that iodine-125 interstitial brachytherapy is an effective and safe option for the treatment of primary locally advanced ACC of the base of the tongue, with reasonably satisfactory LC and OS.

Therapeutic Options in Unresectable Oral Squamous Cell Carcinoma: A Systematic Review

Purpose

This review describes the current scientific evidence of therapeutic options in unresectable oral squamous cell carcinoma.

Methods

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We searched MEDLINE (Via PubMed) to identify studies assessing treatments for unresectable oral squamous cell carcinoma. The methodological quality assessment of the included studies was performed using the Joanna Briggs Institute (JBI) checklist tool. The evidence was organized and presented using tables and narrative synthesis.

Results

Thirty-three studies met the eligibility criteria. Most studies had an observational design. The sample size varied from 16 to 916 participants. The methodology quality of the included studies ranged from 2.5 to 10 using the JBI tool. Overall, the optimal treatment of patients with unresectable oral cancer is challenging, so there is a sprinkling of studies assessing a variety of therapeutic options, such as radiotherapy, chemotherapy, concurrent chemoradiotherapy, immunotherapy, targeted therapy plus chemotherapy or radiotherapy, and gene therapy plus chemotherapy.

Conclusion

There is lacking evidence about the benefits of some therapeutic options for unresectable oral squamous cell carcinoma. Overall, these patients can be treated using a multimodal approach such as concurrent chemoradiotherapy or induction chemotherapy followed by chemoradiotherapy, which have shown good clinical outcomes. However, other options could be considered depending on the assessment of risk/benefits, tumor extension, and patient values and preferences.

Hybrid Intracavitary-Interstitial brachytherapy in a case of nasal vestibule cancer penetrating the hard palate

Because of its rarity, no standard therapy exists for localized squamous cell carcinoma of the nasal vestibule. Interstitial brachytherapy (ISBT) is reported to be a preferable treatment modality of choice for early-stage localized nasal vestibule cancer. In this report, a nasal vestibule cancer with hard palate invasion (T3) was treated by definitive radiation therapy. Because it was considered to be difficult to cover the entire target volume only by ISBT, a hybrid of intracavitary (dental mold-based) and ISBT was applied to the patient following external beam radiation therapy.

Brachytherapy of the head and neck: An University of California Los Angeles guide to morbidity reduction

The head and neck (H&N) region is among the most intricate and functional part of our anatomy. Major functional nerves and blood vessels with importance that affect the entire body emanate from the base of skull. Brachytherapy plays an important role as a single modality therapy in early cancer of the lip and oral cavity and a supplemental role in the pharynx or in advanced or recurrent disease. Morbidity in the H&N is intensely personal and disabling. Its avoidance is critical in determining the success or failure of a treatment program, and it is essential to preservation of quality of life. This article summarizes the current literature regarding morbidity related to H&N brachytherapy to aid patients and physicians to achieve optimal outcomes.

Image-guided interstitial brachytherapy boost for keratinizing squamous cell carcinoma of inferior wall of the nasopharynx

High-dose-rate interstitial brachytherapy (HDR-ISBT) is relatively rarely applied for the head and neck cancer because of its anatomical complexity and difficulty of applicator placement. However, its dose distribution is more confined even better than intensity-modulated radiation therapy (IMRT) and can deliver a higher dose while sparing surrounding normal tissues. In this case report, the effectiveness of HDR-ISBT as a boost following IMRT for keratinizing squamous cell carcinoma of nasopharynx was presented. A 76-year-old female who suffered from cT3N0M0 keratinizing squamous cell carcinoma of the nasopharynx was treated with definitive concurrent chemoradiation therapy involving IMRT. However, physical examination and laryngoscope fibre finding showed evident residual tumour at 60 Gy of IMRT, then, boost HDR-ISBT was proposed. After delivering 66 Gy of IMRT, CT image-guided HDR-ISBT 4 Gy in a single fraction was performed under local anaesthesia and sedation. MRI taken 5 months after HDR-ISBT showed remarkable shrinkage of the primary tumour. After HDR-ISBT, the remaining session of IMRT was delivered from the next day until 70 Gy in 35 fractions. It was demonstrated that boost HDR-ISBT combined with IMRT for keratinizing squamous cell carcinoma of the nasopharynx was performed safely and showed favourable efficacy.

Image-guided interstitial brachytherapy boost for nasopharyngeal carcinoma: technical aspects

Nasopharyngeal cancer generally responds well to concurrent chemoradiotherapy (CCRT). However, there is a small group of patients who respond poorly to CCRT, and experience local residual tumor or local relapse. Although several attempts have been performed to such a group of patients including re-irradiation with external beam radiation therapy (EBRT) or salvage surgery, clinical results remain unsatisfactory. Intracavitary brachytherapy (ICBT) boost after CCRT with EBRT has been explored, however, its efficacy is limited to those with superficial residual tumors. For those residual tumors thickness with more than 5 mm, interstitial brachytherapy (ISBT) boost would be an appropriate modality of choice. Here, we describe technical aspects of the high-dose-rate interstitial brachytherapy (HDR-ISBT) boost for nasopharyngeal cancer (NPC) patients who responded poorly to the CCRT with EBRT.

Per-oral interstitial brachytherapy catheter insertion for boost in case of recurrent tonsillar carcinoma: dosimetry and clinical outcome

High-dose-rate interstitial brachytherapy (HDR-ISBT) is relatively rarely applied for the head and neck cancer. However, its dose distribution is more confined than intensity modulated radiation therapy (IMRT) and can deliver higher dose while sparing surrounding normal tissues. In this case report, the effectiveness of HDR-ISBT as a boost following IMRT for post-operative recurrent oropharyngeal cancer patient was indicated. A 73-year-old male who developed local recurrence after surgery for oropharyngeal squamous cell carcinoma. Salvage IMRT up to 70 Gy concurrent with weekly cetuximab was planned. However, CT taken at 60 Gy found a residual tumor, then, boost HDR-ISBT was proposed. 1 week after 60 Gy of IMRT, HDR-ISBT, 12 Gy in 2 fractions, was delivered under local anesthesia. MRI taken 2 months after HDR-ISBT showed no residual tumor. It was demonstrated that boost HDR-ISBT following IMRT for local recurrence of oropharyngeal cancer was performed safely and showed favorable efficacy.

Image guided high-dose-rate brachytherapy versus volumetric modulated arc therapy for head and neck cancer: A comparative analysis of dosimetry for target volume and organs at risk

Background The aim of the study was to present dosimetric comparison of image guided high-dose-rate brachytherapy (IGBT) with volumetric modulated arc therapy (VMAT) for head and neck cancer regarding conformity of dose distribution to planning target volume (PTV) and doses to organs at risk (OARs). Patients and methods Thirty-eight consecutive patients with T1-4 mobile tongue, floor of mouth and base of tongue cancer treated with IGBT were selected. For these patients additional VMAT treatment plans were also prepared using identical computed tomography data. OARs and PTV related parameters (e.g. V98, D0.1cm3, Dmean, etc.) were compared. Results Mean V98 of the PTV was 90.2% vs. 90.4% (p > 0.05) for IGBT and VMAT, respectively. Mean D0.1cm3 to the mandible was 77.0% vs. 85.4% (p < 0.05). Dmean to ipsilateral and contralateral parotid glands was 4.6% vs. 4.6% and 3.0% vs. 3.9% (p > 0.05). Dmean to ipsilateral and contralateral submandibular glands was 16.4% vs. 21.9% (p > 0.05) and 8.2% vs. 16.9% (p < 0.05), respectively. Conclusions Both techniques showed excellent target coverage. With IGBT dose to normal tissues was lower than with VMAT. The results prove the superiority of IGBT in the protection of OARs and the important role of this invasive method in the era of new external beam techniques.

The American College of Radiology and the American Brachytherapy Society practice parameter for the performance of radionuclide-based high-dose-rate brachytherapy

Brachytherapy is a radiation therapy method in which radionuclide sources are used to deliver a radiation dose at a distance of up to a few centimeters by surface, intracavitary, intraluminal, or interstitial application. This practice parameter refers only to the use of radionuclides for brachytherapy. Brachytherapy alone or combined with external beam therapy plays an important role in the management and treatment of patients with cancer. High-dose-rate (HDR) brachytherapy uses radionuclides such as iridium-192 at dose rates of 20 cGy per minute (12 Gy per hour) or more to a designated target point or volume. High-dose-rate (HDR) brachytherapy is indicated for treating malignant or benign tumors where the treatment volume or targeted points are defined and accessible.

American Brachytherapy Society Task Group Report: Combined external beam irradiation and interstitial brachytherapy for base of tongue tumors and other head and neck sites in the era of new technologies

Irradiation plays an important role in the treatment of cancers of the head and neck providing a high locoregional tumor control and preservation of organ functions. External beam irradiation (EBI) results in unnecessary radiation exposure of the surrounding normal tissues increasing the incidence of side effects (xerostomy, osteoradionecrosis, and so forth). Brachytherapy (BT) seems to be the best choice for dose escalation over a short treatment period and for minimizing radiation-related normal tissue damage due to the rapid dose falloff around the source. Low-dose-rate BT is being increasingly replaced by pulsed-dose-rate and high-dose-rate BT because the stepping source technology offers the advantage of optimizing dose distribution by varying dwell times. Pulsed-dose and high-dose rates appear to yield local control and complication rates equivalent to those of low-dose rate. BT may be applied alone; but in case of high risk of nodal metastases, it is used together with EBI. This review presents the results and the indications of combined BT and EBI in carcinoma of the base of tongue and other sites of the head and neck region, as well as the role BT plays among other-normal tissue protecting-modern radiotherapy modalities (intensity-modulated radiotherapy, stereotactic radiotherapy) applied in these localizations.

On the impact of improved dosimetric accuracy on head and neck high dose rate brachytherapy

PURPOSE

To study the effect of finite patient dimensions and tissue heterogeneities in head and neck high dose rate brachytherapy.

METHODS AND MATERIALS

The current practice of TG-43 dosimetry was compared to patient specific dosimetry obtained using Monte Carlo simulation for a sample of 22 patient plans. The dose distributions were compared in terms of percentage dose differences as well as differences in dose volume histogram and radiobiological indices for the target and organs at risk (mandible, parotids, skin, and spinal cord).

RESULTS

Noticeable percentage differences exist between TG-43 and patient specific dosimetry, mainly at low dose points. Expressed as fractions of the planning aim dose, percentage differences are within 2% with a general TG-43 overestimation except for the spine. These differences are consistent resulting in statistically significant differences of dose volume histogram and radiobiology indices. Absolute differences of these indices are however small to warrant clinical importance in terms of tumor control or complication probabilities.

CONCLUSIONS

The introduction of dosimetry methods characterized by improved accuracy is a valuable advancement. It does not appear however to influence dose prescription or call for amendment of clinical recommendations for the mobile tongue, base of tongue, and floor of mouth patient cohort of this study.

Modern head and neck brachytherapy: from radium towards intensity modulated interventional brachytherapy

Intensity modulated brachytherapy (IMBT) is a modern development of classical interventional radiation therapy (brachytherapy), which allows the application of a high radiation dose sparing severe adverse events, thereby further improving the treatment outcome. Classical indications in head and neck (H&N) cancers are the face, the oral cavity, the naso- and oropharynx, the paranasal sinuses including base of skull, incomplete resections on important structures, and palliation. The application type can be curative, adjuvant or perioperative, as a boost to external beam radiation as well as without external beam radiation and with palliative intention. Due to the frequently used perioperative application method (intraoperative implantation of inactive applicators and postoperative performance of radiation), close interdisciplinary cooperation between surgical specialists (ENT-, dento-maxillary-facial-, neuro- and orbital surgeons), as well interventional radiotherapy (brachytherapy) experts are obligatory. Published results encourage the integration of IMBT into H&N therapy, thereby improving the prognosis and quality of life of patients.