[Brachytherapy in combination with function-preserving surgery. An interdisciplinary challenge]

Brachytherapy in head and neck malignancies: Indian Brachytherapy Society (IBS) recommendations and guidelines

PURPOSE

Brachytherapy (BT) forms major treatment modality in squamous cell carcinoma of head and neck cancers (HNC). However, there is a dearth of literature and guidelines for the use in various indications. High-dose-rate brachytherapy (HDR-BT) in Indian scenario is an important treatment modality, and the recommendations in this guidelines aim to provide the necessary recommendations for the use of HDR-BT for uniform application across the country in patients with HNC.

MATERIAL AND METHODS

A panel consisting of members of the Indian Brachytherapy Society (IBS), based on their clinical experience was invited. The process involved defining important steps, precautions, target volumes and indications, thorough literature review, and discussion with fellow members. The guidelines were established and formulated the recommendations for HDR-BT based on available evidences and individual experience for sites, relevant to Indian settings.

RESULTS

The IBS recommends the use of HDR brachytherapy as a part of treatment of head and neck tumors. The scope of these guidelines and recommendations included practical suggestions, ensuring efficient use of brachytherapy treatment as radical with external beam radiotherapy (EBRT) boost, palliative and adjuvant as definitive, or re-radiation as salvage for HNC in India. The IBS has made specific site-wise recommendations for previously untreated and recurrent HNC patients on their selection criteria, implant techniques, target volume definition, and HDR treatment parameters, such as time, dose rate, total dose, and fractionation schedules. Limited experience exists with HDR-BT in patients with head and neck cancers in India and across the globe.

CONCLUSIONS

IBS provided a consensus statement and guidelines for the head and neck brachytherapy and believed that these recommendations will overcome the fear of practicing radiation oncologists. This should generate interest amongst students and will help radiation oncologists all across the country to use the art of brachytherapy carefully in HNC patients, with better curative and salvage options.

A new multimodal, image-guided, robot-assisted, interstitial brachytherapy for the treatment of head and neck tumors-A preliminary study

BACKGROUND

Interstitial brachytherapy (BT) is becoming an accepted treatment option for head and neck cancer patients for whom surgery poses high risks. Multimodal, image-guided, robotic surgery has the potential to allow precise seed implantation into tumors. Our aim was to introduce a new multimodal, image-guided surgical robot during the performance of interstitial BT for the treatment of tumors in the head and neck regions.

METHODS

Clinical data for three patients were analyzed, retrospectively; patients had received ¹²⁵ I seed implantations from July 2019 to October 2019. Multimodal, image-guided, robotic surgery was performed in all patients. Postoperative computed tomography data were imported to software to evaluate the accuracy of the seed position and the operation times.

RESULTS

The mean placement error of the ¹²⁵ I seed was 1.9 ± 0.74 mm. The mean operation time is 47 minutes.

CONCLUSION

The experimental results showed that the Remebot has promise for use during BT for the head and neck.

Interstitial brachytherapy for orbital soft tissue sarcoma: an innovative technique

Purpose

To report an innovative technique of interstitial brachytherapy developed for treatment of orbital soft tissue tumors.

Material and methods

A 4-month-old child diagnosed with rhabdomyosarcoma of orbit was treated with multiagent chemotherapy (CTh) and brachytherapy. Pre-planning computed tomography (CT) images were obtained and clinical target volume (CTV) was defined using the pre-treatment magnetic resonance imaging (MRI). Brachytherapy plan was generated for deciding optimal catheter placement. With the child under general anesthesia, catheter entry points were extrapolated and marked on the skin as determined from the pre-planning CT scan. Implantation of catheters was performed as per pre-determined catheter position and depths. Brachytherapy plan was generated and evaluated using dose volume histograms (DVH). A comparative external beam radiotherapy (EBRT) plan using RapidArc was also generated for the CTV with a 3 mm margin as the planning target volume (PTV).

Results

The mean CTV dose with brachytherapy was 158% compared to 101% with RapidArc. The CTV V₁₀₀ was 90% for brachytherapy vs. 95% for RapidArc. The mean dose to Lt Lens were 51% and 60%, respectively for brachytherapy and RapidArc, while the corresponding mean doses to the bony orbit were 39% and 68%, respectively. Follow-up MRI at 3 months showed complete response of the tumor.

Conclusions

Interstitial brachytherapy for orbit using this innovative technique is a safe and effective modality of local treatment for appropriately selected orbital soft tissue tumors. Brachytherapy resulted in excellent disease control with significant reduction of dose to surrounding ocular structures compared to EBRT.

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.

[Principles of radiation therapy for malignant tumors of the orbit and the periorbital area]

Primary malignant tumors of the orbit and the orbital adnexal area are rare, variform and in the majority of cases need an interdisciplinary treatment. According to tumor entity, tumor localization, and tumor extent the complete spectrum of radiotherapeutic therapy options is necessary. In the majority of malignant tumors, such as those of the eyelids, lachrymal glands, orbit, metastases, sarcoma or lymphoma, radiotherapy is used as a high energy therapy by means of medical linear accelerators as so-called teletherapy. In addition, new therapy methods, such as stereotactic highly conformal radiation or intensity-modulated radiation therapy (IMRT) were developed to achieve a higher local tumor control by a better configuration of the radiotherapy fields to the tumor borders and to contribute to a reduction of acute and chronic side effects in normal tissue by blurring of the dose. The application of ionizing radiation sources, such as so-called interstitial brachytherapy can also be just as carefully as effectively used. Particle beam radiotherapy is limited only to specially licensed centers and light hydrogen ions as proton therapy or carbon ions as heavy ion radiotherapy are in use. This overview will show the options as well as important progress in the field of radiotherapy in the treatment of tumors of the orbit and periorbital area.