High dose rate versus low dose rate interstitial radiotherapy for carcinoma of the floor of mouth

[Brachytherapy for head and neck cancers]

The main indications of the brachytherapy of head and neck cancers are the limited tumours of the lip, the nose, the oral cavity and the oropharynx. Nasopharynx tumours are nowadays treated by intensity-modulated radiotherapy. This technique can be exclusive, associated with external radiotherapy or postoperative. It can also be a salvage treatment for the second primaries in previously irradiated areas. If the low dose rate brachytherapy rules remain the reference, the pulse dose rate technique allows the prescription of the dose rate and the optimisation of the dose distribution. Results of high dose rate brachytherapy are now published. This paper reports the recommendations of the Gec-ESTRO, published in 2017, and takes into account the data of the historical low dose rate series, and is upgraded with the pulsed-dose rate and high dose rate series.

GEC-ESTRO ACROP recommendations for head & neck brachytherapy in squamous cell carcinomas: 1st update - Improvement by cross sectional imaging based treatment planning and stepping source technology

The Head and Neck Working Group of the GEC-ESTRO (Groupe Européen de Curiethérapie - European Society for Therapeutic Radiology and Oncology) published in 2009 the consensus recommendations for low-dose rate, pulsed-dose rate and high-dose rate brachytherapy in head & neck cancers. The use of brachytherapy in combination with external beam radiotherapy and/or surgery was also covered as well as the use of brachytherapy in previously irradiated patients. Given the developments in the field, these recommendations needed to be updated to reflect up-to-date knowledge. The present update does not repeat basic knowledge which was published in the first recommendation but covers in a general part developments in (1) dose and fractionation, (2) aspects of treatment selection for brachytherapy alone versus combined BT+EBRT and (3) quality assurance issues. Detailed expert committee opinion intends to help the clinical practice in lip-, oral cavity-, oropharynx-, nasopharynx-, and superficial cancers. Different aspects of adjuvant treatment techniques and their results are discussed, as well the possibilities of salvage brachytherapy applications.

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.

High-dose-rate brachytherapy using molds for lip and oral cavity tumors

Background

High-dose-rate (HDR) brachytherapy using the mold technique is a less invasive treatment for early lip and oral cavity cancer. However, limited reports exist regarding the feasibility of this method. In this retrospective study, we evaluated the outcome of this therapy and investigated its feasibility for lip and oral cavity tumors.

Methods

Between May 2002 and December 2010, 17 patients (median age, 80.0 years) with histologically confirmed squamous cell carcinoma of the lip or oral cavity were treated by means of HDR brachytherapy using the mold technique after external beam radiotherapy (EBRT). Tumor sites included the buccal mucosa in eight cases, the gingiva in three cases, the lips in two cases, the floor of the mouth in two cases, and the hard palate in two cases. For all patients, EBRT (30 Gy/15 fractions), was performed before HDR brachytherapy. Two 6-Gy fractions were delivered twice daily for 2 days a week with an interval of 6 hours between the fractions. The total HDR brachytherapy dose was 24 Gy. Prior to EBRT, two patients with neck metastasis underwent neck dissection, and one patient with an exophytic tumor underwent tumor resection.

Results

The median follow-up period was 53.4 (range, 4.8–83.4) months. Of the 17 patients, 14 (82.4%) achieved a complete response, and three (17.6%) displayed a partial response.

The overall 3- and 5-year survival rates were both 68.8%, the 3- and 5-year disease-specific survival rates were both 86.7%, and the 3- and 5-year local control rates were both 54.1%. Seven patients developed local recurrence at a median time of 3.4 (range, 1.7–29.1) months after treatment. Nodal and lung metastases occurred separately in two patients. By the end of the follow-up period, two patients had died of the primary disease and four patients had died of other causes.

Conclusions

Although there is a need to improve the technical aspects of the treatment protocol, HDR brachytherapy using the mold technique might be a therapeutic option for superficial lip or oral cavity tumors, especially in older patients who have a poor performance status or are in poor physical condition.

High dose rate versus low dose rate brachytherapy for oral cancer--a meta-analysis of clinical trials

OBJECTIVE

To compare the efficacy and safety of high dose rate (HDR) and low dose rate (LDR) brachytherapy in treating early-stage oral cancer.

DATA SOURCES

A systematic search of MEDLINE, EMBASE and Cochrane Library databases, restricted to English language up to June 1, 2012, was performed to identify potentially relevant studies.

STUDY SELECTION

Only randomized controlled trials (RCT) and controlled trials that compared HDR to LDR brachytherapy in treatment of early-stage oral cancer (stages I, II and III) were of interest.

DATA EXTRACTION AND SYNTHESIS

Two investigators independently extracted data from retrieved studies and controversies were solved by discussion. Meta-analysis was performed using RevMan 5.1. One RCT and five controlled trials (607 patients: 447 for LDR and 160 for HDR) met the inclusion criteria. The odds ratio showed no statistically significant difference between LDR group and HDR group in terms of local recurrence (OR = 1.12, CI 95% 0.62-2.01), overall mortality (OR = 1.01, CI 95% 0.61-1.66) and Grade 3/4 complications (OR = 0.86, CI 95% 0.52-1.42).

CONCLUSIONS

This meta-analysis indicated that HDR brachytherapy was a comparable alternative to LDR brachytherapy in treatment of oral cancer. HDR brachytherapy might become a routine choice for early-stage oral cancer in the future.

High dose rate brachytherapy for oral cancer

Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer.

Shielding effect of a customized intraoral mold including lead material in high-dose-rate 192-Ir brachytherapy for oral cavity cancer

A high-dose-rate (HDR) 192-Ir brachytherapy using a customized intraoral mold is effective for superficial oral cavity cancer, and the surrounding normal tissue is kept away from the radioactive source with gauze pads and/or mouth piece for reducing the dose on the normal tissues. In the Tokushima university hospital, the mold has a lead shield which utilizes the space prepared with sufficient border-molding by a specific dental technique using modeling compound. In HDR 192-Ir brachytherapy using a lead shielded customized intraoral mold, there are no reports measuring the absorbed dose. The purpose of the present study is to measure the absorbed dose and discuss the optimum thickness of lead in HDR 192-Ir brachytherapy using a customized intraoral mold with lead shield using a 1 cm thickness mimic mold. The thickness of lead in the mold could be changed by varying the arrangement of 0.1 cm thickness sheet of the acrylic resin plate and lead. The measured doses at the lateral surface of the mold with thermo-luminescence dosimeter were reduced to 1.12, 0.79, 0.57, 0.41, 0.31, 0.24 and 0.19 Gy and the ratios to the prescription dose were reduced to 56, 40, 29, 21, 16, 12 and 10 percent as lead thickness increased from 0 to 0.6 cm in 0.1 cm increments, respectively. A 0.3 cm thickness lead was considered to be required for a 1 cm thickness mold, and it was necessary to thicken the lead as much as possible with the constraint of limited space in the oral cavity, especially at the fornix vestibule.

Two-piece customized mold technique for high-dose-rate brachytherapy on cancers of the buccal mucosa and lip

OBJECTIVE

High-dose-rate (HDR) brachytherapy using a customized mold is a minimally invasive treatment for oral cancer; however, it is difficult to use this technique for buccal and lip cancers involving the commissura labiorum, owing to its anatomic form. The purpose of this study was to introduce an improved customized mold consisting of 2 pieces to allow the fixation of molds to these sites.

STUDY DESIGN

Five patients with buccal carcinoma and 1 patient with lip carcinoma were treated with this technique after external beam radiotherapy. One patient with neck metastasis underwent both neck dissection and partial tumor resection before HDR brachytherapy.

RESULTS

At the end of the follow-up period, 5 patients had no tumor recurrence, and 1 patient had suffered local recurrence.

CONCLUSIONS

Our technique is a viable therapeutic option for patients with buccal and lip carcinomas for whom the therapeutic modalities are limited by age, performance status, and other factors.

Comparison of efficacy and safety of low-dose-rate vs. high-dose-rate intraluminal brachytherapy boost in patients with superficial esophageal cancer

PURPOSE

To compare the efficacy and the incidence of complications of high-dose-rate (HDR) and low-dose-rate (LDR) intraluminal brachytherapy (IBT) boost after external beam radiation therapy in patients with superficial esophageal cancer.

METHODS AND MATERIALS

Fifty-four consecutive patients with Stage I thoracic esophageal squamous cell carcinoma who were treated with definitive radiotherapy using IBT between 1991 and 2007 were studied retrospectively. LDR-IBT and HDR-IBT were performed for 19 and 35 patients, respectively. After external beam radiation therapy of 56-60 Gy with a conventional fractionation, LDR-IBT (5 Gy × 2) or HDR-IBT (3 Gy × 3) was given within 2 weeks. The median follow-up was 47 months (7-151 months).

RESULTS

Overall, the 5-year overall survival, cause-specific survival (CSS), and locoregional control (LRC) rates were 61%, 86%, and 79%, respectively. The 5-year overall survival, CCS, and LRC rates did not differ significantly between the LDR-IBT and HDR-IBT groups (68% vs. 58% (p=0.50), 83% vs. 85% (p=0.63), and 84% vs. 75% (p=0.42), respectively). Salvage treatment was given in 8 locally recurrent patients, and 6 patients were rescued. The Grade ≥2 late morbidities of esophagus and heart/lung were observed in 5 patients (4 in the LDR-IBT group and 1 in the HDR-IBT group) and 2 patients (one from each group), respectively.

CONCLUSIONS

In view of the safety profile and effectiveness, our results encourage the continued adoption of HDR-IBT as radiation boost in medically inoperable or elderly superficial esophageal cancer patients undergoing definitive radiotherapy.

High-dose-rate brachytherapy for patients with maxillary gingival carcinoma using a novel customized intraoral mold technique

OBJECTIVE

The purpose of this study was to introduce a novel customized intraoral mold treatment for maxillary gingival carcinoma (UGC).

STUDY DESIGN

Two patients with UGC were treated as salvage therapy using this technique. The mold was designed to keep normal soft tissues adjacent to the tumor away from the radioactive source as much as possible, and it was shielded by lead. The radiation dose on the buccal mucosa and tongue was measured at the inner and outer surfaces of the intraoral mold before starting high-dose-rate brachytherapy by the remote afterloading system, and was reduced to almost one tenth.

RESULTS

The patient had no recurrence and no severe adverse effects on the normal soft tissue adjacent to the tumor until the end of the follow-up period.

CONCLUSION

High-dose-rate brachytherapy using the novel customized intraoral mold might be a treatment option of not only salvage therapy, but definitive therapy of UGC.

Carcinoma of the floor of the mouth: a case treated with precisely controlled external beam radiotherapy

A new external radiotherapy system has been developed for head and neck cancer and a case with T2 oral floor carcinoma treated with this system is presented in this report. The system consists of real-time tumor-tracking equipment and a gold-marker implanted mouthpiece. Accuracy of the order of 2 mm was achieved during the entire course of fractionated radiotherapy (a total of 52.5 Gy in 15 fractions). Planning target volume became smaller compared to the conventional parallel-opposed technique. Dose-volume histogram analysis demonstrated a significant reduction in the dose to the mandible bone compared to the conventional technique. A confluent fibrinous mucositis developed in the oral floor mucosa that corresponded to 90% dose area. Mucositis in the lower gum was minimal and analgesics were not required. The patient is currently free from both tumor and complication during a follow-up period of 48 months. External radiotherapy can be an option as a curative treatment for early stage carcinoma of the floor of the mouth provided that patient set-up is rigid and reproducible.

High-dose-rate brachytherapy in the treatment of recurrent and residual head and neck cancer

OBJECTIVES/HYPOTHESIS

Interstitial and endocavitary brachytherapy are well-accepted kinds of radiotherapy that are commonly used in recurrent head and neck cancer. Most reports about brachytherapy in the successful treatment of head and neck tumors used low-dose-rate brachytherapy. There are only a few reports about high-dose-rate brachytherapy (HDRBT) in head and neck cancer patients.

METHODS

After 10 years of experience with HDRBT with Ir 192, we have analyzed the results regarding response rates, survival time, and side effects. Between 1991 and 2000, 90 consecutive patients (68 men, 22 women) were treated with interstitial (68 patients) or intracavitary (22 patients) HDRBT in the head and neck area. Primary tumor locations were as follows: oropharynx (n = 26), tongue/floor of mouth (n = 22), nasopharynx (n = 10), nose/paranasal sinuses (n = 9), salivary glands (n = 5), hypopharynx (n = 5), CUP syndrome (n = 5), and others (n = 8). High-dose-rate brachytherapy was administered in 51 patients with recurrent disease and in 32 patients with residual tumor after primary radiochemotherapy. Seven patients were given exclusive HDRBT in a primary palliative situation. The single dose per fraction ranged from 1.5 to 7.5 Gy (median value, 5 Gy), and the total HDRBT dose ranged from 4.0 to 42.0 Gy (median value, 17.5 Gy).

RESULTS

The overall remission rate was 81% with a 46% rate of complete remissions. We observed no change in or progression of tumor in 17 cases (19%). The rate of complete remissions (and median overall survival time) was different in the three therapy groups: in case of recurrent disease, 28% (6 mo); in case of residual tumor, 84% (25 mo); and in primary palliative brachytherapy, 0% (1 mo). Late toxicities III and IV (radiation treatment oncology group score) occurred in 6 of 90 (6.7%) patients.

CONCLUSIONS

High-dose-rate brachytherapy proved to be an effective treatment modality in locoregional recurrent head and neck cancer. In cases with persistent or residual tumor after primary radiochemotherapy a local boost with brachytherapy can improve the chance of cure of tumor disease.

Phase III trial of high- vs. low-dose-rate interstitial radiotherapy for early mobile tongue cancer

PURPOSE

Early mobile tongue cancer can be controlled with interstitial radiotherapy (ISRT). We carried out a Phase III trial to compare the treatment results of low-dose-rate (LDR) ISRT and high-dose-rate (HDR) ISRT for early mobile tongue cancer.

METHODS AND MATERIALS

From April 1992 through October 1996, 59 patients with cancer of the early mobile tongue were registered in this Phase III study. Eight patients were excluded from the evaluation because of violations of the requirements for this study. Of 51 eligible patients, 26 patients were treated with LDR-ISRT (70 Gy/4-9 days) and 25 patients with HDR-ISRT (60 Gy/10 fractions/1 week). For the hyperfractionated HDR-ISRT, the time interval between 2 fractions was more than 6 h.

RESULTS

Five-year local control rates of the LDR and HDR groups were 84% and 87% respectively. Nodal metastasis occurred in 6 patients in each group. Five-year nodal control rates of the LDR and HDR groups were 77% and 76%, respectively.

CONCLUSION

Hyperfractionated HDR-ISRT for early mobile tongue cancer has the same local control compared with continuous LDR-ISRT. Hyperfractionated HDR-ISRT is an alternative treatment for continuous LDR-ISRT.

High-dose-rate brachytherapy for primary carcinomas of the oral cavity and oropharynx

OBJECTIVE

Local control for patients treated with primary radiation therapy for tumors of the oral cavity is improved using low-dose-rate brachytherapy. Oropharyngeal carcinomas have also been treated with brachytherapy. The few reports in the literature regarding high-dose-rate brachytherapy (HDRBT) for head and neck cancer involve small numbers of patients and often contain a mix of palliative and curative cases. The purpose of this study is to evaluate the feasibility of HDRBT in the largest reported cohort of primary head and neck cancer patients treated with primary radiation therapy.

STUDY DESIGN

This is a prospective nonrandomized study.

METHODS

Fifty-five patients with primary untreated squamous cell carcinomas of the oral cavity and oropharynx were analyzed. There were 16 patients with T1, 26 with T2, 8 with T3, and 5 with T4 tumors. All patients received external-beam radiotherapy (EBRT) followed by HDRBT. Thirty-eight patients received hyperfractionated (twice daily) EBRT followed by HDRBT two or three times daily. Patients with cervical adenopathy also received hyperthermia and an electron boost to the site(s) of positive nodes. Median follow-up was 2.7 years. Toxicity and local control were analyzed. Data were analyzed by the Kaplan-Meier life-table method with statistical significance determined by the X2 and log-rank tests.

RESULTS

High-dose-rate brachytherapy was extremely well tolerated. Only 9 patients (16%) developed a complication. Four patients developed osteoradionecrosis, and five developed soft tissue necrosis, all of which healed with conservative medical management. No complication required surgical intervention or hospitalization. Actuarial 2-year local control for the entire cohort was 79%. Local control was 87% for patients with T1 (15/16) and T2 (22/26) tumors versus 47% for T3 (5/8) and T4 (2/5) tumors (P < .01).

CONCLUSIONS

High-dose-rate brachytherapy is feasible as a boost for patients with primary squamous cell carcinomas of the oral cavity and oropharynx. Patients with T1 and T2 tumors fared exceptionally well; those with advanced tumors may require more aggressive treatment, such as higher radiation doses, surgical resection, or systemic chemotherapy. The use of HDRBT both shortens the overall treatment time and limits the volume of tissue exposed to high doses of radiation therapy. In the future, as more patients treated with HDRBT are evaluable, we hope to identify potential factors that predict for local control so that we may select patients optimally for this treatment.

Feasibility and tolerance of pulsed dose rate interstitial brachytherapy

PURPOSE

Pulsed dose rate (PDR) treatment is a new approach that associates the physical advantages of high-dose-rate (HDR) technology with the potential radiobiological advantages of low-dose-rate (LDR) brachytherapy. This retrospective study analyzes the feasibility, toxicity, and preliminary oncologic results in a series of 43 patients treated with PDR interstitial brachytherapy.

METHODS AND MATERIALS

Twenty-four patients with pelvic, 17 patients with head and neck, and 2 patients with breast cancers were treated. Twenty-eight patients had primary and 15 recurrent tumors; 14 had received prior external irradiation to the same site. The doses per pulse at the prescription isodose were 0.4-1 Gy (median 0.5 Gy), delivered using a single cable-driven 0.3-1.0 Ci 192-iridium source (PDR Nucletron Micro-Selectron).

RESULTS

The median treated volumes (at the prescribed isodose) were 28 cc for pelvic, 8.33 cc for head and neck, and 40 cc for breast malignancies. Of 14,499 source and 14,499 dummy source transfer procedures, 3 technical machine failure events were observed (0.02%). Grade 3 acute toxicities were seen in 5/43 patients (4 oral stomatitis, 1 vaginal mucositis) and grade 4 acute toxicity in one patient (rectovaginal fistula). Grade 3-4 late complications were observed in 4/41 (9.8%) patients: 1 pubic fracture, 1 rectovaginal fistula, 1 vesicovaginal fistula and 1 local necrosis. With a median follow-up of 18 months, 10/41 patients progressed locoregionally (6 pelvic, 4 head and neck), 3 developed local recurrence and distant metastasis (3 pelvic), 3 only distant metastasis (2 pelvic, 1 head and neck). Two patients are lost to follow-up.

CONCLUSION

PDR interstitial brachytherapy for pelvic, head and neck, and breast malignancies is feasible and the acute and late toxicities seem acceptable. Although the physical advantages of PDR are clear, further follow-up is required to determine how results compare with those obtained with standard LDR brachytherapy.