Iridium-192 interstitial implant and external beam radiation therapy in the management of squamous cell carcinomas of the tonsil and soft palate

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.

The Role of Brachytherapy in the Management of Oropharyngeal Carcinomas: The Trento Experience

Aims

This study was undertaken to determine the outcome of patients with oropharyngeal cancer treated at the Radiotherapy Department of the Santa Chiara Hospital (Trento, Italy) with brachytherapy alone or combined with external beam radiotherapy (EBRT).

Material and methods

We retrospectively reviewed the medical records of 87 patients with squamous cell carcinoma of the oropharynx treated by radiation therapy between January 1986 and September 1999. The median age was 59 years and all patients had a minimum follow-up of one year. Tumor locations were 46 tonsillar region, 31 soft palate and 10 base of the tongue. The patients were staged as follows: 41 T1, 35 T2, 11 T3 with 70 N0, 9 N1 and 8 N2. They received either brachytherapy alone (14 patients) or a combination of external beam irradiation and brachytherapy (73 patients) using an afterloading iridium technique in a plastic tube.

Results

Overall primary tumor control, including salvage surgery, was 81/87 (93%). Control of metastatic cervical adenopathy was as follows: clinical stage N1, 5/9 patients; N2, 2/8 patients. The estimated five-year cause-specific survival and overall survival rates were 81% and 47%, respectively. After interstitial irradiation severe complications were limited to one case of osteoradionecrosis of the mandible and seven cases of mucosal ulcer.

Conclusion

This study confirms that iridium-192 interstitial implant alone or as a boost after external beam irradiation is a safe and effective therapy in the management of oropharyngeal carcinomas.

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.

Squamous cell carcinoma of the oropharynx: surgery, radiation therapy, or both

BACKGROUND

The treatment of patients with squamous cell carcinoma (SCC) of the oropharynx remains controversial. No randomized trial has addressed adequately the question of whether surgery (S), radiation therapy (RT), or combined treatment is most effective.

METHODS

Treatment results from North American academic institutions that used S with or without adjuvant RT (S +/- RT) or used RT alone or followed by neck dissection (RT +/- ND) for patients with SCC of the tonsillar region or the base of tongue were compiled through a MEDLINE search (from 1970 to August, 2000) and from the references cited in each report. Studies were eligible for inclusion if they contained direct, actuarial (life-table), or Kaplan-Meier calculations for the following end points: local control, local-regional control, 5-year absolute survival, 5-year cause specific survival, or severe or fatal treatment complications. Weighted average results, which took into account series size, were calculated for each end point for the purposes of treatment comparison. Results and conclusions were based on data from 51 reported series, representing the treatment of approximately 6400 patients from the United States and Canada.

RESULTS

The results for patients with SCC of the base of tongue who underwent S +/- RT versus RT +/- ND, respectively, were as follows: local control, 79% versus 76% (P = 0.087); local-regional control, 60% versus 69% (P = 0.009); 5-year survival, 49% versus 52% (P = 0.2); 5-year cause specific survival, 62% versus 63% (P = 0.4); severe complications, 32% versus 3.8% (P < 0.001); and fatal complications, 3.5% versus 0.4% (P < 0.001). The results for patients with SCC in the tonsillar region who underwent S +/- RT versus RT +/- ND, respectively, were as follows: local control, 70% versus 68% (P = 0.2); local-regional control, 65% versus 69% (P = 0.1); 5-year survival, 47% versus 43% (P = 0.2); 5-year cause specific survival, 57% versus 59% (P = 0.3); severe complications, 23% versus 6% (P < 0.001); and fatal complications, 3.2% versus 0.8% (P < 0.001).

CONCLUSIONS

The information in this article provides a useful benchmark for evidence-based counseling of patients with SCC of the oropharynx. The rates of local control, local-regional control, 5-year survival, and 5-year cause specific survival were similar for patients who underwent S +/- RT or RT +/- ND, whereas the rates of severe or fatal complications were significantly greater for the S +/- RT group. Furthermore, available data on the functional consequences of treatment suggest the superiority of RT +/- ND. The authors conclude that RT +/- ND is preferable for the majority of patients with SCC of the oropharynx.

Possibilities of preventing osteoradionecrosis during complex therapy of tumors of the oral cavity

In recent years, there has been a dramatic increase in the number of tumors of the head and neck. Their successful treatment is one of the greatest challenges for physicians dealing with oncotherapy. An organic part of the complex therapy is preoperative or postoperative irradiation. Application of this is accompanied by a lower risk of recurrences, and by a higher proportion of cured patients. Unfortunately, irradiation also has a disadvantage: the development of osteoradionecrosis, a special form of osteomyelitis, in some patients (mainly in those cases where irradiation occurs after bone resection or after partial removal of the periosteum). Once the clinical picture of this irradiation complication has developed, its treatment is very difficult. A significant result or complete freedom from complaints can be attained only rarely. Attention must therefore be focussed primarily on prevention, and the oral surgeon, the oncoradiologist and the patient too can all do much to help prevent the occurrence of osteoradionecrosis. Through coupling of an up-to-date, functional surgical attitude with knowledge relating to modern radiology and radiation physics, the way may be opened to forestall this complication that is so difficult to cure.

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.

The role of brachytherapy in head and neck cancer

By precision dose delivery to a well-defined target, brachytherapy fulfills the complementary goals of delivering sufficient dose for tumor cell kill while sparing normal adjacent structures. The unique properties of this modality, either used alone or implemented in a combined modality setting with surgery or external-beam irradiation, offer an ideal means of enhancing the therapeutic ratio by exploiting the effect of local therapies while respecting normal tissue tolerance. Brachytherapy also provides an effective technique for the retreatment of patients with recurrent, persistent, or second primary head and neck malignant tumors in a previously irradiated region. The benefits of this treatment modality are reflected in excellent reported local control rates, shortened overall treatment times, reduced functional deficits, improved quality of life, and decreased costs. Successful brachytherapy relies, however, on close collaborative efforts between radiation oncologists and surgeons, careful assessment of the patient, precise planning, and technique that adheres to the rules of a system. Brachytherapy has been clearly identified as an effective, safe, and appealing modality in the treatment of head and neck malignancies.

The impact of temporary iodine-125 interstitial implant boost in the primary management of squamous cell carcinoma of the oropharynx

BACKGROUND

To define the impact of interstitial boost of the oropharynx on local control and complications using iodine-125 (I-125) brachytherapy.

METHODS

Between October 1986 and September 1991, 19 patients with cancer of the oropharynx received treatment at William Beaumont Hospital. Primary tumors consisted of 13 base of tongue, 4 tonsillar, and 2 pharyngeal wall lesions. All patients received 45-66 Gy (median, 54 Gy) external beam irradiation to the primary and regional nodes, followed by an interstitial implant of 22-32 Gy (median, 25 Gy) with I-125.

RESULTS

Median follow-up was 58 months (range, 12-89 months). Three patients failed within the tumor bed, for a 5-year actuarial rate of local control of 83% (T1/T2, 82%; T3/T4, 86%). Two of the three local failures were salvaged surgically, for an overall 5-year actuarial local control rate of 94%. The 5-year actuarial overall survival rate was 64%. Complications included one case of soft tissue ulceration and two cases of osteoradionecrosis, all managed conservatively.

CONCLUSIONS

Patients with cancer of the oropharynx judged to be candidates for boosts with interstitial implants can be effectively treated with I-125. Local control was excellent, and complications were minimal.