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

Unetsubo T, Matsuzaki H, Takemoto M, Katsui K, Hara M, Katayama N, Waki T, Kanazawa S, Asaumi J - Radiat Oncol (2015)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Department of Oral and Maxillofacial Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 5-1 Shikata-cho, 2-chome, Kita-ku, Okayama, 700-8525, Japan. t-unetsubo@okayama-u.ac.jp.

ABSTRACT

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.

No MeSH data available.


Related in: MedlinePlus

Radiotherapy treatment schedule. EBRT: External beam radiotherapy, HDR: High-dose-rate.
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Fig1: Radiotherapy treatment schedule. EBRT: External beam radiotherapy, HDR: High-dose-rate.

Mentions: The radiotherapy treatment schedule is detailed in Figure 1. In all patients, external beam radiotherapy (EBRT) involving a radiation dose of 30 Gy (2 Gy/day, five fractions/week) was performed with 4-MV X-rays before HDR brachytherapy. All patients were treated with parallel opposing lateral or anterior-posterior fields. Before HDR brachytherapy, a mold made of resin was prepared for each patient. Prior to embedment of the catheters into the mold, the gross tumor volume (GTV) was determined after EBRT. We defined the area displaying mucositis after EBRT as the GTV by direct inspection and using findings from magnetic resonance imaging and/or ultrasonography performed before EBRT. To minimize the area at risk of complications, we used the GTV as the clinical target volume (CTV), and 5 mm was added to the CTV to obtain the planning target volume (PTV). A median of 4 (range, 3–10) catheters were embedded in the mold at parallel intervals of 10 mm so that they could cover a sufficient proportion of the PTV. For six patients we used the two-piece mold technique, which is a method for shifting the irradiation plane by dividing the mold for the tumors close to the commissure of the lips [12]. Because the catheter was hard and had poor flexibility, an adequate radiation dose could not be administered to a tumor that had extended towards the skin region from the corner of the mouth, or near the corner of the mouth. Indeed, it is not the way that the tumor is irradiated from the skin side. The dose reference point was set at 5 mm below the surface of the mucosa for all patients. The dose distributions were calculated using a computer software program (Plato Brachytherapy: Nucletron Co., Veenendaal, The Netherlands). HDR brachytherapy was performed after EBRT. The interval between EBRT and HDR brachytherapy had a median duration of 8 (range, 7–20) days. Two 6-Gy fractions were delivered twice a day for 2 days a week with an interval of 6 hours between the fractions. The total HDR brachytherapy dose was 24 Gy (Figure 2).Figure 1


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

Unetsubo T, Matsuzaki H, Takemoto M, Katsui K, Hara M, Katayama N, Waki T, Kanazawa S, Asaumi J - Radiat Oncol (2015)

Radiotherapy treatment schedule. EBRT: External beam radiotherapy, HDR: High-dose-rate.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4465005&req=5

Fig1: Radiotherapy treatment schedule. EBRT: External beam radiotherapy, HDR: High-dose-rate.
Mentions: The radiotherapy treatment schedule is detailed in Figure 1. In all patients, external beam radiotherapy (EBRT) involving a radiation dose of 30 Gy (2 Gy/day, five fractions/week) was performed with 4-MV X-rays before HDR brachytherapy. All patients were treated with parallel opposing lateral or anterior-posterior fields. Before HDR brachytherapy, a mold made of resin was prepared for each patient. Prior to embedment of the catheters into the mold, the gross tumor volume (GTV) was determined after EBRT. We defined the area displaying mucositis after EBRT as the GTV by direct inspection and using findings from magnetic resonance imaging and/or ultrasonography performed before EBRT. To minimize the area at risk of complications, we used the GTV as the clinical target volume (CTV), and 5 mm was added to the CTV to obtain the planning target volume (PTV). A median of 4 (range, 3–10) catheters were embedded in the mold at parallel intervals of 10 mm so that they could cover a sufficient proportion of the PTV. For six patients we used the two-piece mold technique, which is a method for shifting the irradiation plane by dividing the mold for the tumors close to the commissure of the lips [12]. Because the catheter was hard and had poor flexibility, an adequate radiation dose could not be administered to a tumor that had extended towards the skin region from the corner of the mouth, or near the corner of the mouth. Indeed, it is not the way that the tumor is irradiated from the skin side. The dose reference point was set at 5 mm below the surface of the mucosa for all patients. The dose distributions were calculated using a computer software program (Plato Brachytherapy: Nucletron Co., Veenendaal, The Netherlands). HDR brachytherapy was performed after EBRT. The interval between EBRT and HDR brachytherapy had a median duration of 8 (range, 7–20) days. Two 6-Gy fractions were delivered twice a day for 2 days a week with an interval of 6 hours between the fractions. The total HDR brachytherapy dose was 24 Gy (Figure 2).Figure 1

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Department of Oral and Maxillofacial Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 5-1 Shikata-cho, 2-chome, Kita-ku, Okayama, 700-8525, Japan. t-unetsubo@okayama-u.ac.jp.

ABSTRACT

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.

No MeSH data available.


Related in: MedlinePlus