Spectrophotometer and ultrasound ev

Spectrophotometer and ultrasound evaluation of late toxicity following breast-cancer radiotherapy

DISCUSSION

In this clinical study, we compared spectrophotometry and quantitative ultrasound as assessment tools of late toxicity in breast-cancer radiotherapy. Two spectrophotometer parameters (melanin and erythema) were used to quantify changes in skin color. Two ultrasound parameters (skin thickness and Pearson coefficient) that measure structural changes of the parenchyma were used to evaluate subcutaneous fibrosis. We did not observe a correlation between ultrasound and spectrophotometer parameter values suggesting that skin discoloration does not correlate with the development of fibrosis.

The breast is composed of complex structures that change over time and vary significantly among individuals. Both baseline (contralateral) and irradiated breast characteristics among our patient population reflected this diversity (Table TABLE III.). For example, spectrophotometer melanin measurements of fair-skinned women were generally within the range of 50-250, while those of dark-skinned women were generally within the range of 600-999. To account for these variations, we examined relative changes for each parameter—a comparison of the ratios of the treated to untreated breast. All four parameters demonstrated significant differences in the treated breast with respect to the contralateral breast (Table TABLE III.). We validated these relative changes with RTOG clinical assessments (Table TABLE IV.) and compared quantitative ultrasound with spectrophotometer parameters (Table TABLE V.).

Of the five patients who had no signs of late toxicity after radiotherapy (RTOG = 0), 2 patients had a decrease in melanin index and two patients had a decrease in erythema index. Those who were found to have a decrease in postradiation melanin have very fair skin (melanin < 100) at baseline, while those who were found to have a decrease in post-radiation erythema have either very fair (melanin < 100) or very dark (melanin > 750) skin at baseline. This may suggest that a relative change in melanin index is a better marker of toxicity than erythema index in women with darker skin.

For this study, we used the average value of four breast quadrants for each of the four parameters to represent overall changes in the irradiated breast. One limitation of this approach is that the average parameter values do not differentiate the boosted (receiving doses of 60.0-66.4 Gy) from the nonboosted (receiving doses ≤ 50.0 Gy) regions. Further, the small number of patients enrolled and the absence of patients with high-grade tissue toxicity must be addressed in future studies. Despite the study’s limitations, our preliminary results suggest that skin discoloration cannot be used as a marker for fibrosis. Moreover, these findings provide early evidence that skin toxicity and subcutaneous toxicity require separate objective evaluations.

A detailed understanding of nontargeted normal-tissue response is necessary for the optimization of radiation treatment in cancer therapy. Quantitative techniques of toxicity evaluation provide more specific measures than subjective RTOG scoring criteria, which are confined to 5 grades. This tool may be useful in clinical trials to compare various treatment strategies, such as external beam radiation vs MammoSite or standard dose fractionation vs hypofractionation. Although this study was conducted in breast-cancer radiotherapy, both spectrophotometry and quantitative ultrasound can be easily adapted for other treatment sites, such as the head and neck. These quantitative toxicity assessment tools will prove valuable as we continue to enhance our understanding and management of radiation toxicity in breast-cancer radiotherapy.

ผลลัพธ์ (ไทย) 3:

Spectrophotometer and ultrasound evaluation of late toxicity following breast-cancer radiotherapy

DISCUSSION

In this clinical study, we compared spectrophotometry and quantitative ultrasound as assessment tools of late toxicity in breast-cancer radiotherapy. Two spectrophotometer parameters (melanin and erythema) were used to quantify changes in skin color.สองพารามิเตอร์อัลตราซาวด์ ( ความหนาของผิวหนังและสัมประสิทธิ์สหสัมพันธ์ ) วัดการเปลี่ยนแปลงโครงสร้างของมีถูกใช้เพื่อประเมินใต้ผิวหนัง การเกิดพังผืด เราไม่ได้สังเกตความสัมพันธ์ระหว่างค่าพารามิเตอร์เครื่องอัลตร้าซาวน์ และบอกว่ากระผิว ไม่มีความสัมพันธ์กับการพัฒนาของ fibrosis .

The breast is composed of complex structures that change over time and vary significantly among individuals. Both baseline (contralateral) and irradiated breast characteristics among our patient population reflected this diversity (Table TABLE III.). For example, spectrophotometer melanin measurements of fair-skinned women were generally within the range of 50-250,ในขณะที่คนผิวคล้ำ ผู้หญิงโดยทั่วไปภายในช่วงของ 600-999 . บัญชีสำหรับการเปลี่ยนแปลงเหล่านี้ เราตรวจสอบการเปลี่ยนแปลงสัมพัทธ์ของแต่ละ parameter-a เปรียบเทียบอัตราส่วนการรักษานมดิบ ทั้งหมดสี่พารามิเตอร์แสดงให้เห็นความแตกต่างในการรักษามะเร็งเต้านมและเต้านมรูปขนาดย่อ ( โต๊ะ III ) We validated these relative changes with RTOG clinical assessments (Table TABLE IV.) and compared quantitative ultrasound with spectrophotometer parameters (Table TABLE V.).

Of the five patients who had no signs of late toxicity after radiotherapy (RTOG = 0), 2 patients had a decrease in melanin index and two patients had a decrease in erythema index. Those who were found to have a decrease in postradiation melanin have very fair skin (melanin < 100) at baseline, while those who were found to have a decrease in post-radiation erythema have either very fair (melanin < 100) or very dark (melanin > 750) skin at baseline. This may suggest that a relative change in melanin index is a better marker of toxicity than erythema index in women with darker skin.

For this study, we used the average value of four breast quadrants for each of the four parameters to represent overall changes in the irradiated breast. One limitation of this approach is that the average parameter values do not differentiate the boosted (receiving doses of 60.0-66.4 Gy) from the nonboosted (receiving doses ≤ 50.0 Gy) regions. Further, the small number of patients enrolled and the absence of patients with high-grade tissue toxicity must be addressed in future studies. Despite the study’s limitations, our preliminary results suggest that skin discoloration cannot be used as a marker for fibrosis. Moreover, these findings provide early evidence that skin toxicity and subcutaneous toxicity require separate objective evaluations.

A detailed understanding of nontargeted normal-tissue response is necessary for the optimization of radiation treatment in cancer therapy.เทคนิคเชิงปริมาณของการประเมินความเป็นพิษให้เพิ่มเติมมาตรการเฉพาะกว่าอัตนัย rtog เกณฑ์การให้คะแนน ซึ่งอยู่ถึง 5 คะแนน เครื่องมือนี้อาจเป็นประโยชน์ในการทดลองทางคลินิกเปรียบเทียบกลยุทธ์การรักษาต่าง ๆ เช่น คานภายนอก VS รังสี mammosite หรือมาตรฐานยา ( vs hypofractionation . ถึงแม้ว่าการศึกษานี้ดำเนินการในรังสีรักษามะเร็งเต้านม both spectrophotometry and quantitative ultrasound can be easily adapted for other treatment sites, such as the head and neck. These quantitative toxicity assessment tools will prove valuable as we continue to enhance our understanding and management of radiation toxicity in breast-cancer radiotherapy.