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Short-term clinical outcome and dosimetric comparison of tandem and ring versus tandem and ovoids intracavitary applicators.

Ma JK, Mourad WF, Allbright R, Packianathan S, Harrell LM, Chinchar E, Nguyen A, Vijayakumar S - J Contemp Brachytherapy (2015)

Bottom Line: Treatment time and irradiated tissue volume were compared.No significant differences in the dose to the right and left point A, or the left point B were observed.Long-term clinical outcomes will be elucidated with longer follow up period.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology.

ABSTRACT

Purpose: To compare the short-term toxicity and dosimetry of tandem and ring (TR), and tandem and ovoid (TO) applicators in treatment of gynecologic malignancy.

Material and methods: Following pelvic external beam radiation therapy (EBRT), a total of 52 computed tomography-based plans from 13 patients with cervical cancer (FIGO IB2-IIIB) were evaluated for HDR brachytherapy. Prescription was 7 Gy to the ICRU point A for four weekly fractions. Gastrointestinal and genitourinary toxicities were evaluated. Clinical target volume (CTV) and organs at risk were delineated on CT scans. Bladder, rectum, and sigmoid mean doses and D2cc were calculated. Treatment time and irradiated tissue volume were compared. Percent of CTV receiving 100% (CTV100%) of the prescribed dose as well as the percent of the prescription dose covering 90% of the CTV (D90) were evaluated.

Results: Gastrointestinal and genitourinary toxicities were not different between TO and TR applicators. No significant differences in the dose to the right and left point A, or the left point B were observed. TO delivered a higher dose to right point B. Organs at risk doses were similar between the two applicators, except mean rectal dose was lower for TO applicator. Overall, TO treats a larger tissue volume than TR. Mean treatment time was shorter for TR. Tumor coverage (D90 and CTV100%) was equivalent between TO and TR applicators.

Conclusion: Although TO treats a larger tissue volume than TR, short-term toxicities and tumor coverage are similar. Long-term clinical outcomes will be elucidated with longer follow up period.

No MeSH data available.


Related in: MedlinePlus

Coronal and axial views of isodose distribution and prescription points A (left and right). Coronal view of tandem and ovoids isodose lines (A). Coronal view of tandem and ring isodose lines (B). Axial view of tandem and ovoids isodose lines (C). Axial view of tandem and ring isodose lines (D). Isodose lines as a percentage of the prescribed dose to point A: yellow (200%), red (100%), green (95%), cyan (85%), magenta (50%), and blue (20%). Isodose lines are shown for small ovoids in TO applicators
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Figure 0002: Coronal and axial views of isodose distribution and prescription points A (left and right). Coronal view of tandem and ovoids isodose lines (A). Coronal view of tandem and ring isodose lines (B). Axial view of tandem and ovoids isodose lines (C). Axial view of tandem and ring isodose lines (D). Isodose lines as a percentage of the prescribed dose to point A: yellow (200%), red (100%), green (95%), cyan (85%), magenta (50%), and blue (20%). Isodose lines are shown for small ovoids in TO applicators

Mentions: Retrospectively, CTV was contoured using the CT based high risk CTV delineation guidelines by Viswanathan et al. [15]. Mean treatment time and total volume of all tissues receiving 95% (V95%), 85% (V85%), 50% (V50%), and 20% (V20%) of the brachytherapy prescription dose were compared. Percent of CTV receiving 100% (CTV100%) of the prescribed dose as well as the percent of prescription dose covering 90% of the CTV (D90) were evaluated. Examples of the isodose lines are shown in the coronal plane for TO (Fig. 2A) and TR (Fig. 2B) as well as in the axial plane for TO (Fig. 2C) and TR (Fig. 2D) applicators.


Short-term clinical outcome and dosimetric comparison of tandem and ring versus tandem and ovoids intracavitary applicators.

Ma JK, Mourad WF, Allbright R, Packianathan S, Harrell LM, Chinchar E, Nguyen A, Vijayakumar S - J Contemp Brachytherapy (2015)

Coronal and axial views of isodose distribution and prescription points A (left and right). Coronal view of tandem and ovoids isodose lines (A). Coronal view of tandem and ring isodose lines (B). Axial view of tandem and ovoids isodose lines (C). Axial view of tandem and ring isodose lines (D). Isodose lines as a percentage of the prescribed dose to point A: yellow (200%), red (100%), green (95%), cyan (85%), magenta (50%), and blue (20%). Isodose lines are shown for small ovoids in TO applicators
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4499513&req=5

Figure 0002: Coronal and axial views of isodose distribution and prescription points A (left and right). Coronal view of tandem and ovoids isodose lines (A). Coronal view of tandem and ring isodose lines (B). Axial view of tandem and ovoids isodose lines (C). Axial view of tandem and ring isodose lines (D). Isodose lines as a percentage of the prescribed dose to point A: yellow (200%), red (100%), green (95%), cyan (85%), magenta (50%), and blue (20%). Isodose lines are shown for small ovoids in TO applicators
Mentions: Retrospectively, CTV was contoured using the CT based high risk CTV delineation guidelines by Viswanathan et al. [15]. Mean treatment time and total volume of all tissues receiving 95% (V95%), 85% (V85%), 50% (V50%), and 20% (V20%) of the brachytherapy prescription dose were compared. Percent of CTV receiving 100% (CTV100%) of the prescribed dose as well as the percent of prescription dose covering 90% of the CTV (D90) were evaluated. Examples of the isodose lines are shown in the coronal plane for TO (Fig. 2A) and TR (Fig. 2B) as well as in the axial plane for TO (Fig. 2C) and TR (Fig. 2D) applicators.

Bottom Line: Treatment time and irradiated tissue volume were compared.No significant differences in the dose to the right and left point A, or the left point B were observed.Long-term clinical outcomes will be elucidated with longer follow up period.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology.

ABSTRACT

Purpose: To compare the short-term toxicity and dosimetry of tandem and ring (TR), and tandem and ovoid (TO) applicators in treatment of gynecologic malignancy.

Material and methods: Following pelvic external beam radiation therapy (EBRT), a total of 52 computed tomography-based plans from 13 patients with cervical cancer (FIGO IB2-IIIB) were evaluated for HDR brachytherapy. Prescription was 7 Gy to the ICRU point A for four weekly fractions. Gastrointestinal and genitourinary toxicities were evaluated. Clinical target volume (CTV) and organs at risk were delineated on CT scans. Bladder, rectum, and sigmoid mean doses and D2cc were calculated. Treatment time and irradiated tissue volume were compared. Percent of CTV receiving 100% (CTV100%) of the prescribed dose as well as the percent of the prescription dose covering 90% of the CTV (D90) were evaluated.

Results: Gastrointestinal and genitourinary toxicities were not different between TO and TR applicators. No significant differences in the dose to the right and left point A, or the left point B were observed. TO delivered a higher dose to right point B. Organs at risk doses were similar between the two applicators, except mean rectal dose was lower for TO applicator. Overall, TO treats a larger tissue volume than TR. Mean treatment time was shorter for TR. Tumor coverage (D90 and CTV100%) was equivalent between TO and TR applicators.

Conclusion: Although TO treats a larger tissue volume than TR, short-term toxicities and tumor coverage are similar. Long-term clinical outcomes will be elucidated with longer follow up period.

No MeSH data available.


Related in: MedlinePlus