Patterns of pathologic lymph nodes in anal cancer : a PET-CT-based analysis with implications for radiotherapy treatment volumes
(2021) In BMC Cancer 21(1).- Abstract
Background: This study investigates the patterns of PET-positive lymph nodes (LNs) in anal cancer. The aim was to provide information that could inform future anal cancer radiotherapy contouring guidelines. Methods: The baseline [18F]-FDG PET-CTs of 190 consecutive anal cancer patients were retrospectively assessed. LNs with a Deauville score (DS) of ≥3 were defined as PET-positive. Each PET-positive LN was allocated to a LN region and a LN sub-region; they were then mapped on a standard anatomy reference CT. The association between primary tumor localization and PET-positive LNs in different regions were analyzed. Results: PET-positive LNs (n = 412) were identified in 103 of 190 patients (54%). Compared to anal canal tumors with... (More)
Background: This study investigates the patterns of PET-positive lymph nodes (LNs) in anal cancer. The aim was to provide information that could inform future anal cancer radiotherapy contouring guidelines. Methods: The baseline [18F]-FDG PET-CTs of 190 consecutive anal cancer patients were retrospectively assessed. LNs with a Deauville score (DS) of ≥3 were defined as PET-positive. Each PET-positive LN was allocated to a LN region and a LN sub-region; they were then mapped on a standard anatomy reference CT. The association between primary tumor localization and PET-positive LNs in different regions were analyzed. Results: PET-positive LNs (n = 412) were identified in 103 of 190 patients (54%). Compared to anal canal tumors with extension into the rectum, anal canal tumors with perianal extension more often had inguinal (P < 0.001) and less often perirectal (P < 0.001) and internal iliac (P < 0.001) PET-positive LNs. Forty-two patients had PET-positive LNs confined to a solitary region, corresponding to first echelon nodes. The most common solitary LN region was inguinal (25 of 42; 60%) followed by perirectal (26%), internal iliac (10%), and external iliac (2%). No PET-positive LNs were identified in the ischiorectal fossa or in the inguinal area located posterolateral to deep vessels. Skip metastases above the bottom of the sacroiliac joint were quite rare. Most external iliac PET-positive LNs were located posterior to the external iliac vein; only one was located in the lateral external iliac sub-region. Conclusions: The results support some specific modifications to the elective clinical target volume (CTV) in anal cancer. These changes would lead to reduced volumes of normal tissue being irradiated, which could contribute to a reduction in radiation side-effects.
(Less)
- author
- Frennered, Anna LU ; Scherman, Jonas ; Buchwald, Pamela LU ; Johnsson, Anders LU ; Sartor, Hanna LU ; Zackrisson, Sophia LU ; Trägårdh, Elin LU and Nilsson, Martin P. LU
- organization
- publishing date
- 2021-12
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Anal cancer, Anal carcinoma, Contouring guidelines, Lymph node metastasis, PET-CT
- in
- BMC Cancer
- volume
- 21
- issue
- 1
- article number
- 447
- pages
- 9 pages
- publisher
- BioMed Central (BMC)
- external identifiers
-
- scopus:85104577048
- pmid:33888074
- ISSN
- 1471-2407
- DOI
- 10.1186/s12885-021-08187-8
- language
- English
- LU publication?
- yes
- id
- c7ae5e80-343a-4b41-9b9d-a8b65b863310
- date added to LUP
- 2021-05-03 12:02:59
- date last changed
- 2024-06-15 10:44:33
@article{c7ae5e80-343a-4b41-9b9d-a8b65b863310,
abstract = {{<p>Background: This study investigates the patterns of PET-positive lymph nodes (LNs) in anal cancer. The aim was to provide information that could inform future anal cancer radiotherapy contouring guidelines. Methods: The baseline [18F]-FDG PET-CTs of 190 consecutive anal cancer patients were retrospectively assessed. LNs with a Deauville score (DS) of ≥3 were defined as PET-positive. Each PET-positive LN was allocated to a LN region and a LN sub-region; they were then mapped on a standard anatomy reference CT. The association between primary tumor localization and PET-positive LNs in different regions were analyzed. Results: PET-positive LNs (n = 412) were identified in 103 of 190 patients (54%). Compared to anal canal tumors with extension into the rectum, anal canal tumors with perianal extension more often had inguinal (P < 0.001) and less often perirectal (P < 0.001) and internal iliac (P < 0.001) PET-positive LNs. Forty-two patients had PET-positive LNs confined to a solitary region, corresponding to first echelon nodes. The most common solitary LN region was inguinal (25 of 42; 60%) followed by perirectal (26%), internal iliac (10%), and external iliac (2%). No PET-positive LNs were identified in the ischiorectal fossa or in the inguinal area located posterolateral to deep vessels. Skip metastases above the bottom of the sacroiliac joint were quite rare. Most external iliac PET-positive LNs were located posterior to the external iliac vein; only one was located in the lateral external iliac sub-region. Conclusions: The results support some specific modifications to the elective clinical target volume (CTV) in anal cancer. These changes would lead to reduced volumes of normal tissue being irradiated, which could contribute to a reduction in radiation side-effects.</p>}},
author = {{Frennered, Anna and Scherman, Jonas and Buchwald, Pamela and Johnsson, Anders and Sartor, Hanna and Zackrisson, Sophia and Trägårdh, Elin and Nilsson, Martin P.}},
issn = {{1471-2407}},
keywords = {{Anal cancer; Anal carcinoma; Contouring guidelines; Lymph node metastasis; PET-CT}},
language = {{eng}},
number = {{1}},
publisher = {{BioMed Central (BMC)}},
series = {{BMC Cancer}},
title = {{Patterns of pathologic lymph nodes in anal cancer : a PET-CT-based analysis with implications for radiotherapy treatment volumes}},
url = {{http://dx.doi.org/10.1186/s12885-021-08187-8}},
doi = {{10.1186/s12885-021-08187-8}},
volume = {{21}},
year = {{2021}},
}