Patterns of pathologic lymph nodes in anal cancer: a PET-CT-based analysis with implications for radiotherapy treatment volumes
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 r...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2021-04-01
|
| Series: | BMC Cancer |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s12885-021-08187-8 |
| _version_ | 1829480614798032896 |
|---|---|
| author | Anna Frennered Jonas Scherman Pamela Buchwald Anders Johnsson Hanna Sartor Sophia Zackrisson Elin Trägårdh Martin P. Nilsson |
| author_facet | Anna Frennered Jonas Scherman Pamela Buchwald Anders Johnsson Hanna Sartor Sophia Zackrisson Elin Trägårdh Martin P. Nilsson |
| author_sort | Anna Frennered |
| collection | DOAJ |
| description | 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 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. |
| first_indexed | 2024-12-14T21:10:37Z |
| format | Article |
| id | doaj.art-75cfc34cc39f4c3595aaa2af789dddfe |
| institution | Directory Open Access Journal |
| issn | 1471-2407 |
| language | English |
| last_indexed | 2024-12-14T21:10:37Z |
| publishDate | 2021-04-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Cancer |
| spelling | doaj.art-75cfc34cc39f4c3595aaa2af789dddfe2022-12-21T22:47:16ZengBMCBMC Cancer1471-24072021-04-012111910.1186/s12885-021-08187-8Patterns of pathologic lymph nodes in anal cancer: a PET-CT-based analysis with implications for radiotherapy treatment volumesAnna Frennered0Jonas Scherman1Pamela Buchwald2Anders Johnsson3Hanna Sartor4Sophia Zackrisson5Elin Trägårdh6Martin P. Nilsson7Diagnostic Radiology, Department of Translational Medicine, Skåne University Hospital, Lund UniversityRadiation Physics, Department of Hematology, Oncology and Radiation PhysicsDepartment of Surgery, Colorectal Unit, Skåne University HospitalDepartment of Hematology, Oncology and Radiation Physics, Skåne University HospitalDiagnostic Radiology, Department of Translational Medicine, Skåne University Hospital, Lund UniversityDiagnostic Radiology, Department of Translational Medicine, Skåne University Hospital, Lund UniversityClinical Physiology and Nuclear Medicine, Skåne University Hospital, Lund UniversityDepartment of Hematology, Oncology and Radiation Physics, Skåne University HospitalAbstract 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.https://doi.org/10.1186/s12885-021-08187-8Anal cancerAnal carcinomaPET-CTLymph node metastasisContouring guidelines |
| spellingShingle | Anna Frennered Jonas Scherman Pamela Buchwald Anders Johnsson Hanna Sartor Sophia Zackrisson Elin Trägårdh Martin P. Nilsson Patterns of pathologic lymph nodes in anal cancer: a PET-CT-based analysis with implications for radiotherapy treatment volumes BMC Cancer Anal cancer Anal carcinoma PET-CT Lymph node metastasis Contouring guidelines |
| title | Patterns of pathologic lymph nodes in anal cancer: a PET-CT-based analysis with implications for radiotherapy treatment volumes |
| title_full | Patterns of pathologic lymph nodes in anal cancer: a PET-CT-based analysis with implications for radiotherapy treatment volumes |
| title_fullStr | Patterns of pathologic lymph nodes in anal cancer: a PET-CT-based analysis with implications for radiotherapy treatment volumes |
| title_full_unstemmed | Patterns of pathologic lymph nodes in anal cancer: a PET-CT-based analysis with implications for radiotherapy treatment volumes |
| title_short | Patterns of pathologic lymph nodes in anal cancer: a PET-CT-based analysis with implications for radiotherapy treatment volumes |
| title_sort | patterns of pathologic lymph nodes in anal cancer a pet ct based analysis with implications for radiotherapy treatment volumes |
| topic | Anal cancer Anal carcinoma PET-CT Lymph node metastasis Contouring guidelines |
| url | https://doi.org/10.1186/s12885-021-08187-8 |
| work_keys_str_mv | AT annafrennered patternsofpathologiclymphnodesinanalcancerapetctbasedanalysiswithimplicationsforradiotherapytreatmentvolumes AT jonasscherman patternsofpathologiclymphnodesinanalcancerapetctbasedanalysiswithimplicationsforradiotherapytreatmentvolumes AT pamelabuchwald patternsofpathologiclymphnodesinanalcancerapetctbasedanalysiswithimplicationsforradiotherapytreatmentvolumes AT andersjohnsson patternsofpathologiclymphnodesinanalcancerapetctbasedanalysiswithimplicationsforradiotherapytreatmentvolumes AT hannasartor patternsofpathologiclymphnodesinanalcancerapetctbasedanalysiswithimplicationsforradiotherapytreatmentvolumes AT sophiazackrisson patternsofpathologiclymphnodesinanalcancerapetctbasedanalysiswithimplicationsforradiotherapytreatmentvolumes AT elintragardh patternsofpathologiclymphnodesinanalcancerapetctbasedanalysiswithimplicationsforradiotherapytreatmentvolumes AT martinpnilsson patternsofpathologiclymphnodesinanalcancerapetctbasedanalysiswithimplicationsforradiotherapytreatmentvolumes |