Impact of radiation dose and standardized uptake value of (18)FDG PET on nodal control in locally advanced cervical cancer.
BACKGROUND
Despite local control now exceeding 90% with image-guided adaptive brachytherapy (IGABT), regional and distant metastases continue to curb survival in locally advanced cervical cancer. As regional lymph nodes often represent first site of metastatic spread, improved nodal control could improve survival. The aim of this study was to examine optimal volume and dose of external beam radiotherapy (EBRT) to maximize regional control including dose contribution from IGABT.


METHODS
In total 139 patients from the EMBRACE study were analyzed. Individual nodal dose was determined by dose-maps from EBRT and IGABT. All PET/CT scans were re-evaluated and nodal maximal standard uptake value (SUVmax) was determined. Nodal failures were registered to planning scans and related to boosted nodes and treated volume. Relation between SUVmax and nodal control as well as the pattern of regional nodal failure were analyzed.


RESULTS
Eighty-four patients were node positive. Nine patients had all metastatic nodes surgically removed. Seventy-five patients had 209 nodes boosted with EBRT. Median nodal boost dose was 62 Gy EQD2 (53-69 Gy EQD2). Median SUVmax was 6 (2-22). No patients had persistent nodal disease, but six patients recurred in a boosted node. SUVmax was significantly higher in nodes that recurred (p = 0.02). However, there was no correlation to nodal dose or volume. Twenty-one patients had a nodal failure including para-aortic nodal (PAN) metastases above the irradiated volume. Nine patients had a PAN-only failure. Patients receiving ≤ 4 cycles of weekly cisplatin had higher risk of nodal failure (p < 0.01).


CONCLUSIONS
Current RT practice provides a high level of control in both boosted nodes and the elective irradiated regional target. However, a high nodal SUVmax is a negative prognostic predictor for nodal control. Attention should be raised to administration of a complete schedule of concurrent chemotherapy as well as treatment of para-aortic nodes.
a Department of Oncology , Aarhus University Hospital , Denmark.
Anne
A
Ramlov
b Department of Radiation Oncology , University Medical Center Utrecht , The Netherlands.
Petra S
PS
Kroon
b Department of Radiation Oncology , University Medical Center Utrecht , The Netherlands.
Ina M
IM
Jürgenliemk-Schulz
b Department of Radiation Oncology , University Medical Center Utrecht , The Netherlands.
Astrid A C
AA
De Leeuw
c Department of Nuclear Medicine and PET Center , Aarhus University Hospital , Denmark.
Lars Christian
LC
Gormsen
a Department of Oncology , Aarhus University Hospital , Denmark.
Lars Ulrik
LU
Fokdal
a Department of Oncology , Aarhus University Hospital , Denmark.
Kari
K
Tanderup
a Department of Oncology , Aarhus University Hospital , Denmark.
Jacob Christian
JC
Lindegaard
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001011:Aorta; D001918:Brachytherapy; D002294:Carcinoma, Squamous Cell / Q000556:secondary* / Q000628:therapy*; D002945:Cisplatin / Q000627:therapeutic use; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000528:radiation effects* / Q000601:surgery; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis; D010388:Pelvis; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated; D014057:Tomography, X-Ray Computed; D017211:Treatment Failure; D002583:Uterine Cervical Neoplasms / Q000473:pathology / Q000628:therapy*; D055815:Young Adult
D000970:Antineoplastic Agents; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D002945:Cisplatin