Keywords:
Radiation therapy / Oncology, CT, Oncology, Toxicity
Authors:
F. Kasraei, M. Lee, P. Vial, C. Ochoa; NSW/AU
DOI:
10.1594/ranzcr2018/R-0111
Results
617 patients with DVH documents generated for definitive radiotherapy plans in the first 6 months of 2017 were assessed in Mosaiq.
11 patients were excluded as 7 did not complete the course of radiotherapy and 4 were converted to palliative plans as not safe to proceed with radical radiotherapy.
8 patients in genitourinary group had 2 separate plans,
one for external beam radiotherapy (EBRT) and one for stereotactic body radiotherapy (SBRT) boost,
therefore a total of 614 plans were assessed.
There were 210 plans (34%) accepted with at least one major protocol variation of recommended dose constraints (red),
161 plans(26%) had minor variation (yellow) and 243 plans (40%) did not have any variation (green) (Figure1).
We clustered treatments into three main groups 1) Head & Neck/skin/Central Nervous System (CNS); 2) Thorax – including lung and breast,
and abdomen/pelvis – including abdominal tumours and genitourinary tumours.
10 subgroups were included breast,
lung,
head & neck (H&N),
CNS,
gastrointestinal (GI),
gynaecologic (gynae),
genitourinary (GU),
skin,
lymphoma and SBRT.
H&N/CNS/Skin group had the most major variations (70%) and thorax group had the least (16%) while abdomen/pelvis group was in between with 43% of the plans with objectives in red (Figure 2).
In the subgroups,
H&N and skin had the most rate of major variations (77% and 75% respectively).
(Tables 1 and 2) The best groups in adherence to treatment protocol were breast,
lung,
lymphoma and SBRT groups with 15%,
16%,
and 18% major variation rates respectively.
(Figure3) There were total of 27 grade 3 toxicities excluding skin toxicity.
There was no grade 4 toxicity observed.
As a whole G3 toxicity was observed in 1%,
4% and 9% of patients who were in Green,
Yellow and Red categories.
We noted a correlation with grade 3 toxicities between acceptable plans and ones with a minor or major variation.
(1% vs 7% p<0.05).
Most of the grade 3 toxicities were observed in H&N group with grade 3 mucositis,
odynophagia and dysphagia (Figure4).