Dosimetric Analysis of Major Wound Complications Following Preoperative Ultra-Hypofractionated Radiation Therapy for Soft Tissue Sarcoma

PURPOSE/OBJECTIVE(S)

Preoperative radiation therapy (RT) for soft tissue sarcomas (STS), delivered with conventional fractionation, has been shown to reduce long-term toxicity at the expense of increased postoperative major wound complications (MWC). Ultra-hypofractionated RT has emerged as a potential alternative preoperative modality with early but comparable outcomes to conventional regimens. However, limited data are available evaluating dosimetric, patient, and treatment specific factors associated with development of MWC in this setting.

MATERIALS/METHODS

This IRB approved review included STS patients treated with preoperative 5 fraction daily RT followed by surgical resection within 7 days. Patients were evaluated for MWCs in association with patient and tumor characteristics, dosimetric parameters, and treatment techniques. MWCs were defined as a return to operating room, readmission for wound care or IV antibiotics, and persistent deep packing for >120 days. Prescription isodose line, PTV mean dose and the PTV volume exposed to 105% and 110% of prescribed dose were recorded. Dose to tissue likely to be involved in wound healing was assessed by creating a 1 cm thick superficial skin strip within 2 cm of the PTV which was then evaluated for volume, mean dose, V15, V21, V27, and V30. Secondary endpoints were locoregional control (LRC), metastasis free survival (MFS), and overall survival (OS).

RESULTS

A total of 31 patients with a median age of 66 years (range 28-87) and a median follow up of 21 months (IQR 8-43) were included. All patients received 30 Gy in 5 fractions using IMRT/VMAT. There were 11 upper limb (36%) and 20 lower limb (65%) tumors included. Median time to resection following RT was 1 day (IQR 0-3). Median tumor size was 8 cm (IQR 5-13). MWC occurred in 13 patients (42%) with 10 patients (32%) requiring additional surgery. Dehiscence and infection requiring IV antibiotics occurred in 12 (39%) and 6 patients (19%), respectively. RT plans were predominately prescribed to the PTV mean (87%) with a median prescription isodose of 97% (IQR 96-97) and PTV mean dose of 3110 cGy (IQR 3089-3142). Median PTV volume, mean dose, and volume of PTV receiving 105% and 110% of the prescribed dose were higher in the MWC cohort although none reached significance. Similarly, for the 1 cm skin strip the median volume, mean dose, V30, V27, V21, and V15 were all higher in the MWC cohort without significant difference. Among patient, treatment, and tumor factors: tumor size, location, grade, margin status, type of wound closure, and prior non-oncologic resection were not associated with MWC. LRC, MFS, and OS at 3-years were 96%, 67%, and 76%, respectively.

CONCLUSION

Although not reaching significance, increased plan homogeneity and reduced dose/volume relationships in proximity to the skin trended to reduced MWC in this limited cohort. Multi-institutional collaboration may be warranted to better identify factors associated with MWC in patients treated with preoperative ultra-hypofractionated RT.

How did formative research inform the development of a women's group intervention in rural Nepal?

Inability to reduce neonatal and maternal mortality in poor countries is sometimes blamed on a lack of contextual knowledge about care practices and care-seeking behavior. There is a lack of knowledge about how to translate formative research into effective interventions to improve maternal and newborn health. We describe the findings of formative research and how they were used to inform the development of such an intervention in rural Nepal. Formative research was carried out in four parts. Part 1 involved familiarization with the study area and literature review, and parts 2, 3 and 4 involved community mapping, audit of health services, and qualitative and quantitative studies of perinatal care behaviors. Participatory approaches have been successful at reducing neonatal mortality and may be suitable in our context. Community mapping and profiling helped to describe the community context, and we found that community-based organizations often sought to involve the Female Community Health Volunteer in community mobilization. She was not routinely conducting monthly meetings and found them difficult to sustain without support and supervision. In health facilities, most primary care staff were in post, but doctors and staff nurses were absent from referral centers. Mortality estimates reflected under-reporting of deaths and hygiene and infection control strategies had low coverage. The majority of women give birth at home with their mother-in-law, friends and neighbors. Care during perinatal illness was usually sought from traditional healers. Cultural issues of shyness, fear and normalcy restricted women's behavior during pregnancy, birth and the postpartum period, and decisions about her health were usually made after communications with the family and community. The formative research indicated the type of intervention that could be successful. It should be community-based and should not be exclusively for pregnant women. It should address negotiations within families, and should tailor information to the needs of local groups and particular stakeholders such as mothers-in-law and traditional healers. The intervention should not only accept cultural constructs but also be a forum in which to discuss ideas of pollution, shame and seclusion. We used these guidelines to develop a participatory, community-based women's group intervention, facilitated through a community action cycle. The success of our intervention may be because of its acceptability at the community level and its sensitivity to the needs and beliefs of families and communities.

DESIGN OF A SURVEILLANCE SYSTEM FOR PREGNANCY AND ITS OUTCOMES IN RURAL NEPAL

IntroductionCommunity trials in low-income countries require monitoring and evaluation systems.The requirements of a community surveillance system include coherent design, training,field supervision and reporting, as well as the need for a robust and flexible database.Materials and methodsThis paper describes a surveillance system for identification of pregnancy and itsoutcomes in a rural area of Nepal. Mother Infant Research Activities (MIRA), incollaboration with the Institute of Child Health, London, are presently conducting astudy on the impact of a community-based participatory intervention to improveessential newborn care (ENC) in rural Nepal. The study is a cluster randomisedcontrolled trial involving 12 pairs of Village Development Committees (VDCs) inMakwanpur District. The surveillance system covers approximately 28 000 householdsand 28 000 married women of reproductive age. It was designed to identify pregnancy,its outcome for mother and infant, and activities such as antenatal care and problem-related health care seeking behaviour.DiscussionThe paper describes the processes of mapping and enumeration, pregnancyidentification, conduct of interviews, quality control and data management.Key Words: data quality, database, rural Nepal.