RETURN TO INTENDED ONCOLOGIC TREATMENT(RIOT)

  RETURN TO INTENDED ONCOLOGIC TREATMENT( RIOT)

BACKGROUND: The oncosurgical procedures involve strategies of postoperative adjuvant systemic therapy following surgical tumor resection. Association of comorbid conditions and postoperative complications curtail the patients in continuing their subsequent therapies. This delay in patients receiving consequent oncological treatment have shown further increase in cancer recurrence and decrease survival rate curtailing the benefits of surgery. In order to quote the time to return to intended oncological treatment, a novel quality metric indicator to describe perioperative care in surgical oncology patients has been popularized recently termed as RIOT ( Return To Intended Oncological Treatment ).

DEFINITION:  The duration( in Days) between surgery and either commencement of intended oncological therapy 

                                                          (OR)

            Resumption of neoadjuvant preoperative therapy after a break for surgery

                                                          (OR)

            Ratio between the number of patients who undergo planned oncologic therapy after surgery within a specified time and the total number of postoperative patients for whom oncologic therapy was planned.

Studies have shown varying definitions of early and late chemotherapy resumption ranging from 15 days to 12 weeks after surgery.

1st  report on prospective RIOT was studied in patients undergoing liver resection. This observational study showed adoption of ERAS programme reduced the time interval to starting chemotherapy by 10 days. If we take an anesthetic intervention, the 1st  trial to use RIOT as the primary outcome was studied in 40 women undergoing surgical debulking of ovarian cancer. This study is about intraperitoneal infiltration of 0.1% Ropivacaine with an intermittent infusion for 72 hours after operation reduced RIOT interval. This remarkable improvement raised the  question of whether RIOT could be an early marker of improved oncological outcomes.

Postoperative complications and postoperative debility can hinder the patients to undergo subsequent oncologic therapies and henceforth negate the value of surgical intervention. Oncologists must think beyond perioperative outcomes and indulge the interventions to change the impact on long term survival and longer recurrence free state. Enhanced recovery after surgery(ERAS) protocols have revolutionized significantly improving the perioperative strategies and improving the outcomes. The following perioperative factors in recent trials studied have shown their significant impact on RIOT interval.

1.  Minimally invasive surgery(MIS): MIS group demonstrated a RIOT rate of 100%. It was first observed in liver resection cases where a significant 4 week reduction in time to reinitiation of cancer treatment was seen.
2. Chemotherapy : Multiple lines of preoperative chemotherapy was the strongest independent predictor of inability to RIOT, increasing the risk to 6- fold compared to patients undergoing single line or no chemotherapy. 
3. Hypertension: Patients with uncontrolled preoperative hypertension have shown to be an independent association for inability to RIOT with both shorter disease free state(DFS) and overall survival(OS). 
4. Age: Patients with age greater than 60 years was another independent risk factor for shorter RIOT rate.
5. Postoperative Complications: As expected, postoperative complications have shown a two fold lower RIOT rate. One factor was multiple preoperative chemotherapy, which results in increased postoperative complications. Considering most common complications in major onco surgeries being sepsis, ARDS, venous thromboembolism, acute kidney injury and cardiac complications. Major ERAS strategies which include prehabilitation( nutritional enhancement, physiological conditioning, anemia management, behavioral therapy), intraoperative strategies( Goal directed fluid management, lesser blood transfusions, optimal opioid usage, regional anesthesia, lignocaine infusion), postoperative( early mobilization, lesser drains, fast track discharge) have shown tremendous benefits in decreasing these postoperative complications. These strategies work mainly by  having lesser negative physiologic impact of resections, speedy recovery and henceforth facilitate additional oncologic therapies.

Conclusion: Most interventions in Onco - anesthesia are focused on intraoperative period, our ability to alter RIOT with current intraoperative techniques and ERAS programmes alone may be limited. Perhaps, we should focus more on preoperative comorbidities if we were to optimize RIOT interval. Future studies may focus on how prehabilitation may play its significant influence on RIOT. RIOT may be used as a short term surrogate marker of recovery after surgery, but its correlation with overall survival remains uncertain.